SlideShare a Scribd company logo

Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf

•
•
Jessica Navarro
Jessica Navarro

Custom Writing Service http://StudyHub.vip/Anesthesia-Books-2017-Essentials-Of-Neu

Education
1 of 1068
Download to read offline
https://t.me/Anesthesia_Books
ESSENTIALS OF NEUROANESTHESIA
This page intentionally left blank
ESSENTIALS OF NEUROANESTHESIA Edited by HEMANSHU PRABHAKAR Department of Neuroanaesthesiology and Critical Care All India Institute of Medical Sciences New Delhi, India
Academic Press is an imprint of Elsevier 125 London Wall, London EC2Y 5AS, United Kingdom 525 B Street, Suite 1800, San Diego, CA 92101-4495, United States 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom Copyright © 2017 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library ISBN: 978-0-12-805299-0 For information on all Academic Press publications visit our website at https://www.elsevier.com/books-and-journals Publisher: Mara Conner Acquisition Editor: Melanie Tucker Editorial Project Manager: Kristi Anderson Production Project Manager: Edward Taylor Designer: Maria Ines Cruz Typeset by TNQ Books and Journals
Dedicated to my parents—Avinash and Kanti Prabhakar The best gifts they stored for me—Kavita and Hemant, who in turn gifted me Sunil and Deepali To those who mean the world to me—Pallavi, Anavi, and Amyra To Aishwarya, Avi, and Anav
This page intentionally left blank
vii Contents List of Contributors xvii Foreword xix Preface xxi Acknowledgments xxiii Introduction and Brief History of Neuroanesthesia W. S. Jellish xxv I NEUROANATOMY 1. Neuroanatomy D. GUPTA Introduction 3 Embryological Differentiation of Different Parts of Brain 4 Anatomy of Brain 4 Vascular Supply of the Brain 30 The Meninges and Cerebrospinal Fluid 33 Acknowledgment 39 References 40 2. Neuroembryology G.P. SINGH Formation of Zygote 41 Formation of Blastocyst 41 Formation of Embryonic or Germ Disc 42 Formation of Definitive Notochord 44 Development of Nervous System 45 References 50 3. Blood–Brain Barrier A.K. KHANNA AND E. FARAG Introduction 51 Permeability at the Blood–Brain Barrier 51 Cellular and Molecular Effects of Anesthetics on the Blood–Brain Barrier 52 Clinical and Experimental Implications of Anesthetics on the Blood–Brain Barrier 54 Conclusion 56 References 56 II NEUROPHYSIOLOGY 4. Neurophysiology M. SETHURAMAN Intracranial Pressure 62 Introduction 62 Normal Intracranial Pressure 62 Cerebral Compliance 62 Importance of Intracranial Pressure 63 Summary 68 Cerebral Blood Flow 68 Introduction 68 Vascular Anatomy 68 Summary 74 Brain Metabolism 74 Introduction 74 Normal Cerebral Metabolism 74 Summary 79 Cerebrospinal Fluid 79 Introduction 79 Ventricular System 79 Summary 83 The Spinal Cord 83 Introduction 83 Anatomy 84 Organization of the Spinal Cord 84 Summary 89 References 89 5. Brain Protection in Neurosurgery H. EL BEHEIRY Introduction 91 Nonpharmacological Strategies 91 Mild Hypothermia 92 Blood Pressure Control 93 Induced Arterial Hypertension 94 Normoglycemia 94 Target Hemoglobin Concentration 95 Pharmacological Strategies 96 Nonanesthetic Agents 97 Anesthetic Agents 97 Conclusion 98 References 98
CONTENTS viii III NEUROPHARMACOLOGY 6. Neuropharmacology P. GANJOO AND I. KAPOOR Anesthetic Drugs and Sedatives 104 Intravenous Anesthetic Agents 104 Inhalational Anesthetic Agents 111 Neuromuscular Blocking Agents 115 Local Anesthetic Agents 116 Miscellaneous Drugs 116 Future Directions in Neuropharmacology 116 Conclusion 116 References 118 7. Anesthetic Agents: Neurotoxics or Neuroprotectives? J. FIORDA-DIAZ, N. STOICEA AND S.D. BERGESE Introduction 123 Pharmacological Considerations 124 Anesthesia Practice: Clinical Outcomes 126 Anesthesia and Fragile Brain 127 Conclusion 127 Abbreviations 128 References 128 IV NEUROMONITORING 8. Neuromonitoring V.J. RAMESH AND M. RADHAKRISHNAN Introduction 134 Cerebral Blood Flow 134 Transcranial Sonography 139 Thermal Diffusion Flowmetry 139 Laser Doppler Flowmetry 139 Intra-Arterial 133Xenon 139 CT Perfusion 139 Xenon Enhanced CT 139 Positron Emission Tomography 140 Single Photon Emission Computed Tomography 140 Magnetic Resonance Imaging 140 Intracranial Pressure 140 Electroencephalogram 143 Evoked Potential Monitoring 145 Motor Evoked Potentials 149 Depth of Anesthesia 150 Cerebral Oxygenation Monitoring 152 Jugular Venous Oximetry 152 Regional Cerebral Oximetry 154 Brain Tissue Oxygen Monitoring 156 Cerebral Microdialysis 158 Conclusion 159 References 159 9. Multimodal Monitoring A. DEFRESNE AND V. BONHOMME Introduction 161 Temperature 162 Oxygen Transport, Hemodynamics, and Brain Metabolism 162 Intracranial Pressure Monitoring 171 Electroencephalography and Depth of Anesthesia Monitoring 173 Miscellaneous 174 Integration of Information and Decision- Helping Systems 175 Clinical Pearls 176 References 176 V POSITIONS IN NEUROSURGERY 10. Positioning in Neurosurgery G. SINGH Introduction 184 Historical Background 184 Principles of Positioning 184 The Conduct of Positioning 185 Surgical Approach for Craniotomies 186 Positioning for Craniotomy 187 Positions Used for Craniotomies 189 Surgical Approach for Procedures of the Spine 195 Patient Positioning For Spinal Procedures 195 Conclusion 203 Abbreviations 203 References 204 VI PREANESTHETIC EVALUATION 11. Preanesthetic Evaluation of Neurosurgical Patients R. MARIAPPAN Introduction 209 Preoperative Evaluation of Patient-Related Risk Factors 210 Preoperative Evaluation of Specific Neurosurgical Conditions 217 References 225
CONTENTS ix VII NEUROSURGERY 12. Supratentorial Lesions H. BHAGAT AND S. MAHAJAN Introduction 231 Classification 232 Pathophysiology and Clinical Correlations 233 Clinical Features 235 Neuroimaging 235 Intraoperative Considerations: The Team Approach 236 Anesthetic Management 236 Intraoperative Management 238 Emergence From Anesthesia 240 Postoperative Management 241 Awake Craniotomy 242 Conclusions 245 Acknowledgment 245 References 245 13. Emergence From Anesthesia M. ECHEVERRÍA, J. FIORDA-DIAZ, N. STOICEA AND S.D. BERGESE Introduction 247 Neurophysiological Response During Emergence in Neurosurgical Patients 248 Specific Perioperative Considerations 248 Delayed Emergence and Arousal 250 Complications 251 Conclusion 252 References 252 14. Anesthesia for Posterior Fossa Surgery K. SANDHU AND N. GUPTA Introduction 255 Anatomy 255 Clinical Presentation 256 Perioperative Management of Patients for Posterior Fossa Surgery 256 Venous Air Embolism 264 Postoperative Management 271 Complications 272 Abbreviations 272 References 273 15. Transesophageal Echocardiography A. LELE AND V. KRISHNAMOORTHY Introduction 277 Basics of Transesophageal Echocardiography 277 Summary 283 References 283 16. Anesthesia for Epilepsy Surgery N. GUPTA Introduction 285 Surgical Management of Epilepsy 286 Types of Surgical Treatment 286 Presurgical Evaluation 287 Anesthesia for Epilepsy Surgery 288 Effect of Anesthetic Agents in Patients With Epilepsy 288 Antiepileptic Drug Interactions 290 Preanesthetic Evaluation and Preparation 291 Anesthetic Management of Preoperative Procedures 292 Anesthesia for Intracranial Electrode Insertion 294 Anesthetic Management of Resection of Seizure Focus 295 Awake Craniotomy 295 Resection of Epileptogenic Focus Under General Anesthesia 300 Neurostimulation for Drug-Resistant Epilepsy 301 Anesthetic Management of the Patient With Epilepsy for Incidental Surgery 302 Abbreviations 303 References 304 17. Refractory Status Epilepticus M. PANEBIANCO AND A. MARSON Introduction 309 Epidemiology 309 Classification 310 Cause 310 Pathophysiology 311 Diagnosis 311 Management 311 Treatment 312 Conclusions 313 References 314 18. Aneurysmal Subarachnoid Hemorrhage C. MAHAJAN History 316 Introduction 316 Clinical Presentation and Diagnosis 317 Grading of Subarachnoid Hemorrhage 319 Initial Management Concerns in Neurocritical Care Unit 321 Timing of Surgery 327 Clipping or Coiling 327 Evaluation of a Patient With Subarachnoid Hemorrhage for Anesthesia 328 Anesthetic Management 328 Temporary Clipping and Brain Protection Strategy 330 Intraoperative Aneurysm Rupture 330 Giant Aneurysms and Circulatory Arrest 331 Endovascular Management for Aneurysm Ablation 331 Postoperative Management of Patients 333 Conclusion 333 References 333
CONTENTS x 19. Circulatory Arrest D.E. TRAUL Introduction 339 Deep Hypothermic Circulatory Arrest 339 Anesthesia Management 340 Complications 341 Adenosine-Induced Circulatory Arrest 341 Anesthesia Considerations 342 Complications 342 Summary 342 References 343 20. Cerebrovascular Disease M. ABRAHAM AND M. MARDA Intracerebral Hemorrhage 346 Incidence and Risk Factors 346 Imaging 346 Clinical Presentation 346 Management of Intracerebral Hemorrhage 348 Arteriovenous Malformations 352 Cause and Incidence 352 Natural History 353 Pathophysiologic Effects and Clinical Presentation 353 Grading of Arteriovenous Malformations 353 Imaging 354 Cerebral Hemodynamics in Arteriovenous Malformation 354 Management 354 Surgical Resection of Arteriovenous Malformation 355 Anesthetic Considerations for Resection of Arteriovenous Malformation 355 Postoperative Management 356 Anesthetic Considerations for Arteriovenous Malformation Embolization 356 Complications During Arteriovenous Malformation Embolization 357 Pediatric Arteriovenous Malformations 357 Pregnancy and Arteriovenous Malformations 358 Vein of Galen Aneurysmal Malformations 358 Dural Arteriovenous Fistula 360 Clinical Presentation 360 Management 360 Carotid Endarterectomy 360 Preoperative Evaluation 362 Management of Carotid Artery Disease 362 Monitoring 362 Intraoperative Management 363 Postoperative Complications and Outcomes 363 Coronary Angioplasty and Stenting 363 Moyamoya Disease 363 Management of Moyamoya Disease 364 References 364 21. Flow Arrest in Cerebrovascular Surgery M.L. JAMES, M.-A. BABI AND S.A. KHAN Deep Hypothermic Circulatory Arrest 367 Adenosine-Assisted Cerebral Blood Flow Arrest 370 Rapid Ventricular Pacing–Assisted Cerebral Blood Flow Arrest 372 References 373 22. Neuroendocrine Lesions P.K. BITHAL Hypothalamic-Pituitary–Adrenal Axis Evaluation 376 Neuroendocrine Response Related to Anesthesia and Surgery 377 Pituitary Gland Adenomas 377 Physiology of Pituitary Gland 379 Endocrine Diseases 380 Nonfunctioning Tumors 382 Intraoperative Considerations 383 Advantages of Endoscopic Endonasal Approach 384 Relative Contraindications to Transsphenoidal Approach 384 Intraoperative Issues 384 Disorder of Water and Electrolytes 387 References 389 23. Pituitary Apoplexy S.S. THOTA Clinical Features 395 Management 395 References 397 24. Spinal Surgery M.S. TANDON AND D. SAIGAL Introduction 400 Spine 400 Types of Spine Surgeries 401 Surgical Approaches to the Spine 403 Common Spine Disorders 403 Imaging in Spine Lesions 417 Positioning for Spine Surgeries 417 Neurophysiological Intraoperative Monitoring During Spine Surgeries 418 Preanesthetic Assessment and Optimization 420 Anesthesia Management 423 Postoperative Management 430 Special Considerations 431 Conclusion 437 References 437 25. Postoperative Visual Loss K.M. KLA AND L.A. LEE Introduction 441 Central Retinal Artery Occlusion 441 Ischemic Optic Neuropathy 442 Cortical Blindness 442 Recent Advances 443 Conclusion 445 References 445
CONTENTS xi 26. Neuroendoscopy S. MONINGI AND D.K. KULKARNI Introduction 447 Anesthetic Goals and Management 450 Anesthetic Management of Specific Neuroendoscopic Procedures 453 Advances in Neuroendoscopy 466 Conclusion 467 Clinical Pearls 467 References 468 27. Pressure Inside the Neuroendoscope N. FÀBREGAS AND L. SALVADOR Introduction 471 Indications and Procedures 471 How Do Neurosurgeons Perform an Intraventricular Endoscopic Procedure? 472 Anesthetic Procedure: What to Take Into Account? 473 Perioperative Complications 475 Conclusion 477 References 477 28. Anesthesia for Functional Neurosurgery S.K. DUBE Introduction 479 Procedure 479 Anesthetic Consideration 481 Anesthetic Techniques 484 Complications 485 Anesthesia in Patients With Deep Brain Stimulator In Situ 486 Conclusion 486 References 486 29. Awake Craniotomy P.H. MANNINEN AND T. Y. YEOH Introduction 489 Patient Selection 490 Awake Craniotomy for Tumor Surgery 490 Awake Craniotomy for Epilepsy 496 Conclusion 499 References 499 VIII NEURORADIOLOGY 30. Anesthesia for Neuroradiology K. SRIGANESH AND B. VINAY Introduction 505 Issues Relating to Anesthesia Care in Neuroradiology 506 Anesthesia for Computed Tomographic Study 506 Anesthesia for Magnetic Resonance Imaging Study 506 Anesthesia for Diagnostic Angiography 510 Anesthetic Management of Endovascular Coiling 510 Anesthetic Management of Endovascular Embolization of Arteriovenous Malformation, Arteriovenous Fistula, and Vein of Galen Malformation 513 Anesthesia for Stroke Interventions 514 Issues Related to Radiation During Neurointervention 515 Anesthesia for Stereotactic Radiosurgery 516 Pregnancy and Neuroradiology 516 Clinical Pearls 517 References 517 31. Magnetic Resonance Imaging: Anesthetic Implications F. RABAI AND R. RAMANI Introduction: The Road From X-Ray to Magnetic Resonance Imaging 519 Principles of Nuclear Magnetic Resonance and Magnetic Resonance Imaging 521 Various Types of Signals Recorded 522 Hazards Related to Magnetic Resonance Imaging 524 Magnetic Resonance Imaging Safety: General Considerations 526 Magnetic Resonance Imaging Safety: Management of Cardiac Implantable Electronic Devices and Other Implantable Devices 527 Anesthesia for Magnetic Resonance Imaging 530 Research Applications/Emerging Clinical Applications of Magnetic Resonance Imaging 531 References 532 IX NEUROTRAUMA 32. Neurotrauma D. PADMAJA, A. LUTHRA AND R. MITRA Traumatic Brain Injury 536 Introduction 536 Definition 536 Epidemiology 536 Classification of Traumatic Brain Injury 537 Physiologic Response to Brain Injury 543 Neuroimaging 545 Severity of Traumatic Brain Injury 549 Management of Traumatic Brain Injury 549 Outcome 559 Emerging Treatment Modalities 559 Conclusion 560 Spine and Spinal Cord Trauma 560 Introduction 560 Epidemiology 560 Classification of Spinal Injury 561 Pathophysiology of Spinal Cord Trauma 563 Systemic Complications of Spinal Cord Injuries 565
CONTENTS xii Management of Spine and Spinal Cord Injury 567 Emerging Treatment Modalities 578 References 582 33. Biomarkers in Traumatic Brain Injury J. ŽUREK Introduction 587 Conclusion 590 References 590 X NEUROINTENSIVE CARE 34. Neurological Critical Care G.S. UMAMAHESWARA RAO AND S. BANSAL Introduction 595 History of Neurocritical Care 596 Design of a Neurocritical Care Unit 596 Clinical Conditions Requiring Admission to Neurocritical Care Unit 596 Justification for Neurological Critical Care Units 596 Pathophysiological Issues in Neurological Critical Care 597 Management of Patients in a Neurological Intensive Care Unit 598 Management of General Systemic Physiology 598 Specific Therapeutic Issues in Individual Clinical Conditions 603 Advanced Neuromonitoring 603 Outcomes of Neurological Intensive Care Unit 606 End-of-Life Issues in Neurological Critical Care 606 Clinical Pearls 608 References 608 35. Antibiotics: Prophylactic and Therapeutics S. ERB, L.A. STEINER AND C. OETLIKER Introduction 613 Principles of Antimicrobial Therapy in Neurosurgery 613 Treatment of Central Nervous System Infections in the Neurosurgical Patient 616 Antimicrobial Prophylaxis in Neurosurgery 620 References 623 XI SPECIAL CONSIDERATIONS 36. Pediatric Neuroanesthesia G.P. RATH Overview 629 Pediatric Neurophysiology 629 General Principles of Pediatric Neuroanesthesia 630 Intraoperative Management 631 Postoperative Considerations 633 Management of Specific Conditions 633 Conclusion 641 References 641 37. Fluid and Blood Transfusion in Pediatric Neurosurgery S. RAJAN AND S. RAO Introduction 643 Fluid and Electrolyte Choices 644 Type of Fluids for Perioperative Administration in Pediatric Patients 645 Fluid Management in Pediatric Neurosurgery 645 Osmotherapy 646 Fluid and Electrolyte Disturbances in Pediatric Neurosurgery 647 Blood Transfusion 647 Blood Components 648 Special Situations 649 Epilepsy Surgery 649 Scoliosis 649 Conclusion 650 References 650 38. Geriatric Neuroanesthesia S. TRIPATHY Introduction 653 Implications of Surgical Stress and Anesthesia on the Elderly 653 Neurosurgical Concerns Unique to the Elderly 654 Conclusion 658 References 658 39. Postoperative Cognitive Dysfunction A. BOROZDINA, L. PORCELLA AND F. BILOTTA Introduction 661 Definitions, Epidemiology, and Pathophysiology 661 Risk Factors 663 Prevention 664 Screening Tools 664 Treatment 665 Outcome 666 References 666 40. Pregnancy V. SINGHAL Requirement of Neurosurgery During Pregnancy 670 Physiological Alterations During Pregnancy 671 Effect of Anesthetic Agents on Fetal Outcome 673 Uteroplacental Drug Transfer and Neonatal Depression 674 Timing and Method of Delivery 675 Anesthetic Considerations During Pregnancy 675 Induction: Rapid Sequence Versus Slow Neuroinduction 676 Combined Cesarean Delivery and Neurosurgery 678
CONTENTS xiii Intracranial Pressure and Regional Anesthesia 678 Postoperative Management 678 Anesthesia for Interventional Neurosurgical Procedures 679 References 679 41. Cerebral Venous Thrombosis E.E. SHARPE AND J.J. PASTERNAK Definition 681 Venous Anatomy 681 Incidence of Cerebral Venous Thrombosis 681 Risk Factors 683 Pathophysiology 684 Clinical Manifestations 685 Diagnostic Evaluation 687 Treatment 688 Anesthetic Management 689 Prognosis 690 Conclusion 690 References 690 42. Neurosurgical Anesthesia in Patients With Coexisting Cardiac Disease S. SRIVASTAVA AND A. KANNAUJIA Introduction 693 Preoperative Evaluation 694 Risk Stratification 694 Perioperative Monitoring 695 Ischemic Heart Disease 695 Valvular Heart Disease 697 Tumors of the Heart 699 Congenital Heart Disease 700 Hypertension 700 Conclusion 701 References 701 43. Intraoperative Cardiopulmonary Resuscitation R. GORJI AND M. SIDANI Introduction 703 Incidence, Morbidity, and Mortality 703 Survival From Intraoperative Cardiac Arrest 704 Predictors 704 Cause of Intraoperative Cardiac Arrest 705 Cardiopulmonary Resuscitation Quality 706 Cardiac Arrest and Cardiopulmonary Resuscitation in Neurosurgical Patients 706 Prognosis 709 Conclusion 709 References 710 44. Coexisting Diabetes Mellitus in Neurosurgical Patients N.B. PANDA, S. SAHU AND A. SWAIN Introduction 714 Incidence of Diabetes Mellitus 714 Glycemic Indices 714 Modes of Glucose Measurement 714 Pathophysiology of Diabetes Mellitus 715 Cerebral Glucose Metabolism 715 Hyperglycemia and the Brain 715 Hyperglycemic Neuropathy 716 Diabetic Dysautonomia 716 Hypoglycemia and the Brain 716 Evidence of Glycemic Control in Important Neurosurgical Subsets 717 Traumatic Brain Injury 717 Subarachnoid Hemorrhage 717 Cerebrovascular Accidents 717 Tumor Surgery 718 Spine Surgery 718 Blood Sugar Management in Perioperative Period and Neurocritical Care 718 Intraoperative Management 719 Anesthetic Management 719 Postoperative Glycemic Management 719 Blood Sugar Control in Emergency Neurosurgical Patient 720 Blood Sugar Control in Intensive Care Setup 720 Nutrition 720 Conclusions 720 Coexisting Hypertension in Neurosurgical Patients 721 Introduction 721 Physiology of Cerebral Circulation 721 Pathophysiology of Arterial Hypertension 722 Hypertension in Patients With Traumatic Brain Injury 723 Perioperative Management 724 Preoperative Evaluation 724 Antihypertensive Drugs 725 Intraoperative Management 725 Monitoring 725 Induction of Anesthesia 725 Maintenance of Anesthesia 726 Recovery From Anesthesia 726 Postoperative Care 726 Neurocritical Care 727 Conclusion 727 References 727 45. Neuromuscular Disorders P.U. BIDKAR AND M.V.S. SATYA PRAKASH Introduction 734 Myasthenia Gravis 735 Myasthenic Crisis 743 Lambert–Eaton Myasthenic Syndrome 747 Guillain–Barré Syndrome 748 Periodic Paralysis 753 Myotonias 755 Muscular Dystrophies 758 Motor Neuron Diseases 759 Multiple Sclerosis 760 Parkinson’s Disease 761 Alzheimer’s Disease 763 Huntington’s Disease 764 References 765
CONTENTS xiv 46. Neuromuscular Electrical Stimulation in Critically Ill Patients N. LATRONICO, N. FAGONI AND M. GOBBO Introduction 771 Neuromuscular Electrical Stimulation: Basic Concepts and Practical Considerations 772 Neuromuscular Electrical Stimulation in the Intensive Care Unit 775 Contraindications and Adverse Effects 776 Recommendations for the Use of Neuromuscular Electrical Stimulation in the Intensive Care Unit 777 References 780 47. Neurological Patients for Nonneurosurgeries K. JANGRA, V.K. GROVER AND H. BHAGAT Neurodegenerative Diseases 784 Demyelinating Disease 788 Neuromuscular Disease: Myasthenia Gravis 791 Epilepsy 793 Intracranial Tumors 794 Traumatic Brain Injury 797 References 800 48 Anesthesia for Electroconvulsive Therapy U. GRUNDMANN Background 805 Technique of Electroconvulsive Therapy 805 Contraindications 806 Preprocedure Management 806 Anesthesia for Electroconvulsive Therapy 806 Side Effects 809 Special Conditions 809 Conclusion 810 References 810 XII FLUIDS AND ELECTROLYTE MANAGEMENT 49. Fluids and Electrolyte Management J.N. MONTEIRO Introduction 815 Anatomy and Physiology 815 Pathophysiology 817 Definitions 817 Choice of Fluids 818 Hypertonic Fluids 818 Isotonic Fluids 820 Colloids 820 Hypotonic Fluids 821 Fluid Management 822 Commonly Encountered Fluid Abnormalities 823 Conclusion 824 Clinical Pearls 825 References 825 50. Crystalloid and Colloid Fluids R.G. HAHN Crystalloid Fluids 827 Colloid Fluids 829 Which Fluid to Choose? 830 Conclusions 831 References 832 XIII PAIN MANAGEMENT 51. Pain Management Z. ALI, S. SINGH, N. HASSAN AND I. NAQASH Postcraniotomy Pain 836 Introduction 836 Incidence 836 Anatomical and Physiological Basis of Pain Following Craniotomy 836 Pain-Sensitive Structures of Cranium 838 Pathogenesis of Postcraniotomy Pain 838 Factors Affecting Postcraniotomy Pain 838 Classification and Assessment of Postcraniotomy Pain 839 Preemption of Pain 840 Treatment of Acute Pain 840 Postcraniotomy Pain Management in the Pediatric Population 843 Conclusion 843 Acute Pain Management After Spinal Surgery 843 Pathophysiology 844 Treatment Modalities for Acute Postoperative Spinal Pain 844 Conclusion 848 References 849 XIV BRAIN DEATH AND ETHICAL ISSUES 52. Brain Death and Ethical Issues in Neuroanesthesia Practice M. RADHAKRISHNAN AND S. LALWANI Part A: Brain Death 856 Introduction 856 Criteria for Diagnosing Death 856 Need for Brain Death Diagnosis 856 Rules Regulating Diagnosis of Brain Death 856 Criteria for Certifying Brain Stem Death 857 Pitfalls/Controversies 859
CONTENTS xv Conclusion 861 Appendix I 861 Part B: Ethical Issues in Neuroanesthesia Practice 863 Introduction 863 Ethical Issues in Clinical Care 863 Ethical Issues Related to Research 867 Ethical Issues Related to Team Work 868 Ethical Issues Related to Training 868 Ethical Issues Related to Innovative Neurosurgery 869 Conclusion 869 References 869 53. Organ Donation M.J. SOUTER Introduction 871 Conclusion 876 References 876 XV EVIDENCE-BASED PRACTICE 54. Evidence-Based Practice of Neuroanesthesia I. KAPOOR AND H. PRABHAKAR Introduction 881 Evidence-Based Practice and Neuroanesthesia 883 Evidence and the Brain Trauma Foundation Guidelines 887 Unresolved Issues in the Practice of Neuroanesthesia 887 Conclusion 887 Clinical Pearls 889 References 889 55. Translational Research M. IDA AND M. KAWAGUCHI Introduction 891 Definition 891 In Neuroanesthesia 893 Why Not Lead to Clinical 893 To Be a Successful Translation 894 Conclusion 894 References 894 XVI RECENT ADVANCES 56. Recent Advances in Neuroanesthesiology T.L. WELCH AND J.J. PASTERNAK Introduction 897 Endovascular Treatment of Stroke and Perioperative Stroke 897 Indications for Deep Brain Stimulation 898 Anesthetic Neurotoxicity 899 Pre- and Postconditioning 900 Brain Monitoring 901 New Assays for Creutzfeldt–Jakob Disease 902 References 903 57. Stem Cell Therapy S. SHARMA AND R. AGGARWAL Hypothesis of Stem Cell Research 907 Stem Cell 907 Historical Background 908 Types of Stem Cells 908 Sources of Stem Cells 908 Mesenchymal Stem Cells 909 Stem Cells in Neurological Diseases 909 Mode of Action of Stem Cell Therapy 910 Ethical Issues 910 Recent Advances 911 References 911 58. Pharmacogenomics Y.N. MARTIN AND W.T. NICHOLSON Introduction 913 Basic Genetic Principles 914 Basic Pharmacologic Principles 914 Anesthesia Contribution to the History of Pharmacogenomics 915 Pharmacogenomics: Current Application to Clinical Anesthesia 916 Conclusion 921 References 922 XVII STERILIZATION TECHNIQUES 59. Sterilization and Disinfection S. MOHAPATRA Background 930 Recommendation of Preferred Methods for Various Medical Devices 931 Recommendation for the Cleaning and Decontamination of Environmental Surfaces 931 Recommendation for Blood Spill on the Surface 932 Cleaning and Disinfection of Medical Instruments 933 Cleaning and Reprocessing of Patient Care Equipment 933 Reprocessing of Respiratory Apparatus and Endoscopes 935 Reprocessing of Endoscopes 936 Specific Issues 938 Special Precaution for Inactivation of Creutzfeldt–Jakob Disease 939 Health Care–Associated Infections 940 Infections in Operating Rooms and Intensive Care Units 940 Conclusion 943 References 943
CONTENTS xvi 60. Universal Precautions in the Intensive Care Unit A.YU LUBNIN AND K.A. POPUGAEV Introduction 945 Prophylactics of Health Care–Associated Infections in the Intensive Care Unit 946 Early Diagnosis of Pathogens and Infection Complications in the Intensive Care Unit 947 Rational Antibiotic Therapy 947 Systemic Approach 948 Conclusion 948 References 948 XVIII PALLIATIVE CARE 61. Palliative Care to Neurological and Neurosurgical Patients S. BHATNAGAR AND S.J. BHARTI Introduction 953 References 961 62. Quality of Life and Health-Related Issues L. VENKATRAGHAVAN AND S. BHARADWAJ Introduction 963 Quality of Life and Health-Related Quality of Life 963 Utility of Health-Related Quality of Life 964 Tools for Measuring Health-Related Quality of Life 964 Uses of Measuring Health-Related Quality of Life 965 Health-Related Quality of Life in Relation to Neurosurgical/Neurological Conditions 965 Conclusion 970 References 970 XIX BIOSTATISTICS 63. Biostatistics M. KALAIVANI, S. AMUDHAN, A.D. UPADHYAY AND V.K. KAMAL Introduction to Biostatistics 976 Definition of Statistics 976 Biostatistics and Its Applications 976 Uses of Statistical Methods in Medical Sciences 976 Some Basic Statistical Concepts 976 Population and Sample 977 Scale of Measurements 977 Constant 977 Variables 977 Parameter and Statistic 978 Ratio, Proportion, and Rate 978 Statistical Inference 979 Estimation 979 Hypothesis Testing 979 Steps in Hypothesis Testing or Testing the Statistical Significance 979 Defining the Null and Alternative Hypotheses 980 Calculating the Test Statistic 980 Obtaining, Using, and Interpreting the p-Value 980 Errors in Hypothesis Testing 980 The Possible Mistakes We Can Make 980 Other Important Concepts That Are Essential in Statistical Inference 981 Parametric and Nonparametric Statistical Methods 981 Basic Principles of Statistics 981 Probability Distributions 982 Study Design 982 Sample Size 985 Data Collection and Preparing Data for Analysis 987 Analysis and Presentation of Data 989 Summarizing Data 989 Comparing Groups: Continuous Data 989 Comparing Groups: Categorical Data 991 Comparing Groups: Time to Event Data 991 Relation Between Two Continuous Variables 992 Multivariable Analysis 994 Conclusion 995 References 995 Index 997
xvii List of Contributors M. Abraham Max Hospital Panchsheel, New Delhi, India R. Aggarwal All India Institute of Medical Sciences, New Delhi, India Z. Ali SKIMS, Srinagar, India S. Amudhan NIMHANS, Bengaluru, India M.-A. Babi Duke University, Durham, NC, United States S. Bansal National Institute of Mental Health and NeuroSciences (NIMHANS), Bangalore, India S.D. Bergese Ohio State University, Columbus, OH, United States H. Bhagat Postgraduate Institute of Medical Education and Research, Chandigarh, India S. Bharadwaj NIMHANS, Bangalore, India S.J. Bharti AIIMS, New Delhi, India S. Bhatnagar AIIMS, New Delhi, India P.U. Bidkar JIPMER, Puducherry, India F. Bilotta Sapienza University of Rome, Rome, Italy P.K. Bithal AIIMS, New Delhi, India V. Bonhomme CHR Citadelle, Liege, Belgium A. Borozdina I.M. Sechenov First Moscow Medical University, Moscow, Russia A. Defresne CHR Citadelle, Liege, Belgium S.K. Dube All India Institute of Medical Sciences, New Delhi, India M. Echeverría Centro Médico Docente Paraíso, Maracaibo, Venezuela H. El Beheiry University of Toronto, Toronto, ON, Canada; Trillium Health Partners, Toronto, ON, Canada S. Erb University Hospital Basel, Basel, Switzerland N. Fàbregas Hospital Clinic Universitari, Barcelona, Spain N. Fagoni University of Brescia, Brescia, Italy E. Farag Cleveland Clinic Foundation, Cleveland, OH, United States J. Fiorda-Diaz Ohio State University, Columbus, OH, United States P. Ganjoo GB Pant Hospital, New Delhi, India M. Gobbo University of Brescia, Brescia, Italy R. Gorji Upstate Medical University, Syracuse, NY, United States V.K. Grover Postgraduate Institute of Medical Education and Research, Chandigarh, India U. Grundmann Saarland University Medical Center, Homburg/Saar, Germany D. Gupta Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India N. Gupta Indraprastha Apollo Hospital, New Delhi, India R.G. Hahn Södertälje Hospital, Södertälje, Sweden N. Hassan Government Gousia Hospital, Srinagar, India M. Ida Nara Medical University, Kashihara, Japan M.L. James Duke University, Durham, NC, United States K. Jangra Postgraduate Institute of Medical Education and Research, Chandigarh, India M. Kalaivani AIIMS, New Delhi, India V.K. Kamal AIIMS, New Delhi, India A. Kannaujia Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India I. Kapoor All India Institute of Medical Sciences, New Delhi, India M. Kawaguchi Nara Medical University, Kashihara, Japan A.K. Khanna Cleveland Clinic Foundation, Cleveland, OH, United States S.A. Khan Duke-NUS Medical School, Singapore, Singapore K.M. Kla Vanderbilt University Medical Center, Nashville, TN, United States V. Krishnamoorthy University of Washington, Seattle, WA, United States D.K. Kulkarni Nizam’s Institute of Medical Sciences, Hyderabad, India S. Lalwani All India Institute of Medical Sciences, New Delhi, India N. Latronico University of Brescia, Brescia, Italy L.A. Lee Kadlec Regional Medical Center, Richland, WA, United States A. Lele University of Washington, Seattle, WA, United States A.Yu Lubnin Neurocritical Care of Burdenko Research Neurosurgical Institute, Ministry of Health, Moscow, Russia A. Luthra PGIMER, Chandigarh, India C. Mahajan AIIMS, New Delhi, India S. Mahajan Postgraduate Institute of Medical Education and Research, Chandigarh, India P.H. Manninen Toronto Western Hospital, Toronto, ON, Canada M. Marda Max Hospital Panchsheel, New Delhi, India R. Mariappan Christian Medical College, Vellore, India
