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Usmle pretest surgery. gueller 9ed 2001

  1. 1. PRE TEST ® SurgeryPreTest® Self-Assessment and Review
  2. 2. NOTICEMedicine is an ever-changing science. As new research and clinical experiencebroaden our knowledge, changes in treatment and drug therapy are required. Theauthors and the publisher of this work have checked with sources believed to bereliable in their efforts to provide information that is complete and generally inaccord with the standards accepted at the time of publication. However, in view ofthe possibility of human error or changes in medical sciences, neither the authorsnor the publisher nor any other party who has been involved in the preparation orpublication of this work warrants that the information contained herein is in everyrespect accurate or complete, and they disclaim all responsibility for any errors oromissions or for the results obtained from use of the information contained in thiswork. Readers are encouraged to confirm the information contained herein withother sources. For example and in particular, readers are advised to check the prod-uct information sheet included in the package of each drug they plan to administerto be certain that the information contained in this work is accurate and thatchanges have not been made in the recommended dose or in the contraindicationsfor administration. This recommendation is of particular importance in connectionwith new or infrequently used drugs.
  3. 3. PRE TEST ® SurgeryPreTest® Self-Assessment and Review Ninth Edition PETER L. GELLER, M.D. Associate Professor of Clinical Surgery Columbia University College of Physicians & Surgeons New York, New York McGraw-Hill Medical Publishing Division PreTest® Series NEW YORK ST. LOUIS SAN FRANCISCO AUCKLAND BOGATÁ CARACAS LISBON LONDON MADRID MEXICO CITY MILAN MONTREAL NEW DELHI SAN JUAN SINGAPORE SYDNEY TOKYO TORONTO
  4. 4. Copyright © 2001, 1998, 1995, 1992, 1989, 1987, 1985, 1982, 1978 by The McGraw-Hill Companies,Inc. All rights reserved. Manufactured in the United States of America. Except as permitted under theUnited States Copyright Act of 1976, no part of this publication may be reproduced or distributed in anyform or by any means, or stored in a database or retrieval system, without the prior written permissionof the publisher.0-07-137638-0The material in this eBook also appears in the print version of this title: 0-07-135954-0.All trademarks are trademarks of their respective owners. Rather than put a trademark symbol afterevery occurrence of a trademarked name, we use names in an editorial fashion only, and to the benefitof the trademark owner, with no intention of infringement of the trademark. Where such designationsappear in this book, they have been printed with initial caps.McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales pro-motions, or for use in corporate training programs. For more information, please contact GeorgeHoare, Special Sales, at george_hoare@mcgraw-hill.com or (212) 904-4069.TERMS OF USEThis is a copyrighted work and The McGraw-Hill Companies, Inc. (“McGraw-Hill”) and its licensorsreserve all rights in and to the work. Use of this work is subject to these terms. Except as permittedunder the Copyright Act of 1976 and the right to store and retrieve one copy of the work, you may notdecompile, disassemble, reverse engineer, reproduce, modify, create derivative works based upon,transmit, distribute, disseminate, sell, publish or sublicense the work or any part of it withoutMcGraw-Hill’s prior consent. You may use the work for your own noncommercial and personal use;any other use of the work is strictly prohibited. Your right to use the work may be terminated if youfail to comply with these terms.THE WORK IS PROVIDED “AS IS”. McGRAW-HILL AND ITS LICENSORS MAKE NO GUAR-ANTEES OR WARRANTIES AS TO THE ACCURACY, ADEQUACY OR COMPLETENESS OFOR RESULTS TO BE OBTAINED FROM USING THE WORK, INCLUDING ANY INFORMA-TION THAT CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK OR OTHERWISE,AND EXPRESSLY DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUTNOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR APARTICULAR PURPOSE. McGraw-Hill and its licensors do not warrant or guarantee that the func-tions contained in the work will meet your requirements or that its operation will be uninterrupted orerror free. Neither McGraw-Hill nor its licensors shall be liable to you or anyone else for any inaccu-racy, error or omission, regardless of cause, in the work or for any damages resulting therefrom.McGraw-Hill has no responsibility for the content of any information accessed through the work.Under no circumstances shall McGraw-Hill and/or its licensors be liable for any indirect, incidental,special, punitive, consequential or similar damages that result from the use of or inability to use thework, even if any of them has been advised of the possibility of such damages. This limitation of lia-bility shall apply to any claim or cause whatsoever whether such claim or cause arises in contract, tortor otherwise.DOI: 10.1036/0071376380 Terms of Use
  5. 5. CONTENTSPreface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viiIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix PRE- AND POSTOPERATIVE CAREQuestions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . . 16 CRITICAL CARE:ANESTHESIOLOGY, BLOOD GASES, RESPIRATORY CAREQuestions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . . 47 SKIN:WOUNDS, INFECTIONS, BURNS; HANDS; PLASTIC SURGERYQuestions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . . 73 TRAUMA AND SHOCKQuestions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . . 98 TRANSPLANTS, IMMUNOLOGY, AND ONCOLOGYQuestions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 135 ENDOCRINE PROBLEMS AND BREASTQuestions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 165 GASTROINTESTINAL TRACT, LIVER, AND PANCREASQuestions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 208 v Terms of Use
  6. 6. vi Contents CARDIOTHORACIC PROBLEMS Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 252 PERIPHERAL VASCULAR PROBLEMS Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 277 UROLOGY Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 291 ORTHOPEDICS Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 301 NEUROSURGERY Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307 Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 312 OTOLARYNGOLOGY Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 322 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 Terms of Use
  7. 7. PREFACENo longer can students assume that this kind of continuing education endswith the completion of formal training and the successful completion oflicensing or certifying examinations. As of October 1979, all 22 memberboards of the American Board of Medical Specialties committed themselvesto the principle of periodic recertification of their members. Despite theBoard’s recognition that the cognitive skills measured in the objectiveexamination do not assure clinical competence, recertification efforts—insofar as they involve examinations—are based on the assumption thatknowledge of current information on which good clinical decisions shouldbe made is worth cultivating; that, while such information does not guar-antee competent practice, lack of it probably impedes competent practice,that this knowledge, unlike technical skills, is reasonably easy to assess;and that it can be acquired by well-motivated physicians. These assump-tions all seem reasonable. The questions presented in this book deal with issues of relativeimportance to medical students; other problem-oriented materials arebecoming available that are aimed at more sophisticated audiences—groups that, within a very few years, will include the present generation ofstudents. Regular review of such material is a habit worth developing. Wehope that this edition of Surgery: PreTest® Self-Assessment and Review willjustify your efforts in working through the problems by providing guidancefor further study and by helping you to develop enduring learning habits. PETER L. GELLER, M.D. vii
  8. 8. INTRODUCTIONEach question in Surgery: PreTest® Self-Assessment and Review, Ninth Edition,is accompanied by an answer, a paragraph explanation, and a specific pagereference to either a current journal article, a textbook, or both. A bibliog-raphy, which lists all the sources used in the book, follows the last chapter. Perhaps the most effective way to use this book is to allow yourself oneminute to answer each question in a given chapter; as you proceed, indi-cate your answer beside each question. By following this suggestion, youwill be approximating the time limits imposed by the board examinations. When you have finished answering the questions in a chapter, youshould then spend as much time as you need verifying your answers andcarefully reading the explanations. Although you should pay special atten-tion to the explanations for the questions you answered incorrectly, youshould read every explanation. The authors of this book have designed theexplanations to reinforce and supplement the information tested by thequestions. If, after reading the explanations for a given chapter, you feelyou need still more information about the material covered, you shouldconsult and study the references indicated.STUDENT REVIEWERJeffrey J. AndereggThe University of Iowa College of MedicineIowa City, Iowaviii
