2. Purpose
• Assessment of the patient’s overall health status.
• Optimization of the patient’s medical condition
• Perioperative risk determination
• Shared decision- making.
• Informed consent
• Development of perioperative care plan.
• Education of the patient about surgery, anesthesia
3. • Careful documentation of preoperative neurological
status
• Understanding of the impact of surgery & anaesthesia on
intracranial physiology
• Reduction of costs, shortening of hospital stay, reduction
of cancellations and increase patient satisfaction.
• Minimise risk for all patients
• Ensure patient safety
4. Skill
The anaesthetist has the skills necessary to
–assess, optimise and estimate risk
–support patients deciding whether to proceed
with surgery and anaesthesia
Anesthesia clinic.
6. • Past history
• Current history,
• Surgical history,
• Family history,
• Social history (use of tobacco, alcohol and illegal
drugs),
• History of allergies, current and recent drug therapy,
• History of previous anesthesia.
7. Past and current history
• Neurological manifestation
• Supratentorial Intracranial Tumors
Documentation : Any altered level of consciousness, signs, and
symptoms of raised ICP, sensory or motor deficits and seizures
Evaluate are the hydration and volume status of the patient
Presence of inappropriate secretion of anti diuretic hormone
syndrome (SIADH), or cerebral salt wasting.
Meningiomas is often associated with significant blood loss
Preoperative steroids, dexamethasone, and antiepileptic
8. • Awake Craniotomy for Tumor Surgery
• The degree of anxiousness, tolerance to pain & the ability
to cooperate should be checked
• Predicted difficult airway ,obesity and OSA
anesthesiologist must plan for possible emergent
manipulation of the airway in a difficult position
• Educating the patient : various tests during mapping.
9. • Pituitary Tumor
• Optimize comorbidities associated with the specific
endocrine dysfunction.
• Acromegaly: large body mass ,an unpredictable difficult
airway and OSA
• Cushing's disease : hypertension, glucose intolerance,
myelopathy, osteoporosis, obesity, difficult airway & OSA.
• All endocrine related medications need to be continued.
• Hypopituitarism should receive steroid and hormone
replacement therapy perioperatively
10. • Posterior Fossa Surgery
• Rule out the presence of an intracardiac (persistent foramen ovale)
or an intrapulmonary shunt
• Patients with a diminished gag reflex may require continued
intubation postoperatively.
• Cerebral Aneurysm
• Cardiac complications include abnormalities in rhythm and ECG
changes, elevated cardiac enzymes, and myocardial dysfunction
• Neurogenic pulmonary edema can occur at time of cerebral insult
or up to two weeks after SAH
• Electrolyte abnormalities including hyponatremia, hypokalemia,
hypomagnesaemia and hypocalcaemia
11. • Cardiovascular system”
• Patients with neurological disorders may have:
Blood pressure fluctuations,
ECG abnormalities, arrhythmias,
Myocardial ischemia or failure.
• They can occur as consequences of central neurogenic
effects on the myocardium and the ANS or concurrently
associated medical conditions.
12. • Preexisting cardiac disease should be identified,
• Assessment of functional capacity .
• Further diagnostic evaluations should follow guidelines
• Perioperative beta blockade should be used in patients on
beta blockers and those with positive stress test
undergoing major vascular surgery
• Statins have been shown to improve perioperative cardiac
outcome,
13. Meticulous history of pacemakers, aneurysm clips or
implanted ferrous metal should be obtained.
A history of percutaneous coronary intervention (PCI)
…require antiplatelet therapy
Patient with HTN should elicit any history of end-organ
disease. Ischemia, myocardial infarction, diastolic
dysfunction ,renal failure, & cerebrovascular disease all
may be consequences of untreated hypertension.
14. Pulmonary disease
• Patients with neurological disorders may have:
Aspiration of gastric contents
Pneumonia,
Neurogenic pulmonary edema may occur in patients with
brain injury, subarachnoid hemorrhage (SAH), and stroke.
Obstructive sleep apnea (OSA): high incidence in
acromegaly and Cushing's disease
Patients on CPAP
15. Chronic pulmonary conditions increase the risk of
postoperative respiratory failure.
History OF COPD or asthma (cough, wheeze).
An acute bacterial process,
Arrangements for postoperative chest physiotherapy.
Current symptoms may restrict the choice of anesthetic
options.
16. Gastrointestinal system
• The history of reflux should be carefully documented, and
their severity should be quantified.