LIST OF CONTRIBUTORS xviii A. Marson University of Liverpool, Liverpool, United Kingdom Y.N. Martin Mayo Clinic, Rochester, MN, United States R. Mitra Care Hospital, Bhubhaneswar, India S. Mohapatra AIIMS, New Delhi, India S. Moningi Nizam’s Institute of Medical Sciences, Hyderabad, India J.N. Monteiro P.D. Hinduja Hospital and Medical Research Centre, Mumbai, India I. Naqash SKIMS, Srinagar, India W.T. Nicholson Mayo Clinic, Rochester, MN, United States C. Oetliker University Hospital Basel, Basel, Switzerland D. Padmaja Nizam’s Institute of Medical Sciences, Hyderabad, India N.B. Panda Post Graduate Institute of Medical Education and Research, Chandigarh, India M. Panebianco University of Liverpool, Liverpool, United Kingdom J.J. Pasternak Mayo Clinic College of Medicine, Rochester, MN, United States K.A. Popugaev Federal Medical-Biological Agency, Ministry of Health, Moscow, Russia L. Porcella Spedali Civili University Hospital, Brescia, Italy H. Prabhakar All India Institute of Medical Sciences, New Delhi, India F. Rabai University of Florida, Gainesville, FL, United States M. Radhakrishnan National Institute of Mental Health and NeuroSciences, Bengaluru, India S. Rajan Cleveland Clinic, Cleveland, OH, United States R. Ramani University of Florida, Gainesville, FL, United States V.J. Ramesh National Institute of Mental Health and NeuroSciences, Bengaluru, India S. Rao Yale New Haven Hospital, New Haven, CT, United States G.P. Rath All India Institute of Medical Sciences (AIIMS), New Delhi, India S. Sahu Tata Main Hospital, Jamshedpur, India D. Saigal University of Delhi, New Delhi, India L. Salvador Consorcio Hospital General Universitario de Valencia, Valencia, Spain K. Sandhu Max Superspeciality Hospital, New Delhi, India M.V.S. Satya Prakash JIPMER, Puducherry, India M. Sethuraman Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India S. Sharma All India Institute of Medical Sciences, New Delhi, India E.E. Sharpe Mayo Clinic College of Medicine, Rochester, MN, United States M. Sidani Upstate Medical University, Syracuse, NY, United States V. Singhal Medanta (The Medicity), Gurgaon, India G. Singh Christian Medical College, Vellore, India G.P. Singh AIIMS, New Delhi, India S. Singh SKIMS, Srinagar, India M.J. Souter University of Washington, Seattle, WA, United States K. Sriganesh NIMHANS, Bangalore, India S. Srivastava Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India L.A. Steiner University Hospital Basel, Basel, Switzerland N. Stoicea Ohio State University, Columbus, OH, United States A. Swain Tata Main Hospital, Jamshedpur, India M.S. Tandon University of Delhi, New Delhi, India S.S. Thota Upstate Medical University, State University of New York, Syracuse, NY, United States D.E. Traul Cleveland Clinic, Cleveland, OH, United States S. Tripathy All India Institute of Medical Sciences Bhubaneswar, Bhubaneswar, India G.S. Umamaheswara Rao National Institute of Mental Health and NeuroSciences (NIMHANS), Bangalore, India A.D. Upadhyay AIIMS, New Delhi, India L. Venkatraghavan University of Toronto, Toronto, ON, Canada B. Vinay Gulf Medical University, Ajman, United Arab Emirates T.L. Welch Mayo Clinic College of Medicine, Rochester, MN, United States T.Y. Yeoh Toronto Western Hospital, Toronto, ON, Canada J. Žurek University Hospital Brno, Brno, Czech Republic
xix Foreword There has been substantial flux in the field of neuroanesthesia over the past two decades. This followed what could be viewed as a relatively quiescent and narrowly focused period in neuroanesthesia. During the latter period much of the focus was on the roles of hypotension in aneurysm surgery, hyperventilation for head injury, anesthetics as cerebral protectants, and endless debates about intravenous versus inhaled anesthetics. More recently the purview of neuroanesthesia broadened substantially partly reflecting the huge expansion in the way patients with neurologi- cal diseases are managed. Patients are cared for not only in the traditional operating theater and intensive care unit but also in more complex ways inside and outside the operating theater. Examples include endovascular treatment of aneurysms, magnetic resonance imaging (MRI)- and computed tomography (CT)-guided surgery, minimally inva- sive approaches such as deep brain stimulation (DBS), the growth in neurological monitoring from the awake patient to complex electrophysiology, and the ever increasingly aggressive spine reconstructions. The neuroanesthesiologist of today is not only a traveler going to different parts of the hospital but needs to be an expert in patient management in all the newer scenarios. Furthermore, this expansion of the repertoire requires greater refinement in our intimate knowledge of how drugs and techniques may enhance or adversely affect the nuanced neurosurgical outcomes. Given the above changes in practice, the novice and experienced neuroanesthesia practitioners now, more than ever, need an authoritative text not just full of “book knowledge” but written by those who on a daily basis meld the academic with the practical. To his credit, Hemanshu Prabhakar has brought together an accomplished group of international experts to contribute to this excellent volume. Their writing is authoritative and up to date while being practical and easy to understand. There is no doubt that this book is a very useful contribution to the modern practice of neuroanesthesia. Adrian W. Gelb Distinguished Professor Department of Anesthesia and Perioperative Care University of California San Francisco
This page intentionally left blank
xxi Preface Neuroanesthesia is growing fast as a superspecialty as more and more research is being conducted to improve the practice. The focus is now not restricted to the bench but has also extended to the bedside. There is a need to have a volume that provides a comprehensive view of various topics and issues related to neuroanesthesia. This book provides easy understanding of anesthesia related to neurological sciences. This book will be useful for any medi- cal practitioner associated with neurosurgical and allied branches such as neurology and neuroradiology. This book also caters to the needs of all those anesthetists who practice neuroanesthesia but do not have a formal training in it. It will provide a quick and easy access to understand neuroanesthesia. This book will provide an insight into all possible aspects of anesthetic management of neurosurgical and neurologic patients. This book has been written mainly for the residents and students appearing for examination and anesthetists practicing neuroanesthesia. This book includes the basic sciences such as anatomy, physiology, and pharmacology related to brain and spinal cord. This book also provides an understanding of related issues such as palliative care, evidence-based practice of neuro- anesthesia, sterilization techniques, and ethical issues. This book covers all topics related to neuroanesthesia and provides complete knowledge about brain and spinal cord. The book includes chapters related to allied specialties such as critical care, neurology, and neuroradiology. This book also contains a section on biostatistics, which would be extremely useful to residents and trainees who have to submit dissertation or thesis during their course. This book contains pieces of information that have been brought together, which may have otherwise been avail- able in different books. I am grateful to all my authors across the globe, from as many as 14 different countries. The knowledge and infor- mation shared by the authors through different chapters is the representation of the global practice of neuroanesthe- sia and not limited to geographical boundaries. I sincerely hope this endeavor will improve our knowledge in the management of neurologically compromised patients and bring about an improved patient care. Hemanshu Prabhakar
This page intentionally left blank
xxiii Acknowledgments I wish to acknowledge the support of the administration of the All India Institute of Medical Sciences (AIIMS), New Delhi, in allowing me to conduct this academic task. Words are not enough to express my gratitude for the constant support and encouragement from Prof. P.K. Bithal (Former Head of Neuroanesthesiology and Critical Care, AIIMS, New Delhi). I thank the faculty and staff of the department of Neuroanesthesiology and Critical Care, for their support. Special thanks are due to the production team at Elsevier.
This page intentionally left blank
xxv Introduction and Brief History of Neuroanesthesia W.S. Jellish Loyola University Medical Center, Maywood, IL, United States Neuroanesthesia has evolved as a subspecialty of anesthesiology and has continued to evolve in association with further surgical advancements such as minimally invasive techniques and three-dimensional imaging using neuro- navigation. Neuroradiology has also advanced with invasive neurovascular procedures, once done in the operating rooms, now performed in the neurointerventional radiology suite with the support of the anesthesiologists. Early neuroanesthesia was performed as a method to support the practice of trephination. It was uncertain whether brain surgery had been performed during this trephination or if it was part of a religious or social ritual (Fig. 1). Some were obviously related to injury, but the presence of multiple defects in the absence of other apparent injuries in both young and old suggested a possible therapeutic purpose. A popular aspect was that these openings were used to alleviate pain or allow the escape of evil spirits and humors or to drain pus or reduce inflammation. No matter what the reason for the trephination, skulls with these types of defects have been found all over the world. There are several documented examples, which point out that these skull defects were produced as part of a neu- rosurgical procedure. The Edwin Smith Papyrus is one of the earliest written records of surgical practice (Fig. 2). The text may well represent the first neurosurgical practitioner’s manual as it describes 48 cases that consist of 15 head injuries, 12 facial wounds and fractures, and 7 vertebral injuries. Several other written works produced around 400 BC have been linked to Hippocrates. One of the texts on injuries of the head describes trephination for skull frac- tures, epilepsy, blindness, and headaches. The practitioner was advised to avoid suture lines and the temporal areas because of fear of damaging the anatomy that would lead to contralateral convulsions.1 It was also noted that the inner table should be preserved to protect the dura and this bone fragment would later be extracted by suppuration. Despite the advanced neurosurgical and neuroanatomical knowledge for the times in Greece and Rome, use and understanding of neuroanesthesia did not appear to be much different from those of fellow practitioners elsewhere in the world. In the prehistoric period, anesthesia was probably done by chewing or locally applying a mixture of coca and yucca.2 Daturas had also been used with its anesthetic effect thought to be produced by its contents of sco- polamine, hyoscyamine, and atropine. In early cultures, wine making was highly developed. In Egypt the soporific effects of alcohol had been well documented in hieroglyphic writings. It is considered likely that some analgesia and amnesic effects were derived from this source. Sometimes just compression of the carotid artery was used to induce unconsciousness.3 Progress in neurosurgery slowed considerable during the Middle Ages. The Roman Catholic Church became very influential in medical care and monasteries were the centers for science and knowledge. With the edict of AD 1163 entitled, “Ecclesia abhoret a sanguine,” there were restrictions placed on the use of human bodies for anatomical studies, and progress in the field of surgery was almost halted. At the beginning of the 10th century, Rhazes com- piled the Liber Continens, a collection of all literature belonging to the Arab world including medicine, philosophy, religion, mathematics, and astronomy. Among the several important observations he made with this work, one was particularly remarkable. He wrote that the pressure on the brain, rather than the presence of the skull fracture itself, was more important in determining the outcome after head injury.4 It was not until later in the 10th century with the establishment of a medical school in Salerno, Italy, that this and other medical principles were brought forward to revive European medicine. Few references were made on the use of anesthesia, perhaps because pain was mentioned so many times in reli- gious teachings and was felt to be a noble state that served God’s purpose. When anesthesia was attempted, opium, hyoscyamine, and sometimes wine were used as agents to alleviate pain.5 On occasion Cannabis indica and henbane were used, along with a sponge containing opium, marberry, water hemlock, and ivy which was boiled and then applied to the patient’s nose during the surgery.6 It was thought that wine was added to the sponge during boiling to enhance its sedative power. The physicians of Myddavi, herbalist from Wales, further advised that to improve
INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxvi anesthetic efficiency, when you prepare to operate on a patient, direct them to avoid sleep as long as possible then let some of the potion be poured into the nostril of the patient who will fall asleep without fail.7 The first account of inducing anesthesia and reversing sedation was attempted by two Hindu brothers who per- formed a craniotomy in AD 927 to remove an unidentified tumor from the brain of the King of Dhar. They induced anesthesia with a drug called samohine and reversed the anesthetic effects by pouring an onion compounded with vinegar into the subject’s mouth.7 Numerous other concoctions both oral and topical were administered to patients for better outcomes. Some combined puppies boiled in an oil of lilies and earthworms and prepared in turpentine of Venice.2 Other mixtures used were rose oil, egg yolk, and turpentine, which were either heated in cold weather or cooled in warm weather to maintain temperature. This was done to produce optimal wound healing. The major improvements and overall advancement in anesthesia for neurosurgery occurred in the latter half of the 18th century. The discovery of carbon dioxide, hydrogen, and nitrogen along with experiments by Priestly and others using several gases including oxygen and nitrous oxide created interest in the use of these agents to support patients who were sedated or anesthetized for procedures.8 However, the reluctance of surgeons to perform cranial operations slowed the implementation of anesthesia for neurosurgery. Nevertheless, the accumulation of knowledge of functional neuroanatomy, establishment of concepts of asepsis, and the discovery of general anesthesia all moved the process of neurosurgery accompanied by anesthesia forward. William Macewen was the first neurosurgeon to excise a brain tumor under endotracheal intubation. He was the first to show the necessity of controlling the airway and ventilation during craniotomy. At the beginning of the 20th century there was a great deal of controversy as to what was the best inhalational anesthetic, chloroform, or either. Victor Horsley performed a series of experiments in animals in 1883–85 and concluded that, although ether was the safer drug, it was not to be recommended in favor of chloroform because it produced a rise in blood pressure and an FIGURE 2 The Edwin Smith Papyrus. The terms of brain, as original term “iesh,” pointed by an arrow (and depicted below) can be seen. From James Henry Breasted. The Edwin Smith Surgical Papyrus. Chicago: University Chicago Press; 1930 (reproduced from Eric R Kandel, James H Schwartz, Thomas M Jessell, editors Principles of Neural Science. 4th ed. New York: McGraw-Hill; 2000). FIGURE 1 The trephined skulls discovered in paracus, Peru (≈500 BC), and obsidian blades. The surgical holes are covered with roles of cotton dressing (A). The trepanation had been performed using obsidian blade (B).
INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxvii increase in blood viscosity with a potential for hemorrhage.9 He also noted a propensity for postoperative vomiting and concluded it should not be used for neurosurgery. Also, since morphine constricted blood flow, he suggested that a combination of morphine and chloroform be used. He subsequently abandoned morphine use because of its recognized depressant effect on respiration.9 Death related to the administration of chloroform was not uncommon, and several commissions were set up to study the effects of the drug. In 1901, The British Medical Association appointed a special chloroform committee to study its use. It was known that approximately 2% chloroform vapor in air was sufficient to induce anesthesia with much less required for maintenance. Some believed that the concentration should be strictly controlled with a vapor- izer, while others thought it could be administered strictly by sprinkling onto a cloth. Horsley was of the opinion that the concentration should be controlled and used a vaporizer designed by Vernon Harcourt, which delivered chloroform at a 2% maximum (Fig. 3). In patients undergoing craniotomy, Horsley felt that chloroform administra- tion should be reduced to 0.5% once the bone flap was removed.10 Determination of concentration was particularly important in patients with raised intracranial pressure (ICP) since higher concentrations in these patients could be fatal. Horsley also contributed to neuroscience and neurosurgery by his support and defense of surgery done on ani- mals for scientific research and to advance clinical knowledge. His work and testimony against the Anti-Vivisection Society helped to defend the use of animal models to advance neurosurgery.11 Around the same time, the use of local anesthesia began to gain prominence. Cocaine had been formally discov- ered in 1860 and was introduced in surgery in 1884. Procaine was first synthesized in 1905 and immediately became commonplace among surgical anesthesia. Most neurosurgeons used local anesthetics selectively. However, in 1913 deMartel popularized its use, and it became common practice for use in all craniotomies. By 1917, Harvey Cushing, considered the founder of neurosurgery, recommended the use of local anesthesia for all neurosurgical cases.7 Besides being one of the leading neurosurgeons of the early 20th century, Cushing introduced numerous new methods of anesthesiology. His first contracts in providing anesthesia were not entirely successful. He had several notable patient deaths while providing ether for procedural anesthesia. In all instances, he was told the deaths occurred due to the patient’s condition, but he remained unconvinced that adverse reactions to anesthesia were due only to the condition of the patients. At the coaxing of Dr. F. B. Harrington, Cushing and fellow student Amory Codman tried to determine who gave the best anesthetics. To make the decision objective, they documented their anesthesia in the form of “ether charts” (Fig. 4).12 Their most important parameters measured were the pulse rate, FIGURE 3 The Vernon Harcourt vaporizer arranged with a cylinder of compressed oxygen.
INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxviii breathing, and temperature of the patients. According to Cushing, “a perfect anesthetic was supposed to be one in which the patient was sufficiently conscious to respond when left in the ward with the nurse and did not sub- sequently vomit.” The use of these either charts was a major step toward improvement in what had been a casual administration of a very dangerous drug. In 1900, Cushing began an extended tour of Europe, and while in Bern, he recognized the association between raised ICP and systemic arterial hypertension.13 While in Padua, Italy, at the Ospidale di St. Matteo, he learned the use of Riva-Rocci’s method of blood pressure measurement (Fig. 5). After returning to Baltimore, he adopted this method of blood pressure measurement into clinical practice. He gave a lecture in 1903 titled, “Considerations of Blood Pressure,” only to have a committee of the Harvard Medical School state that, “the skilled finger was of much greater value clinically for determination of the state of circulation than any pneumatic instrument, and the work should be put aside, as of no significance.” Even though blood pressure monitoring was not supported by thought leaders at that time, Cushing still supported the recording of blood pressure during surgery. He also attached great importance to continuous auscultation of the heart and lungs, a technique he learned from his anesthesiologist, Dr. S. Griffith Davis.14 The precordial auscultation device used a transmitter of the phonendoscope secured by adhe- sive strips over the precordium and was connected with a long tube to the anesthesiologist’s ear. The receiver was held in place by a device similar to a telephone operator’s headgear.15 Cushing remained skeptical about general anesthesia for neurosurgery. Mortality was still high and many of the anesthetics were performed by students. He began to experiment on work started by Halsted with block anesthesia using circumferential cocaine infiltration.16 He popularized the use of several local anesthetic techniques and coined the term “regional anesthesia.” From his first work dealing with regional anesthesia, it was noted that the purpose of administering it was to avoid side effects in patients with full stomachs and to ensure better cardiovascular stability in elderly patients. FIGURE 4 An example of the ether charts made by Cushing.
INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxix Dr. Fedor Krause, the founder of German neurosurgery, was exposed to combination morphine–chloroform anes- thesia but was not convinced of its worth for neurosurgery. He felt that controlled hypotension produced by higher concentrations of chloroform alone were beneficial to reduce bleeding.17 He also noted that sudden death could occur in patients with intracranial tumors who stopped breathing. He used the Roth-Drager oxygen–chloroform apparatus which allowed high concentrations of oxygen to be administered. He also noted the brain was insensitive to pain, and only very light planes of anesthesia were needed to perform these surgeries.18 He concluded a good neurosurgical outcome required a rapid aseptic technique, minimal blood loss, normothermia, and general narcosis. During the early 20th century, new delivery systems for anesthesia were being developed. The Junker bottle used a hand bellows to blow air through a vaporizer and the Ombrédanne ether inhaler could be used in the prone posi- tion (Fig. 6). Airway management became less supportive and passive and more active with endotracheal intubation and insufflation of air to maintain oxygenation without ventilation. By 1930, endotracheal anesthesia was recom- mended for neurosurgery. Inhalational anesthetics such as trichloroethylene with nitrous oxide were developed as a neuroanesthetic technique,18 while other physicians such as Hershenson used low concentrations of closed circuit cyclopropane and reported this method in 1942.19 Volwiler and Tabern developed thiopental in 1930 and was introduced into clinical practice 4years later.20 Halothane was synthesized in 1956 and introduced into practice that same year.21 Though popular, its propensity to increase ICP and brain size made it a concern to anesthesiologists and neurosurgeons alike. In 1932, most fluids were given rectally along with a wide variety of anesthetic techniques including ether-based anesthesia, rectal ether in oil, ethylene, and nitrous oxide. Certain large centers began to publish their outcomes for neurosurgical procedures and many included a descrip- tion of the anesthetic techniques used. The Montreal Neurologic Institute showed that of 1000 cases, 700 were per- formed under general anesthesia and 300 with local anesthetics.22 The major concerns were still airway management and fluid replacement. A wide variety of agents were used. However, by 1949 and the early 1950s, pentothal was the induction agent of choice for oral intubation. Throat packing and the use of a nonrebreathing valve to prevent the buildup of carbon dioxide was also common. After World War II, great advances in neuroanesthetic techniques were brought on by the development of new anesthetic agents and advanced knowledge of neurophysiology and pharmacology. Lundy in 1942 noted that in the presence of hypoventilation it was difficult to reduce ICP unless the patient was artificially ventilated.23 The effects of hypoventilation on intracranial and systemic dynamics were further elucidated by Keaty and Schmidt (Fig. 7). They also described methods to measure cerebral blood flow using inhaled N2O.24 Another group used the injection of intraarterial krypton to measure blood flow in the brain and speed of washout.25 The measurement of ICP had been discovered by Cannon in 1901 but continuous ICP measurement was not described until 1960.26 The link between CO2, O2 tension and cerebral blood flow was also developed at this time. Dr. Thomas Langfitt further FIGURE 5 Dr. Harvey Cushing’s sketch of Riva-Rocci’s blood pressure device.
INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxx Venous Arterial A-V 1 1 2 3 4 5 Time (minutes) 6 7 8 9 10 N 2 O Conc Vol% 2 3 4 5 FIGURE 7 Kety–Schmidt method of arterial and venous nitrous oxide concentration for calculating cerebral blood flow. FIGURE 6 (A) Ombrédanne inhaler. (B) Ombrédanne inhaler in use.
INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxxi defined intracranial dynamics based on previous work and developed the pressure volume curves along with the concept of intracranial compliance.27 Three major anesthesia groups contributed to the development of the specialty, the Glascow Group, Pennsylvania Group, and the Mayo Clinic Group. All the three centers were considered think tanks in the development of neuro- anesthetic principles and techniques to help improve intracranial surgery. Most of the principles for neuroanesthesia have been developed over the last 70years. The term, “neuroanesthesia” was coined by John Michenfelder from the Mayo Clinic.28 In the 1960s, researchers at the University of Pennsylvania studied the cerebral effects of nitrous oxide, cyclopro- pane, halothane, enflurane, hypotension, and hyperventilation.29–31 These studies formed many of the basics for neu- roanesthesia principles today. At the same time, researchers at the University of Glascow studied anesthetic effects on intracranial dynamics. This group was one of the first to confirm that anesthetic agents did indeed exert a measur- able effect on cerebral blood flow and metabolism in patients with intracranial mass lesions.32,33 It was some of these studies that were used to justify the abandonment of the use of halothane because of its vasodilating properties, espe- cially in patients with mass lesions in the brain. At the Mayo Clinic the only emphasis of research by Michenfelder was of providing cerebral protection, especially with hypothermia during neurovascular procedures. These same three centers continued to expand their influence in neuroanesthesia, and at the University of Pennsylvania the role of the neuroanesthesiologist was expanded to the intensive care unit. In the 1980s, research continued on glucose control and again on the effects of modest hypothermia. A wide range of drugs emerged as possible cerebral protective agents. A much clearer understanding of pathways involved in cell damage was also achieved. Research on brain trauma and survival also became important because of the effects of war on traumatic brain injury. Despite much of this research, the morbidity and mortality from subarachnoid hemorrhage, stroke, trauma, and neoplastic lesions have remained largely unchanged in the past several decades. Nevertheless, neuroanesthesia practice has appreciably changed over the past few decades. Hyperventilation has long been known to reduce ICP. At the beginning of the 1990s it was widely held that this had therapeutic value for intracranial procedures. However, with the use of oximetric pulmonary artery catheters, investigators have been able to do retrograde cannulation of the jugular vein up to the bulb to examine venous Hb saturation in response to therapeutic hyperventilation in head trauma patients. In some patients, this hyperventila- tion resulted in increased hypoxia that has resulted in abandonment of hyperventilation unless surgical conditions dictate. However, other recent studies have demonstrated that hyperventilation, especially for supratentorial brain tumors, was associated with reduced ICP and a 45% reduction in brain bulk, once again demonstrating its worth, especially with supratentorial surgery.34 The early 1990s also demonstrated a surge of new anesthetic techniques and drugs. Both desflurane and sevoflu- rane were introduced and were found to have cerebral metabolic properties similar to isoflurane. However, some questions still remain regarding desflurane causing an insidious increase in ICP. There are also questions concerning the metabolism of sevoflurane and possible renal toxicity, especially with the effect of anticonvulsants on hepatic function. Since both drugs have been accepted and widely used as neuroanesthetics, these concerns do not seem to hold major importance. Remifentanil was also introduced in the 1990s and was found to be essentially identical to other opioids with respect to µ-opioid agonist-mediated events. It does have a much more rapid and predictable emergence compared to other opioid-based techniques. However, the drug produces hypertension and tachycardia with increased sympathetic activity during emergence which could be especially problematic with large tumor resec- tions where hemodynamic stability during emergence to prevent bleeding is imperative. The administration of proper IV fluids and correct fluid replacement therapy was better developed in the 1990s. There was a widespread acceptance that glucose-containing solutions were not essential in patients undergoing neurosurgical procedures. Perioperative glycemic control is one of the important topics that have been investigated in the 1980s and 1990s. Hyperglycemia in ischemic conditions has been proven to be detrimental, and strict control of plasma glucose has been shown to produce better outcomes in critically ill patients. Many studies have demon- strated that plasma glucose levels are well maintained at close to normal ranges with nonglucose-containing solu- tions, while patients who received glucose had high plasma levels which fluctuated dramatically during their care. Therefore, routine use of glucose-containing solutions should be avoided during neurosurgery. The use of crystalloid solutions has also been altered by studies from the last 20years. In the 1980s it remained a standard practice to dehydrate patients with intracranial pathology under the assumption that brain volume would be decreased. This was often performed at the expense of stable hemodynamics and cerebral perfusion pressure. However, extensive studies have demonstrated that fluid restriction for neurosurgical procedures may be detrimen- tal. In addition, many large trials evaluating colloid versus crystalloid solutions, especially with trauma-related injury, showed that saline resuscitation may be of greater benefit than treatment with albumin. In fact, studies demonstrated
INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxxii a detrimental effect of albumin treatment, especially with the relative risk of death within 24months.35 This has led to a recommendation that colloids not be used for resuscitation in patients with brain injury. The early 1990s also provided consistent evidence that small changes in brain temperature could have a major impact on outcome from ischemic or traumatic brain injury.36 These changes did not require overt cooling or the use of extracorporeal perfusions but were well within the range of routine manipulation by anesthesiologists. The prac- tice of the use of mild hypothermia increased, but there were other warnings about inadvertent hypothermia from other patient populations, which caused concerns. In the late 1990s, a multinational consortium of investigators was formed to examine the risks and benefits of mild hypothermia in patients undergoing aneurysm clipping and was inconclusive as to the benefit of hypothermia on survival and outcome after a neurologic event producing ischemia. Based on clinical data, mild hypothermia may still have beneficial effects in patients with good grade subarachnoid hemorrhage (SAH).37 The latest American Heart Association and American Stroke Association guidelines for the management of aneurysmal SAH recommend induced hypothermia as a reasonable option in selected cases.38 At the clinical level, no progress has been made in pharmacologic neuroprotection. Despite successful experi- mental studies, by far no anesthetic technique has been convincingly shown to provide profound neuroprotection in humans. Barbiturates remain the gold standard, although clinical evidence of efficacy from this class of compounds is suspected on methodologic grounds. In a post hoc analysis of IHAST (intraoperative hypothermia for aneurysm surgery trial) data administration of thiopentanil or etomidate was not found to have a demonstrable effect on postoperative neurological outcomes in patients undergoing temporary clipping.39 Use of etomidate has waned as a neuroprotective agent as a result of absence of clinical evidence of benefit in both clinical and laboratory studies. Some of the most exciting and important clinical advances in neuroanesthesia have been in the area of monitor- ing, both in the operating room and neurointensive care units. With the advancement of near-infrared spectros- copy (NIRS) and transcranial Doppler, the detection of cerebral ischemia, especially under general anesthesia, has improved tremendously. Multimodal intraoperative monitoring of spinal cord sensory and motor function during surgical correction of adult spinal deformity is feasible and provides useful neurophysiological data with an overall sensitivity of 100% and specificity of 84.3%.40 In the neurointensive care unit, insertion of microdialysis and multipa- rameter biochemical probes into traumatized human brains has confirmed findings. Cytokine production and pro- apoptotic markers have been detected during oxidative stress, and these markers have recovered during enhanced perfusion. Ischemic events have been associated with tissue acidosis, and spontaneous depolarizations have been observed. Use of these monitors in the operating room has occurred. What remains to be totally defined is what val- ues constitute thresholds for interventions. These thresholds have been characterized mostly for NIRS monitoring, and much of this has revolutionized the treatment of patients with the possibility of cerebral hypoperfusion. The development of neuroanesthesia has paralleled advances in neurosurgery. As techniques and procedures have become advanced, so have the techniques and protocols to anesthetize and monitor neurologic function. The overall goal is to provide a good surgical outcome and better quality of life. Procedures will become less invasive with more functional neurosurgery requiring a cooperative patient. This makes the anesthetic management for these procedures even more complex. It is also likely that there will be greater integration of neurosurgery and neuroradi- ology, with greater emphasis on maintaining cerebral vascular function without the effects of inhalational anesthet- ics and opioids. Neurosurgery is ever evolving; the practice of anesthesiology for these procedures will also have to evolve to accommodate the demands of the surgeon and improve patient outcomes. Neuroanesthesia practice will shadow neurosurgical breakthroughs. These changes will accelerate over the next 10years as scientific advances, and the understanding of the diseases we treat enhance the capacity of the anesthesiologist to develop techniques to provide an ideal surgical environment with rapid awakening to assess neurologic function. References 1. Hippocrates on injuries of the head [Adams F, Trans.]. London: The Genuine Works of Hippocrates, in 2 vols.; 1849. 2. Frost EAM. A history of neuroanesthesia. In: Eger E, Saidman LJ, Westhope RN, editors. The wondrous story of anesthesia. New York: Springer; 2014. p. 871–85. 3. Gunther RT. Dioscorides Pedanius. The greek herbal of dioscorides. Oxford: Oxford University Press; 1934. 4. Cooper A. Lectures on the principles and practice of surgery. London: Westley; 1829. 5. Raper HR. Man against pain: the epic of anesthesia. New York: Prentice-Hall; 1945. p. 8. 6. Robinson V. Victory over pain: a history of anesthesia. New York: Henry Schumann; 1945. p. 29. 7. Walker AE. A history of neurological surgery. New York: Hafner; 1967. 8. Priestley J. Experiments and observations on different kinds of air. London: Thomas Pearson; 1790. 9. Horsley V. On the technique of operations on the central nervous system. BMJ 1906;2:411–23. 10. Horsley V. On the technique of operations on the central nervous system. Address in Surgery. Toronto Lancet 1906;2:484.
INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxxiii 11. Lyons JB. Citizen surgeon. London: Peter Downay; 1966. 12. Beecher HK. The first anesthesia records (Codman Cushing). Surg Gynecol Obstet 1940;71:689. 13. Cushing HW. Concerning a definitive regulatory mechanism of the vasomotor center which controls blood pressure during cerebral compres- sion. Bull Johns Hopkins Hosp 1901;12:290. 14. Cushing HW. Some principles of cerebral surgery. JAMA 1909;52:184. 15. Shephard DA. Harvey Cushing and anesthesia. Can Anaesth Soc J 1965;12:431–2. 16. Halsted WS. Surgical papers. Baltimore: Johns Hopkins Press; 1924. p. 167. 17. Krause F. [Haubold H, Thorek M, Trans.]. Surgery of the brain and spinal cord based on personal experiences, vol. 1. New York: Rebman & Co.; 1912. p. 137. 18. Jackson DE. A study of analgesia and anesthesia with special reference to such substances as trichloroethylene and vinesthene together with apparatus for their administration. Anesth Analg (Curr Res) 1934;13:198. 19. Hershenson BB. Some observations on anesthesia for neurosurgery. NY State J Med 1942;42:2111. 20. Lundy JS. Intravenous anesthesia: preliminary report of the use of two new thiobarbiturates. Mayo Clin Proc 1935;10:536. 21. Johnstone M. The human cardiovascular response to flurothane anaesthesia. Br J Anesth 1956;28:392. 22. Stephen CR, Pasquet A. Anesthesia for neurosurgical procedures. Analysis of 1000 cases. Anesth Analg 1949;28:77. 23. Lundy JS. Clinical anesthesia. Philadelphia: WB Saunders; 1942. p. 3. 24. Kety SS, Schmidt CF. Determination of cerebral blood flow in man by the use of nitrous oxide in low concentrations. Am J Physiol 1945;143:53. 25. Lassen NA, Ingvar DH. The blood flow of the cerebral cortex determined by radioactive krypton. Experientia 1961;17:42. 26. Lundberg N. Continuous recording and control of ventricular fluid pressure in neurosurgical practice. Acta Psychiatr Neurol Scand 1960;36 (Suppl. 149). 27. Langfitt TW. Increased intracranial pressure. Clin Neurosurg 1969;16:438. 28. Michenfelder JD, Gronert VA, Rehder K. Neuroanesthesia. Anesthesiology 1969;30:65–100. 29. Alexander SC, Wollman H, Cohen PJ, Chase PE, Behar M. Cerebral vascular responses to PaCO2 during halothane anesthesia in man. J Appl Physiol 1964;19:561. 30. Smith AL, Wollman J. Cerebral blood flow and metabolism: Effects of anesthetic drugs and techniques. Anesthesiology 1972;36:378. 31. Pierce Jr EC, Lambertsen CJ, Deutsch S, Chase PE, Linde HW, Dripps RD, et al. Cerebral circulation and metabolism during thiopental anes- thesia and hyperventilation in man. J Clin Invest 1962;41:1664. 32. Okuda Y, McDowall DG, Ali MM, Lane JR. Changes in CO2 responsiveness and in autoregulation of the cerebral circulation during and after halothane induced hypotension. J Neurol Neurosurg Psychiatry 1972;39:221. 33. Harper AM, Bell RA. The effect of metabolic acidosis and alkalosis on the blood flow through the cerebral cortex. J Neurol Neurosurg Psychiatry 1963;26:341. 34. Gelb AW, Craen RA, Rao GS, Reddy KR, Megvesi J, Mohanty B, et al. Does hyperventilation improve operating condition during supratento- rial craniotomy? A multicenter randomized crossover trial. Anesth Analg 2008;106:585–94. 35. SAFE Study Investigators, Australian and New Zealand Intensive Care Society Clinical Trials Group, Australian Red Cross Blood Service, George Institute for International Health, Myburgh J, Cooper DJ, Finfer S, Bellomo R, Norton R, Bishop N, et al. Saline or albumin for fluid resuscitation in patients with traumatic brain injury. N Engl J Med 2007;357:874–84. 36. Clifton GL, Valadka A, Zygun D, Coffey CS, Drever P, Fourwinds S, et al. Very early hypothermia induction in patients with severe brain injury (the National Acute Brain Injury Study: Hypothermia II): a randomized trial. Lancet Neurol 2011;10:131–9. 37. Li LR, You C, Chaudhary B. Intraoperative mild hypothermia for postoperative neurological deficits in intracranial aneurysm patients. Cochrane Database Syst Rev 2012;2:CD008–445. 38. Connolly Jr ES, Rabinstein AA, Carhuapoma JR, Derdeyn CP, Dion J, Higashida RT, et al. Guidelines for the management of aneurysmal subarachnoid hemorrhage: a guideline for healthcare professionals from the American Heart Association. Stroke 2012;43:1711–37. 39. Hindman BJ, Bayman EO, Pfisterer WK, Torner JC, Todd MM. IHAST Investigators. No association between intraoperative hypothermia of supplemental protective drug and neurologic outcomes in patients undergoing temporary clipping during cerebral aneurysm surgery: find- ings from the intraoperative hypothermia for aneurysm surgery trial. Anesthesiology 2010;112(1):86–101. 40. Quraishi NA, Lewis SJ, Kelleher MO, Sarjeant R, Rampersaud UR, Fehlings MG. Intraoperative multimodality monitoring in adult spinal deformity: analysis of a prospective series of one hundred two cases with independent evaluation. Spine (Phil PA 1976) 2009;34:1504–12.
This page intentionally left blank
S E C T I O N I NEUROANATOMY
This page intentionally left blank
Essentials of Neuroanesthesia http://dx.doi.org/10.1016/B978-0-12-805299-0.00001-4 © 2017 Elsevier Inc. All rights reserved. 3 O U T L I N E Introduction 3 Embryological Differentiation of Different Parts of Brain 4 Anatomy of Brain 4 Cerebrum 4 Frontal Lobe 6 Temporal Lobes 6 Parietal Lobe 7 Functional Areas (of Cerebral Cortex) 8 Premotor Area 10 Sensory Areas 10 Visual Area 11 Acoustic (Auditory) Area 11 Association Areas 11 Diencephalon 11 The Thalamus 11 Hypothalamus 13 Epithalamus 15 Habenular Nucleus 15 Afferent Fibers 16 Efferent Fibers 16 Nucleus Subthalamicus 16 Zona Incerta 16 Basal Ganglia 16 Internal Capsule 17 White Matter 18 Corpus Callosum 19 Ventricular System 19 Lateral Ventricles 20 Third Ventricle 21 Fourth Ventricle 22 Limbic System 22 Midbrain (Mesencephalon) 23 Pons 25 Medulla 26 Reticular Formation 29 Cerebellum 29 Vascular Supply of the Brain 30 Arterial System 30 Cerebral Venous System 32 The Meninges and Cerebrospinal Fluid 33 The Meninges 33 Dura Mater 33 The Spinal Cord 34 Ascending Tracts of Spinal Cord (Sensory Tracts) 36 Acknowledgment 39 References 40 C H A P T E R 1 Neuroanatomy D. Gupta Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India INTRODUCTION Why should a well-established neuroanesthetist study clinical neuroanatomy? This question, albeit a vexing one, is very pertinent in the present day scenario. The answer is evident. A tower of knowledge built on broad and diverse information helps one to prepare for all the eventualities that one may encounter. Anatomy is the basis of every procedure that we perform. An anesthetist who embarks on a new journey into the anatomical
1. NEUROANATOMY 4 I. NEUROANATOMY basis of his or her clinical practice has adapted well to a vista that emphasizes fundamental sciences as the basis of all medical education. It helps the person improve his or her procedural skills. Finally, it helps him or her to be better equipped to deal with a changing and unpredictable world where knowledge empowers and also acts as a haven of safety. About 100 billion neurons and 10–50 trillion neuroglias make up the brain, which has a mass of about 1300– 1500 g in adult. On average each neuron forms 1000 synapses with other neurons1. The total number of syn- apses, about 1000 trillion, is larger than the number of stars in the galaxy. The central nervous system (CNS) included the brain and the spinal cord and is composed of (1) cerebral hemisphere, (2) diencephalon, (3) basal ganglion, (4) midbrain, (5) pons, (6) medulla, (7) cerebellum, and (8) spinal cord. This chapter will provide information of these parts individually, that is integrated, informative, and relevant to educational need of the neuroanesthesiologists. EMBRYOLOGICAL DIFFERENTIATION OF DIFFERENT PARTS OF BRAIN Knowledge of the embryological development of the brain is necessary to understand the terminology used for the principal part of the adult brain. The development of the brain is dealt with details in the following chapter. ANATOMY OF BRAIN Cerebrum The cerebrum consists of two cerebral hemispheres that are partially connected with each other by corpus cal- losum. Each hemisphere contains a cavity called the lateral ventricle. The cerebrum is arbitrarily divided into five lobes: frontal, parietal, temporal, occipital, and insula.2 On the lateral surface three sulci (central, lateral or Sylvian, and parietooccipital sulci) and two imaginary lines divide the cerebrum into four lobes (Fig. 1.1). The first imaginary line (lateral parietotemporal line) is drawn from parietooccipital sulcus to preoccipital notch and second (temporo- occipital line) backward continuation of posterior ramus of lateral sulcus before it turns upward to meet first line. The central sulcus and posterior ramus of Sylvian fissure (SF) separate frontal lobe from parietal lobe and temporal lobe. Posteriorly parietooccipital sulcus and lateral parietotemporal line separate occipital lobe from parietal lobe and temporal lobe. Temporal and parietal lobes are separate by posterior ramus of SF and temporo-occipital line (Fig. 1.1). The cerebral cortex is the outermost sheet of neural tissue of the cerebrum whereas white matter lies in the center. Cerebral cortex is folded into sulci and gyri, which actually increases the surface area of cortex. Sulci include the central lateral and parietooccipital. The central sulcus begins by cutting the superomedial border of the hemisphere a little behind the midpoint between the frontal and parietal lobe. It runs on the superolateral surface obliquely downward and forward for about 8–10cm and ends a slight above the posterior ramus of lateral sulcus. It separates precentral gyrus (motor area) from postcen- tral gyrus (sensory area) (Figs. 1.2 and 1.3). It was originally called the fissure of Rolando or the Rolandic fissure. FIGURE 1.1 Schematic diagram of lateral aspect of left cerebral hemisphere. Line 1. Lateral parietotemporal line; Line 2. Temporooccipital line.
ANATOMY OF BRAIN 5 I. NEUROANATOMY FIGURE 1.2 Brain anatomy. Superior view. 1. Longitudinal fissure of cerebrum. 2. Frontal pole. 3. Superior margin of cerebrum. 4. Superior frontal sulcus. 5. Inferior frontal sulcus. 6. Precentral sulcus. 7. Central sulcus. 8. Postcentral sulcus. 9. Intraparietal sulcus. 10. Parietooccipital sulcus. 11. Transverse occipital sulcus. 12. Occipital pole. 13. Superior parietal lobule. 14. Inferior parietal lobule. 15. Paracentral lobule. 16. Postcentral gyrus. 17. Precentral gyrus. 18. Inferior frontal gyrus. 19. Middle frontal gyrus. 20. Superior frontal gyrus. FIGURE 1.3 Brain anatomy. Lateral view of right hemisphere. 1. Central sulcus. 2. Precentral sulcus. 3. Precentral gyrus. 4. Superior frontal gyrus. 5. Superior frontal sulci. 6. Middle frontal gyrus. 7. Middle frontal sulcus. 8. Frontal pole. 9. Orbital gyri. 10. Olfactory bulb. 11. Olfactory tract. 12. Anterior ramus of lateral sulcus (Sylvian fissure (SF)). 13. Frontal operculum. 14. Ascending ramus lateral sulcus (SF). 15. Frontoparietal operculum. 16. Posterior ramus lateral sulcus (SF). 17. Superior temporal gyrus. 18. Middle temporal gyrus. 19. Superior temporal sulcus. 20. Inferior temporal sulcus. 21. Inferior temporal gyrus. 22. Pons. 23. Pyramid (medulla oblongata). 24. Olive. 25. Flocculus. 26. Cerebellar hemi- sphere. 27. Preoccipital notch. 28. Occipital pole. 29. Postcentral gyrus. 30. Supramarginal gyrus. 31. Angular gyrus. 32. Transverse occipital sulcus. 33. Inferior parietal lobule. 34. Intraparietal sulcus. 35. Superior parietal lobule. 36. Postcentral sulcus.
1. NEUROANATOMY 6 I. NEUROANATOMY The lateral sulcus or Sylvian fissure (SF) is one of the earliest-developing sulci of the human brain. It first appears around the 14th gestational week.3 It is the deepest and most prominent of the cortical sulci. The lateral sulcus (SF) separates frontal and parietal lobes from temporal lobe. It begins on the superomedial margin. The SF starts on basal and extends to the lateral surface of the brain. It has both a superficial part and a deep part. Superficial part has a stem and three rami (Figs. 1.2 and 1.3). The anterior portion of the deep part (Sylvian cistern) is called the sphenoidal compartment and the posterior part is called the operculoinsular compartment. SF is an important corridor in neu- rosurgery as it connects the surface of anterior part of brain to its depth with all the neural and vascular components along the way. The structures within the reach through the Transylvian approach include middle cerebral artery; optic nerves; internal carotid artery; and its branched lamina terminalis, insula, basal ganglia, and interpeduncular fossa. Parietooccipital sulcus begins on the medial surface of hemisphere nearly 5cm in front of the occipital pole (Fig. 1.4). The upper end of the sulcus reaches the superomedial border to meet the calcarine sulcus, and a small part of it is seen on the superolateral surface. Frontal Lobe The frontal lobe is an area in the brain of mammals, located at the front of each cerebral hemisphere and positioned anterior to (in front of) the parietal lobe and superior and anterior to the temporal lobes. A prefrontal sulcus runs downward and forward parallel to the central sulcus. The area between it and central sulcus is the precentral gyrus. Two sulcus run horizontally anterior to precentral gyrus, i.e., superior and inferior frontal sulcus and divide the region into superior, middle, and inferior frontal gyri (Fig. 1.3). The frontal lobe contains most of the dopamine-sensitive neurons in the cerebral cortex associated with reward, attention, short-term memory tasks, planning, and motivation. Temporal Lobes Temporal lobes are bounded by SF superiorly and temporo-occipital and lateral parietotemporal line posteriorly (Fig. 1.3). The temporal lobe has two sulci, superior and inferior, that run parallel to the posterior ramus of the lateral sulcus and divide superiolateral surface into superior, middle, and inferior temporal gyri (Fig. 1.3). The temporal lobes are involved in the retention of visual memories, processing sensory input, comprehending language, storing new memories, emotion, and deriving meaning.4 FIGURE 1.4 Brain surface anatomy, view of medial surface of right hemisphere. 1. Frontal pole of frontal lobe. 2. Medial frontal gyrus. 3. Cingulate sulcus. 4. Sulcus of corpus callosum. 5. Cingulate gyrus. 6. Paracentral lobule. 7. Precuneus. 8. Subparietal sulcus. 9. Parietooccipital sulcus. 10. Cuneus. 11. Calcarine fissure. 12. Occipital pole of occipital lobe. 13–16. Corpus callosum (cut surface). (Parts of Corpus callosum 13. Splenium. 14. Trunk. 15. Genu. 16. Rostrum.). 17. Lamina terminalis. 18. Anterior commissure. 19. Septum pellucidum. 20. Fornix. 21. Tela choroidea of the third ventricle. 22. Choroid plexus of the third ventricle. 23. Transverse cerebral fissure. 24. Thalamus. 25. Interthalamic adhesion. 26. Interventricle foramen of Monro. 27. Hypothalamus. 28. Suprapineal recess and pineal body. 29. Vermis of cerebellum. 30. Cerebral hemisphere. 31. Choroid plexus of the fourth ventricle. 32. Medulla oblongata. 33. Pons. 34. Fourth ventricle. 35. Tectal lamina and mesencephalic aqueduct of Sylvius. 36. Mammillary body. 37. Oculomotor nerve. 38. Infundibular recess. 39. Temporal lobe of lateral occipitotemporal gyrus. 40. Rhinal fissure. 41. Hypophysis with adeno- hypophysis (anterior lobe) and neurohypophysis (posterior lobe) of pituitary gland. 42. Optic chiasma. 43. Optic nerve. 44. Olfactory bulb and tract.
ANATOMY OF BRAIN 7 I. NEUROANATOMY Parietal Lobe The parietal lobe is positioned superior to the occipital lobe and posterior to the frontal lobe. The parietal lobe is bounded anteriorly by central sulcus, inferiorly by SF and temporo-occipital line, medially by interhemispheric fissure, and posteriorly by parietotemporal line. The two main sulci are postcentral sulcus, which run downward and forward parallel to central sulcus, and intraparietal sulci, which are directed posteriorly and inferiorly toward occipital pole. Thus divide the parietal lobe into postcentral gyrus, superior parietal lobule, and inferior parietal lobule (Fig. 1.3). The upturn posterior end of the posterior ramus of lateral sulcus or SF extends into inferior parietal lobule, also superior and inferior temporal sulci turn upward to enter into this lobule and constitute supramarginal, angular gyri, and arcus temporo-occipitalis (Fig. 1.3). The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the dorsal stream of the visual system. This enables regions of the parietal cortex to map objects perceived visually into body coordinate positions. Several por- tions of the parietal lobe are important in language processing. Just posterior to the central sulcus lies the postcentral gyrus. This area of the cortex is responsible for somatosensation.5 The occipital lobule occupies space behind the lateral parietotemporal line. It has a number of short lobules divided by short sulci. A horizontal sulci, lateral to occipital sulcus divides the lobe into superior and inferior occipi- tal gyri (Fig. 1.3). A vertical strip anterior to curved lunate sulcus is the gyrus descendens. The transverse occipital sulcus is located in the uppermost part of the occipital lobe. A strip superiolateral to this sulcus is arcus parietooc- cipitalis. The occipital lobe is the visual processing center of the brain containing most of the anatomical region of the visual cortex.6 Insula is a portion of the cerebral cortex folded deep within the lateral sulcus. This area grows less than its sur- rounding areas during development and thus lies deep and not seen from surface view (Fig. 1.5). The surrounding cortical areas are called opercula such as frontal opercula, frontoparietal opercula, and temporal opercula. The insula are believed to be involved in consciousness and play a role in diverse functions usually associated to emotion or the regulation of the body’s homeostasis. These functions include perception, self-awareness, cognitive functioning, and interpersonal experience. Two hemispheres are attached with each other by corpus callosum. On the medial surface above the corpus cal- losum there are many sulci and gyri (Fig. 1.4). The most prominent sulcus is the cingulate sulcus, which follows the curve course parallel of corpus callosum. The area between the cingulate sulcus and corpus callosum is the gyrus cinguli. Above the cingulate sulcus, large anterior part is medial frontal gyrus and posteriorly paracentral lobule (Fig. 1.4). Behind the paracentral lobule, two major sulci, parietooccipital sulcus and calcarine sulcus, cut the area into a triangular area called the cuneus. Between parietooccipital sulcus and paracentral lobule, a quadrangular area is called precuneus, which is anteriorly separated from gyrus cinguli by suprasplenial sulcus. FIGURE 1.5 Coronal section through the brain. 1. Longitudinal fissure of the cerebrum. 2. Cingulate sulcus. 3. Cingulate gyrus. 4. Corpus callosum. 5. Sulcus of corpus callosum. 6. Caudate nucleus. 7. Claustrum. 8. Putamen. 9. Lateral sulcus (Sylvian fissure). 10. Globus pallidus. 11. Thalamus. 12. Subthalamic nucleus. 13. Mammillary body. 14. Amygdala. 15. Optic tract. 16. Third ventricle and choroid plexus. 17. Body of fornix. 18. Lateral ventricle and choroid plexus. 19. Cortex of insula. 6, 8, and 10. Corpus striatum. 8 and 10. Lentiform nucleus.
1. NEUROANATOMY 8 I. NEUROANATOMY The majority of the space of cerebral hemisphere deep to the cortex is full of the white matter. There are some important structures that are embedded within the white matter. On coronal section the corpus callosum is seen as a strip connecting both the hemispheres (Fig. 1.5). Third ventricle is situated in midline just below corpus callosum. Thalamus and hypothalamus, which are derived from diencephalon, lie adjacent to lateral wall of the third ventricle. Caudate nucleus is situated above and lateral to thalamus. Another gray matter mass lentiform nucleus lies more lateral and just deep to insula. There is a strip of gray matter between insula and lentiform nucleus called claustrum (Fig. 1.5). The caudate nucleus, lentiform nucleus, claustrum along with some other gray matter nucleus are (derived from telencephalon) collectively mentioned as basal nuclei or basal ganglia. There is a white matter, an internal cap- sule that lies between thalamus and lentiform nucleus (Fig. 1.5). The white matter that radiates from the upper part of internal capsule to the cortex is called corona radiate. Functional Areas (of Cerebral Cortex) Korbinian Brodmann was a German neurologist who studied the brain in the early part of the 20th century.7 Brodmann originally defined and numbered (from 1 to 52) different areas of cerebral cortex based on cytoarchitecture or how the cells were functionally organized (Box 1.1). Brodmann areas have been discussed, debated, refined, and renamed exhaustively for nearly a century and remain the most widely used and frequently cited cytoarchitectural organization of the human cortex.8 On the basis of function, regions of the cerebral cortex are divided into three functional categories of areas (Fig. 1.6). (1) Primary sensory areas, which receive signals from the sensory nerves and tracts by way of relay nuclei in the thalamus. Primary sensory areas include the somatosensory cortex in the parietal lobe, visual area of the occipital lobe, and the auditory area in parts of the temporal lobe and insular cortex. (2) Primary BOX 1.1 I M P O RTA N T B R O D M A N N A R E A S Frontal lobe contains areas that Brodmann identified as involved in cognitive functioning and in speech and language (Fig. 1.8). t Area 4 corresponds to the precentral gyrus or primary motor area. t Area 6 is the premotor or supplemental motor area. t Area 8 is anterior of the premotor cortex. It facilitates eye movements and is involved in visual reflexes as well as pupil dilation and constriction. t Areas 9, 10, and 11 are anterior to area 8. They are involved in cognitive processes such as reasoning and judgment which may be collectively called biological intelligence. t Area 44 is Broca’s area. Parietal lobe plays a role in somatosensory processes (Fig. 1.8). t Areas 3, 2, and 1 are located on the primary sensory strip, with area 3 being superior to the other two. These are somastosthetic areas, meaning that they are the primary sensory areas for touch and kinesthesia. t Areas 5, 7, and 40 are found posterior to the primary sensory strip and correspond to the presensory to sensory association areas. t Area 39 is the angular gyrus. Temporal lobe: Areas that are involved in the process- ing of auditory information and semantics as well as the appreciation of smell (Fig. 1.8). t Area 41 is the primary auditory area. t Area 42 is immediately inferior to area 41 and also involved in the detection and recognition of speech. The processing done in this area of the cortex provides a more detailed analysis than that done in area 41. t Areas 21 and 22 are the auditory association areas. Both areas are divided into two parts; one half of each area lies on either side of area 42. t Area 37 is found on the posterior–inferior part of the temporal lobe. Occipital lobe contains areas that process visual stimuli (Fig. 1.8). t Area 17 is the primary visual area. t Areas 18 and 19 are the secondary visual areas.
ANATOMY OF BRAIN 9 I. NEUROANATOMY motor cortex, which sends axons down to motor neurons in the brain stem and spinal cord and finally inner- vate voluntary skeletal muscles; (3) remaining parts of the cortex, which are called the association areas. These areas receive input from the sensory areas and lower parts of the brain which integrate sensory information with emotional states, memories, learning, and rational thought processes that we call perception, thought, and decision-making. Motor areas—The motor area is classically located in precentral gyrus on the superiolateral surface of the hemi- sphere and in anterior part of paracentral lobule. It is shaped like a pair of headphones stretching from ear to ear (Fig. 1.6). Specific area within the motor cortex controls voluntary muscle activity on the opposite part of body. The body is represented on the motor strip in an upside–down fashion (Fig. 1.7). The lower parts of the body, such as the FIGURE 1.6 Traditional concept of functional areas on the superolateral aspect of the cerebral hemisphere (left sided). FIGURE 1.7 The motor homunculus in primary motor cortex. Coronal section anterior view of the left hemisphere.
1. NEUROANATOMY 10 I. NEUROANATOMY feet and the legs, receive motor movement commands from the superior part of the precentral gyrus (motor strip). Parts of the face, on the other hand are innervated by the inferior part of the motor strip. The motor strip extends down some distance into the longitudinal cerebral fissure. The portion inside this fissure is its medial aspect. The part on the lateral surface of the hemisphere is called its lateral aspect. The medial cortex controls the movements of the body from the hips on down while the lateral aspect sends commands to the upper body including the larynx, face, hands, shoulders, and trunk (Fig. 1.7). The medial and lateral aspects of the motor strip have different blood supplies. Blood comes to the medial area from the anterior cerebral artery while the lateral cortex is supplied by the middle cerebral artery. Premotor Area There is supplementary motor area on and above the superior part of cingulate sulcus on the medial aspect hemi- sphere that reaches to the premotor cortex (Brodmann areas 6 and 8) on the lateral surface of brain. The cortical area in inferior frontal gyrus corresponds to motor speech area or speech area of Broca (Brodmann areas 44 and 45) and frontal eye area (Fig. 1.8). Lesion into the motor speech area of Broca results in aphasia even the muscles concerned are intact. In 95% of right-handers do have left-hemisphere dominance for language functions, only around 19% of left-handers have right-hemisphere language dominance, with another 20% or so processing language functions in both hemispheres.9 Sensory Areas From the specific nuclei of the thalamus, neurons are projected into two somatosensory areas of the cortex: somato- sensory area I in postcentral gyrus and somatosensory area II in the wall of the SF (Fig. 1.6). The arrangement of the thalamic fibers in somatosensory area I is such that the part of the body is represented in order along the postcentral gyrus, with leg on the top and head at the foot of the gyrus. The area of the cortex that receives sensation from a part FIGURE 1.8 Brodmann areas in the neocortex. A number of important Brodmann areas have been marked out in the figure.
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf
Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf

Recommended

(1) George Fink - Stress_ Neuroendocrinology and Neurobiology_ Handbook of St...
(1) George Fink - Stress_ Neuroendocrinology and Neurobiology_ Handbook of St...(1) George Fink - Stress_ Neuroendocrinology and Neurobiology_ Handbook of St...
(1) George Fink - Stress_ Neuroendocrinology and Neurobiology_ Handbook of St...EricksonArthur
 
Frontiers in Neurology Brochure
Frontiers in Neurology BrochureFrontiers in Neurology Brochure
Frontiers in Neurology BrochureFrontiersIn
 
Key topic (1)
Key topic (1) Key topic (1)
Key topic (1)nisreenbagi
 
X nerve stimulation
X nerve stimulationX nerve stimulation
X nerve stimulationHugo Martinez
 
PhD Thesis: STUDY OF THE CLINICAL PREDICTORS OF
PhD Thesis: STUDY OF THE CLINICAL PREDICTORS OFPhD Thesis: STUDY OF THE CLINICAL PREDICTORS OF
PhD Thesis: STUDY OF THE CLINICAL PREDICTORS OFAkm Mosharraf Hossain
 
PhD.Mosharraf
PhD.MosharrafPhD.Mosharraf
PhD.MosharrafProf. AKM Mosharraf Hossain
 
Impactfactors2021.pdf
Impactfactors2021.pdfImpactfactors2021.pdf
Impactfactors2021.pdfRohini SharmaOhlan
 
Kanwal K. Kher, H. William Schnaper, Larry A. Greenbaum - Clinical Pediatric ...
Kanwal K. Kher, H. William Schnaper, Larry A. Greenbaum - Clinical Pediatric ...Kanwal K. Kher, H. William Schnaper, Larry A. Greenbaum - Clinical Pediatric ...
Kanwal K. Kher, H. William Schnaper, Larry A. Greenbaum - Clinical Pediatric ...Kardahema Mathews
 

Recommended

(1) George Fink - Stress_ Neuroendocrinology and Neurobiology_ Handbook of St...
(1) George Fink - Stress_ Neuroendocrinology and Neurobiology_ Handbook of St...(1) George Fink - Stress_ Neuroendocrinology and Neurobiology_ Handbook of St...
(1) George Fink - Stress_ Neuroendocrinology and Neurobiology_ Handbook of St...EricksonArthur
 
Frontiers in Neurology Brochure
Frontiers in Neurology BrochureFrontiers in Neurology Brochure
Frontiers in Neurology BrochureFrontiersIn
 
Key topic (1)
Key topic (1) Key topic (1)
Key topic (1)nisreenbagi
 
X nerve stimulation
X nerve stimulationX nerve stimulation
X nerve stimulationHugo Martinez
 
PhD Thesis: STUDY OF THE CLINICAL PREDICTORS OF
PhD Thesis: STUDY OF THE CLINICAL PREDICTORS OFPhD Thesis: STUDY OF THE CLINICAL PREDICTORS OF
PhD Thesis: STUDY OF THE CLINICAL PREDICTORS OFAkm Mosharraf Hossain
 
PhD.Mosharraf
PhD.MosharrafPhD.Mosharraf
PhD.MosharrafProf. AKM Mosharraf Hossain
 
Impactfactors2021.pdf
Impactfactors2021.pdfImpactfactors2021.pdf
Impactfactors2021.pdfRohini SharmaOhlan
 
Kanwal K. Kher, H. William Schnaper, Larry A. Greenbaum - Clinical Pediatric ...
Kanwal K. Kher, H. William Schnaper, Larry A. Greenbaum - Clinical Pediatric ...Kanwal K. Kher, H. William Schnaper, Larry A. Greenbaum - Clinical Pediatric ...
Kanwal K. Kher, H. William Schnaper, Larry A. Greenbaum - Clinical Pediatric ...Kardahema Mathews
 
184- The Physiotherapist's Pocket Book.pdf
184- The Physiotherapist's Pocket Book.pdf184- The Physiotherapist's Pocket Book.pdf
184- The Physiotherapist's Pocket Book.pdfMahnoorNaveed17
 
Clinical-Skills-for-OSCEs.pdf
Clinical-Skills-for-OSCEs.pdfClinical-Skills-for-OSCEs.pdf
Clinical-Skills-for-OSCEs.pdfAl-YAQIN DIAGNOSTIC ULTRASONIC CLINIC BAGHDAD
 
Innovations in Cardiology .pdf
Innovations in Cardiology .pdfInnovations in Cardiology .pdf
Innovations in Cardiology .pdfPROFESSOR DR. MD. TOUFIQUR RAHMAN
 
Resolving The Mystery of Puzzling Pulmonary Nodules
Resolving The Mystery of Puzzling Pulmonary NodulesResolving The Mystery of Puzzling Pulmonary Nodules
Resolving The Mystery of Puzzling Pulmonary NodulesKue Lee
 
Echo made easy
Echo made easyEcho made easy
Echo made easyHospital
 
Cardiology Conference in Rome, Italy
Cardiology Conference in Rome, ItalyCardiology Conference in Rome, Italy
Cardiology Conference in Rome, ItalyKuntalChakraborty12
 
A z of emergency radiology, 1 e (2004)
A z of emergency radiology, 1 e (2004)A z of emergency radiology, 1 e (2004)
A z of emergency radiology, 1 e (2004)Lệnh Hồ Xung
 
Essential guide to acute care
Essential guide to acute careEssential guide to acute care
Essential guide to acute careAdarsh
 
Intensive Care Nephrology.pdf
Intensive Care Nephrology.pdfIntensive Care Nephrology.pdf
Intensive Care Nephrology.pdfSomnath Das Gupta
 
07 capnography trends in procedural sedation
07 capnography trends in procedural sedation07 capnography trends in procedural sedation
07 capnography trends in procedural sedationDang Thanh Tuan
 
07 capnography trends in procedural sedation
07 capnography trends in procedural sedation07 capnography trends in procedural sedation
07 capnography trends in procedural sedationDang Thanh Tuan
 
Neurology-2016_Brochure-ilovepdf-compressed
Neurology-2016_Brochure-ilovepdf-compressedNeurology-2016_Brochure-ilovepdf-compressed
Neurology-2016_Brochure-ilovepdf-compressedEva Jones
 
Neurosurgery update course 2013
Neurosurgery update course 2013Neurosurgery update course 2013
Neurosurgery update course 2013Hussien El-Maghraby
 
Nova Publishers Catalog - Just Out! 2015
Nova Publishers Catalog - Just Out! 2015Nova Publishers Catalog - Just Out! 2015
Nova Publishers Catalog - Just Out! 2015NOVA
 
Catalog 2015
Catalog 2015Catalog 2015
Catalog 2015Alexandra Columbus
 
Cerebral autoregulation based blood pressure management in the neuroscience i...
Cerebral autoregulation based blood pressure management in the neuroscience i...Cerebral autoregulation based blood pressure management in the neuroscience i...
Cerebral autoregulation based blood pressure management in the neuroscience i...https://www.facebook.com/garmentspace
 
Acc2015 san diego-eps and ar rhythmia program-samir rafla
Acc2015 san diego-eps and ar rhythmia program-samir raflaAcc2015 san diego-eps and ar rhythmia program-samir rafla
Acc2015 san diego-eps and ar rhythmia program-samir raflaAlexandria University, Egypt
 
On call radiology
On call radiologyOn call radiology
On call radiologyMichel Phuong
 
Manuscript editing service | Primary and secondary data | Neurogenic Shock
Manuscript editing service | Primary and secondary data | Neurogenic ShockManuscript editing service | Primary and secondary data | Neurogenic Shock
Manuscript editing service | Primary and secondary data | Neurogenic ShockPubrica
 
500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdf
500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdf500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdf
500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdfssuser94b2cb1
 
Essay About Ecotourism
Essay About EcotourismEssay About Ecotourism
Essay About EcotourismJessica Navarro
 
Example Discussion Essay
Example Discussion EssayExample Discussion Essay
Example Discussion EssayJessica Navarro
 

More Related Content

Similar to Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf

184- The Physiotherapist's Pocket Book.pdf
184- The Physiotherapist's Pocket Book.pdf184- The Physiotherapist's Pocket Book.pdf
184- The Physiotherapist's Pocket Book.pdfMahnoorNaveed17
 
Resolving The Mystery of Puzzling Pulmonary Nodules
Resolving The Mystery of Puzzling Pulmonary NodulesResolving The Mystery of Puzzling Pulmonary Nodules
Resolving The Mystery of Puzzling Pulmonary NodulesKue Lee
 
Echo made easy
Echo made easyEcho made easy
Echo made easyHospital
 
Cardiology Conference in Rome, Italy
Cardiology Conference in Rome, ItalyCardiology Conference in Rome, Italy
Cardiology Conference in Rome, ItalyKuntalChakraborty12
 
A z of emergency radiology, 1 e (2004)
A z of emergency radiology, 1 e (2004)A z of emergency radiology, 1 e (2004)
A z of emergency radiology, 1 e (2004)Lệnh Hồ Xung
 
Essential guide to acute care
Essential guide to acute careEssential guide to acute care
Essential guide to acute careAdarsh
 
Intensive Care Nephrology.pdf
Intensive Care Nephrology.pdfIntensive Care Nephrology.pdf
Intensive Care Nephrology.pdfSomnath Das Gupta
 
07 capnography trends in procedural sedation
07 capnography trends in procedural sedation07 capnography trends in procedural sedation
07 capnography trends in procedural sedationDang Thanh Tuan
 
07 capnography trends in procedural sedation
07 capnography trends in procedural sedation07 capnography trends in procedural sedation
07 capnography trends in procedural sedationDang Thanh Tuan
 
Neurology-2016_Brochure-ilovepdf-compressed
Neurology-2016_Brochure-ilovepdf-compressedNeurology-2016_Brochure-ilovepdf-compressed
Neurology-2016_Brochure-ilovepdf-compressedEva Jones
 
Nova Publishers Catalog - Just Out! 2015
Nova Publishers Catalog - Just Out! 2015Nova Publishers Catalog - Just Out! 2015
Nova Publishers Catalog - Just Out! 2015NOVA
 
Cerebral autoregulation based blood pressure management in the neuroscience i...
Cerebral autoregulation based blood pressure management in the neuroscience i...Cerebral autoregulation based blood pressure management in the neuroscience i...
Cerebral autoregulation based blood pressure management in the neuroscience i...https://www.facebook.com/garmentspace
 
Acc2015 san diego-eps and ar rhythmia program-samir rafla
Acc2015 san diego-eps and ar rhythmia program-samir raflaAcc2015 san diego-eps and ar rhythmia program-samir rafla
Acc2015 san diego-eps and ar rhythmia program-samir raflaAlexandria University, Egypt
 
Manuscript editing service | Primary and secondary data | Neurogenic Shock
Manuscript editing service | Primary and secondary data | Neurogenic ShockManuscript editing service | Primary and secondary data | Neurogenic Shock
Manuscript editing service | Primary and secondary data | Neurogenic ShockPubrica
 
500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdf
500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdf500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdf
500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdfssuser94b2cb1
 

Similar to Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf (20)

184- The Physiotherapist's Pocket Book.pdf
184- The Physiotherapist's Pocket Book.pdf184- The Physiotherapist's Pocket Book.pdf
184- The Physiotherapist's Pocket Book.pdf
 
Clinical-Skills-for-OSCEs.pdf
Clinical-Skills-for-OSCEs.pdfClinical-Skills-for-OSCEs.pdf
Clinical-Skills-for-OSCEs.pdf
 
Innovations in Cardiology .pdf
Innovations in Cardiology .pdfInnovations in Cardiology .pdf
Innovations in Cardiology .pdf
 
Resolving The Mystery of Puzzling Pulmonary Nodules
Resolving The Mystery of Puzzling Pulmonary NodulesResolving The Mystery of Puzzling Pulmonary Nodules
Resolving The Mystery of Puzzling Pulmonary Nodules
 
Echo made easy
Echo made easyEcho made easy
Echo made easy
 
Cardiology Conference in Rome, Italy
Cardiology Conference in Rome, ItalyCardiology Conference in Rome, Italy
Cardiology Conference in Rome, Italy
 
A z of emergency radiology, 1 e (2004)
A z of emergency radiology, 1 e (2004)A z of emergency radiology, 1 e (2004)
A z of emergency radiology, 1 e (2004)
 
Essential guide to acute care
Essential guide to acute careEssential guide to acute care
Essential guide to acute care
 
Intensive Care Nephrology.pdf
Intensive Care Nephrology.pdfIntensive Care Nephrology.pdf
Intensive Care Nephrology.pdf
 
07 capnography trends in procedural sedation
07 capnography trends in procedural sedation07 capnography trends in procedural sedation
07 capnography trends in procedural sedation
 
07 capnography trends in procedural sedation
07 capnography trends in procedural sedation07 capnography trends in procedural sedation
07 capnography trends in procedural sedation
 
Neurology-2016_Brochure-ilovepdf-compressed
Neurology-2016_Brochure-ilovepdf-compressedNeurology-2016_Brochure-ilovepdf-compressed
Neurology-2016_Brochure-ilovepdf-compressed
 
Neurosurgery update course 2013
Neurosurgery update course 2013Neurosurgery update course 2013
Neurosurgery update course 2013
 
Nova Publishers Catalog - Just Out! 2015
Nova Publishers Catalog - Just Out! 2015Nova Publishers Catalog - Just Out! 2015
Nova Publishers Catalog - Just Out! 2015
 
Catalog 2015
Catalog 2015Catalog 2015
Catalog 2015
 
Cerebral autoregulation based blood pressure management in the neuroscience i...
Cerebral autoregulation based blood pressure management in the neuroscience i...Cerebral autoregulation based blood pressure management in the neuroscience i...
Cerebral autoregulation based blood pressure management in the neuroscience i...
 