  9. 9. PRE- AND POSTOPERATIVE CARE QuestionsDIRECTIONS: Each item below contains a question or incompletestatement followed by suggested responses. Select the one best response toeach question.1. A pregnant woman in her 32nd 3. A 50-year-old patient presentswk of gestation is given magnesium with symptomatic nephrolithiasis.sulfate for pre-eclampsia. The earli- He reports that he underwent aest clinical indication of hypermag- jejunoileal bypass for morbid obe-nesemia is sity when he was 39. One woulda. Loss of deep tendon reflexes expect to findb. Flaccid paralysis a. Pseudohyperparathyroidismc. Respiratory arrest b. Hyperuric aciduriad. Hypotension c. “Hungry bone” syndromee. Stupor d. Hyperoxaluria e. Sporadic unicameral bone cysts2. Five days after an uneventfulcholecystectomy, an asymptomatic 4. Following surgery, a patientmiddle-aged woman is found to develops oliguria. You believe thehave a serum sodium level of 120 patient is hypovolemic, but beforemeq/L. Proper management would increasing intravenous fluids yoube seek corroborative data. Thisa. Administration of hypertonic saline would include solution a. Urine sodium of 28 meq/Lb. Restriction of free water b. Urine chloride of 15 meq/Lc. Plasma ultrafiltration c. Fractional excretion of sodium lessd. Hemodialysis than 1e. Aggressive diuresis with furose- d. Urine/serum creatinine ratio of 20 mide e. Urine osmolality of 350 mOsm/kg 1 Terms of Use
  10. 10. 2 Surgery5. A 45-year-old woman with 7. A 70-year-old man with aorticCrohn’s disease and a small intesti- and mitral valvular regurgitationnal fistula develops tetany during undergoes an emergency sigmoidthe 2nd wk of parenteral nutrition. colectomy and end colostomy forThe laboratory findings include Ca perforated diverticulitis. His post-8.2 meq/L; Na 135 meq/L; K 3.2 operative course is complicated bymeq/L; C1 103 meq/L; PO4 2.4 a myocardial infarction and atrialmeq/L; albumin 2.4; pH 7.48; 38 fibrillation. Four weeks later, hekPa; P 84 kPa; bicarbonate 25 has improved and requests electivemeq/L. The most likely cause of the colostomy closure. You would rec-patient’s tetany is ommenda. Hyperventilation a. Discontinuation of antiarrhythmicb. Hypocalcemia and antihypertensive medicationsc. Hypomagnesemia on the morning of surgeryd. Essential fatty acid deficiency b. Discontinuation of beta-blockinge. Focal seizure medications on the day prior to surgery6. A patient with a nonobstructing c. Control of congestive heart failurecarcinoma of the sigmoid colon is with diuretics and digitalis inbeing prepared for elective resec- severe cases d. Administration of prophylactiction. To minimize the risk of post- antibiotics, other than ampicillinoperative infectious complications, and gentamicin, for patients withyour planning should include valvular heart disease who area. A single preoperative parenteral undergoing gastrointestinal proce- dose of antibiotic effective against dures aerobes and anaerobes e. Postponement of elective surgeryb. Avoidance of oral antibiotics to pre- for 6–8 wk after a subendocardial vent emergence of Clostridium diffi- myocardial infarction cilec. Postoperative administration for 2–4 days of parenteral antibiotics effective against aerobes and anaer- obesd. Postoperative administration for 5–7 days of parenteral antibiotics effective against aerobes and anaer- obese. Operative time less than 5 h
  11. 11. Pre- and Postoperative Care 3Items 8–9 9. The most appropriate therapy for the patient described would be A previously healthy 55-year-old man undergoes elective right a. Infusion of 0.9% NaC1 with sup- plemental KC1 until clinical signshemicolectomy for a Dukes A can- of volume depletion are eliminatedcer of the cecum. His postoperative b. Infusion of isotonic (0.15 N) HC1ileus is somewhat prolonged, and via a central venous catheteron the fifth postoperative day his c. Clamping the nasogastric tube tonasogastric tube is still in place. prevent further acid lossesPhysical examination reveals d. Administration of acetazolamide todiminished skin turgor, dry promote renal excretion of bicar-mucous membranes, and orthosta- bonatetic hypotension. Pertinent labora- e. Intubation and controlledtory values are as follows: hypoventilation on a volume- cycled ventilator to further increase• Arterial blood gases: pH 7.56; PO2 PCO2 85 kPa; PCO2 50 kPa• Serum electrolytes (meq/L): Na+ 132; K+ 3.1; C1− 80; HCO3− 42• Urine electrolytes (meq/L): Na+ 2; K− 5; C1− 68. The values given above allowthe descriptive diagnosis ofa. Uncompensated metabolic alkalo- sisb. Respiratory acidosis with metabolic compensationc. Combined metabolic and respira- tory alkalosisd. Metabolic alkalosis with respiratory compensatione. “Paradoxical” metabolic respiratory alkalosis
  12. 12. 4 SurgeryItems 10–11 12. A 65-year-old man undergoes a technically difficult abdomino- A 23-year-old woman is perineal resection for a rectal cancerbrought to the emergency room during which he receives threefrom a halfway house, where she units of packed red blood cells.apparently swallowed a handful of Four hours later in the intensivepills. The patient complains of care unit he is bleeding heavily fromshortness of breath and tinnitus, his perineal wound. Emergencybut refuses to identify the pills she coagulation studies reveal nor-ingested. Pertinent laboratory val- mal prothrombin, partial thrombo-ues are as follows: plastin, and bleeding times. The fib-• Arterial blood gases: pH 7.45; PO2 rin degradation products are not 126 kPa; PCO2 12 kPa elevated but the serum fibrinogen content is depressed and the• Serum electrolytes (meq/L): Na+ platelet count is 70,000/µL. The 138; K+ 4.8; C1− 102; HCO3− 8 most likely cause of the bleeding is10. The patient’s acid-base distur- a. Delayed blood transfusion reaction b. Autoimmune fibrinolysisbance is best characterized by which c. A bleeding blood vessel in the sur-of the following descriptions? gical fielda. Acute respiratory alkalosis, com- d. Factor VIII deficiency pensated e. Hypothermic coagulopathyb. Chronic respiratory alkalosis, com- pensated 13. A 78-year-old man with ac. Metabolic acids, compensated history of coronary artery diseased. Mixed metabolic acidosis and res- piratory alkalosis and an asymptomatic reduciblee. Mixed metabolic acidosis and res- inguinal hernia requests an elective piratory acidosis hernia repair. You explain to him that valid reasons for delaying the11. The most likely cause of the proposed surgery includedisturbance in this patient is an a. Coronary artery bypass surgery 3overdose of mo earlier b. A history of cigarette smokinga. Phenforminb. Aspirin c. Jugular venous distension d. Hypertensionc. Barbiturates e. Hyperlipidemiad. Methanole. Diazepam (Valium)
  13. 13. Pre- and Postoperative Care 514. A 68-year-old man is admitted 16. A 20-year-old woman is foundto the coronary care unit with an to have an activated partial throm-acute myocardial infarction. His boplastin time (APTT) of 78/32 onpostinfarction course is marked by routine testing prior to cholecystec-congestive heart failure and inter- tomy. Further investigation revealsmittent hypotension. On the fourth a prothrombin time (PT) of 13/12hospital day, he develops severe (patient/control), a template bleed-midabdominal pain. On physical ing time of 13 min, and a plateletexamination, blood pressure is count of 350 × 100/µL. Which one90/60 mm Hg and pulse is 110 of the following characteristics ofbeats/min and regular; the abdomen this woman’s coagulopathy is true?is soft with mild generalized tender- a. Infusion of purified factor VIII isness and distention. Bowel sounds usually required to normalize itsare hypoactive; stool hematest is concentration prior to surgerypositive. The next step in this b. Infusion of cryoprecipitate will notpatient’s management should be be followed by an improvement inwhich of the following? coagulation c. Most of these patients are, ora. Barium enema become, seropositive for HIVb. Upper gastrointestinal series d. Epistaxis or menorrhagia is uncom-c. Angiography mond. Ultrasonography e. Lack of platelet aggregation ine. Celiotomy response to ristocetin is a common feature of this disease15. A 30-year-old woman in thelast trimester of pregnancy sud- 17. The chief surgical risk todenly develops massive swelling of which patients with polycythemiathe left lower extremity from the vera are exposed is that due toinguinal ligament to the ankle. Thecorrect sequence of workup and a. Anemic disturbances b. Hemorrhagetreatment should be c. Infectiona. Venogram, bed rest, heparin d. Renal dysfunctionb. Impedance plethysmography, bed e. Cardiopulmonary complications rest, heparinc. Impedance plethysmography, bed rest, vena caval filterd. Impedance plethysmography, bed rest, heparin, warfarin (Coumadin)e. Clinical evaluation, bed rest, war- farin