• It may result in a change in the anesthetic plan.
17. Reproductive system
• Women of childbearing age should be asked if there
is any chance of pregnancy
• The date of their last menstrual period should be
documented.
• Pregnancy test.
18. Endocrine Dysfunction:
• Diabetes:
• Insulin use, hypo/hyperglycemia, complications
• Tight glycemic control reduced the mortality in
neurosurgical patients and other critically ill patients .
• The goal
avoidance of either hypo or hyperglycemia,
maintenance of sugar levels between 100 mg/dL and
150 mg/dL.
19. • Adrenal: Use of intraoperative steroids and wound
healing, Hyperglycemia
• Thyroid disease:
• -goiter, thyroid storm.
• -Parathyroid: calcium metabolism on myocardial
function, NMJ function
22. Anesthetic history
A history of difficult intubation, or tracheotomy in the
past,
H/ Prolonged weakness, or intubation postoperatively.
H/ postoperative nausea or vomiting .
Rare: Malignant hyperthermia
Poor venous access .
Various fears surrounding anesthesia, such as a mask
“phobia”, post spinal headache.
• Residual damage such as tracheal stenosis .
23. Allergies and social habits
• Including the drug and the reaction.
• Latex allergy has to be excluded from patients who have
had repetitive surgical procedures preformed, such as for
spinal bifida.
• Allergy to contrast medium or protamine sulfate in
radiological and endovascular procedures
• Smoking: Stop smoking at least 6–8 weeks prior to surgery
• Drug abuse and alcoholism :
Increased tolerance to anesthetic agents
Unexpected withdrawal following the surgery.
24. Medications
• A detailed list of medications and dosing schedule .
• Especially, the geriatric population .
• Document both prescribed and nonprescribed
medications, including vitamins and other supplements.
• In general, most medications should be continued up to
and including the morning of operation, although some
adjustment in dosage may be required (e.g.
antihypertensives, insulin).
25. • Preoperative dexamethasone : elevated blood glucose
levels which require careful monitoring
• Patients on antiepileptic : may have adverse effects as well
as intraoperative pharmacokinetic interactions
• Chronic pain medication (trigeminal neuralgia) need a
plane for perioperative pain management.
• Patients with cerebral insufficiency may be on antiplatelet
or anticoagulants for treatment of acute stroke, or
prevention such as cases :coronary artery stents, prostatic
heart valve, and intracardiac thrombus (The risks and the
benefits of discontinuing or continuing therapy should also be discussed with
hematologist, cardiologist , surgeon , patient and family
26. • Factors to consider are the urgency of the procedure and
the presence of thrombotic or hemorrhagic risks.
• For elective surgery with high hemorrhagic risk, such as
intracranial and spinal procedures and moderate to high
thrombotic risks suggest that:
• Aspirin should be continued, but to withhold clopidogrel
• If the neurological and cardiovascular risks are low, the
antiplatelet agents should be withdrawn (7 days for
aspirin, 10 days for clopidogrel and 14 days for ticlopidine)
27. • In general :
• All patients are requested to discontinue their herbal
supplements at least 2 weeks prior to surgery.
• Aspirin should be discontinued 7-10 days before surgery
to avoid excessive bleeding and thienopyridines (such as
clopidogrel) for 2 weeks before surgery.
• Selective cyclooxygenase-2 (COX-2) inhibitors do not
potentiate bleeding and may be continued until surgery.
28. • Medication will be restarted postoperatively.
• Oral anticoagulants should be stopped 4-5 days prior to
invasive procedures, allowing INR to reach a level of 1.5
prior to surgery.
• Angiotensin converting enzyme inhibitors may result in
significant hypotension after induction; holding these
medications on the day of surgery has been previously
recommended but is now generally done only prior to
cardiac surgery.
29. • Some drugs should be discontinued preoperatively. The
monoamine oxidase inhibitors should be withdrawn 2-3
weeks before surgery because of the risk of interactions
with drugs used during anesthesia.
• The oral contraceptive pill should be discontinued at least
6 weeks before elective surgery because of the increased
risk of venous thrombosis.
30. In children,
• Birth history,
• Prematurity at birth,
• Perinatal complications
• Congenital chromosomal or anatomic malformations
• History of recent infections, particularly upper and
lower respiratory tract infections.
32. • Physical examination:
– Venous access issues
– Arterial access: radial, femoral
– Airway / neck for ease of laryngoscopy, necessity
of fiberoptic intubation
33. Airway assessment
• How easy or difficult it will be to intubate a patient
depends on the following points:
• Are they obese?