Acc2015 san diego-eps and ar rhythmia program-samir rafla
Acc2015 san diego-eps and ar rhythmia program-samir raflaAcc2015 san diego-eps and ar rhythmia program-samir rafla
Acc2015 san diego-eps and ar rhythmia program-samir rafla
 
On call radiology
On call radiologyOn call radiology
On call radiology
 
Manuscript editing service | Primary and secondary data | Neurogenic Shock
Manuscript editing service | Primary and secondary data | Neurogenic ShockManuscript editing service | Primary and secondary data | Neurogenic Shock
Manuscript editing service | Primary and secondary data | Neurogenic Shock
 
500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdf
500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdf500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdf
500singlebestanswersinmedicineunitedvrg-150228160807-conversion-gate01.pdf
 

More from Jessica Navarro

Example Discussion Essay
Example Discussion EssayExample Discussion Essay
Example Discussion EssayJessica Navarro
 
Example Essay Argumentative
Example Essay ArgumentativeExample Essay Argumentative
Example Essay ArgumentativeJessica Navarro
 
Argumentative Essay Prompts
Argumentative Essay PromptsArgumentative Essay Prompts
Argumentative Essay PromptsJessica Navarro
 
Essay Websites How To Start A College Admission Essay 12
Essay Websites How To Start A College Admission Essay 12Essay Websites How To Start A College Admission Essay 12
Essay Websites How To Start A College Admission Essay 12Jessica Navarro
 
Printable Pig Stationery PaperCute PigWriting Pape
Printable Pig Stationery PaperCute PigWriting PapePrintable Pig Stationery PaperCute PigWriting Pape
Printable Pig Stationery PaperCute PigWriting PapeJessica Navarro
 
Website That Writes Essays For You Love You - There Is A Website That
Website That Writes Essays For You Love You - There Is A Website ThatWebsite That Writes Essays For You Love You - There Is A Website That
Website That Writes Essays For You Love You - There Is A Website ThatJessica Navarro
 
Critical Analysis Of An Article - Critical Analysis Essay -
Critical Analysis Of An Article - Critical Analysis Essay -Critical Analysis Of An Article - Critical Analysis Essay -
Critical Analysis Of An Article - Critical Analysis Essay -Jessica Navarro
 
How To Write An Effective Narrative Essay
How To Write An Effective Narrative EssayHow To Write An Effective Narrative Essay
How To Write An Effective Narrative EssayJessica Navarro
 
Use Custom Essay Writing Services And Know The Di
Use Custom Essay Writing Services And Know The DiUse Custom Essay Writing Services And Know The Di
Use Custom Essay Writing Services And Know The DiJessica Navarro
 
IB Extended Essay Topics For The Highest Grades
IB Extended Essay Topics For The Highest GradesIB Extended Essay Topics For The Highest Grades
IB Extended Essay Topics For The Highest GradesJessica Navarro
 
Home - Research - LibGuides At Uni
Home - Research - LibGuides At UniHome - Research - LibGuides At Uni
Home - Research - LibGuides At UniJessica Navarro
 
10 Tips For Writing Effective Essay LiveWebTutors
10 Tips For Writing Effective Essay LiveWebTutors10 Tips For Writing Effective Essay LiveWebTutors
10 Tips For Writing Effective Essay LiveWebTutorsJessica Navarro
 
Printable Sentence Strips - Printable Word Searches
Printable Sentence Strips - Printable Word SearchesPrintable Sentence Strips - Printable Word Searches
Printable Sentence Strips - Printable Word SearchesJessica Navarro
 
Website That Does Essays For You
Website That Does Essays For YouWebsite That Does Essays For You
Website That Does Essays For YouJessica Navarro
 

More from Jessica Navarro (20)

Essay About Ecotourism
Essay About EcotourismEssay About Ecotourism
Essay About Ecotourism
 
Example Discussion Essay
Example Discussion EssayExample Discussion Essay
Example Discussion Essay
 
Bonnie And Clyde Essay
Bonnie And Clyde EssayBonnie And Clyde Essay
Bonnie And Clyde Essay
 
Example Essay Argumentative
Example Essay ArgumentativeExample Essay Argumentative
Example Essay Argumentative
 
Racism Today Essay
Racism Today EssayRacism Today Essay
Racism Today Essay
 
Argumentative Essay Prompts
Argumentative Essay PromptsArgumentative Essay Prompts
Argumentative Essay Prompts
 
Writing Border
Writing BorderWriting Border
Writing Border
 
Essay Websites How To Start A College Admission Essay 12
Essay Websites How To Start A College Admission Essay 12Essay Websites How To Start A College Admission Essay 12
Essay Websites How To Start A College Admission Essay 12
 
Printable Pig Stationery PaperCute PigWriting Pape
Printable Pig Stationery PaperCute PigWriting PapePrintable Pig Stationery PaperCute PigWriting Pape
Printable Pig Stationery PaperCute PigWriting Pape
 
Terrorism Essay. Long A
Terrorism Essay. Long ATerrorism Essay. Long A
Terrorism Essay. Long A
 
Website That Writes Essays For You Love You - There Is A Website That
Website That Writes Essays For You Love You - There Is A Website ThatWebsite That Writes Essays For You Love You - There Is A Website That
Website That Writes Essays For You Love You - There Is A Website That
 
Pin On For The Boys
Pin On For The BoysPin On For The Boys
Pin On For The Boys
 
Critical Analysis Of An Article - Critical Analysis Essay -
Critical Analysis Of An Article - Critical Analysis Essay -Critical Analysis Of An Article - Critical Analysis Essay -
Critical Analysis Of An Article - Critical Analysis Essay -
 
How To Write An Effective Narrative Essay
How To Write An Effective Narrative EssayHow To Write An Effective Narrative Essay
How To Write An Effective Narrative Essay
 
Use Custom Essay Writing Services And Know The Di
Use Custom Essay Writing Services And Know The DiUse Custom Essay Writing Services And Know The Di
Use Custom Essay Writing Services And Know The Di
 
IB Extended Essay Topics For The Highest Grades
IB Extended Essay Topics For The Highest GradesIB Extended Essay Topics For The Highest Grades
IB Extended Essay Topics For The Highest Grades
 
Home - Research - LibGuides At Uni
Home - Research - LibGuides At UniHome - Research - LibGuides At Uni
Home - Research - LibGuides At Uni
 
10 Tips For Writing Effective Essay LiveWebTutors
10 Tips For Writing Effective Essay LiveWebTutors10 Tips For Writing Effective Essay LiveWebTutors
10 Tips For Writing Effective Essay LiveWebTutors
 
Printable Sentence Strips - Printable Word Searches
Printable Sentence Strips - Printable Word SearchesPrintable Sentence Strips - Printable Word Searches
Printable Sentence Strips - Printable Word Searches
 
Website That Does Essays For You
Website That Does Essays For YouWebsite That Does Essays For You
Website That Does Essays For You
 

Recently uploaded

Separation of Lanthanides/ Lanthanides and Actinides
Separation of Lanthanides/ Lanthanides and ActinidesSeparation of Lanthanides/ Lanthanides and Actinides
Separation of Lanthanides/ Lanthanides and ActinidesFatimaKhan178732
 
Incoming and Outgoing Shipments in 1 STEP Using Odoo 17
Incoming and Outgoing Shipments in 1 STEP Using Odoo 17Incoming and Outgoing Shipments in 1 STEP Using Odoo 17
Incoming and Outgoing Shipments in 1 STEP Using Odoo 17Celine George
 
Introduction to AI in Higher Education_draft.pptx
Introduction to AI in Higher Education_draft.pptxIntroduction to AI in Higher Education_draft.pptx
Introduction to AI in Higher Education_draft.pptxpboyjonauth
 
The Most Excellent Way | 1 Corinthians 13
The Most Excellent Way | 1 Corinthians 13The Most Excellent Way | 1 Corinthians 13
The Most Excellent Way | 1 Corinthians 13Steve Thomason
 
KSHARA STURA .pptx---KSHARA KARMA THERAPY (CAUSTIC THERAPY)————IMP.OF KSHARA ...
KSHARA STURA .pptx---KSHARA KARMA THERAPY (CAUSTIC THERAPY)————IMP.OF KSHARA ...KSHARA STURA .pptx---KSHARA KARMA THERAPY (CAUSTIC THERAPY)————IMP.OF KSHARA ...
KSHARA STURA .pptx---KSHARA KARMA THERAPY (CAUSTIC THERAPY)————IMP.OF KSHARA ...M56BOOKSTORE PRODUCT/SERVICE
 
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptx
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptxPOINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptx
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptxSayali Powar
 
Concept of Vouching. B.Com(Hons) /B.Compdf
Concept of Vouching. B.Com(Hons) /B.CompdfConcept of Vouching. B.Com(Hons) /B.Compdf
Concept of Vouching. B.Com(Hons) /B.CompdfUmakantAnnand
 
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptx
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptxSOCIAL AND HISTORICAL CONTEXT - LFTVD.pptx
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptxiammrhaywood
 
Sanyam Choudhary Chemistry practical.pdf
Sanyam Choudhary Chemistry practical.pdfSanyam Choudhary Chemistry practical.pdf
Sanyam Choudhary Chemistry practical.pdfsanyamsingh5019
 
Presiding Officer Training module 2024 lok sabha elections
Presiding Officer Training module 2024 lok sabha electionsPresiding Officer Training module 2024 lok sabha elections
Presiding Officer Training module 2024 lok sabha electionsanshu789521
 
Introduction to ArtificiaI Intelligence in Higher Education
Introduction to ArtificiaI Intelligence in Higher EducationIntroduction to ArtificiaI Intelligence in Higher Education
Introduction to ArtificiaI Intelligence in Higher Educationpboyjonauth
 
Software Engineering Methodologies (overview)
Software Engineering Methodologies (overview)Software Engineering Methodologies (overview)
Software Engineering Methodologies (overview)eniolaolutunde
 
mini mental status format.docx
mini mental status format.docxmini mental status format.docx
mini mental status format.docxPoojaSen20
 
microwave assisted reaction. General introduction
microwave assisted reaction. General introductionmicrowave assisted reaction. General introduction
microwave assisted reaction. General introductionMaksud Ahmed
 
Alper Gobel In Media Res Media Component
Alper Gobel In Media Res Media ComponentAlper Gobel In Media Res Media Component
Alper Gobel In Media Res Media ComponentInMediaRes1
 
A Critique of the Proposed National Education Policy Reform
A Critique of the Proposed National Education Policy ReformA Critique of the Proposed National Education Policy Reform
A Critique of the Proposed National Education Policy ReformChameera Dedduwage
 
18-04-UA_REPORT_MEDIALITERAСY_INDEX-DM_23-1-final-eng.pdf
18-04-UA_REPORT_MEDIALITERAСY_INDEX-DM_23-1-final-eng.pdf18-04-UA_REPORT_MEDIALITERAСY_INDEX-DM_23-1-final-eng.pdf
18-04-UA_REPORT_MEDIALITERAСY_INDEX-DM_23-1-final-eng.pdfssuser54595a
 
Contemporary philippine arts from the regions_PPT_Module_12 [Autosaved] (1).pptx
Contemporary philippine arts from the regions_PPT_Module_12 [Autosaved] (1).pptxContemporary philippine arts from the regions_PPT_Module_12 [Autosaved] (1).pptx
Contemporary philippine arts from the regions_PPT_Module_12 [Autosaved] (1).pptxRoyAbrique
 
Class 11 Legal Studies Ch-1 Concept of State .pdf
Class 11 Legal Studies Ch-1 Concept of State .pdfClass 11 Legal Studies Ch-1 Concept of State .pdf
Class 11 Legal Studies Ch-1 Concept of State .pdfakmcokerachita
 

Recently uploaded (20)

Separation of Lanthanides/ Lanthanides and Actinides
Separation of Lanthanides/ Lanthanides and ActinidesSeparation of Lanthanides/ Lanthanides and Actinides
Separation of Lanthanides/ Lanthanides and Actinides
 
Incoming and Outgoing Shipments in 1 STEP Using Odoo 17
Incoming and Outgoing Shipments in 1 STEP Using Odoo 17Incoming and Outgoing Shipments in 1 STEP Using Odoo 17
Incoming and Outgoing Shipments in 1 STEP Using Odoo 17
 
Introduction to AI in Higher Education_draft.pptx
Introduction to AI in Higher Education_draft.pptxIntroduction to AI in Higher Education_draft.pptx
Introduction to AI in Higher Education_draft.pptx
 
The Most Excellent Way | 1 Corinthians 13
The Most Excellent Way | 1 Corinthians 13The Most Excellent Way | 1 Corinthians 13
The Most Excellent Way | 1 Corinthians 13
 
KSHARA STURA .pptx---KSHARA KARMA THERAPY (CAUSTIC THERAPY)————IMP.OF KSHARA ...
KSHARA STURA .pptx---KSHARA KARMA THERAPY (CAUSTIC THERAPY)————IMP.OF KSHARA ...KSHARA STURA .pptx---KSHARA KARMA THERAPY (CAUSTIC THERAPY)————IMP.OF KSHARA ...
KSHARA STURA .pptx---KSHARA KARMA THERAPY (CAUSTIC THERAPY)————IMP.OF KSHARA ...
 
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptx
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptxPOINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptx
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptx
 
Concept of Vouching. B.Com(Hons) /B.Compdf
Concept of Vouching. B.Com(Hons) /B.CompdfConcept of Vouching. B.Com(Hons) /B.Compdf
Concept of Vouching. B.Com(Hons) /B.Compdf
 
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptx
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptxSOCIAL AND HISTORICAL CONTEXT - LFTVD.pptx
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptx
 
Sanyam Choudhary Chemistry practical.pdf
Sanyam Choudhary Chemistry practical.pdfSanyam Choudhary Chemistry practical.pdf
Sanyam Choudhary Chemistry practical.pdf
 
Presiding Officer Training module 2024 lok sabha elections
Presiding Officer Training module 2024 lok sabha electionsPresiding Officer Training module 2024 lok sabha elections
Presiding Officer Training module 2024 lok sabha elections
 
Model Call Girl in Bikash Puri Delhi reach out to us at 🔝9953056974🔝
Model Call Girl in Bikash Puri Delhi reach out to us at 🔝9953056974🔝Model Call Girl in Bikash Puri Delhi reach out to us at 🔝9953056974🔝
Model Call Girl in Bikash Puri Delhi reach out to us at 🔝9953056974🔝
 
Introduction to ArtificiaI Intelligence in Higher Education
Introduction to ArtificiaI Intelligence in Higher EducationIntroduction to ArtificiaI Intelligence in Higher Education
Introduction to ArtificiaI Intelligence in Higher Education
 
Software Engineering Methodologies (overview)
Software Engineering Methodologies (overview)Software Engineering Methodologies (overview)
Software Engineering Methodologies (overview)
 
mini mental status format.docx
mini mental status format.docxmini mental status format.docx
mini mental status format.docx
 
microwave assisted reaction. General introduction
microwave assisted reaction. General introductionmicrowave assisted reaction. General introduction
microwave assisted reaction. General introduction
 
Alper Gobel In Media Res Media Component
Alper Gobel In Media Res Media ComponentAlper Gobel In Media Res Media Component
Alper Gobel In Media Res Media Component
 
A Critique of the Proposed National Education Policy Reform
A Critique of the Proposed National Education Policy ReformA Critique of the Proposed National Education Policy Reform
A Critique of the Proposed National Education Policy Reform
 
18-04-UA_REPORT_MEDIALITERAСY_INDEX-DM_23-1-final-eng.pdf
18-04-UA_REPORT_MEDIALITERAСY_INDEX-DM_23-1-final-eng.pdf18-04-UA_REPORT_MEDIALITERAСY_INDEX-DM_23-1-final-eng.pdf
18-04-UA_REPORT_MEDIALITERAСY_INDEX-DM_23-1-final-eng.pdf
 
Contemporary philippine arts from the regions_PPT_Module_12 [Autosaved] (1).pptx
Contemporary philippine arts from the regions_PPT_Module_12 [Autosaved] (1).pptxContemporary philippine arts from the regions_PPT_Module_12 [Autosaved] (1).pptx
Contemporary philippine arts from the regions_PPT_Module_12 [Autosaved] (1).pptx
 
Class 11 Legal Studies Ch-1 Concept of State .pdf
Class 11 Legal Studies Ch-1 Concept of State .pdfClass 11 Legal Studies Ch-1 Concept of State .pdf
Class 11 Legal Studies Ch-1 Concept of State .pdf
 