  14. 14. 6 Surgery18. A victim of blunt abdominal 20. A 65-year-old woman has atrauma requires a partial hepatec- life-threatening pulmonary embo-tomy. He is rapidly transfused with lus 5 days following removal of a8 units of appropriately cross- uterine malignancy. She is immedi-matched packed red blood cells ately heparinized and maintainedfrom the blood bank. He is noted in in good therapeutic range for thethe recovery room to be bleeding next 3 days, then passes grossfrom intravenous puncture sites blood from her vagina and devel-and the surgical incision. His coag- ops tachycardia, hypotension, andulopathy is likely due to thrombo- oliguria. Following resuscitation,cytopenia and deficiencies of which an abdominal CT scan reveals aclotting factors? major retroperitoneal hematoma.a. II only You should nowb. II and VII a. Immediately reverse heparin by ac. V and VIII calculated dose of protamine andd. IX and X place a vena cava filter (e.g., ae. XI and XII Greenfield filter) b. Reverse heparin with protamine,19. Following celiotomy, normal explore and evacuate thebowel motility can ordinarily be hematoma, and ligate the vena cavapresumed to have returned below the renal veins c. Switch to low-dose heparina. In the stomach in 4 h, the small d. Stop heparin and observe closely bowel in 24 h, and the colon after e. Stop heparin, give fresh frozen the first oral intake plasma (FFP), and begin warfarinb. In the stomach in 24 h, the small therapy bowel in 4 h, and the colon in 3 daysc. In the stomach in 3 days, the small bowel in 3 days, and the colon in 3 daysd. In the stomach in 24 h, the small bowel in 24 h, and the colon in 24 he. In the stomach in 4 h, the small bowel immediately, and the colon in 24 h
  15. 15. Pre- and Postoperative Care 721. Which of the following surgi- 23. A cirrhotic patient with abnor-cal interventions is least likely to mal coagulation studies due toprovide acceptable prolongation of hepatic synthetic dysfunctionlife for patients with AIDS? requires an urgent cholecystec-a. Splenectomy for AIDS-related idio- tomy. A transfusion of fresh frozen pathic thrombocytopenic purpura plasma is planned to minimize theb. Colonic resection for perforation risk of bleeding due to surgery. The secondary to cytomegalovirus infec- optimal timing of this transfusion tion would bec. Cholecystectomy for acalculous a. The day before surgery cholecystitis b. The night before surgeryd. Tracheostomy for ventilator- c. On call to surgery dependent patients with respira- d. Intraoperatively tory failure e. In the recovery roome. Gastric resection for a bleeding gas- tric lymphoma or Kaposi’s sarcoma 24. On postoperative day 3, an22. An elderly diabetic woman otherwise healthy 55-year-old man recovering from a partial hepatec-with chronic steroid-dependent tomy is noted to have scantbronchospasm has an ileocolec-tomy for a perforated cecum. She is serosanguineous drainage from histaken to the ICU intubated and is abdominal incision. His skin sta- ples are removed, revealing a 1.0-maintained on broad-spectrum cm dehiscence of the upperantibiotics, renal-dose dopamine,and a rapid steroid taper. On post- midline abdominal fascia. Which of the following actions is mostoperative day 2 she develops a feverof 39.2°C (102.5°F), hypotension, appropriate?lethargy, and laboratory values a. Removing all suture material andremarkable for hypoglycemia and packing the wound with moist ster- ile gauzehyperkalemia. The most likely b. Starting intravenous antibioticsdiagnosis of this acute event is c. Placing an abdominal (Scultetus)a. Sepsis binderb. Hypovolemia d. Prompt resuturing of the fascia inc. Adrenal insufficiency the operating roomd. Acute tubular necrosis e. Bed reste. Diabetic ketoacidosis
  16. 16. 8 Surgery25. Five days after a sigmoid colec- 28. The surgeon should be particu-tomy for cancer, a patient’s skin sta- larly concerned about which coagu-ples are removed and a large gush of lation function in patients receivingserosanguineous fluid emerges. anti-inflammatory or analgesic med-Examination of the wound reveals ications?an extensive fascial dehiscence. The a. APTTmost appropriate management is b. PTa. Wide opening of the wound to c. Reptilase time assure adequate drainage d. Bleeding timeb. Smear and culture of the fluid and e. Thrombin time appropriate antibiotics after the smear is reviewed 29. The substrate depleted earliestc. Careful reapproximation of the in the postoperative period is wound edges with tape a. Branched-chain amino acidsd. Immediate return to the operating b. Non-branched-chain amino acids room c. Ketonee. Application of a Scultetus binder d. Glycogen e. Glucose26. Signs and symptoms of hemo-lytic transfusion reactions include 30. Diagnostic abdominal laparo-a. Hypothermia scopy is contraindicated in whichb. Hypertension of the following patients?c. Polyuria a. A patient with rebound tendernessd. Abnormal bleeding following a tangential gunshote. Hypesthesia at the transfusion site wound to the abdomen b. A stable patient with a stab wound27. A patient suspected of having to the lower chest walla hemolytic transfusion reaction c. A patient with a mass in the head ofshould be managed with the pancreasa. Removal of nonessential foreign d. A young female with pelvic pain body irritants, e.g., Foley catheter and feverb. Fluid restriction e. An elderly patient in the intensivec. 0.1 M HC1 infusion care unit suspected of havingd. Steroids intestinal ischemiae. Fluids and mannitol
  17. 17. Pre- and Postoperative Care 931. A 23-year-old woman under- 33. The enteric fluid with an elec-goes total thyroidectomy for carci- trolyte (Na+, K+, C1−) content simi-noma of the thyroid gland. On the lar to that of Ringer’s lactate issecond postoperative day, she a. Salivabegins to complain of tingling sen- b. Contents of small intestinesation in her hands. She appears c. Contents of right colonquite anxious and later complains d. Pancreatic secretionsof muscle cramps. Initial therapy e. Gastric juiceshould consist ofa. 10 mL of 10% magnesium sulfate 34. Which of the following med- intravenously ications administered for hyper-b. Oral vitamin D kalemia counteracts the myocardialc. 100 µg of oral Synthroid effects of potassium without reduc-d. Continuous infusion of calcium ing the serum potassium level? gluconate a. Sodium polystyrene sulfonatee. Oral calcium gluconate (Kayexalate) b. Sodium bicarbonate32. Hypocalcemia is associated c. 50% dextrosewith d. Calcium gluconatea. Acidosis e. Insulinb. Shortened QT intervalc. Hypomagnesemiad. Myocardial irritabilitye. Hyperproteinemia
  18. 18. 10 SurgeryItems 35–37 36. Which of the following char- acteristics of this patient might An in-hospital workup of a 78- increase the risk of a wound infec-year-old, hypertensive, mildly asth- tion?matic man who is receivingchemotherapy for colon cancer a. History of colon surgeryreveals symptomatic gallstones. b. Hypertension c. Male sexPreoperative laboratory results are d. Receipt of chemotherapynotable for a hematocrit of 24% e. Asthmaand a urinalysis with 18–25 WBCsand gram-negative bacteria. On call 37. Which of the followingto the operating room he receives changes in the care of this patientintravenous penicillin. His ab- could decrease the chance of adomen is shaved in the operating postoperative wound infection?room. An open cholecystectomy is a. Increasing the length of the preop-performed and, despite a lack of erative hospital stay to prophylacti-indications, the common bile duct cally treat the asthma with steroidsis explored. The wound is closed b. Treating the urinary infection priorprimarily with a Penrose drain exit- to surgerying a separate stab wound. On c. Shaving the abdomen the nightpostoperative day 3 the patient prior to surgerydevelops a wound infection. d. Continuing the prophylactic antibi- otics for three postoperative days35. Which of the following changes e. Use of a closed drainage systemcould make this wound a less favor- brought out through the operative incisionable environment for infection?a. Decreasing the operative time and wound contamination by omitting the common bile duct explorationb. Placing a Penrose drain exiting directly through the lateral corner of the woundc. Using oral rather than intravenous penicillin perioperativelyd. Leaving a seroma in the wound to prevent desiccation of the tissuese. Reinforcing the wound closure with a sheet of prosthetic poly- propylene mesh