• Do they have a short neck and small mouth?
• To what extent can they open their mouth?
• Is there any soft tissue swelling at the back of the
mouth or are there any limitations in neck flexion or
extension?
34. Mallampati score
Scoring is as follows:
Class 1: Full visibility of tonsils, uvula
and soft palate
Class 2: Visibility of hard and soft
palate, upper portion of tonsils and
uvula
Class 3: Soft and hard palate and base
of the uvula are visible
Class 4: Only Hard Palate visible
35. • The upper lip bite test has a high accuracy and specificity,
compared to the thyomental distance, the inter incisor
gap and the sternomental distance and may be useful in
patients with restricted mouth opening and limited neck
mobility
• The presence of raised ICP, SAH, acromegaly, and cervical
spine disease, will influence the technique chosen for
securing of the airway.
36. • The presence of a difficult airway may increase risk of
hypoxemia and hypercarbia which exacerbate the
secondary neurological injury.
• Preoperative planning and discussion is required to ensure
that the safest technique(s) is chosen.
• Fibreoptic intubation is not uncommon in neurosurgery,
with 17% documentation in a review of 1612 cases .
• Multiple factors such as hypophyseal, craniofacial, and
chronic spine pathology may contribute to a difficult
airway, in neurosurgery .
37. Assessment of neurological system
• Patient's preoperative cognitive function (level of
consciousness, communication, and intellect), and
language (ability to communicate in written and verbal
form).
• The Glasgow Coma Scale (GCS)
• A brief examination of the sensory and motor function for
documentation of any deficits, such as a weakness or loss
of sensation of the extremities.
• Cranial nerve involvement or dysfunction
• Preoperative pupil size for assessment of anesthetic depth
and for comparison with postoperative pupil changes.
38. Cardiovascular system
• Cardiac murmurs, abnormal HR and rhythm, poor peripheral
pulses, cardiac failure
• The presence of carotid bruit will require further investigations .
• Baseline pressure
• With the exception of emergency surgery, patients should be
haemodynamically stable and their vital signs normal before
starting anaesthesia.
• Cardiac testing should be requested and reviewed.
• Adequate beta blockade should be established perioperatively, if
indicated.
• Patients receiving calcium channel blockers should continue these
medications, including on the day of surgery.
39. • Respiratory system : abnormal breath sounds.
vital capacity effort .
Any signs of new respiratory disease
• Gastrointestinal system : abdominal masses, previous scars.
• Musculoskeletal system : skeletal malformations such as
kyphoscoliosis……identify susceptible patient for malignant
hyperthermia
• General : local skin infection.
• Regional anatomy: spine
40. • Obesity increases anesthesia risks, intubation challenges,
and comorbid conditions such HTN, DM, and sleep
apnea.
• May require special equipment in OR, including large
blood pressure cuffs, wide stretchers, and larger
operating room beds.
• A major risk for postop. DVT & PE
41. Assessment of intravascular volume status
• Neurosurgical patients often present with:
• Rapid changes in intravascular volume precipitated by
hemorrhage, dehydration, diuretics , mannitol &fluid
restriction.
• The goal :
• Restoration of intravascular volume,
• Maintenance of cerebral perfusion pressure
• Avoidance of hyperglycemic and hypotonic fluids .
•
42. • Iso-osmolar solutions, such as plasmalyte and 0.9% saline
are used
They do not change the plasma osmolality,
Do not increase brain water content.
• Glucose-containing solutions and hypo-osmolar solutions,
such as lactated Ringer's are avoided as
Plasma osmolality is reduced,
Brain water content increases, worsening cerebral edema
Mannitol: carefully titrated in renal impairment and
congestive cardiac failure.
44. • Specialized cardiac evaluations for compromised
functions:
– Ischemia: Dobutamine stress, angiography, TEE for valve
dysfunction.
– Exercise tolerance / intolerance
oTransesophageal echocardiography and transcranial
Doppler ultrasound are used to assess for a persistent
foramen ovale
47. Investigations
• Ordering unnecessary tests is neither helpful nor cost-
effective.
• The test results are usually acceptable for up to 6 months
prior to surgery provided the patient's medical history has
not changed significantly.
• Which tests are necessary for an individual patient? Based:
Age,
Comorbidities
Type of procedure .
48. • CBC
• In a study of 2000 pt, 30 days mortality=
– Pre op. Hb >= 12 1.3% mort.