Anesthesia Books 2017 Essentials of Neuroanesthesia.pdf

  • 4. ESSENTIALS OF NEUROANESTHESIA Edited by HEMANSHU PRABHAKAR Department of Neuroanaesthesiology and Critical Care All India Institute of Medical Sciences New Delhi, India
  • 5. Academic Press is an imprint of Elsevier 125 London Wall, London EC2Y 5AS, United Kingdom 525 B Street, Suite 1800, San Diego, CA 92101-4495, United States 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom Copyright © 2017 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library ISBN: 978-0-12-805299-0 For information on all Academic Press publications visit our website at https://www.elsevier.com/books-and-journals Publisher: Mara Conner Acquisition Editor: Melanie Tucker Editorial Project Manager: Kristi Anderson Production Project Manager: Edward Taylor Designer: Maria Ines Cruz Typeset by TNQ Books and Journals
  • 6. Dedicated to my parents—Avinash and Kanti Prabhakar The best gifts they stored for me—Kavita and Hemant, who in turn gifted me Sunil and Deepali To those who mean the world to me—Pallavi, Anavi, and Amyra To Aishwarya, Avi, and Anav
  • 8. vii Contents List of Contributors xvii Foreword xix Preface xxi Acknowledgments xxiii Introduction and Brief History of Neuroanesthesia W. S. Jellish xxv I NEUROANATOMY 1. Neuroanatomy D. GUPTA Introduction 3 Embryological Differentiation of Different Parts of Brain 4 Anatomy of Brain 4 Vascular Supply of the Brain 30 The Meninges and Cerebrospinal Fluid 33 Acknowledgment 39 References 40 2. Neuroembryology G.P. SINGH Formation of Zygote 41 Formation of Blastocyst 41 Formation of Embryonic or Germ Disc 42 Formation of Definitive Notochord 44 Development of Nervous System 45 References 50 3. Blood–Brain Barrier A.K. KHANNA AND E. FARAG Introduction 51 Permeability at the Blood–Brain Barrier 51 Cellular and Molecular Effects of Anesthetics on the Blood–Brain Barrier 52 Clinical and Experimental Implications of Anesthetics on the Blood–Brain Barrier 54 Conclusion 56 References 56 II NEUROPHYSIOLOGY 4. Neurophysiology M. SETHURAMAN Intracranial Pressure 62 Introduction 62 Normal Intracranial Pressure 62 Cerebral Compliance 62 Importance of Intracranial Pressure 63 Summary 68 Cerebral Blood Flow 68 Introduction 68 Vascular Anatomy 68 Summary 74 Brain Metabolism 74 Introduction 74 Normal Cerebral Metabolism 74 Summary 79 Cerebrospinal Fluid 79 Introduction 79 Ventricular System 79 Summary 83 The Spinal Cord 83 Introduction 83 Anatomy 84 Organization of the Spinal Cord 84 Summary 89 References 89 5. Brain Protection in Neurosurgery H. EL BEHEIRY Introduction 91 Nonpharmacological Strategies 91 Mild Hypothermia 92 Blood Pressure Control 93 Induced Arterial Hypertension 94 Normoglycemia 94 Target Hemoglobin Concentration 95 Pharmacological Strategies 96 Nonanesthetic Agents 97 Anesthetic Agents 97 Conclusion 98 References 98
  • 9. CONTENTS viii III NEUROPHARMACOLOGY 6. Neuropharmacology P. GANJOO AND I. KAPOOR Anesthetic Drugs and Sedatives 104 Intravenous Anesthetic Agents 104 Inhalational Anesthetic Agents 111 Neuromuscular Blocking Agents 115 Local Anesthetic Agents 116 Miscellaneous Drugs 116 Future Directions in Neuropharmacology 116 Conclusion 116 References 118 7. Anesthetic Agents: Neurotoxics or Neuroprotectives? J. FIORDA-DIAZ, N. STOICEA AND S.D. BERGESE Introduction 123 Pharmacological Considerations 124 Anesthesia Practice: Clinical Outcomes 126 Anesthesia and Fragile Brain 127 Conclusion 127 Abbreviations 128 References 128 IV NEUROMONITORING 8. Neuromonitoring V.J. RAMESH AND M. RADHAKRISHNAN Introduction 134 Cerebral Blood Flow 134 Transcranial Sonography 139 Thermal Diffusion Flowmetry 139 Laser Doppler Flowmetry 139 Intra-Arterial 133Xenon 139 CT Perfusion 139 Xenon Enhanced CT 139 Positron Emission Tomography 140 Single Photon Emission Computed Tomography 140 Magnetic Resonance Imaging 140 Intracranial Pressure 140 Electroencephalogram 143 Evoked Potential Monitoring 145 Motor Evoked Potentials 149 Depth of Anesthesia 150 Cerebral Oxygenation Monitoring 152 Jugular Venous Oximetry 152 Regional Cerebral Oximetry 154 Brain Tissue Oxygen Monitoring 156 Cerebral Microdialysis 158 Conclusion 159 References 159 9. Multimodal Monitoring A. DEFRESNE AND V. BONHOMME Introduction 161 Temperature 162 Oxygen Transport, Hemodynamics, and Brain Metabolism 162 Intracranial Pressure Monitoring 171 Electroencephalography and Depth of Anesthesia Monitoring 173 Miscellaneous 174 Integration of Information and Decision- Helping Systems 175 Clinical Pearls 176 References 176 V POSITIONS IN NEUROSURGERY 10. Positioning in Neurosurgery G. SINGH Introduction 184 Historical Background 184 Principles of Positioning 184 The Conduct of Positioning 185 Surgical Approach for Craniotomies 186 Positioning for Craniotomy 187 Positions Used for Craniotomies 189 Surgical Approach for Procedures of the Spine 195 Patient Positioning For Spinal Procedures 195 Conclusion 203 Abbreviations 203 References 204 VI PREANESTHETIC EVALUATION 11. Preanesthetic Evaluation of Neurosurgical Patients R. MARIAPPAN Introduction 209 Preoperative Evaluation of Patient-Related Risk Factors 210 Preoperative Evaluation of Specific Neurosurgical Conditions 217 References 225
  • 10. CONTENTS ix VII NEUROSURGERY 12. Supratentorial Lesions H. BHAGAT AND S. MAHAJAN Introduction 231 Classification 232 Pathophysiology and Clinical Correlations 233 Clinical Features 235 Neuroimaging 235 Intraoperative Considerations: The Team Approach 236 Anesthetic Management 236 Intraoperative Management 238 Emergence From Anesthesia 240 Postoperative Management 241 Awake Craniotomy 242 Conclusions 245 Acknowledgment 245 References 245 13. Emergence From Anesthesia M. ECHEVERRÍA, J. FIORDA-DIAZ, N. STOICEA AND S.D. BERGESE Introduction 247 Neurophysiological Response During Emergence in Neurosurgical Patients 248 Specific Perioperative Considerations 248 Delayed Emergence and Arousal 250 Complications 251 Conclusion 252 References 252 14. Anesthesia for Posterior Fossa Surgery K. SANDHU AND N. GUPTA Introduction 255 Anatomy 255 Clinical Presentation 256 Perioperative Management of Patients for Posterior Fossa Surgery 256 Venous Air Embolism 264 Postoperative Management 271 Complications 272 Abbreviations 272 References 273 15. Transesophageal Echocardiography A. LELE AND V. KRISHNAMOORTHY Introduction 277 Basics of Transesophageal Echocardiography 277 Summary 283 References 283 16. Anesthesia for Epilepsy Surgery N. GUPTA Introduction 285 Surgical Management of Epilepsy 286 Types of Surgical Treatment 286 Presurgical Evaluation 287 Anesthesia for Epilepsy Surgery 288 Effect of Anesthetic Agents in Patients With Epilepsy 288 Antiepileptic Drug Interactions 290 Preanesthetic Evaluation and Preparation 291 Anesthetic Management of Preoperative Procedures 292 Anesthesia for Intracranial Electrode Insertion 294 Anesthetic Management of Resection of Seizure Focus 295 Awake Craniotomy 295 Resection of Epileptogenic Focus Under General Anesthesia 300 Neurostimulation for Drug-Resistant Epilepsy 301 Anesthetic Management of the Patient With Epilepsy for Incidental Surgery 302 Abbreviations 303 References 304 17. Refractory Status Epilepticus M. PANEBIANCO AND A. MARSON Introduction 309 Epidemiology 309 Classification 310 Cause 310 Pathophysiology 311 Diagnosis 311 Management 311 Treatment 312 Conclusions 313 References 314 18. Aneurysmal Subarachnoid Hemorrhage C. MAHAJAN History 316 Introduction 316 Clinical Presentation and Diagnosis 317 Grading of Subarachnoid Hemorrhage 319 Initial Management Concerns in Neurocritical Care Unit 321 Timing of Surgery 327 Clipping or Coiling 327 Evaluation of a Patient With Subarachnoid Hemorrhage for Anesthesia 328 Anesthetic Management 328 Temporary Clipping and Brain Protection Strategy 330 Intraoperative Aneurysm Rupture 330 Giant Aneurysms and Circulatory Arrest 331 Endovascular Management for Aneurysm Ablation 331 Postoperative Management of Patients 333 Conclusion 333 References 333
  • 11. CONTENTS x 19. Circulatory Arrest D.E. TRAUL Introduction 339 Deep Hypothermic Circulatory Arrest 339 Anesthesia Management 340 Complications 341 Adenosine-Induced Circulatory Arrest 341 Anesthesia Considerations 342 Complications 342 Summary 342 References 343 20. Cerebrovascular Disease M. ABRAHAM AND M. MARDA Intracerebral Hemorrhage 346 Incidence and Risk Factors 346 Imaging 346 Clinical Presentation 346 Management of Intracerebral Hemorrhage 348 Arteriovenous Malformations 352 Cause and Incidence 352 Natural History 353 Pathophysiologic Effects and Clinical Presentation 353 Grading of Arteriovenous Malformations 353 Imaging 354 Cerebral Hemodynamics in Arteriovenous Malformation 354 Management 354 Surgical Resection of Arteriovenous Malformation 355 Anesthetic Considerations for Resection of Arteriovenous Malformation 355 Postoperative Management 356 Anesthetic Considerations for Arteriovenous Malformation Embolization 356 Complications During Arteriovenous Malformation Embolization 357 Pediatric Arteriovenous Malformations 357 Pregnancy and Arteriovenous Malformations 358 Vein of Galen Aneurysmal Malformations 358 Dural Arteriovenous Fistula 360 Clinical Presentation 360 Management 360 Carotid Endarterectomy 360 Preoperative Evaluation 362 Management of Carotid Artery Disease 362 Monitoring 362 Intraoperative Management 363 Postoperative Complications and Outcomes 363 Coronary Angioplasty and Stenting 363 Moyamoya Disease 363 Management of Moyamoya Disease 364 References 364 21. Flow Arrest in Cerebrovascular Surgery M.L. JAMES, M.-A. BABI AND S.A. KHAN Deep Hypothermic Circulatory Arrest 367 Adenosine-Assisted Cerebral Blood Flow Arrest 370 Rapid Ventricular Pacing–Assisted Cerebral Blood Flow Arrest 372 References 373 22. Neuroendocrine Lesions P.K. BITHAL Hypothalamic-Pituitary–Adrenal Axis Evaluation 376 Neuroendocrine Response Related to Anesthesia and Surgery 377 Pituitary Gland Adenomas 377 Physiology of Pituitary Gland 379 Endocrine Diseases 380 Nonfunctioning Tumors 382 Intraoperative Considerations 383 Advantages of Endoscopic Endonasal Approach 384 Relative Contraindications to Transsphenoidal Approach 384 Intraoperative Issues 384 Disorder of Water and Electrolytes 387 References 389 23. Pituitary Apoplexy S.S. THOTA Clinical Features 395 Management 395 References 397 24. Spinal Surgery M.S. TANDON AND D. SAIGAL Introduction 400 Spine 400 Types of Spine Surgeries 401 Surgical Approaches to the Spine 403 Common Spine Disorders 403 Imaging in Spine Lesions 417 Positioning for Spine Surgeries 417 Neurophysiological Intraoperative Monitoring During Spine Surgeries 418 Preanesthetic Assessment and Optimization 420 Anesthesia Management 423 Postoperative Management 430 Special Considerations 431 Conclusion 437 References 437 25. Postoperative Visual Loss K.M. KLA AND L.A. LEE Introduction 441 Central Retinal Artery Occlusion 441 Ischemic Optic Neuropathy 442 Cortical Blindness 442 Recent Advances 443 Conclusion 445 References 445
  • 12. CONTENTS xi 26. Neuroendoscopy S. MONINGI AND D.K. KULKARNI Introduction 447 Anesthetic Goals and Management 450 Anesthetic Management of Specific Neuroendoscopic Procedures 453 Advances in Neuroendoscopy 466 Conclusion 467 Clinical Pearls 467 References 468 27. Pressure Inside the Neuroendoscope N. FÀBREGAS AND L. SALVADOR Introduction 471 Indications and Procedures 471 How Do Neurosurgeons Perform an Intraventricular Endoscopic Procedure? 472 Anesthetic Procedure: What to Take Into Account? 473 Perioperative Complications 475 Conclusion 477 References 477 28. Anesthesia for Functional Neurosurgery S.K. DUBE Introduction 479 Procedure 479 Anesthetic Consideration 481 Anesthetic Techniques 484 Complications 485 Anesthesia in Patients With Deep Brain Stimulator In Situ 486 Conclusion 486 References 486 29. Awake Craniotomy P.H. MANNINEN AND T. Y. YEOH Introduction 489 Patient Selection 490 Awake Craniotomy for Tumor Surgery 490 Awake Craniotomy for Epilepsy 496 Conclusion 499 References 499 VIII NEURORADIOLOGY 30. Anesthesia for Neuroradiology K. SRIGANESH AND B. VINAY Introduction 505 Issues Relating to Anesthesia Care in Neuroradiology 506 Anesthesia for Computed Tomographic Study 506 Anesthesia for Magnetic Resonance Imaging Study 506 Anesthesia for Diagnostic Angiography 510 Anesthetic Management of Endovascular Coiling 510 Anesthetic Management of Endovascular Embolization of Arteriovenous Malformation, Arteriovenous Fistula, and Vein of Galen Malformation 513 Anesthesia for Stroke Interventions 514 Issues Related to Radiation During Neurointervention 515 Anesthesia for Stereotactic Radiosurgery 516 Pregnancy and Neuroradiology 516 Clinical Pearls 517 References 517 31. Magnetic Resonance Imaging: Anesthetic Implications F. RABAI AND R. RAMANI Introduction: The Road From X-Ray to Magnetic Resonance Imaging 519 Principles of Nuclear Magnetic Resonance and Magnetic Resonance Imaging 521 Various Types of Signals Recorded 522 Hazards Related to Magnetic Resonance Imaging 524 Magnetic Resonance Imaging Safety: General Considerations 526 Magnetic Resonance Imaging Safety: Management of Cardiac Implantable Electronic Devices and Other Implantable Devices 527 Anesthesia for Magnetic Resonance Imaging 530 Research Applications/Emerging Clinical Applications of Magnetic Resonance Imaging 531 References 532 IX NEUROTRAUMA 32. Neurotrauma D. PADMAJA, A. LUTHRA AND R. MITRA Traumatic Brain Injury 536 Introduction 536 Definition 536 Epidemiology 536 Classification of Traumatic Brain Injury 537 Physiologic Response to Brain Injury 543 Neuroimaging 545 Severity of Traumatic Brain Injury 549 Management of Traumatic Brain Injury 549 Outcome 559 Emerging Treatment Modalities 559 Conclusion 560 Spine and Spinal Cord Trauma 560 Introduction 560 Epidemiology 560 Classification of Spinal Injury 561 Pathophysiology of Spinal Cord Trauma 563 Systemic Complications of Spinal Cord Injuries 565
  • 13. CONTENTS xii Management of Spine and Spinal Cord Injury 567 Emerging Treatment Modalities 578 References 582 33. Biomarkers in Traumatic Brain Injury J. ŽUREK Introduction 587 Conclusion 590 References 590 X NEUROINTENSIVE CARE 34. Neurological Critical Care G.S. UMAMAHESWARA RAO AND S. BANSAL Introduction 595 History of Neurocritical Care 596 Design of a Neurocritical Care Unit 596 Clinical Conditions Requiring Admission to Neurocritical Care Unit 596 Justification for Neurological Critical Care Units 596 Pathophysiological Issues in Neurological Critical Care 597 Management of Patients in a Neurological Intensive Care Unit 598 Management of General Systemic Physiology 598 Specific Therapeutic Issues in Individual Clinical Conditions 603 Advanced Neuromonitoring 603 Outcomes of Neurological Intensive Care Unit 606 End-of-Life Issues in Neurological Critical Care 606 Clinical Pearls 608 References 608 35. Antibiotics: Prophylactic and Therapeutics S. ERB, L.A. STEINER AND C. OETLIKER Introduction 613 Principles of Antimicrobial Therapy in Neurosurgery 613 Treatment of Central Nervous System Infections in the Neurosurgical Patient 616 Antimicrobial Prophylaxis in Neurosurgery 620 References 623 XI SPECIAL CONSIDERATIONS 36. Pediatric Neuroanesthesia G.P. RATH Overview 629 Pediatric Neurophysiology 629 General Principles of Pediatric Neuroanesthesia 630 Intraoperative Management 631 Postoperative Considerations 633 Management of Specific Conditions 633 Conclusion 641 References 641 37. Fluid and Blood Transfusion in Pediatric Neurosurgery S. RAJAN AND S. RAO Introduction 643 Fluid and Electrolyte Choices 644 Type of Fluids for Perioperative Administration in Pediatric Patients 645 Fluid Management in Pediatric Neurosurgery 645 Osmotherapy 646 Fluid and Electrolyte Disturbances in Pediatric Neurosurgery 647 Blood Transfusion 647 Blood Components 648 Special Situations 649 Epilepsy Surgery 649 Scoliosis 649 Conclusion 650 References 650 38. Geriatric Neuroanesthesia S. TRIPATHY Introduction 653 Implications of Surgical Stress and Anesthesia on the Elderly 653 Neurosurgical Concerns Unique to the Elderly 654 Conclusion 658 References 658 39. Postoperative Cognitive Dysfunction A. BOROZDINA, L. PORCELLA AND F. BILOTTA Introduction 661 Definitions, Epidemiology, and Pathophysiology 661 Risk Factors 663 Prevention 664 Screening Tools 664 Treatment 665 Outcome 666 References 666 40. Pregnancy V. SINGHAL Requirement of Neurosurgery During Pregnancy 670 Physiological Alterations During Pregnancy 671 Effect of Anesthetic Agents on Fetal Outcome 673 Uteroplacental Drug Transfer and Neonatal Depression 674 Timing and Method of Delivery 675 Anesthetic Considerations During Pregnancy 675 Induction: Rapid Sequence Versus Slow Neuroinduction 676 Combined Cesarean Delivery and Neurosurgery 678
  • 14. CONTENTS xiii Intracranial Pressure and Regional Anesthesia 678 Postoperative Management 678 Anesthesia for Interventional Neurosurgical Procedures 679 References 679 41. Cerebral Venous Thrombosis E.E. SHARPE AND J.J. PASTERNAK Definition 681 Venous Anatomy 681 Incidence of Cerebral Venous Thrombosis 681 Risk Factors 683 Pathophysiology 684 Clinical Manifestations 685 Diagnostic Evaluation 687 Treatment 688 Anesthetic Management 689 Prognosis 690 Conclusion 690 References 690 42. Neurosurgical Anesthesia in Patients With Coexisting Cardiac Disease S. SRIVASTAVA AND A. KANNAUJIA Introduction 693 Preoperative Evaluation 694 Risk Stratification 694 Perioperative Monitoring 695 Ischemic Heart Disease 695 Valvular Heart Disease 697 Tumors of the Heart 699 Congenital Heart Disease 700 Hypertension 700 Conclusion 701 References 701 43. Intraoperative Cardiopulmonary Resuscitation R. GORJI AND M. SIDANI Introduction 703 Incidence, Morbidity, and Mortality 703 Survival From Intraoperative Cardiac Arrest 704 Predictors 704 Cause of Intraoperative Cardiac Arrest 705 Cardiopulmonary Resuscitation Quality 706 Cardiac Arrest and Cardiopulmonary Resuscitation in Neurosurgical Patients 706 Prognosis 709 Conclusion 709 References 710 44. Coexisting Diabetes Mellitus in Neurosurgical Patients N.B. PANDA, S. SAHU AND A. SWAIN Introduction 714 Incidence of Diabetes Mellitus 714 Glycemic Indices 714 Modes of Glucose Measurement 714 Pathophysiology of Diabetes Mellitus 715 Cerebral Glucose Metabolism 715 Hyperglycemia and the Brain 715 Hyperglycemic Neuropathy 716 Diabetic Dysautonomia 716 Hypoglycemia and the Brain 716 Evidence of Glycemic Control in Important Neurosurgical Subsets 717 Traumatic Brain Injury 717 Subarachnoid Hemorrhage 717 Cerebrovascular Accidents 717 Tumor Surgery 718 Spine Surgery 718 Blood Sugar Management in Perioperative Period and Neurocritical Care 718 Intraoperative Management 719 Anesthetic Management 719 Postoperative Glycemic Management 719 Blood Sugar Control in Emergency Neurosurgical Patient 720 Blood Sugar Control in Intensive Care Setup 720 Nutrition 720 Conclusions 720 Coexisting Hypertension in Neurosurgical Patients 721 Introduction 721 Physiology of Cerebral Circulation 721 Pathophysiology of Arterial Hypertension 722 Hypertension in Patients With Traumatic Brain Injury 723 Perioperative Management 724 Preoperative Evaluation 724 Antihypertensive Drugs 725 Intraoperative Management 725 Monitoring 725 Induction of Anesthesia 725 Maintenance of Anesthesia 726 Recovery From Anesthesia 726 Postoperative Care 726 Neurocritical Care 727 Conclusion 727 References 727 45. Neuromuscular Disorders P.U. BIDKAR AND M.V.S. SATYA PRAKASH Introduction 734 Myasthenia Gravis 735 Myasthenic Crisis 743 Lambert–Eaton Myasthenic Syndrome 747 Guillain–Barré Syndrome 748 Periodic Paralysis 753 Myotonias 755 Muscular Dystrophies 758 Motor Neuron Diseases 759 Multiple Sclerosis 760 Parkinson’s Disease 761 Alzheimer’s Disease 763 Huntington’s Disease 764 References 765
  • 15. CONTENTS xiv 46. Neuromuscular Electrical Stimulation in Critically Ill Patients N. LATRONICO, N. FAGONI AND M. GOBBO Introduction 771 Neuromuscular Electrical Stimulation: Basic Concepts and Practical Considerations 772 Neuromuscular Electrical Stimulation in the Intensive Care Unit 775 Contraindications and Adverse Effects 776 Recommendations for the Use of Neuromuscular Electrical Stimulation in the Intensive Care Unit 777 References 780 47. Neurological Patients for Nonneurosurgeries K. JANGRA, V.K. GROVER AND H. BHAGAT Neurodegenerative Diseases 784 Demyelinating Disease 788 Neuromuscular Disease: Myasthenia Gravis 791 Epilepsy 793 Intracranial Tumors 794 Traumatic Brain Injury 797 References 800 48 Anesthesia for Electroconvulsive Therapy U. GRUNDMANN Background 805 Technique of Electroconvulsive Therapy 805 Contraindications 806 Preprocedure Management 806 Anesthesia for Electroconvulsive Therapy 806 Side Effects 809 Special Conditions 809 Conclusion 810 References 810 XII FLUIDS AND ELECTROLYTE MANAGEMENT 49. Fluids and Electrolyte Management J.N. MONTEIRO Introduction 815 Anatomy and Physiology 815 Pathophysiology 817 Definitions 817 Choice of Fluids 818 Hypertonic Fluids 818 Isotonic Fluids 820 Colloids 820 Hypotonic Fluids 821 Fluid Management 822 Commonly Encountered Fluid Abnormalities 823 Conclusion 824 Clinical Pearls 825 References 825 50. Crystalloid and Colloid Fluids R.G. HAHN Crystalloid Fluids 827 Colloid Fluids 829 Which Fluid to Choose? 830 Conclusions 831 References 832 XIII PAIN MANAGEMENT 51. Pain Management Z. ALI, S. SINGH, N. HASSAN AND I. NAQASH Postcraniotomy Pain 836 Introduction 836 Incidence 836 Anatomical and Physiological Basis of Pain Following Craniotomy 836 Pain-Sensitive Structures of Cranium 838 Pathogenesis of Postcraniotomy Pain 838 Factors Affecting Postcraniotomy Pain 838 Classification and Assessment of Postcraniotomy Pain 839 Preemption of Pain 840 Treatment of Acute Pain 840 Postcraniotomy Pain Management in the Pediatric Population 843 Conclusion 843 Acute Pain Management After Spinal Surgery 843 Pathophysiology 844 Treatment Modalities for Acute Postoperative Spinal Pain 844 Conclusion 848 References 849 XIV BRAIN DEATH AND ETHICAL ISSUES 52. Brain Death and Ethical Issues in Neuroanesthesia Practice M. RADHAKRISHNAN AND S. LALWANI Part A: Brain Death 856 Introduction 856 Criteria for Diagnosing Death 856 Need for Brain Death Diagnosis 856 Rules Regulating Diagnosis of Brain Death 856 Criteria for Certifying Brain Stem Death 857 Pitfalls/Controversies 859
  • 16. CONTENTS xv Conclusion 861 Appendix I 861 Part B: Ethical Issues in Neuroanesthesia Practice 863 Introduction 863 Ethical Issues in Clinical Care 863 Ethical Issues Related to Research 867 Ethical Issues Related to Team Work 868 Ethical Issues Related to Training 868 Ethical Issues Related to Innovative Neurosurgery 869 Conclusion 869 References 869 53. Organ Donation M.J. SOUTER Introduction 871 Conclusion 876 References 876 XV EVIDENCE-BASED PRACTICE 54. Evidence-Based Practice of Neuroanesthesia I. KAPOOR AND H. PRABHAKAR Introduction 881 Evidence-Based Practice and Neuroanesthesia 883 Evidence and the Brain Trauma Foundation Guidelines 887 Unresolved Issues in the Practice of Neuroanesthesia 887 Conclusion 887 Clinical Pearls 889 References 889 55. Translational Research M. IDA AND M. KAWAGUCHI Introduction 891 Definition 891 In Neuroanesthesia 893 Why Not Lead to Clinical 893 To Be a Successful Translation 894 Conclusion 894 References 894 XVI RECENT ADVANCES 56. Recent Advances in Neuroanesthesiology T.L. WELCH AND J.J. PASTERNAK Introduction 897 Endovascular Treatment of Stroke and Perioperative Stroke 897 Indications for Deep Brain Stimulation 898 Anesthetic Neurotoxicity 899 Pre- and Postconditioning 900 Brain Monitoring 901 New Assays for Creutzfeldt–Jakob Disease 902 References 903 57. Stem Cell Therapy S. SHARMA AND R. AGGARWAL Hypothesis of Stem Cell Research 907 Stem Cell 907 Historical Background 908 Types of Stem Cells 908 Sources of Stem Cells 908 Mesenchymal Stem Cells 909 Stem Cells in Neurological Diseases 909 Mode of Action of Stem Cell Therapy 910 Ethical Issues 910 Recent Advances 911 References 911 58. Pharmacogenomics Y.N. MARTIN AND W.T. NICHOLSON Introduction 913 Basic Genetic Principles 914 Basic Pharmacologic Principles 914 Anesthesia Contribution to the History of Pharmacogenomics 915 Pharmacogenomics: Current Application to Clinical Anesthesia 916 Conclusion 921 References 922 XVII STERILIZATION TECHNIQUES 59. Sterilization and Disinfection S. MOHAPATRA Background 930 Recommendation of Preferred Methods for Various Medical Devices 931 Recommendation for the Cleaning and Decontamination of Environmental Surfaces 931 Recommendation for Blood Spill on the Surface 932 Cleaning and Disinfection of Medical Instruments 933 Cleaning and Reprocessing of Patient Care Equipment 933 Reprocessing of Respiratory Apparatus and Endoscopes 935 Reprocessing of Endoscopes 936 Specific Issues 938 Special Precaution for Inactivation of Creutzfeldt–Jakob Disease 939 Health Care–Associated Infections 940 Infections in Operating Rooms and Intensive Care Units 940 Conclusion 943 References 943
  • 17. CONTENTS xvi 60. Universal Precautions in the Intensive Care Unit A.YU LUBNIN AND K.A. POPUGAEV Introduction 945 Prophylactics of Health Care–Associated Infections in the Intensive Care Unit 946 Early Diagnosis of Pathogens and Infection Complications in the Intensive Care Unit 947 Rational Antibiotic Therapy 947 Systemic Approach 948 Conclusion 948 References 948 XVIII PALLIATIVE CARE 61. Palliative Care to Neurological and Neurosurgical Patients S. BHATNAGAR AND S.J. BHARTI Introduction 953 References 961 62. Quality of Life and Health-Related Issues L. VENKATRAGHAVAN AND S. BHARADWAJ Introduction 963 Quality of Life and Health-Related Quality of Life 963 Utility of Health-Related Quality of Life 964 Tools for Measuring Health-Related Quality of Life 964 Uses of Measuring Health-Related Quality of Life 965 Health-Related Quality of Life in Relation to Neurosurgical/Neurological Conditions 965 Conclusion 970 References 970 XIX BIOSTATISTICS 63. Biostatistics M. KALAIVANI, S. AMUDHAN, A.D. UPADHYAY AND V.K. KAMAL Introduction to Biostatistics 976 Definition of Statistics 976 Biostatistics and Its Applications 976 Uses of Statistical Methods in Medical Sciences 976 Some Basic Statistical Concepts 976 Population and Sample 977 Scale of Measurements 977 Constant 977 Variables 977 Parameter and Statistic 978 Ratio, Proportion, and Rate 978 Statistical Inference 979 Estimation 979 Hypothesis Testing 979 Steps in Hypothesis Testing or Testing the Statistical Significance 979 Defining the Null and Alternative Hypotheses 980 Calculating the Test Statistic 980 Obtaining, Using, and Interpreting the p-Value 980 Errors in Hypothesis Testing 980 The Possible Mistakes We Can Make 980 Other Important Concepts That Are Essential in Statistical Inference 981 Parametric and Nonparametric Statistical Methods 981 Basic Principles of Statistics 981 Probability Distributions 982 Study Design 982 Sample Size 985 Data Collection and Preparing Data for Analysis 987 Analysis and Presentation of Data 989 Summarizing Data 989 Comparing Groups: Continuous Data 989 Comparing Groups: Categorical Data 991 Comparing Groups: Time to Event Data 991 Relation Between Two Continuous Variables 992 Multivariable Analysis 994 Conclusion 995 References 995 Index 997
  • 18. xvii List of Contributors M. Abraham Max Hospital Panchsheel, New Delhi, India R. Aggarwal All India Institute of Medical Sciences, New Delhi, India Z. Ali SKIMS, Srinagar, India S. Amudhan NIMHANS, Bengaluru, India M.-A. Babi Duke University, Durham, NC, United States S. Bansal National Institute of Mental Health and NeuroSciences (NIMHANS), Bangalore, India S.D. Bergese Ohio State University, Columbus, OH, United States H. Bhagat Postgraduate Institute of Medical Education and Research, Chandigarh, India S. Bharadwaj NIMHANS, Bangalore, India S.J. Bharti AIIMS, New Delhi, India S. Bhatnagar AIIMS, New Delhi, India P.U. Bidkar JIPMER, Puducherry, India F. Bilotta Sapienza University of Rome, Rome, Italy P.K. Bithal AIIMS, New Delhi, India V. Bonhomme CHR Citadelle, Liege, Belgium A. Borozdina I.M. Sechenov First Moscow Medical University, Moscow, Russia A. Defresne CHR Citadelle, Liege, Belgium S.K. Dube All India Institute of Medical Sciences, New Delhi, India M. Echeverría Centro Médico Docente Paraíso, Maracaibo, Venezuela H. El Beheiry University of Toronto, Toronto, ON, Canada; Trillium Health Partners, Toronto, ON, Canada S. Erb University Hospital Basel, Basel, Switzerland N. Fàbregas Hospital Clinic Universitari, Barcelona, Spain N. Fagoni University of Brescia, Brescia, Italy E. Farag Cleveland Clinic Foundation, Cleveland, OH, United States J. Fiorda-Diaz Ohio State University, Columbus, OH, United States P. Ganjoo GB Pant Hospital, New Delhi, India M. Gobbo University of Brescia, Brescia, Italy R. Gorji Upstate Medical University, Syracuse, NY, United States V.K. Grover Postgraduate Institute of Medical Education and Research, Chandigarh, India U. Grundmann Saarland University Medical Center, Homburg/Saar, Germany D. Gupta Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India N. Gupta Indraprastha Apollo Hospital, New Delhi, India R.G. Hahn Södertälje Hospital, Södertälje, Sweden N. Hassan Government Gousia Hospital, Srinagar, India M. Ida Nara Medical University, Kashihara, Japan M.L. James Duke University, Durham, NC, United States K. Jangra Postgraduate Institute of Medical Education and Research, Chandigarh, India M. Kalaivani AIIMS, New Delhi, India V.K. Kamal AIIMS, New Delhi, India A. Kannaujia Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India I. Kapoor All India Institute of Medical Sciences, New Delhi, India M. Kawaguchi Nara Medical University, Kashihara, Japan A.K. Khanna Cleveland Clinic Foundation, Cleveland, OH, United States S.A. Khan Duke-NUS Medical School, Singapore, Singapore K.M. Kla Vanderbilt University Medical Center, Nashville, TN, United States V. Krishnamoorthy University of Washington, Seattle, WA, United States D.K. Kulkarni Nizam’s Institute of Medical Sciences, Hyderabad, India S. Lalwani All India Institute of Medical Sciences, New Delhi, India N. Latronico University of Brescia, Brescia, Italy L.A. Lee Kadlec Regional Medical Center, Richland, WA, United States A. Lele University of Washington, Seattle, WA, United States A.Yu Lubnin Neurocritical Care of Burdenko Research Neurosurgical Institute, Ministry of Health, Moscow, Russia A. Luthra PGIMER, Chandigarh, India C. Mahajan AIIMS, New Delhi, India S. Mahajan Postgraduate Institute of Medical Education and Research, Chandigarh, India P.H. Manninen Toronto Western Hospital, Toronto, ON, Canada M. Marda Max Hospital Panchsheel, New Delhi, India R. Mariappan Christian Medical College, Vellore, India