  19. 19. Pre- and Postoperative Care 11Items 38–39 40. Four days after surgical evacu- ation of an acute subdural The two solutions most com- hematoma, a 44-year-old manmonly used to maintain fluid and becomes mildly lethargic andelectrolyte balance in the postoper- develops asterixis. He has receivedative management of patients are 2400 mL of 5% dextrose in water5% dextrose in 0.9% sodium chlo- intravenously each day sinceride and lactated Ringer’s solution. surgery, and he appears well hydrated. Pertinent laboratory val-38. A correct statement regarding ues are as follows:5% dextrose in 0.9% saline iswhich of the following? • Serum electrolytes (meq/L): Na+a. It contains the same concentration 118; K+ 3.4; C1− 82; HCO3− 24 of sodium ions as does plasma • Serum osmolality: 242 mOsm/Lb. It can be given in large quantities without seriously affecting acid- • Urine sodium: 47 meq/L base balance • Urine osmolality: 486 mOsm/Lc. It is isosmotic with plasmad. It has a pH of 7.4 A correct statement about thise. It may cause a dilutional acidosis patient’s fluid and electrolyte status is which of the following?39. Correct statements regarding a. His low serum sodium indicateslactated Ringer’s solution include sodium deficiency, which shouldwhich of the following? be treated with 3% saline infusion b. He probably has the syndrome ofa. It contains a higher concentration inappropriate secretion of anti- of sodium ions than does plasma diuretic hormoneb. It is most appropriate for replace- c. His blood glucose level should be ment of nasogastric tube losses checked because the hyponatremiac. It is isosmotic with plasma may be artifactuald. It has a pH of less than 7.0 d. Water restriction is rarely effectivee. It may induce a significant meta- in severe cases of hyponatremia bolic acidosis e. The underlying problem is the inappropriate excretion of sodium (renal sodium wasting)
  20. 20. 12 Surgery41. A 43-year-old woman develops acute renal failure following an emer-gency resection of a leaking abdominal aortic aneurysm. Three days aftersurgery, the following laboratory values are obtained:• Serum electrolytes (meq/L): Na+ 127; K+ 5.9; C1− 92; HCO3− 15• Blood urea nitrogen: 82 mg/dL• Serum creatinine: 6.7 mg/dL The patient has gained 4 kg since surgery and is mildly dyspneic atrest. Eight hours after these values are reported, the electrocardiogramshown below is obtained. The initial treatment for this patient should bea. 10% calcium gluconate, 10 mLb. Digoxin, 0.25 mg every 3 h for three dosesc. Oral Kayexalated. Lidocaine, 100 mge. Emergent hemodialysis42. Prophylactic regimens of documented benefit in decreasing the risk ofpostoperative thromboembolism includea. Early ambulationb. External pneumatic compression devices placed on the upper extremitiesc. Elastic stockingsd. Leg elevation for 24 h postoperativelye. Dipyridamole therapy for 48 h postoperatively
  21. 21. Pre- and Postoperative Care 1343. Signs and symptoms associ-ated with early sepsis includea. Respiratory acidosisb. Decreased cardiac outputc. Hypoglycemiad. Increased arteriovenous oxygen dif- ferencee. Cutaneous vasodilation
  22. 22. 14 SurgeryDIRECTIONS: Each group of questions below consists of letteredoptions followed by numbered items. For each numbered item, select theappropriate lettered option(s). Each lettered option may be used once,more than once, or not at all. Choose exactly the number of optionsindicated following each item.Items 44–46 Match the gastrointestinal content at each site with its appropriateionic composition (meq/L). Na K C1 HCO3 a. 140 5 104 30 b. 140 5 75 115 c. 60 10 130 0 d. 10 26 10 30 e. 60 30 40 5044. Salivary (SELECT 1 COMPOSITION)45. Stomach (SELECT 1 COMPOSITION)46. Small bowel (SELECT 1 COMPOSITION)Items 47–50 A 42-year-old man has a calculated resting energy expenditure of 1800kcal/day (basal energy expenditure plus 10%). Match the following clinicalsituations with the appropriate daily energy requirement.a. 1600b. 2300c. 2800d. 3600e. 4500
  23. 23. Pre- and Postoperative Care 1547. Sepsis (SELECT 1 EXPENDI- 49. Third-degree burns of 60% ofTURE) body surface area (BSA) (SELECT 1 EXPENDITURE)48. Skeletal trauma (SELECT 1EXPENDITURE) 50. Prolonged starvation (SELECT 1 EXPENDITURE)
  24. 24. PRE- AND POSTOPERATIVE CARE Answers1. The answer is a. (Schwartz, 7/e, pp 65–66.) States of magnesiumexcess are characterized by generalized neuromuscular depression. Clini-cally, severe hypermagnesemia is rarely seen except in those patients withadvanced renal failure treated with magnesium-containing antacids.Hypermagnesemia is produced intentionally, however, by obstetricianswho use parenteral magnesium sulfate (MgSO4) to treat preeclampsia.MgSO4 is administered until depression of the deep tendon reflexes isobserved, a deficit that occurs with modest hypermagnesemia (over 4meq/L). Greater elevations of magnesium produce progressive weakness,which culminates in flaccid quadriplegia and in some cases respiratoryarrest from paralysis of the chest bellows mechanism. Hypotension mayoccur because of the direct arteriolar relaxing effect of magnesium.Changes in mental status occur in the late stages of the syndrome and arecharacterized by somnolence that progresses to coma.2. The answer is b. (Schwartz, 7/e, pp 57–63.) Acute severe hypona-tremia sometimes occurs following elective surgical procedures. It is usu-ally the result of the combination of appropriate postoperative stimulationof antidiuretic hormone and injudicious administration of excess freewater in the first few postoperative days. Totally sodium-free intravenousfluids (e.g., dextrose and water) should be given with great caution post-operatively, since occasionally the resulting hyponatremia can be associ-ated with sudden death from a flaccid heart or with severe permanentbrain damage. The condition is usually best treated by withholding freewater and allowing the patient to reequilibrate spontaneously. At levelsbelow 115 meq/L, seizures or mental obtundation may mandate treatmentwith hypertonic sodium solutions. This must be done with extreme carebecause the risk of fluid overload with acute pulmonary or cerebral edemais high.16
  25. 25. Pre- and Postoperative Care Answers 173. The answer is d. (Sabiston, 15/e, p 931.) Any patient who has lostmuch of the ileum (whether from injury, disease, or elective surgery) is athigh risk of developing enteric hyperoxaluria if the colon remains intact.Calcium oxalate stones will develop in at least 10% of these patients. Thecondition results from excessive absorption of oxalate from the colonthrough two related synergistic mechanisms: unabsorbed fatty acids com-bine with calcium, which prevents the formation of insoluble calciumoxalate and allows oxalate to remain available for colonic absorption; andunabsorbed fatty acids and bile acids also increase the permeability of thecolon to the oxalate.4. The answer is c. (Schwartz, 7/e, pp 452–455.) When oliguria occurspostoperatively, it is important to differentiate between low output causedby the physiologic response to intravascular hypovolemia and that causedby acute tubular necrosis. The fractional excretion of sodium (FENa) is anespecially useful test to aid in this differentiation. Values of FE < 1% in anoliguric setting indicate aggressive sodium reclamation in the tubules; val-ues above this suggest tubular injury. The fractional excretion is a simplecalculation: (urine Na × serum creatinine) ÷ (serum sodium × urinary cre-atinine). In the setting of postoperative hypovolemia, all findings wouldreflect the kidney’s efforts to retain volume: the urine sodium would bebelow 20 meq/L, the urine chloride would not be helpful except in themetabolically alkalotic patient, the serum osmolality would be over 500mOsm/kg, and the urine/serum creatinine ratio would be above 40.5. The answer is c. (Schwartz, 7/e, pp 64–66.) Magnesium deficiency iscommon in malnourished patients and patients with large gastrointestinalfluid losses. The neuromuscular effects resemble those of calcium defi-ciency—namely, paresthesia, hyperreflexia, muscle spasm, and ultimatelytetany. The cardiac effects are more like those of hypercalcemia. An electro-cardiogram therefore provides a rapid means of differentiating betweenhypocalcemia and hypomagnesemia. Hypomagnesemia also causes potas-sium wasting by the kidney. Many hospital patients with refractory hypocal-cemia will be found to be magnesium deficient. Often this deficiencybecomes manifest during the response to parenteral nutrition when normalcellular ionic gradients are restored. A normal blood pH and arterial PCO2rule out hyperventilation. The serum calcium in this patient is normal when