– Pre op. Hb < 6 33.3% mort.
Anaemia.
Increases the risk of intra-operative hypoxia or increased cardiac
workload.
An increased risk of myocardial infarction or cerebrovascular event
and delayed healing.
A baseline measure of Hb if the proposed operation is expected to
cause substantial blood loss.
49. Renal funct.
• For renal deficiency.
• Possibility of developing acute kidney failure after
major surgery.
• It may also influence the choice of drugs given within
the anaesthetic.
• Cr level is recommended esp. in
– >50 yr
– Hypotension expected
– Nephrotoxic Rx
50. LFTs
Only 0.3% of healthy ppl. Have abnormal LFTs
routine LFT pre op. in healthy ppl isn’t recommended
Does the patient have any underlying malnutrition? This
may affect the patient's ability to heal.
Is there a clotting problem?
51. Hemostasis
• Routine preoperative tests of hemostasis are NOT
recommended.
• Should be restricted to patients with a known
bleeding tendency.
• Clotting and platelet function for the patients who
take aspirin or warfarin;
• Also, for patients with altered LFTs for any reason.
52. Electrolytes
• It is recommended for patient on dehydrating measures
• Sodium imbalances may indicate posterior pituitary
dysfunction in the form of diabetes insipidus or SIADH
Calcium
• Is there a suggestion of underlying malignancy?
• Abnormal calcium levels can impact on heart rhythm and
so may need to be corrected prior to any surgery.
53. Hemoglobin level
• Base line hemoglobin (Hb) predict the need for
subsequent transfusion
• Ensure that there is an appropriate cross match for blood
transfusion for each procedure.
• Severe anemia risks tissue hypoxia from impaired oxygen
delivery.
• In neurosurgical patients, hematocrit (Hct) of 30–33%
ensures optimal combination of oxygen carrying capacity
and viscosity .
54. Blood group and save (or hold)
• The patient's blood type is identified and held, for possible
request for units of blood or blood products.
• Cross-match
• The surgeon makes a prediction (in units of blood) for the
procedure.
• That amount, typed specifically for that patient, is held in the
blood bank for 24 hours.
• The decision should be judged on the current hematological
status of the patient as well as the estimated blood loss.
55. Urinalysis
• Done to:
–Undiagnosed diabetes
–Detect hematuria or abnormal protein loss.
–UTI
• It is not necessary for the detection of asymptomatic
renal disease if a serum creatinine measurement is
Normal
• Relationship between asymptomatic UTI and surgical
infection is unclear
• not recommended as routine
56. CXR• X ray chest :
• Recommended in:
–>50 yr undergoing major surg.
–Suspected cardiac or pulm. disease
• Help plan for postoperative physiotherapy.
• X ray cervical spine : Patients with ankylosing
spondylitis …………the anesthetists should bear this
in mind when extending the patient's neck during
intubation.
57. Neuroradiological images
• Review of neuroradiological images such as the computer
tomography (CT), magnetic resonance imaging (MRI), and
angiography.
• Valuable information pertaining to the size of the lesion,
its location, possible vascularity, and the surrounding
structures can be obtained.
58. PFT
• Not indicated for healthy patients prior to surgery
• Reserved for patients who have SOB that remains
unexplained after careful clinical evaluation
• Useful in patients with obstructive or restrictive patterns of
disease.
59. ECG
• Guidelines :
–Men > 45 years
–Women > 55 years
–Known cardiac disease
–Clinical evaluation suggesting the possibility of
cardiac disease
–Patients at risk for electrolyte abnormalities, such as
diuretic use
–Systemic disease associated with possible
unrecognized heart disease, such as DM, HTN
–Patients undergoing major surgical procedures
60. ECG
• Show any silent myocardial ischaemia or infarction.
• A baseline to compare against possible
postoperative events.
• Arrhythmias.
61. Sickle cell testing
• For patients who have a family history of sickle cell anaemia ,
particularly where there is no previous surgical history.
At-risk groups include:
• African
• Caribbean
• Eastern Mediterranean
• Middle Eastern
• Asian
62. Pregnancy testing
• The woman should be asked .
• If there is any doubt about pregnancy , a test should be
done with the woman's consent.
• Similar questioning should be carried out before a CXR.
63. Premedication
• In patient with Supratentorial Intracranial Tumors:
Premedication for sedation can be risky
• In Functional Neurosurgery: Deep Brain Stimulators
• Premedications can interfere with the interpretation of
tremor and hence is avoided.