  • 19. LIST OF CONTRIBUTORS xviii A. Marson University of Liverpool, Liverpool, United Kingdom Y.N. Martin Mayo Clinic, Rochester, MN, United States R. Mitra Care Hospital, Bhubhaneswar, India S. Mohapatra AIIMS, New Delhi, India S. Moningi Nizam’s Institute of Medical Sciences, Hyderabad, India J.N. Monteiro P.D. Hinduja Hospital and Medical Research Centre, Mumbai, India I. Naqash SKIMS, Srinagar, India W.T. Nicholson Mayo Clinic, Rochester, MN, United States C. Oetliker University Hospital Basel, Basel, Switzerland D. Padmaja Nizam’s Institute of Medical Sciences, Hyderabad, India N.B. Panda Post Graduate Institute of Medical Education and Research, Chandigarh, India M. Panebianco University of Liverpool, Liverpool, United Kingdom J.J. Pasternak Mayo Clinic College of Medicine, Rochester, MN, United States K.A. Popugaev Federal Medical-Biological Agency, Ministry of Health, Moscow, Russia L. Porcella Spedali Civili University Hospital, Brescia, Italy H. Prabhakar All India Institute of Medical Sciences, New Delhi, India F. Rabai University of Florida, Gainesville, FL, United States M. Radhakrishnan National Institute of Mental Health and NeuroSciences, Bengaluru, India S. Rajan Cleveland Clinic, Cleveland, OH, United States R. Ramani University of Florida, Gainesville, FL, United States V.J. Ramesh National Institute of Mental Health and NeuroSciences, Bengaluru, India S. Rao Yale New Haven Hospital, New Haven, CT, United States G.P. Rath All India Institute of Medical Sciences (AIIMS), New Delhi, India S. Sahu Tata Main Hospital, Jamshedpur, India D. Saigal University of Delhi, New Delhi, India L. Salvador Consorcio Hospital General Universitario de Valencia, Valencia, Spain K. Sandhu Max Superspeciality Hospital, New Delhi, India M.V.S. Satya Prakash JIPMER, Puducherry, India M. Sethuraman Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India S. Sharma All India Institute of Medical Sciences, New Delhi, India E.E. Sharpe Mayo Clinic College of Medicine, Rochester, MN, United States M. Sidani Upstate Medical University, Syracuse, NY, United States V. Singhal Medanta (The Medicity), Gurgaon, India G. Singh Christian Medical College, Vellore, India G.P. Singh AIIMS, New Delhi, India S. Singh SKIMS, Srinagar, India M.J. Souter University of Washington, Seattle, WA, United States K. Sriganesh NIMHANS, Bangalore, India S. Srivastava Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India L.A. Steiner University Hospital Basel, Basel, Switzerland N. Stoicea Ohio State University, Columbus, OH, United States A. Swain Tata Main Hospital, Jamshedpur, India M.S. Tandon University of Delhi, New Delhi, India S.S. Thota Upstate Medical University, State University of New York, Syracuse, NY, United States D.E. Traul Cleveland Clinic, Cleveland, OH, United States S. Tripathy All India Institute of Medical Sciences Bhubaneswar, Bhubaneswar, India G.S. Umamaheswara Rao National Institute of Mental Health and NeuroSciences (NIMHANS), Bangalore, India A.D. Upadhyay AIIMS, New Delhi, India L. Venkatraghavan University of Toronto, Toronto, ON, Canada B. Vinay Gulf Medical University, Ajman, United Arab Emirates T.L. Welch Mayo Clinic College of Medicine, Rochester, MN, United States T.Y. Yeoh Toronto Western Hospital, Toronto, ON, Canada J. Žurek University Hospital Brno, Brno, Czech Republic
  • 20. xix Foreword There has been substantial flux in the field of neuroanesthesia over the past two decades. This followed what could be viewed as a relatively quiescent and narrowly focused period in neuroanesthesia. During the latter period much of the focus was on the roles of hypotension in aneurysm surgery, hyperventilation for head injury, anesthetics as cerebral protectants, and endless debates about intravenous versus inhaled anesthetics. More recently the purview of neuroanesthesia broadened substantially partly reflecting the huge expansion in the way patients with neurologi- cal diseases are managed. Patients are cared for not only in the traditional operating theater and intensive care unit but also in more complex ways inside and outside the operating theater. Examples include endovascular treatment of aneurysms, magnetic resonance imaging (MRI)- and computed tomography (CT)-guided surgery, minimally inva- sive approaches such as deep brain stimulation (DBS), the growth in neurological monitoring from the awake patient to complex electrophysiology, and the ever increasingly aggressive spine reconstructions. The neuroanesthesiologist of today is not only a traveler going to different parts of the hospital but needs to be an expert in patient management in all the newer scenarios. Furthermore, this expansion of the repertoire requires greater refinement in our intimate knowledge of how drugs and techniques may enhance or adversely affect the nuanced neurosurgical outcomes. Given the above changes in practice, the novice and experienced neuroanesthesia practitioners now, more than ever, need an authoritative text not just full of “book knowledge” but written by those who on a daily basis meld the academic with the practical. To his credit, Hemanshu Prabhakar has brought together an accomplished group of international experts to contribute to this excellent volume. Their writing is authoritative and up to date while being practical and easy to understand. There is no doubt that this book is a very useful contribution to the modern practice of neuroanesthesia. Adrian W. Gelb Distinguished Professor Department of Anesthesia and Perioperative Care University of California San Francisco
  • 22. xxi Preface Neuroanesthesia is growing fast as a superspecialty as more and more research is being conducted to improve the practice. The focus is now not restricted to the bench but has also extended to the bedside. There is a need to have a volume that provides a comprehensive view of various topics and issues related to neuroanesthesia. This book provides easy understanding of anesthesia related to neurological sciences. This book will be useful for any medi- cal practitioner associated with neurosurgical and allied branches such as neurology and neuroradiology. This book also caters to the needs of all those anesthetists who practice neuroanesthesia but do not have a formal training in it. It will provide a quick and easy access to understand neuroanesthesia. This book will provide an insight into all possible aspects of anesthetic management of neurosurgical and neurologic patients. This book has been written mainly for the residents and students appearing for examination and anesthetists practicing neuroanesthesia. This book includes the basic sciences such as anatomy, physiology, and pharmacology related to brain and spinal cord. This book also provides an understanding of related issues such as palliative care, evidence-based practice of neuro- anesthesia, sterilization techniques, and ethical issues. This book covers all topics related to neuroanesthesia and provides complete knowledge about brain and spinal cord. The book includes chapters related to allied specialties such as critical care, neurology, and neuroradiology. This book also contains a section on biostatistics, which would be extremely useful to residents and trainees who have to submit dissertation or thesis during their course. This book contains pieces of information that have been brought together, which may have otherwise been avail- able in different books. I am grateful to all my authors across the globe, from as many as 14 different countries. The knowledge and infor- mation shared by the authors through different chapters is the representation of the global practice of neuroanesthe- sia and not limited to geographical boundaries. I sincerely hope this endeavor will improve our knowledge in the management of neurologically compromised patients and bring about an improved patient care. Hemanshu Prabhakar
  • 24. xxiii Acknowledgments I wish to acknowledge the support of the administration of the All India Institute of Medical Sciences (AIIMS), New Delhi, in allowing me to conduct this academic task. Words are not enough to express my gratitude for the constant support and encouragement from Prof. P.K. Bithal (Former Head of Neuroanesthesiology and Critical Care, AIIMS, New Delhi). I thank the faculty and staff of the department of Neuroanesthesiology and Critical Care, for their support. Special thanks are due to the production team at Elsevier.
  • 26. xxv Introduction and Brief History of Neuroanesthesia W.S. Jellish Loyola University Medical Center, Maywood, IL, United States Neuroanesthesia has evolved as a subspecialty of anesthesiology and has continued to evolve in association with further surgical advancements such as minimally invasive techniques and three-dimensional imaging using neuro- navigation. Neuroradiology has also advanced with invasive neurovascular procedures, once done in the operating rooms, now performed in the neurointerventional radiology suite with the support of the anesthesiologists. Early neuroanesthesia was performed as a method to support the practice of trephination. It was uncertain whether brain surgery had been performed during this trephination or if it was part of a religious or social ritual (Fig. 1). Some were obviously related to injury, but the presence of multiple defects in the absence of other apparent injuries in both young and old suggested a possible therapeutic purpose. A popular aspect was that these openings were used to alleviate pain or allow the escape of evil spirits and humors or to drain pus or reduce inflammation. No matter what the reason for the trephination, skulls with these types of defects have been found all over the world. There are several documented examples, which point out that these skull defects were produced as part of a neu- rosurgical procedure. The Edwin Smith Papyrus is one of the earliest written records of surgical practice (Fig. 2). The text may well represent the first neurosurgical practitioner’s manual as it describes 48 cases that consist of 15 head injuries, 12 facial wounds and fractures, and 7 vertebral injuries. Several other written works produced around 400 BC have been linked to Hippocrates. One of the texts on injuries of the head describes trephination for skull frac- tures, epilepsy, blindness, and headaches. The practitioner was advised to avoid suture lines and the temporal areas because of fear of damaging the anatomy that would lead to contralateral convulsions.1 It was also noted that the inner table should be preserved to protect the dura and this bone fragment would later be extracted by suppuration. Despite the advanced neurosurgical and neuroanatomical knowledge for the times in Greece and Rome, use and understanding of neuroanesthesia did not appear to be much different from those of fellow practitioners elsewhere in the world. In the prehistoric period, anesthesia was probably done by chewing or locally applying a mixture of coca and yucca.2 Daturas had also been used with its anesthetic effect thought to be produced by its contents of sco- polamine, hyoscyamine, and atropine. In early cultures, wine making was highly developed. In Egypt the soporific effects of alcohol had been well documented in hieroglyphic writings. It is considered likely that some analgesia and amnesic effects were derived from this source. Sometimes just compression of the carotid artery was used to induce unconsciousness.3 Progress in neurosurgery slowed considerable during the Middle Ages. The Roman Catholic Church became very influential in medical care and monasteries were the centers for science and knowledge. With the edict of AD 1163 entitled, “Ecclesia abhoret a sanguine,” there were restrictions placed on the use of human bodies for anatomical studies, and progress in the field of surgery was almost halted. At the beginning of the 10th century, Rhazes com- piled the Liber Continens, a collection of all literature belonging to the Arab world including medicine, philosophy, religion, mathematics, and astronomy. Among the several important observations he made with this work, one was particularly remarkable. He wrote that the pressure on the brain, rather than the presence of the skull fracture itself, was more important in determining the outcome after head injury.4 It was not until later in the 10th century with the establishment of a medical school in Salerno, Italy, that this and other medical principles were brought forward to revive European medicine. Few references were made on the use of anesthesia, perhaps because pain was mentioned so many times in reli- gious teachings and was felt to be a noble state that served God’s purpose. When anesthesia was attempted, opium, hyoscyamine, and sometimes wine were used as agents to alleviate pain.5 On occasion Cannabis indica and henbane were used, along with a sponge containing opium, marberry, water hemlock, and ivy which was boiled and then applied to the patient’s nose during the surgery.6 It was thought that wine was added to the sponge during boiling to enhance its sedative power. The physicians of Myddavi, herbalist from Wales, further advised that to improve
  • 27. INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxvi anesthetic efficiency, when you prepare to operate on a patient, direct them to avoid sleep as long as possible then let some of the potion be poured into the nostril of the patient who will fall asleep without fail.7 The first account of inducing anesthesia and reversing sedation was attempted by two Hindu brothers who per- formed a craniotomy in AD 927 to remove an unidentified tumor from the brain of the King of Dhar. They induced anesthesia with a drug called samohine and reversed the anesthetic effects by pouring an onion compounded with vinegar into the subject’s mouth.7 Numerous other concoctions both oral and topical were administered to patients for better outcomes. Some combined puppies boiled in an oil of lilies and earthworms and prepared in turpentine of Venice.2 Other mixtures used were rose oil, egg yolk, and turpentine, which were either heated in cold weather or cooled in warm weather to maintain temperature. This was done to produce optimal wound healing. The major improvements and overall advancement in anesthesia for neurosurgery occurred in the latter half of the 18th century. The discovery of carbon dioxide, hydrogen, and nitrogen along with experiments by Priestly and others using several gases including oxygen and nitrous oxide created interest in the use of these agents to support patients who were sedated or anesthetized for procedures.8 However, the reluctance of surgeons to perform cranial operations slowed the implementation of anesthesia for neurosurgery. Nevertheless, the accumulation of knowledge of functional neuroanatomy, establishment of concepts of asepsis, and the discovery of general anesthesia all moved the process of neurosurgery accompanied by anesthesia forward. William Macewen was the first neurosurgeon to excise a brain tumor under endotracheal intubation. He was the first to show the necessity of controlling the airway and ventilation during craniotomy. At the beginning of the 20th century there was a great deal of controversy as to what was the best inhalational anesthetic, chloroform, or either. Victor Horsley performed a series of experiments in animals in 1883–85 and concluded that, although ether was the safer drug, it was not to be recommended in favor of chloroform because it produced a rise in blood pressure and an FIGURE 2 The Edwin Smith Papyrus. The terms of brain, as original term “iesh,” pointed by an arrow (and depicted below) can be seen. From James Henry Breasted. The Edwin Smith Surgical Papyrus. Chicago: University Chicago Press; 1930 (reproduced from Eric R Kandel, James H Schwartz, Thomas M Jessell, editors Principles of Neural Science. 4th ed. New York: McGraw-Hill; 2000). FIGURE 1 The trephined skulls discovered in paracus, Peru (≈500 BC), and obsidian blades. The surgical holes are covered with roles of cotton dressing (A). The trepanation had been performed using obsidian blade (B).
  • 28. INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxvii increase in blood viscosity with a potential for hemorrhage.9 He also noted a propensity for postoperative vomiting and concluded it should not be used for neurosurgery. Also, since morphine constricted blood flow, he suggested that a combination of morphine and chloroform be used. He subsequently abandoned morphine use because of its recognized depressant effect on respiration.9 Death related to the administration of chloroform was not uncommon, and several commissions were set up to study the effects of the drug. In 1901, The British Medical Association appointed a special chloroform committee to study its use. It was known that approximately 2% chloroform vapor in air was sufficient to induce anesthesia with much less required for maintenance. Some believed that the concentration should be strictly controlled with a vapor- izer, while others thought it could be administered strictly by sprinkling onto a cloth. Horsley was of the opinion that the concentration should be controlled and used a vaporizer designed by Vernon Harcourt, which delivered chloroform at a 2% maximum (Fig. 3). In patients undergoing craniotomy, Horsley felt that chloroform administra- tion should be reduced to 0.5% once the bone flap was removed.10 Determination of concentration was particularly important in patients with raised intracranial pressure (ICP) since higher concentrations in these patients could be fatal. Horsley also contributed to neuroscience and neurosurgery by his support and defense of surgery done on ani- mals for scientific research and to advance clinical knowledge. His work and testimony against the Anti-Vivisection Society helped to defend the use of animal models to advance neurosurgery.11 Around the same time, the use of local anesthesia began to gain prominence. Cocaine had been formally discov- ered in 1860 and was introduced in surgery in 1884. Procaine was first synthesized in 1905 and immediately became commonplace among surgical anesthesia. Most neurosurgeons used local anesthetics selectively. However, in 1913 deMartel popularized its use, and it became common practice for use in all craniotomies. By 1917, Harvey Cushing, considered the founder of neurosurgery, recommended the use of local anesthesia for all neurosurgical cases.7 Besides being one of the leading neurosurgeons of the early 20th century, Cushing introduced numerous new methods of anesthesiology. His first contracts in providing anesthesia were not entirely successful. He had several notable patient deaths while providing ether for procedural anesthesia. In all instances, he was told the deaths occurred due to the patient’s condition, but he remained unconvinced that adverse reactions to anesthesia were due only to the condition of the patients. At the coaxing of Dr. F. B. Harrington, Cushing and fellow student Amory Codman tried to determine who gave the best anesthetics. To make the decision objective, they documented their anesthesia in the form of “ether charts” (Fig. 4).12 Their most important parameters measured were the pulse rate, FIGURE 3 The Vernon Harcourt vaporizer arranged with a cylinder of compressed oxygen.
  • 29. INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxviii breathing, and temperature of the patients. According to Cushing, “a perfect anesthetic was supposed to be one in which the patient was sufficiently conscious to respond when left in the ward with the nurse and did not sub- sequently vomit.” The use of these either charts was a major step toward improvement in what had been a casual administration of a very dangerous drug. In 1900, Cushing began an extended tour of Europe, and while in Bern, he recognized the association between raised ICP and systemic arterial hypertension.13 While in Padua, Italy, at the Ospidale di St. Matteo, he learned the use of Riva-Rocci’s method of blood pressure measurement (Fig. 5). After returning to Baltimore, he adopted this method of blood pressure measurement into clinical practice. He gave a lecture in 1903 titled, “Considerations of Blood Pressure,” only to have a committee of the Harvard Medical School state that, “the skilled finger was of much greater value clinically for determination of the state of circulation than any pneumatic instrument, and the work should be put aside, as of no significance.” Even though blood pressure monitoring was not supported by thought leaders at that time, Cushing still supported the recording of blood pressure during surgery. He also attached great importance to continuous auscultation of the heart and lungs, a technique he learned from his anesthesiologist, Dr. S. Griffith Davis.14 The precordial auscultation device used a transmitter of the phonendoscope secured by adhe- sive strips over the precordium and was connected with a long tube to the anesthesiologist’s ear. The receiver was held in place by a device similar to a telephone operator’s headgear.15 Cushing remained skeptical about general anesthesia for neurosurgery. Mortality was still high and many of the anesthetics were performed by students. He began to experiment on work started by Halsted with block anesthesia using circumferential cocaine infiltration.16 He popularized the use of several local anesthetic techniques and coined the term “regional anesthesia.” From his first work dealing with regional anesthesia, it was noted that the purpose of administering it was to avoid side effects in patients with full stomachs and to ensure better cardiovascular stability in elderly patients. FIGURE 4 An example of the ether charts made by Cushing.
  • 30. INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxix Dr. Fedor Krause, the founder of German neurosurgery, was exposed to combination morphine–chloroform anes- thesia but was not convinced of its worth for neurosurgery. He felt that controlled hypotension produced by higher concentrations of chloroform alone were beneficial to reduce bleeding.17 He also noted that sudden death could occur in patients with intracranial tumors who stopped breathing. He used the Roth-Drager oxygen–chloroform apparatus which allowed high concentrations of oxygen to be administered. He also noted the brain was insensitive to pain, and only very light planes of anesthesia were needed to perform these surgeries.18 He concluded a good neurosurgical outcome required a rapid aseptic technique, minimal blood loss, normothermia, and general narcosis. During the early 20th century, new delivery systems for anesthesia were being developed. The Junker bottle used a hand bellows to blow air through a vaporizer and the Ombrédanne ether inhaler could be used in the prone posi- tion (Fig. 6). Airway management became less supportive and passive and more active with endotracheal intubation and insufflation of air to maintain oxygenation without ventilation. By 1930, endotracheal anesthesia was recom- mended for neurosurgery. Inhalational anesthetics such as trichloroethylene with nitrous oxide were developed as a neuroanesthetic technique,18 while other physicians such as Hershenson used low concentrations of closed circuit cyclopropane and reported this method in 1942.19 Volwiler and Tabern developed thiopental in 1930 and was introduced into clinical practice 4years later.20 Halothane was synthesized in 1956 and introduced into practice that same year.21 Though popular, its propensity to increase ICP and brain size made it a concern to anesthesiologists and neurosurgeons alike. In 1932, most fluids were given rectally along with a wide variety of anesthetic techniques including ether-based anesthesia, rectal ether in oil, ethylene, and nitrous oxide. Certain large centers began to publish their outcomes for neurosurgical procedures and many included a descrip- tion of the anesthetic techniques used. The Montreal Neurologic Institute showed that of 1000 cases, 700 were per- formed under general anesthesia and 300 with local anesthetics.22 The major concerns were still airway management and fluid replacement. A wide variety of agents were used. However, by 1949 and the early 1950s, pentothal was the induction agent of choice for oral intubation. Throat packing and the use of a nonrebreathing valve to prevent the buildup of carbon dioxide was also common. After World War II, great advances in neuroanesthetic techniques were brought on by the development of new anesthetic agents and advanced knowledge of neurophysiology and pharmacology. Lundy in 1942 noted that in the presence of hypoventilation it was difficult to reduce ICP unless the patient was artificially ventilated.23 The effects of hypoventilation on intracranial and systemic dynamics were further elucidated by Keaty and Schmidt (Fig. 7). They also described methods to measure cerebral blood flow using inhaled N2O.24 Another group used the injection of intraarterial krypton to measure blood flow in the brain and speed of washout.25 The measurement of ICP had been discovered by Cannon in 1901 but continuous ICP measurement was not described until 1960.26 The link between CO2, O2 tension and cerebral blood flow was also developed at this time. Dr. Thomas Langfitt further FIGURE 5 Dr. Harvey Cushing’s sketch of Riva-Rocci’s blood pressure device.
  • 31. INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxx Venous Arterial A-V 1 1 2 3 4 5 Time (minutes) 6 7 8 9 10 N 2 O Conc Vol% 2 3 4 5 FIGURE 7 Kety–Schmidt method of arterial and venous nitrous oxide concentration for calculating cerebral blood flow. FIGURE 6 (A) Ombrédanne inhaler. (B) Ombrédanne inhaler in use.
  • 32. INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxxi defined intracranial dynamics based on previous work and developed the pressure volume curves along with the concept of intracranial compliance.27 Three major anesthesia groups contributed to the development of the specialty, the Glascow Group, Pennsylvania Group, and the Mayo Clinic Group. All the three centers were considered think tanks in the development of neuro- anesthetic principles and techniques to help improve intracranial surgery. Most of the principles for neuroanesthesia have been developed over the last 70years. The term, “neuroanesthesia” was coined by John Michenfelder from the Mayo Clinic.28 In the 1960s, researchers at the University of Pennsylvania studied the cerebral effects of nitrous oxide, cyclopro- pane, halothane, enflurane, hypotension, and hyperventilation.29–31 These studies formed many of the basics for neu- roanesthesia principles today. At the same time, researchers at the University of Glascow studied anesthetic effects on intracranial dynamics. This group was one of the first to confirm that anesthetic agents did indeed exert a measur- able effect on cerebral blood flow and metabolism in patients with intracranial mass lesions.32,33 It was some of these studies that were used to justify the abandonment of the use of halothane because of its vasodilating properties, espe- cially in patients with mass lesions in the brain. At the Mayo Clinic the only emphasis of research by Michenfelder was of providing cerebral protection, especially with hypothermia during neurovascular procedures. These same three centers continued to expand their influence in neuroanesthesia, and at the University of Pennsylvania the role of the neuroanesthesiologist was expanded to the intensive care unit. In the 1980s, research continued on glucose control and again on the effects of modest hypothermia. A wide range of drugs emerged as possible cerebral protective agents. A much clearer understanding of pathways involved in cell damage was also achieved. Research on brain trauma and survival also became important because of the effects of war on traumatic brain injury. Despite much of this research, the morbidity and mortality from subarachnoid hemorrhage, stroke, trauma, and neoplastic lesions have remained largely unchanged in the past several decades. Nevertheless, neuroanesthesia practice has appreciably changed over the past few decades. Hyperventilation has long been known to reduce ICP. At the beginning of the 1990s it was widely held that this had therapeutic value for intracranial procedures. However, with the use of oximetric pulmonary artery catheters, investigators have been able to do retrograde cannulation of the jugular vein up to the bulb to examine venous Hb saturation in response to therapeutic hyperventilation in head trauma patients. In some patients, this hyperventila- tion resulted in increased hypoxia that has resulted in abandonment of hyperventilation unless surgical conditions dictate. However, other recent studies have demonstrated that hyperventilation, especially for supratentorial brain tumors, was associated with reduced ICP and a 45% reduction in brain bulk, once again demonstrating its worth, especially with supratentorial surgery.34 The early 1990s also demonstrated a surge of new anesthetic techniques and drugs. Both desflurane and sevoflu- rane were introduced and were found to have cerebral metabolic properties similar to isoflurane. However, some questions still remain regarding desflurane causing an insidious increase in ICP. There are also questions concerning the metabolism of sevoflurane and possible renal toxicity, especially with the effect of anticonvulsants on hepatic function. Since both drugs have been accepted and widely used as neuroanesthetics, these concerns do not seem to hold major importance. Remifentanil was also introduced in the 1990s and was found to be essentially identical to other opioids with respect to µ-opioid agonist-mediated events. It does have a much more rapid and predictable emergence compared to other opioid-based techniques. However, the drug produces hypertension and tachycardia with increased sympathetic activity during emergence which could be especially problematic with large tumor resec- tions where hemodynamic stability during emergence to prevent bleeding is imperative. The administration of proper IV fluids and correct fluid replacement therapy was better developed in the 1990s. There was a widespread acceptance that glucose-containing solutions were not essential in patients undergoing neurosurgical procedures. Perioperative glycemic control is one of the important topics that have been investigated in the 1980s and 1990s. Hyperglycemia in ischemic conditions has been proven to be detrimental, and strict control of plasma glucose has been shown to produce better outcomes in critically ill patients. Many studies have demon- strated that plasma glucose levels are well maintained at close to normal ranges with nonglucose-containing solu- tions, while patients who received glucose had high plasma levels which fluctuated dramatically during their care. Therefore, routine use of glucose-containing solutions should be avoided during neurosurgery. The use of crystalloid solutions has also been altered by studies from the last 20years. In the 1980s it remained a standard practice to dehydrate patients with intracranial pathology under the assumption that brain volume would be decreased. This was often performed at the expense of stable hemodynamics and cerebral perfusion pressure. However, extensive studies have demonstrated that fluid restriction for neurosurgical procedures may be detrimen- tal. In addition, many large trials evaluating colloid versus crystalloid solutions, especially with trauma-related injury, showed that saline resuscitation may be of greater benefit than treatment with albumin. In fact, studies demonstrated