  26. 26. 18 Surgeryadjusted for the low albumin. Hypomagnesemia causes functional hypo-parathyroidism, which can lower serum calcium and thus result in a com-bined defect.6. The answer is c. (Schwartz, 7/e, pp 143–149.) Many clinical and experi-mental studies have looked at the optimum bowel preparation and preoper-ative regimen for elective colonic surgery to reduce the postoperativeinfectious complications of wound infection, intraabdominal abscess, andanastomotic leakage. Currently, a postoperative rate of wound infection ofonly 5% can be attained by combining mechanical cleansing, oral antibiotics,and perioperative parenteral antibiotics. The type of mechanical cleansingdoes not matter as long as it is effective. Preoperative oral antibiotics may beadministered one or more days prior to surgery and should cover aerobesand anaerobes (e.g., neomycin-erythromycin). Parenteral antibiotics effectiveagainst aerobes and anaerobes (e.g., cefoxitin) should be administered on callto the operating room as a single dose and no more than 24 h postoperatively.Both antibiotic regimens yield maximum prophylaxis without fostering resis-tant transformation of microbes. Procedures that require operative timegreater than 3 h or that involve the extraperitoneal rectum are associated withan increased risk of infectious complications.7. The answer is c. (Schwartz, 7/e, pp 462–465.) There are several recom-mended interventions in cardiac patients who are undergoing noncardiacsurgery. The two factors that correlate best with postoperative life-threatening or fatal cardiac complications are myocardial infarction (trans-mural or subendocardial) and uncontrolled congestive heart failure.Hence, delay of elective surgery for 6 mo after myocardial infarction andpreoperative control of congestive heart failure with diuretics and digitalis,in severe cases, will have the greatest effect in decreasing the risks ofsurgery. A patient’s cardiac medications should be continued preopera-tively, including during the morning of surgery, to maintain adequate ther-apeutic levels. This is especially true for beta blockers, which can manifestwithdrawal rebound hypertension and tachycardia approximately 24 hafter discontinuation. Patients with prosthetic valves or valvular heart dis-ease should be given prophylactic antibiotics to prevent seeding of theirvalves during episodes of significant bacteremia. This most commonlyoccurs during gastrointestinal or genitourinary procedures. Ampicillin and
  27. 27. Pre- and Postoperative Care Answers 19gentamicin cover the flora frequently encountered, including enterococciand gram-negative organisms.8. The answer is d. (Greenfield, 2/e, pp 259–266.) Both the arterial pHand the PCO2 are elevated in the patient presented in the question; the dis-turbance is alkalosis with hypoventilation. The PCO2 typically increases by0.5–1.0 pKa for each meq/L increase in serum bicarbonate. These findingssuggest that the hypoventilation is compensatory rather than a primaryphenomenon. This assumption is further supported by the absence of clin-ical lung disease.9. The answer is a. (Greenfield, 2/e, pp 259–266.) The development of aclinically significant metabolic alkalosis in a patient requires not only theloss of acid or addition of alkali, but renal responses that maintain the alka-losis. The normal kidney can tremendously augment its excretion of acid oralkali in response to changes in ingested load. However, in the presence ofsignificant volume depletion and consequent excessive salt and waterretention, the tubular maximum for bicarbonate reabsorption is increased.Correction of volume depletion alone is usually sufficient to correct thealkalosis, since the kidney will then excrete the excess bicarbonate. HClinfusion is usually unnecessary and can be dangerous. Acetazolamide isunlikely to be effective in the face of distal Na+ reabsorption (in exchangefor H+ secretion). Moreover, to the extent that acetazolamide causes natri-uresis, it will exacerbate the volume depletion.10. The answer is d. (Greenfield, 2/e, pp 260–266.) The patient presentedin the question is in a state of metabolic acidosis as shown by a markedlyincreased anion gap of 28 meq unmeasured anions per liter of plasma.However, the respiratory response is greater than can be explained by acompensatory response, since the patient is mildly alkalemic. The distur-bance cannot be pure respiratory alkalosis, since the serum bicarbonatedoes not drop below 15 meq/L as a result of renal compensation and theanion gap does not vary by more than 1–2 meq/L from its normal value of12 in response to a respiratory disturbance. The renal response to hyper-ventilation involves wasting of bicarbonate and compensatory retention ofchloride; it does not involve a change in the concentration of “unmeasured”anions, such as albumin and organic acids.
  28. 28. 20 Surgery11. The answer is b. (Anderson, Ann Intern Med 85:745–748, 1976.) Theacid-base disturbance in the patient described in the previous questiondemonstrates the value of extracting all available information from a smallamount of rapidly retrievable data, e.g., arterial blood gases. Salicylatesdirectly stimulate the respiratory center and produce respiratory alkalosis.By building up an accumulation of organic acids, salicylates also produce aconcomitant metabolic acidosis. Characteristically both disturbances existsimultaneously following massive ingestion of salicylates. If sedative agentshave been taken as well, the respiratory alkalosis (and even the respiratorycompensation) may be absent. Phenformin and methanol overdoses alsoproduce “high-anion-gap” metabolic acidosis, but without the simultane-ous respiratory disturbance. In the case presented, the patient’s history oftinnitus in conjunction with her mixed metabolic acidosis–respiratoryalkalosis is essentially pathognomonic of salicylate intoxication.12. The answer is c. (Sabiston, 15/e, pp 131–133.) Whenever significantbleeding is noted in the early postoperative period, the presumptionshould always be that it is due to an error in surgical control of blood ves-sels in the operative field. Hematologic disorders that are not apparent dur-ing the long operation are most unlikely to surface as problemspostoperatively. Blood transfusion reactions can cause diffuse loss of clotintegrity; the sudden appearance of diffuse bleeding during an operationmay be the only evidence of an intraoperative transfusion reaction. In thepostoperative period, transfusion reactions usually present as unexplainedfever, apprehension, and headache—all symptoms difficult to interpret inthe early postoperative period. Factor VIII deficiency (hemophilia) wouldalmost certainly be known by history in a 65-year-old man, but if not,intraoperative bleeding would have been a problem earlier in this longoperation. Severely hypothermic patients will not be able to form clotseffectively, but clot dissolution does not occur. Care should be taken to pre-vent the development of hypothermia during long operations through theuse of warmed intravenous fluid, gas humidifiers, and insulated skin barri-ers.13. The answer is c. (Goldman, J Cardiothorac Anesth 1:237, 1987.) Thework of Goldman and others has served to identify risk factors for periop-erative myocardial infarction. The highest likelihood is associated withrecent myocardial infarction: the more recent the event, the higher the risk
  29. 29. Pre- and Postoperative Care Answers 21up to 6 mo. It should be noted, however, that the risk never returns to nor-mal. A non-Q-wave infarction may not have destroyed much myocardium,but it leaves the surrounding area with borderline perfusion; hence the par-ticularly high risk of subsequent perioperative infarction. Evidence of con-gestive heart failure, such as jugular venous distention, or S3 gallop alsocarries a high risk, as does the frequent occurrence of ectopic beats. Oldage and emergency surgery are risk factors independent of these others.Coronary revascularization by coronary artery bypass graft (CABG) tendsto protect against myocardial infarction. Smoking, diabetes, hypertension,and hyperlipidemia (all of which predispose to coronary artery disease) aresurprisingly not independent risk factors, although they may increase thedeath rate should an infarct occur. The value of this information and dataderived from further testing is that it identifies the patient who needs to bemonitored invasively with a systemic arterial catheter and pulmonary arte-rial catheter. Most perioperative infarcts occur postoperatively when the“third-space” fluids return to the circulation, which increases the preloadand the myocardial oxygen consumption. This generally occurs around thethird postoperative day.14. The answer is c. (Schwartz, 7/e, pp 966–967.) Acute mesentericischemia may be difficult to diagnose. The condition should be suspected inpatients with either systemic manifestations of arteriosclerotic vascular dis-ease or low cardiac output states associated with a sudden development ofabdominal pain that is out of proportion to the physical findings. Lactic aci-dosis and an elevated hematocrit reflecting hemoconcentration are commonlaboratory findings. Abdominal films show a nonspecific ileus pattern. Thecause may be embolic occlusion or thrombosis of the superior mesentericartery, primary mesenteric venous occlusion, or nonocclusive mesentericischemia secondary to low cardiac output states. A mortality of 65–100% isreported. The majority of affected patients are at high operative risk, butsince early diagnosis followed by revascularization or resectional surgery orboth is the only hope for survival, celiotomy must be performed once thediagnosis of arterial occlusion or bowel infarction has been made. Initialtreatment of nonocclusive mesenteric ischemia includes measures toincrease cardiac output and blood pressure and the direct intraarterial infu-sion of vasodilators such as papaverine into the superior mesenteric system.The patient presented in the question is at risk for both occlusive andnonocclusive mesenteric ischemic disease. If his clinical status permits,