64. Communication
• The communication with the surgeon and/or
neuroradiologist regarding :
The urgency
Possible difficulties of the procedure
Positioning,
Use of intraoperative neurologic monitoring
The plan for postoperative care .
65. Consent and instructions
Discussion with the patient and family
The techniques of anesthesia,
Requirements for the specific procedure such as invasive
monitoring,
The risks associated with anesthesia
The patient's medical comorbidities,
The plans for the postoperative care, such as postoperative
ventilation and pain management.
For day surgery : assess the ability of the patient and family to do
this, plus instructions need to be clarified during their preoperative
interview
66. Consent should be:
Clearly written in simple language
Specific, avoiding vague terms such as “may be”
Directions to exact location in the hospital
67. Patients should be given instructions regarding:
• Medications
• The day of procedure and postoperative recovery.
• Fasting time.
• Written instructions should be provided, including a
contact phone number, requirements for discharge,
such as transportation home.
• Recommendations on clothing .
68. Summary of Fasting Recommendations
• Ingested Material & Minimum Fasting Period
• Clear liquids 2 h
• Breast milk 4 h
• Infant formula 6 h
• Nonhuman milk 6 h
• Light meal 6 h
• Heavy meal 8h
69. Emergency
In extreme cases, it may not be possible to perform more
than a very brief preoperative assessment; so, it is
important to prioritize the assessment.
A few critical facts may be helpful.
• Family history of anesthetic issues,
• History of difficult intubation or tracheotomy, or any
allergies?
• A list of medications,
• Any laboratory testing should be quickly reviewed.
70. Cancellations
• Sometimes it is necessary to postpone a procedure based
on preoperative examination,.
• The anesthesiologist should communicate with the patient
and the surgeon and explain why the patient is not ready
for surgery and what should be done before the patient is
rescheduled.
An adjustment in medications
Additional tests
Consultations LIKE a cardiology
71. One common cause of day-of-surgery
cancellation is a change in the patient’s status
or a new infection.
Patients should be provided with clear
guidelines of what to do if they develop URTI
or other illness.
73. What’s the ASA (The American Society
of Anesthesiologists?
• ASA I Healthy patient
• ASA II Mild systemic disease with no functional limitation - for
example, controlled hypertension
• ASA III Severe systemic disease with definite functional limitation -
for example, chronic obstructive pulmonary disease
• ASA IV Severe systemic disease that is a constant threat to life - for
example, unstable angina
• ASA V Moribund patient who is not expected to survive for 24
hours with or without surgery - for example, with an abdominal
aortic aneurysm
Suffix E Emergency procedure
74. The risk for surgical complications depends on
individual factors and the type of surgical procedure.
Advanced age increase the risk for surgical
morbidity and mortality.
<60 yr 1.3% mortality
80-89 yr 11.3%
Age 70 as turning point
75. • Diseases associated with high risk for surgical
complications include respiratory and cardiac disease,
malnutrition and diabetes mellitus.
• The type of surgery: major vascular, intraabdominal and
intrathroracic ,neurosurgical procedures are frequently
associated with increased perioperative morbidity and
mortality
• Urgent and emergency procedures constitute higher risk
with a limited opportunity for preoperative evaluation and
treatment.
76.
77. • Patients with respiratory disease may benefit from
perioperative use of bronchodilators or steroids.
• Patients at increased risk of pulmonary
complications should receive
instruction in deep-breathing exercises
incentive spirometry.
78. • Assessment of nutritional status should be
performed.
• An albumin level of less than 3.2 mg per dL (32 g
per L) suggests an increased risk of complications.
• Patients deemed at risk because of compromised
nutritional status may benefit from pre- and
postoperative nutritional supplementation.
79. CARDIAC RISK INDEX
• Hx of ischemic heart disease
• Hx of compensated or prior HF
• Hx of cerebrovascular disease
• Diabetes mellitus
• Renal insufficiency
80. Patients with good functional capacity do not require
preoperative cardiac stress testing in most surgical
cases.
• Unstable angina, myocardial infarction within 6
weeks and aortic or peripheral vascular surgery
place a patient into a high-risk category for
perioperative cardiac complications.
81. Summary
• Proper preoperative evaluation of the patient is critical to
the success of the outcome
• Understand the pathophysiological disturbances, the
systemic manifestations, the procedure and its special
requirements .
• Communication with the patient and family, as well as the
neurosurgeon and neuroradiologist