  • 33. INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxxii a detrimental effect of albumin treatment, especially with the relative risk of death within 24months.35 This has led to a recommendation that colloids not be used for resuscitation in patients with brain injury. The early 1990s also provided consistent evidence that small changes in brain temperature could have a major impact on outcome from ischemic or traumatic brain injury.36 These changes did not require overt cooling or the use of extracorporeal perfusions but were well within the range of routine manipulation by anesthesiologists. The prac- tice of the use of mild hypothermia increased, but there were other warnings about inadvertent hypothermia from other patient populations, which caused concerns. In the late 1990s, a multinational consortium of investigators was formed to examine the risks and benefits of mild hypothermia in patients undergoing aneurysm clipping and was inconclusive as to the benefit of hypothermia on survival and outcome after a neurologic event producing ischemia. Based on clinical data, mild hypothermia may still have beneficial effects in patients with good grade subarachnoid hemorrhage (SAH).37 The latest American Heart Association and American Stroke Association guidelines for the management of aneurysmal SAH recommend induced hypothermia as a reasonable option in selected cases.38 At the clinical level, no progress has been made in pharmacologic neuroprotection. Despite successful experi- mental studies, by far no anesthetic technique has been convincingly shown to provide profound neuroprotection in humans. Barbiturates remain the gold standard, although clinical evidence of efficacy from this class of compounds is suspected on methodologic grounds. In a post hoc analysis of IHAST (intraoperative hypothermia for aneurysm surgery trial) data administration of thiopentanil or etomidate was not found to have a demonstrable effect on postoperative neurological outcomes in patients undergoing temporary clipping.39 Use of etomidate has waned as a neuroprotective agent as a result of absence of clinical evidence of benefit in both clinical and laboratory studies. Some of the most exciting and important clinical advances in neuroanesthesia have been in the area of monitor- ing, both in the operating room and neurointensive care units. With the advancement of near-infrared spectros- copy (NIRS) and transcranial Doppler, the detection of cerebral ischemia, especially under general anesthesia, has improved tremendously. Multimodal intraoperative monitoring of spinal cord sensory and motor function during surgical correction of adult spinal deformity is feasible and provides useful neurophysiological data with an overall sensitivity of 100% and specificity of 84.3%.40 In the neurointensive care unit, insertion of microdialysis and multipa- rameter biochemical probes into traumatized human brains has confirmed findings. Cytokine production and pro- apoptotic markers have been detected during oxidative stress, and these markers have recovered during enhanced perfusion. Ischemic events have been associated with tissue acidosis, and spontaneous depolarizations have been observed. Use of these monitors in the operating room has occurred. What remains to be totally defined is what val- ues constitute thresholds for interventions. These thresholds have been characterized mostly for NIRS monitoring, and much of this has revolutionized the treatment of patients with the possibility of cerebral hypoperfusion. The development of neuroanesthesia has paralleled advances in neurosurgery. As techniques and procedures have become advanced, so have the techniques and protocols to anesthetize and monitor neurologic function. The overall goal is to provide a good surgical outcome and better quality of life. Procedures will become less invasive with more functional neurosurgery requiring a cooperative patient. This makes the anesthetic management for these procedures even more complex. It is also likely that there will be greater integration of neurosurgery and neuroradi- ology, with greater emphasis on maintaining cerebral vascular function without the effects of inhalational anesthet- ics and opioids. Neurosurgery is ever evolving; the practice of anesthesiology for these procedures will also have to evolve to accommodate the demands of the surgeon and improve patient outcomes. Neuroanesthesia practice will shadow neurosurgical breakthroughs. These changes will accelerate over the next 10years as scientific advances, and the understanding of the diseases we treat enhance the capacity of the anesthesiologist to develop techniques to provide an ideal surgical environment with rapid awakening to assess neurologic function. References 1. Hippocrates on injuries of the head [Adams F, Trans.]. London: The Genuine Works of Hippocrates, in 2 vols.; 1849. 2. Frost EAM. A history of neuroanesthesia. In: Eger E, Saidman LJ, Westhope RN, editors. The wondrous story of anesthesia. New York: Springer; 2014. p. 871–85. 3. Gunther RT. Dioscorides Pedanius. The greek herbal of dioscorides. Oxford: Oxford University Press; 1934. 4. Cooper A. Lectures on the principles and practice of surgery. London: Westley; 1829. 5. Raper HR. Man against pain: the epic of anesthesia. New York: Prentice-Hall; 1945. p. 8. 6. Robinson V. Victory over pain: a history of anesthesia. New York: Henry Schumann; 1945. p. 29. 7. Walker AE. A history of neurological surgery. New York: Hafner; 1967. 8. Priestley J. Experiments and observations on different kinds of air. London: Thomas Pearson; 1790. 9. Horsley V. On the technique of operations on the central nervous system. BMJ 1906;2:411–23. 10. Horsley V. On the technique of operations on the central nervous system. Address in Surgery. Toronto Lancet 1906;2:484.
  • 34. INTRODUCTION AND BRIEF HISTORY OF NEUROANESTHESIA xxxiii 11. Lyons JB. Citizen surgeon. London: Peter Downay; 1966. 12. Beecher HK. The first anesthesia records (Codman Cushing). Surg Gynecol Obstet 1940;71:689. 13. Cushing HW. Concerning a definitive regulatory mechanism of the vasomotor center which controls blood pressure during cerebral compres- sion. Bull Johns Hopkins Hosp 1901;12:290. 14. Cushing HW. Some principles of cerebral surgery. JAMA 1909;52:184. 15. Shephard DA. Harvey Cushing and anesthesia. Can Anaesth Soc J 1965;12:431–2. 16. Halsted WS. Surgical papers. Baltimore: Johns Hopkins Press; 1924. p. 167. 17. Krause F. [Haubold H, Thorek M, Trans.]. Surgery of the brain and spinal cord based on personal experiences, vol. 1. New York: Rebman & Co.; 1912. p. 137. 18. Jackson DE. A study of analgesia and anesthesia with special reference to such substances as trichloroethylene and vinesthene together with apparatus for their administration. Anesth Analg (Curr Res) 1934;13:198. 19. Hershenson BB. Some observations on anesthesia for neurosurgery. NY State J Med 1942;42:2111. 20. Lundy JS. Intravenous anesthesia: preliminary report of the use of two new thiobarbiturates. Mayo Clin Proc 1935;10:536. 21. Johnstone M. The human cardiovascular response to flurothane anaesthesia. Br J Anesth 1956;28:392. 22. Stephen CR, Pasquet A. Anesthesia for neurosurgical procedures. Analysis of 1000 cases. Anesth Analg 1949;28:77. 23. Lundy JS. Clinical anesthesia. Philadelphia: WB Saunders; 1942. p. 3. 24. Kety SS, Schmidt CF. Determination of cerebral blood flow in man by the use of nitrous oxide in low concentrations. Am J Physiol 1945;143:53. 25. Lassen NA, Ingvar DH. The blood flow of the cerebral cortex determined by radioactive krypton. Experientia 1961;17:42. 26. Lundberg N. Continuous recording and control of ventricular fluid pressure in neurosurgical practice. Acta Psychiatr Neurol Scand 1960;36 (Suppl. 149). 27. Langfitt TW. Increased intracranial pressure. Clin Neurosurg 1969;16:438. 28. Michenfelder JD, Gronert VA, Rehder K. Neuroanesthesia. Anesthesiology 1969;30:65–100. 29. Alexander SC, Wollman H, Cohen PJ, Chase PE, Behar M. Cerebral vascular responses to PaCO2 during halothane anesthesia in man. J Appl Physiol 1964;19:561. 30. Smith AL, Wollman J. Cerebral blood flow and metabolism: Effects of anesthetic drugs and techniques. Anesthesiology 1972;36:378. 31. Pierce Jr EC, Lambertsen CJ, Deutsch S, Chase PE, Linde HW, Dripps RD, et al. Cerebral circulation and metabolism during thiopental anes- thesia and hyperventilation in man. J Clin Invest 1962;41:1664. 32. Okuda Y, McDowall DG, Ali MM, Lane JR. Changes in CO2 responsiveness and in autoregulation of the cerebral circulation during and after halothane induced hypotension. J Neurol Neurosurg Psychiatry 1972;39:221. 33. Harper AM, Bell RA. The effect of metabolic acidosis and alkalosis on the blood flow through the cerebral cortex. J Neurol Neurosurg Psychiatry 1963;26:341. 34. Gelb AW, Craen RA, Rao GS, Reddy KR, Megvesi J, Mohanty B, et al. Does hyperventilation improve operating condition during supratento- rial craniotomy? A multicenter randomized crossover trial. Anesth Analg 2008;106:585–94. 35. SAFE Study Investigators, Australian and New Zealand Intensive Care Society Clinical Trials Group, Australian Red Cross Blood Service, George Institute for International Health, Myburgh J, Cooper DJ, Finfer S, Bellomo R, Norton R, Bishop N, et al. Saline or albumin for fluid resuscitation in patients with traumatic brain injury. N Engl J Med 2007;357:874–84. 36. Clifton GL, Valadka A, Zygun D, Coffey CS, Drever P, Fourwinds S, et al. Very early hypothermia induction in patients with severe brain injury (the National Acute Brain Injury Study: Hypothermia II): a randomized trial. Lancet Neurol 2011;10:131–9. 37. Li LR, You C, Chaudhary B. Intraoperative mild hypothermia for postoperative neurological deficits in intracranial aneurysm patients. Cochrane Database Syst Rev 2012;2:CD008–445. 38. Connolly Jr ES, Rabinstein AA, Carhuapoma JR, Derdeyn CP, Dion J, Higashida RT, et al. Guidelines for the management of aneurysmal subarachnoid hemorrhage: a guideline for healthcare professionals from the American Heart Association. Stroke 2012;43:1711–37. 39. Hindman BJ, Bayman EO, Pfisterer WK, Torner JC, Todd MM. IHAST Investigators. No association between intraoperative hypothermia of supplemental protective drug and neurologic outcomes in patients undergoing temporary clipping during cerebral aneurysm surgery: find- ings from the intraoperative hypothermia for aneurysm surgery trial. Anesthesiology 2010;112(1):86–101. 40. Quraishi NA, Lewis SJ, Kelleher MO, Sarjeant R, Rampersaud UR, Fehlings MG. Intraoperative multimodality monitoring in adult spinal deformity: analysis of a prospective series of one hundred two cases with independent evaluation. Spine (Phil PA 1976) 2009;34:1504–12.
  • 36. S E C T I O N I NEUROANATOMY
  • 38. Essentials of Neuroanesthesia http://dx.doi.org/10.1016/B978-0-12-805299-0.00001-4 © 2017 Elsevier Inc. All rights reserved. 3 O U T L I N E Introduction 3 Embryological Differentiation of Different Parts of Brain 4 Anatomy of Brain 4 Cerebrum 4 Frontal Lobe 6 Temporal Lobes 6 Parietal Lobe 7 Functional Areas (of Cerebral Cortex) 8 Premotor Area 10 Sensory Areas 10 Visual Area 11 Acoustic (Auditory) Area 11 Association Areas 11 Diencephalon 11 The Thalamus 11 Hypothalamus 13 Epithalamus 15 Habenular Nucleus 15 Afferent Fibers 16 Efferent Fibers 16 Nucleus Subthalamicus 16 Zona Incerta 16 Basal Ganglia 16 Internal Capsule 17 White Matter 18 Corpus Callosum 19 Ventricular System 19 Lateral Ventricles 20 Third Ventricle 21 Fourth Ventricle 22 Limbic System 22 Midbrain (Mesencephalon) 23 Pons 25 Medulla 26 Reticular Formation 29 Cerebellum 29 Vascular Supply of the Brain 30 Arterial System 30 Cerebral Venous System 32 The Meninges and Cerebrospinal Fluid 33 The Meninges 33 Dura Mater 33 The Spinal Cord 34 Ascending Tracts of Spinal Cord (Sensory Tracts) 36 Acknowledgment 39 References 40 C H A P T E R 1 Neuroanatomy D. Gupta Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India INTRODUCTION Why should a well-established neuroanesthetist study clinical neuroanatomy? This question, albeit a vexing one, is very pertinent in the present day scenario. The answer is evident. A tower of knowledge built on broad and diverse information helps one to prepare for all the eventualities that one may encounter. Anatomy is the basis of every procedure that we perform. An anesthetist who embarks on a new journey into the anatomical
  • 39. 1. NEUROANATOMY 4 I. NEUROANATOMY basis of his or her clinical practice has adapted well to a vista that emphasizes fundamental sciences as the basis of all medical education. It helps the person improve his or her procedural skills. Finally, it helps him or her to be better equipped to deal with a changing and unpredictable world where knowledge empowers and also acts as a haven of safety. About 100 billion neurons and 10–50 trillion neuroglias make up the brain, which has a mass of about 1300– 1500 g in adult. On average each neuron forms 1000 synapses with other neurons1. The total number of syn- apses, about 1000 trillion, is larger than the number of stars in the galaxy. The central nervous system (CNS) included the brain and the spinal cord and is composed of (1) cerebral hemisphere, (2) diencephalon, (3) basal ganglion, (4) midbrain, (5) pons, (6) medulla, (7) cerebellum, and (8) spinal cord. This chapter will provide information of these parts individually, that is integrated, informative, and relevant to educational need of the neuroanesthesiologists. EMBRYOLOGICAL DIFFERENTIATION OF DIFFERENT PARTS OF BRAIN Knowledge of the embryological development of the brain is necessary to understand the terminology used for the principal part of the adult brain. The development of the brain is dealt with details in the following chapter. ANATOMY OF BRAIN Cerebrum The cerebrum consists of two cerebral hemispheres that are partially connected with each other by corpus cal- losum. Each hemisphere contains a cavity called the lateral ventricle. The cerebrum is arbitrarily divided into five lobes: frontal, parietal, temporal, occipital, and insula.2 On the lateral surface three sulci (central, lateral or Sylvian, and parietooccipital sulci) and two imaginary lines divide the cerebrum into four lobes (Fig. 1.1). The first imaginary line (lateral parietotemporal line) is drawn from parietooccipital sulcus to preoccipital notch and second (temporo- occipital line) backward continuation of posterior ramus of lateral sulcus before it turns upward to meet first line. The central sulcus and posterior ramus of Sylvian fissure (SF) separate frontal lobe from parietal lobe and temporal lobe. Posteriorly parietooccipital sulcus and lateral parietotemporal line separate occipital lobe from parietal lobe and temporal lobe. Temporal and parietal lobes are separate by posterior ramus of SF and temporo-occipital line (Fig. 1.1). The cerebral cortex is the outermost sheet of neural tissue of the cerebrum whereas white matter lies in the center. Cerebral cortex is folded into sulci and gyri, which actually increases the surface area of cortex. Sulci include the central lateral and parietooccipital. The central sulcus begins by cutting the superomedial border of the hemisphere a little behind the midpoint between the frontal and parietal lobe. It runs on the superolateral surface obliquely downward and forward for about 8–10cm and ends a slight above the posterior ramus of lateral sulcus. It separates precentral gyrus (motor area) from postcen- tral gyrus (sensory area) (Figs. 1.2 and 1.3). It was originally called the fissure of Rolando or the Rolandic fissure. FIGURE 1.1 Schematic diagram of lateral aspect of left cerebral hemisphere. Line 1. Lateral parietotemporal line; Line 2. Temporooccipital line.
  • 40. ANATOMY OF BRAIN 5 I. NEUROANATOMY FIGURE 1.2 Brain anatomy. Superior view. 1. Longitudinal fissure of cerebrum. 2. Frontal pole. 3. Superior margin of cerebrum. 4. Superior frontal sulcus. 5. Inferior frontal sulcus. 6. Precentral sulcus. 7. Central sulcus. 8. Postcentral sulcus. 9. Intraparietal sulcus. 10. Parietooccipital sulcus. 11. Transverse occipital sulcus. 12. Occipital pole. 13. Superior parietal lobule. 14. Inferior parietal lobule. 15. Paracentral lobule. 16. Postcentral gyrus. 17. Precentral gyrus. 18. Inferior frontal gyrus. 19. Middle frontal gyrus. 20. Superior frontal gyrus. FIGURE 1.3 Brain anatomy. Lateral view of right hemisphere. 1. Central sulcus. 2. Precentral sulcus. 3. Precentral gyrus. 4. Superior frontal gyrus. 5. Superior frontal sulci. 6. Middle frontal gyrus. 7. Middle frontal sulcus. 8. Frontal pole. 9. Orbital gyri. 10. Olfactory bulb. 11. Olfactory tract. 12. Anterior ramus of lateral sulcus (Sylvian fissure (SF)). 13. Frontal operculum. 14. Ascending ramus lateral sulcus (SF). 15. Frontoparietal operculum. 16. Posterior ramus lateral sulcus (SF). 17. Superior temporal gyrus. 18. Middle temporal gyrus. 19. Superior temporal sulcus. 20. Inferior temporal sulcus. 21. Inferior temporal gyrus. 22. Pons. 23. Pyramid (medulla oblongata). 24. Olive. 25. Flocculus. 26. Cerebellar hemi- sphere. 27. Preoccipital notch. 28. Occipital pole. 29. Postcentral gyrus. 30. Supramarginal gyrus. 31. Angular gyrus. 32. Transverse occipital sulcus. 33. Inferior parietal lobule. 34. Intraparietal sulcus. 35. Superior parietal lobule. 36. Postcentral sulcus.
  • 41. 1. NEUROANATOMY 6 I. NEUROANATOMY The lateral sulcus or Sylvian fissure (SF) is one of the earliest-developing sulci of the human brain. It first appears around the 14th gestational week.3 It is the deepest and most prominent of the cortical sulci. The lateral sulcus (SF) separates frontal and parietal lobes from temporal lobe. It begins on the superomedial margin. The SF starts on basal and extends to the lateral surface of the brain. It has both a superficial part and a deep part. Superficial part has a stem and three rami (Figs. 1.2 and 1.3). The anterior portion of the deep part (Sylvian cistern) is called the sphenoidal compartment and the posterior part is called the operculoinsular compartment. SF is an important corridor in neu- rosurgery as it connects the surface of anterior part of brain to its depth with all the neural and vascular components along the way. The structures within the reach through the Transylvian approach include middle cerebral artery; optic nerves; internal carotid artery; and its branched lamina terminalis, insula, basal ganglia, and interpeduncular fossa. Parietooccipital sulcus begins on the medial surface of hemisphere nearly 5cm in front of the occipital pole (Fig. 1.4). The upper end of the sulcus reaches the superomedial border to meet the calcarine sulcus, and a small part of it is seen on the superolateral surface. Frontal Lobe The frontal lobe is an area in the brain of mammals, located at the front of each cerebral hemisphere and positioned anterior to (in front of) the parietal lobe and superior and anterior to the temporal lobes. A prefrontal sulcus runs downward and forward parallel to the central sulcus. The area between it and central sulcus is the precentral gyrus. Two sulcus run horizontally anterior to precentral gyrus, i.e., superior and inferior frontal sulcus and divide the region into superior, middle, and inferior frontal gyri (Fig. 1.3). The frontal lobe contains most of the dopamine-sensitive neurons in the cerebral cortex associated with reward, attention, short-term memory tasks, planning, and motivation. Temporal Lobes Temporal lobes are bounded by SF superiorly and temporo-occipital and lateral parietotemporal line posteriorly (Fig. 1.3). The temporal lobe has two sulci, superior and inferior, that run parallel to the posterior ramus of the lateral sulcus and divide superiolateral surface into superior, middle, and inferior temporal gyri (Fig. 1.3). The temporal lobes are involved in the retention of visual memories, processing sensory input, comprehending language, storing new memories, emotion, and deriving meaning.4 FIGURE 1.4 Brain surface anatomy, view of medial surface of right hemisphere. 1. Frontal pole of frontal lobe. 2. Medial frontal gyrus. 3. Cingulate sulcus. 4. Sulcus of corpus callosum. 5. Cingulate gyrus. 6. Paracentral lobule. 7. Precuneus. 8. Subparietal sulcus. 9. Parietooccipital sulcus. 10. Cuneus. 11. Calcarine fissure. 12. Occipital pole of occipital lobe. 13–16. Corpus callosum (cut surface). (Parts of Corpus callosum 13. Splenium. 14. Trunk. 15. Genu. 16. Rostrum.). 17. Lamina terminalis. 18. Anterior commissure. 19. Septum pellucidum. 20. Fornix. 21. Tela choroidea of the third ventricle. 22. Choroid plexus of the third ventricle. 23. Transverse cerebral fissure. 24. Thalamus. 25. Interthalamic adhesion. 26. Interventricle foramen of Monro. 27. Hypothalamus. 28. Suprapineal recess and pineal body. 29. Vermis of cerebellum. 30. Cerebral hemisphere. 31. Choroid plexus of the fourth ventricle. 32. Medulla oblongata. 33. Pons. 34. Fourth ventricle. 35. Tectal lamina and mesencephalic aqueduct of Sylvius. 36. Mammillary body. 37. Oculomotor nerve. 38. Infundibular recess. 39. Temporal lobe of lateral occipitotemporal gyrus. 40. Rhinal fissure. 41. Hypophysis with adeno- hypophysis (anterior lobe) and neurohypophysis (posterior lobe) of pituitary gland. 42. Optic chiasma. 43. Optic nerve. 44. Olfactory bulb and tract.
  • 42. ANATOMY OF BRAIN 7 I. NEUROANATOMY Parietal Lobe The parietal lobe is positioned superior to the occipital lobe and posterior to the frontal lobe. The parietal lobe is bounded anteriorly by central sulcus, inferiorly by SF and temporo-occipital line, medially by interhemispheric fissure, and posteriorly by parietotemporal line. The two main sulci are postcentral sulcus, which run downward and forward parallel to central sulcus, and intraparietal sulci, which are directed posteriorly and inferiorly toward occipital pole. Thus divide the parietal lobe into postcentral gyrus, superior parietal lobule, and inferior parietal lobule (Fig. 1.3). The upturn posterior end of the posterior ramus of lateral sulcus or SF extends into inferior parietal lobule, also superior and inferior temporal sulci turn upward to enter into this lobule and constitute supramarginal, angular gyri, and arcus temporo-occipitalis (Fig. 1.3). The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the dorsal stream of the visual system. This enables regions of the parietal cortex to map objects perceived visually into body coordinate positions. Several por- tions of the parietal lobe are important in language processing. Just posterior to the central sulcus lies the postcentral gyrus. This area of the cortex is responsible for somatosensation.5 The occipital lobule occupies space behind the lateral parietotemporal line. It has a number of short lobules divided by short sulci. A horizontal sulci, lateral to occipital sulcus divides the lobe into superior and inferior occipi- tal gyri (Fig. 1.3). A vertical strip anterior to curved lunate sulcus is the gyrus descendens. The transverse occipital sulcus is located in the uppermost part of the occipital lobe. A strip superiolateral to this sulcus is arcus parietooc- cipitalis. The occipital lobe is the visual processing center of the brain containing most of the anatomical region of the visual cortex.6 Insula is a portion of the cerebral cortex folded deep within the lateral sulcus. This area grows less than its sur- rounding areas during development and thus lies deep and not seen from surface view (Fig. 1.5). The surrounding cortical areas are called opercula such as frontal opercula, frontoparietal opercula, and temporal opercula. The insula are believed to be involved in consciousness and play a role in diverse functions usually associated to emotion or the regulation of the body’s homeostasis. These functions include perception, self-awareness, cognitive functioning, and interpersonal experience. Two hemispheres are attached with each other by corpus callosum. On the medial surface above the corpus cal- losum there are many sulci and gyri (Fig. 1.4). The most prominent sulcus is the cingulate sulcus, which follows the curve course parallel of corpus callosum. The area between the cingulate sulcus and corpus callosum is the gyrus cinguli. Above the cingulate sulcus, large anterior part is medial frontal gyrus and posteriorly paracentral lobule (Fig. 1.4). Behind the paracentral lobule, two major sulci, parietooccipital sulcus and calcarine sulcus, cut the area into a triangular area called the cuneus. Between parietooccipital sulcus and paracentral lobule, a quadrangular area is called precuneus, which is anteriorly separated from gyrus cinguli by suprasplenial sulcus. FIGURE 1.5 Coronal section through the brain. 1. Longitudinal fissure of the cerebrum. 2. Cingulate sulcus. 3. Cingulate gyrus. 4. Corpus callosum. 5. Sulcus of corpus callosum. 6. Caudate nucleus. 7. Claustrum. 8. Putamen. 9. Lateral sulcus (Sylvian fissure). 10. Globus pallidus. 11. Thalamus. 12. Subthalamic nucleus. 13. Mammillary body. 14. Amygdala. 15. Optic tract. 16. Third ventricle and choroid plexus. 17. Body of fornix. 18. Lateral ventricle and choroid plexus. 19. Cortex of insula. 6, 8, and 10. Corpus striatum. 8 and 10. Lentiform nucleus.
  • 43. 1. NEUROANATOMY 8 I. NEUROANATOMY The majority of the space of cerebral hemisphere deep to the cortex is full of the white matter. There are some important structures that are embedded within the white matter. On coronal section the corpus callosum is seen as a strip connecting both the hemispheres (Fig. 1.5). Third ventricle is situated in midline just below corpus callosum. Thalamus and hypothalamus, which are derived from diencephalon, lie adjacent to lateral wall of the third ventricle. Caudate nucleus is situated above and lateral to thalamus. Another gray matter mass lentiform nucleus lies more lateral and just deep to insula. There is a strip of gray matter between insula and lentiform nucleus called claustrum (Fig. 1.5). The caudate nucleus, lentiform nucleus, claustrum along with some other gray matter nucleus are (derived from telencephalon) collectively mentioned as basal nuclei or basal ganglia. There is a white matter, an internal cap- sule that lies between thalamus and lentiform nucleus (Fig. 1.5). The white matter that radiates from the upper part of internal capsule to the cortex is called corona radiate. Functional Areas (of Cerebral Cortex) Korbinian Brodmann was a German neurologist who studied the brain in the early part of the 20th century.7 Brodmann originally defined and numbered (from 1 to 52) different areas of cerebral cortex based on cytoarchitecture or how the cells were functionally organized (Box 1.1). Brodmann areas have been discussed, debated, refined, and renamed exhaustively for nearly a century and remain the most widely used and frequently cited cytoarchitectural organization of the human cortex.8 On the basis of function, regions of the cerebral cortex are divided into three functional categories of areas (Fig. 1.6). (1) Primary sensory areas, which receive signals from the sensory nerves and tracts by way of relay nuclei in the thalamus. Primary sensory areas include the somatosensory cortex in the parietal lobe, visual area of the occipital lobe, and the auditory area in parts of the temporal lobe and insular cortex. (2) Primary BOX 1.1 I M P O RTA N T B R O D M A N N A R E A S Frontal lobe contains areas that Brodmann identified as involved in cognitive functioning and in speech and language (Fig. 1.8). t Area 4 corresponds to the precentral gyrus or primary motor area. t Area 6 is the premotor or supplemental motor area. t Area 8 is anterior of the premotor cortex. It facilitates eye movements and is involved in visual reflexes as well as pupil dilation and constriction. t Areas 9, 10, and 11 are anterior to area 8. They are involved in cognitive processes such as reasoning and judgment which may be collectively called biological intelligence. t Area 44 is Broca’s area. Parietal lobe plays a role in somatosensory processes (Fig. 1.8). t Areas 3, 2, and 1 are located on the primary sensory strip, with area 3 being superior to the other two. These are somastosthetic areas, meaning that they are the primary sensory areas for touch and kinesthesia. t Areas 5, 7, and 40 are found posterior to the primary sensory strip and correspond to the presensory to sensory association areas. t Area 39 is the angular gyrus. Temporal lobe: Areas that are involved in the process- ing of auditory information and semantics as well as the appreciation of smell (Fig. 1.8). t Area 41 is the primary auditory area. t Area 42 is immediately inferior to area 41 and also involved in the detection and recognition of speech. The processing done in this area of the cortex provides a more detailed analysis than that done in area 41. t Areas 21 and 22 are the auditory association areas. Both areas are divided into two parts; one half of each area lies on either side of area 42. t Area 37 is found on the posterior–inferior part of the temporal lobe. Occipital lobe contains areas that process visual stimuli (Fig. 1.8). t Area 17 is the primary visual area. t Areas 18 and 19 are the secondary visual areas.
  • 44. ANATOMY OF BRAIN 9 I. NEUROANATOMY motor cortex, which sends axons down to motor neurons in the brain stem and spinal cord and finally inner- vate voluntary skeletal muscles; (3) remaining parts of the cortex, which are called the association areas. These areas receive input from the sensory areas and lower parts of the brain which integrate sensory information with emotional states, memories, learning, and rational thought processes that we call perception, thought, and decision-making. Motor areas—The motor area is classically located in precentral gyrus on the superiolateral surface of the hemi- sphere and in anterior part of paracentral lobule. It is shaped like a pair of headphones stretching from ear to ear (Fig. 1.6). Specific area within the motor cortex controls voluntary muscle activity on the opposite part of body. The body is represented on the motor strip in an upside–down fashion (Fig. 1.7). The lower parts of the body, such as the FIGURE 1.6 Traditional concept of functional areas on the superolateral aspect of the cerebral hemisphere (left sided). FIGURE 1.7 The motor homunculus in primary motor cortex. Coronal section anterior view of the left hemisphere.
  • 45. 1. NEUROANATOMY 10 I. NEUROANATOMY feet and the legs, receive motor movement commands from the superior part of the precentral gyrus (motor strip). Parts of the face, on the other hand are innervated by the inferior part of the motor strip. The motor strip extends down some distance into the longitudinal cerebral fissure. The portion inside this fissure is its medial aspect. The part on the lateral surface of the hemisphere is called its lateral aspect. The medial cortex controls the movements of the body from the hips on down while the lateral aspect sends commands to the upper body including the larynx, face, hands, shoulders, and trunk (Fig. 1.7). The medial and lateral aspects of the motor strip have different blood supplies. Blood comes to the medial area from the anterior cerebral artery while the lateral cortex is supplied by the middle cerebral artery. Premotor Area There is supplementary motor area on and above the superior part of cingulate sulcus on the medial aspect hemi- sphere that reaches to the premotor cortex (Brodmann areas 6 and 8) on the lateral surface of brain. The cortical area in inferior frontal gyrus corresponds to motor speech area or speech area of Broca (Brodmann areas 44 and 45) and frontal eye area (Fig. 1.8). Lesion into the motor speech area of Broca results in aphasia even the muscles concerned are intact. In 95% of right-handers do have left-hemisphere dominance for language functions, only around 19% of left-handers have right-hemisphere language dominance, with another 20% or so processing language functions in both hemispheres.9 Sensory Areas From the specific nuclei of the thalamus, neurons are projected into two somatosensory areas of the cortex: somato- sensory area I in postcentral gyrus and somatosensory area II in the wall of the SF (Fig. 1.6). The arrangement of the thalamic fibers in somatosensory area I is such that the part of the body is represented in order along the postcentral gyrus, with leg on the top and head at the foot of the gyrus. The area of the cortex that receives sensation from a part FIGURE 1.8 Brodmann areas in the neocortex. A number of important Brodmann areas have been marked out in the figure.