  30. 30. 22 Surgeryangiographic studies should be performed before the operation to establishthe diagnosis and to determine whether embolectomy, revascularization, ornonsurgical management is indicated as initial treatment.15. The answer is b. (Schwartz, 7/e, pp 1007–1014.) This patient has aleft iliofemoral vein thrombosis, as evidenced by sudden massive swellingof her entire left lower extremity. Noninvasive venous testing should bequite helpful as the venous obstruction extends above the knee; therefore,venography and x-ray exposure are unnecessary. Heparin is the preferredagent because it does not cross the placenta, while warfarin does. The venacaval filter is not indicated because there is no contraindication to heparintherapy and there has not been any evidence of pulmonary embolus.16. The answer is e. (Sabiston, 15/e, pp 134–135.) von Willebrand dis-ease has an autosomal dominant pattern of inheritance that affects bothmen and women. The deficiency of factor VIII activity is generally lesssevere than in classic hemophilia and tends to fluctuate even in anuntreated patient. However, the bleeding tendency is compounded byabnormal platelet function. This is responsible for the common occurrenceof epistaxis and menorrhagia. In 70% of patients, platelets fail to aggregatein response to the diagnostic reagent ristocetin. Transfusion of cryoprecip-itate provides factor VIII R:WF (the von Willebrand factor), whereas infu-sions of high-purity concentrates of factor VIII:C are not effective. Thesepatients do not generally require treatment unless they need surgery or areseverely injured; therefore, they have not usually received the contami-nated concentrates responsible for the 80% prevalence of HIV seropositiv-ity among hemophiliacs.17. The answer is b. (Schwartz, 7/e, pp 85–87.) Intraoperative and post-operative hemorrhage is a significant problem in the patient with poly-cythemia vera. Despite thrombocytosis, these patients have a hemorrhagictendency generally ascribed to a qualitative deficiency of the platelets. Elec-tive surgery should be postponed until the hematocrit and platelet countreach normal levels. Alkylating agents, such as busulfan or chlorambucil,are effective in this regard. In the emergency situation, phlebectomy shouldbe performed prior to operation and also an especially careful hemostatictechnique should be employed. Infection is also a problem in patients with
  31. 31. Pre- and Postoperative Care Answers 23polycythemia vera, but hemorrhagic problems are the more frequentlyencountered complications.18. The answer is c. (Schwartz, 7/e, p 96.) When large amounts of bankedblood are transfused, the recipient becomes deficient in factors V and VIII(the “labile” factors) and an acquired coagulopathy ensues. Since bankedblood is also deficient in platelets, thrombocytopenia may also develop.19. The answer is b. (Schwartz, 7/e, p 467.) The misconception that theentire bowel does not function in the early postoperative period is stillwidely held. Intestinal motility and absorption studies have clarified thepatterns by which bowel activity resumes. The stomach remains uncoordi-nated in its muscular activity and does not empty efficiently for about 24 hafter abdominal procedures. The small bowel functions normally withinhours of surgery and is able to accept nutrients promptly, either by naso-duodenal or percutaneous jejunal feeding catheters or, after 24 h, by gas-tric emptying. The colon is stimulated in large measure by the gastrocolicreflex but ordinarily is relatively inactive for 3–4 days.20. The answer is a. (Greenfield, 2/e, pp 96–97.) In a heparinized patientwith significant life-threatening hemorrhage, immediate reversal of heparinanticoagulation is indicated. Protamine sulfate is a specific antidote toheparin and should be given as 1 mg for each 100 U heparin if hemorrhagebegins shortly after a bolus of heparin. For a patient (such as this) in whomheparin therapy is ongoing, the dose should be based on the half-life ofheparin (90 min). Since protamine is also an anticoagulant, only half thecalculated circulating heparin should be reversed. The protaminizationshould be followed by placement of a percutaneous vena cava filter (Green-field filter). In this critically ill patient, exploration of the retroperitonealspace would be surgically challenging and meddlesome.21. The answer is d. (Diettrich, Arch Surg 126:860–865, 1991.) Patientswho have AIDS frequently present with problems that potentially requiresurgical care. The involvement of surgeons with these patients will increaseas more effective treatments are developed and the AIDS patient’s survivalis prolonged. AIDS patients not only suffer from common surgical illnesses,they also develop problems especially associated with their altered immune
  32. 32. 24 Surgerystatus, such as bleeding from gastrointestinal lymphomas or Kaposi’slesions, bowel ischemia, perforation from parasitic or viral infection, acal-culous cholecystitis, and retroperitoneal and intraabdominal masses due tomassive lymphadenitis. With the exception of tracheostomy, experiencehas demonstrated that surgery can be performed with acceptable morbid-ity and mortality and that it seems to provide comfort and prolong qualitylife. Though it may facilitate nursing care, tracheostomy does not reverse orslow the pulmonary failure once the patient has become ventilator depen-dent.22. The answer is c. (Schwartz, 7/e, pp 1639–1640.) Acute adrenal insuffi-ciency is classically manifested as changing mental status, increased tem-perature, cardiovascular collapse, hypoglycemia, and hyperkalemia. Thediagnosis can be difficult to make and requires a high index of suspicion. Itsclinical presentation is similar to that of sepsis; however, sepsis is generallyassociated with hyperglycemia and no significant change in potassium. Thetreatment for adrenal crisis is hydrocortisone 100 mg intravenously, volumeresuscitation, and other supportive measures to treat any new or ongoingstress. Then, 200–400 hydrocortisone mg is administered over the next 24h, followed by a taper of the steroid as tolerated.23. The answer is c. (Schwartz, 7/e, pp 95–96.) Transfusions with freshfrozen plasma (FFP) are given to replenish clotting factors. The effective-ness of the transfusion in maintaining hemostasis is dependent on thequantity of each factor delivered and its half-life. The half-life of the moststable clotting factor, factor VII, is 4–6 h. A reasonable transfusion schemewould be to give FFP on call to the operating room. This way the transfu-sion is complete prior to the incision with circulating factors to cover theoperative and immediate postoperative period.24. The answer is c. (Sabiston, 15/e, pp 344–345.) Serosanguineousdrainage is classically associated with fascial dehiscence. A reasonableapproach to this problem is to remove several sutures and gently explorethe wound to determine the extent of the dehiscence. A small fascial dehis-cence (1–2 cm) can be treated conservatively with local wound care and anabdominal binder to support the fascia. A larger dehiscence requires reop-eration for formal reclosure of the fascia. High-risk patients with a large fas-cial dehiscence may be treated with an abdominal binder and modified bed
  33. 33. Pre- and Postoperative Care Answers 25rest, which allows both intraabdominal adhesion formation and local gran-ulation. Although fascial dehiscence can occur from local infection, it isusually not an infectious process and does not require parenteral antibiotictherapy.25. The answer is d. (Sabiston, 15/e, pp 344–345.) The appearance of agush of serosanguineous fluid from an abdominal incision is pathogno-monic of a disruption of the deep fascia. The source of large amounts ofserous fluid is the peritoneum. The temptation to avoid direct reclosure ofthese wounds when the fascial defect is larger than 1–2 cm should beresisted because delayed resumption of normal ambulation and activitywith a late ventral hernia is the best outcome to be hoped for. Evisceration,wound infection, or protracted convalescence is far more likely. Recurrenceof eviscerations following reclosure of these wounds is extremely rare,though 10–20% will later develop incisional hernias. The Scultetus binderis a corsetlike cloth wrap that was once a favored support to reduce likeli-hood of evisceration in those wounds in which the fascia was left unre-paired after dehiscence.26. The answer is d. (Sabiston, 15/e, p 124.) Allergic and febrile reactionsoccur in about 1% of all transfusions. Hemolytic transfusion reactions aremuch less common (0.2%) with fatal reactions in 1:100,000 transfusions.Hemolytic transfusion reactions are due to the reaction of recipient anti-bodies against transfused antigens. These reactions can be both immediateand delayed. Symptoms of a hemolytic transfusion reaction include fever,chills, and pain and heat at the infusion site, as well as respiratory distress,anxiety, hypotension, and oliguria. During surgery a hemolytic transfusionreaction can manifest as abnormal bleeding.27. The answer is e. (Sabiston, 15/e, p 124.) Hemolytic transfusion reac-tions lead to hypotension and oliguria. The increased hemoglobin in theplasma will be cleared via the kidneys, which leads to hemoglobinuria.Placement of an indwelling Foley catheter with subsequent demonstrationof oliguria and hemoglobinuria not only confirms the diagnosis of ahemolytic transfusion reaction but is useful in monitoring corrective ther-apy. Treatment begins with discontinuation of the transfusion, followed byaggressive fluid resuscitation to support the hypotensive episode andincrease urine output. Inducing a diuresis through aggressive fluid resusci-
  34. 34. 26 Surgerytation and osmotic diuretics is important to clear the hemolyzed red cellmembranes, which can otherwise collect in glomeruli and cause renaldamage. Alkalinization of the urine (pH > 7) helps prevent hemoglobinclumping and renal damage. Steroids do not have a role in the treatment ofhemolytic transfusion reactions.28. The answer is d. (Sabiston, 15/e, p 133.) Platelet dysfunction, mea-sured by bleeding time, has been associated with a long list of drugs.Among nonsteroidal anti-inflammatory and analgesic medications, aspirin,indomethacin, phenylbutazone, acetominophen, and phenacetin havebeen implicated, along with aminopyrine and codeine. Ibuprofen, how-ever, has not. In addition, many antibiotics, anticonvulsants, and sedativeshave been associated with thrombasthenia. Any time platelet abnormalitiesare suspected, a careful review of the drugs the patient is receiving shouldbe undertaken, and a measurement should be made of the platelet countand bleeding time. Platelet dysfunction does not affect APTT, PT, reptilase,or thrombin times.29. The answer is d. (Sabiston, 15/e, pp 60–62.) The metabolic responseto surgery (and other trauma) is a result of neuroendocrine stimulation thatsharply accelerates protein breakdown, stimulates gluconeogenesis, andproduces glucose intolerance. The glycogen stores are rapidly depletedbecause of a fall in insulin and a rise in glucagon levels in the plasma. Theperipheral effects of the neuroendocrine secretion result in an increase inplasma levels of amino acids, free fatty acids, lactate, glucose, and glycerol.In the liver, the cortisol and glucagon stimulate glycogenolysis, gluconeo-genesis, and increased substrate uptake.30. The answer is a. (Berci, Am J Surg 161:332–335, 1991.) The indica-tions for diagnostic laparoscopic exploration are increasing rapidly as thetools and techniques for such intervention improve. In the stable traumapatient with a tangential gunshot wound or with a stab wound to the lowerchest wall or abdomen, laparoscopy may show no actual peritoneal pene-tration and might make a laparotomy unnecessary. If the peritoneum ordiaphragm is injured, subsequent laparotomy and exploration are gener-ally indicated to exclude other possible injuries and to facilitate repair ofthe diaphragm. All unstable patients or those with signs of peritoneal irri-tation (e.g., rebound tenderness) should undergo prompt celiotomy.
  35. 35. Pre- and Postoperative Care Answers 27Laparoscopic staging of malignancies allows improved preoperative assess-ment of the resectability of intraabdominal malignancies. The procedurehas proved particularly useful in cases with pancreatic carcinoma. Laparo-scopic evaluations may expedite differentiation of competing etiologies ofright lower quadrant pain; this would allow appendectomy for appendici-tis or appropriate therapy such as intravenous antibiotics for pelvic inflam-matory disease and preempt celiotomy. In critically ill patients, thedevelopment of low flow or embolic ischemic insults to the bowel can befatal if not recognized and treated early. Many such patients are alreadybeing ventilated in intensive care units; in this setting, bedside laparoscopycan ascertain the need for early exploration for bowel revascularization orresection.31. The answer is d. (Schwartz, 7/e, p 1693.) Postthyroidectomyhypocalcemia is usually due to transient ischemia of the parathyroid glandsand is self-limited. When it becomes symptomatic, it should be treatedwith intravenous infusions of calcium. In most cases the problem isresolved in several days. If hypocalcemia persists, oral therapy is thenadded with calcium gluconate. Vitamin D preparations are only used ifhypocalcemia is prolonged and permanent hypocalcemia is suspected.There is no role for thyroid hormone replacement or magnesium sulfate inthe treatment of hypocalcemia.32. The answer is c. (Schwartz, 7/e, p 64.) Hypocalcemia is associatedwith a prolonged QT interval and may be aggravated by both hypomagne-semia and alkalosis. Serum calcium levels below 7.0 mg/dL, encounteredmost frequently following parathyroid or thyroid surgery or in patientswith acute pancreatitis, should be treated with intravenous calcium glu-conate or lactate. The myocardium is very sensitive to calcium levels; there-fore calcium is considered a positive inotropic agent. Calcium increases thecontractile strength of cardiac muscle as well as the velocity of shortening.In its absence the efficiency of the myocardium decreases. Hypocalcemiaoften occurs with hypoproteinemia even though the ionized serum calciumfraction remains normal.33. The answer is b. (Schwartz, 7/e, p 56.) Bile and the fluids found inthe duodenum, jejunum, and ileum all have an electrolyte content similarto that of Ringer’s lactate. Saliva, gastric juice, and right colon fluids have
  36. 36. 28 Surgeryhigh K+ and low Na+ content. Pancreatic secretions are high in bicarbonate.It is important to consider these variations in electrolyte patterns when cal-culating replacement requirements following gastrointestinal losses.34. The answer is d. (Schwartz, 7/e, p 63.) Reduction of an elevatedserum potassium level is important to avoid the cardiovascular complica-tions that ultimately culminate in diastolic cardiac arrest. Kayexalate is acation exchange resin that is instilled into the gastrointestinal tract andexchanges sodium for potassium ions. Its use is limited to semiacute andchronic potassium elevations. Sodium bicarbonate causes a rise in serumpH and shifts potassium intracellularly. Administration of glucose initiatesglycogen synthesis and uptake of potassium. Insulin can be used in con-junction with this to aid in the shift of potassium intracellularly. Calciumgluconate does not affect the serum potassium level but rather counteractsthe myocardial effects of hyperkalemia.35–37. The answers are 35-a, 36-d, 37-b. (Schwartz, 7/e, pp 448–452.)The determinants of a postoperative wound infection include those relatedto the bacteria, the environment (i.e., the wound), and the host’s defensemechanisms. Within this triad there are factors predetermined by the sta-tus of the patient [e.g., age, obesity, steroid dependence, multiple diagnoses(more than three), immunosuppression] and by the type of procedure(e.g., contaminated versus clean, emergent versus elective). However, thereare several factors that can be optimized by the surgeon. Decreasing thebacterial inoculum and virulence by limiting the patient’s prehospital stay,clipping the operative site in the operating room, administering periopera-tive antibiotics (within a 24-h period surrounding operation) with anappropriate antimicrobial spectrum, treating remote infections, avoidingbreaks in technique, using closed drainage systems (if needed at all) thatexit the skin away from the surgical incision, and minimizing the durationof the operation have all been shown to decrease postoperative infection.Making a wound less favorable to infection requires attention to basic hal-stedian principles of hemostasis, anatomic dissection, and gentle handlingof tissues as well as limiting the amount of foreign body and necrotic tissuein the wound. Although they are the most difficult factors to influence, hostdefense mechanisms can be improved by optimizing nutritional status, tis-sue perfusion, and oxygen delivery.
  37. 37. Pre- and Postoperative Care Answers 2938–39. The answers are 38-e, 39-d. (Schwartz, 7/e, pp 66–67.) Isotonicsaline solutions contain 154 meq/L of both sodium and chloride ions. Eachion is in a substantially higher concentration than is found in the normalserum (Na = 142 meq/L; C1 = 103 meq/L). When isotonic solutions aregiven in large quantities, they overload the kidney’s ability to excrete chlo-ride ion, which results in a dilutional acidosis. They also may intensify pre-existing acidosis by reducing the base bicarbonate:carbonic acid ratio inthe body. Isotonic saline solutions are particularly useful in hyponatremicor hypochloremic states and whenever a tendency to metabolic alkalosis ispresent, as occurs with significant nasogastric suction losses or vomiting. Administration of lactated Ringer’s solution is appropriate for replac-ing gastrointestinal losses and correcting extracellular fluid deficits. Con-taining 130 meq/L sodium, lactated Ringer’s is hyposmolar with respect tosodium and provides approximately 150 mL of free water with each litergiven. Although this is ordinarily not a significant load, in some clinical sit-uations it can be. Lactated Ringer’s is sufficiently “physiological” to enableadministration of large amounts without significantly affecting the body’sacid-base balance. It is worth noting that both isotonic saline and lactatedRinger’s are acidic with respect to the plasma: 0.9% NaC1/5% dextrose hasa pH of 4.5; lactated Ringer’s has a pH of 6.5.40. The answer is b. (Schwartz, 7/e, pp 473–474.) The patient presentedhas the syndrome of inappropriate antidiuretic hormone secretion (SIADH).Although this syndrome is primarily associated with diseases of the centralnervous system or of the chest (e.g., oat cell carcinoma of the lung), exces-sive amounts of antidiuretic hormone are also present in most postoperativepatients. The pathophysiology of SIADH involves an inability to dilute theurine; administered water is therefore retained, which produces dilutionalhyponatremia. Body sodium stores and fluid balance are normal, as evi-denced by the absence of the clinical findings suggestive of abnormalities ofextracellular fluid volume. While hypertonic saline infusions can transientlyimprove hyponatremia, the appropriate therapy is to restrict water ingestionto a level below the patient’s ability to excrete water. Hypertonic saline maybe dangerous, since it can shift accumulated water into the extracellularfluid and precipitate pulmonary edema in the patient who suffers from lowcardiac reserves. Hyperglycemia cannot account for the hyponatremia seenin this patient because the serum osmolality, as well as the serum sodium, is
  38. 38. 30 Surgerydepressed. Hyponatremia resulting from hyperglycemia would be associ-ated with an elevated serum osmolality.41. The answer is a. (Schwartz, 7/e, p 63.) The electrocardiogram exhib-ited in the question demonstrates changes that are essentially diagnostic ofsevere hyperkalemia. Correct treatment for the affected patient includesadministration of a source of calcium ions (which will immediately opposethe neuromuscular effect of potassium) and administration of sodium ions(which, by producing a mild alkalosis, will shift potassium into cells); eachwill temporarily reduce serum potassium concentration. Infusion of glu-cose and insulin would also effect a temporary transcellular shift of potas-sium. However, these maneuvers are only temporarily effective; definitivetreatment calls for removal of potassium from the body. The sodium-potassium exchange resin sodium polystyrene sulfonate (Kayexalate)would accomplish this removal, but over a period of hours and at the priceof adding a sodium ion for each potassium ion that is removed. Hemodial-ysis or peritoneal dialysis is probably required for this patient, since theseprocedures also rectify the other consequences of acute renal failure, butthey would not be the first line of therapy given the acute need to reducethe potassium level. Both lidocaine and digoxin would not only be ineffec-tive but contraindicated, since they would further depress the myocardialconduction system.42. The answer is b. (Sabiston 15/e, pp 1594–1616.) The problem of deepvein thrombosis and pulmonary embolism is significant in general surgery.There are approximately 2.5 million episodes of deep vein thrombosis and600,000 pulmonary embolic events that result in 200,000 deaths annually.The problem is exacerbated by the disorder’s frequent unheralded progres-sion—only 20–25% of fatal pulmonary emboli are suspected clinically bythe physician or manifest by classic signs or symptoms. The fact that mostdeaths due to pulmonary embolism occur before effective therapy can bestarted highlights the importance of preventive measures. Several docu-mented factors help identify those at increased risk, including age greaterthan 40, obesity, malignancy, venous disease, congestive heart failure andatrial fibrillation, and prolonged bed rest. Virchow initially attributedvenous thrombosis to the combination of venous stasis, hypercoagulability,and endothelial injury. The first two conditions are exacerbated by opera-tive positioning and stress such that 25% of patients at moderate risk will
  39. 39. Pre- and Postoperative Care Answers 31develop venous thromboembolism, 50% within 24 h and 80% within 72 hpostoperatively. The recommendation for prophylaxis in those at high riskis preoperative anticoagulation with warfarin. No prophylaxis is recom-mended for those at low risk (e.g., those less than age 40 with normalweight and no venous disease). Prophylactic regimens for those at moder-ate risk are basically chemical or mechanical, and the best two, which haveequivalent effectiveness, are representative of each type. First, low-doseheparin (5000 U) started 2 h preoperatively and continued every 12 hpostoperatively will decrease the risk of deep vein thrombosis from 25 to7% and of major pulmonary embolus from 6 to 0.6%. External pneumaticcompression devices not only obviate venous stasis, but they also have asystemic effect on coagulation, such that use on the arms also significantlyreduces venous thromboembolism of the lower extremities. Early ambula-tion, elastic stockings, leg elevation, and dipyridamole (Persantine) alonehave not been documented to be effective.43. The answer is e. (Schwartz, 7/e, pp 115–120.) It is important to iden-tify and treat occult or early sepsis before it progresses to septic shock andthe associated complications of multiple organ failure. An immunocom-promised host may not manifest some of the more typical signs and symp-toms of infection, such as elevated temperature and white cell count; thisforces the clinician to focus on more subtle signs and symptoms. Early sep-sis is a physiologically hyperdynamic, hypermetabolic state representing asurge of catecholamines, cortisol, and other stress-related hormones. Achanging mental status, tachypnea that leads to respiratory alkalosis, andflushed skin are often the earliest manifestations of sepsis. Intermittenthypotension requiring increased fluid resuscitation to maintain adequateurine output is characteristic of occult sepsis. Hyperglycemia and insulinresistance during sepsis are typical in diabetic as well as nondiabeticpatients. This relates to the gluconeogenic state of the stress response. Thecardiovascular response to early sepsis is characterized by an increased car-diac output, decreased systemic vascular resistance, and decreased periph-eral utilization of oxygen, which yields a decreased arteriovenous oxygendifference.44–46. The answers are 44-d, 45-c, 46-a. (Schwartz, 7/e, p 56.) One ofthe most common causes of dehydration and metabolic disarray in surgicalpatients is the failure to replace gastrointestinal losses. External losses can
  40. 40. 32 Surgeryoften be collected for measurement of volume and ionic composition.Accurate replacement of these measured losses is clearly the best method ofavoiding imbalance. However, a knowledge of the ionic composition of theintestinal contents at various sites permits an accurate estimate for earlyreplacement. Most of these secretions start as extracellular fluid (with acomposition similar to that of plasma) and are modified by intestinalglands. The stomach substitutes hydrogen ions for sodium and thus elimi-nates all but a tiny fraction of bicarbonate. The glands of the small intestinesecrete various amounts of bicarbonate; the chloride content is depressedto an equivalent degree (to maintain ionic balance). Colonic contents(stool) and saliva are most notable for their potassium content. Stool alsohas a high bicarbonate content. Severe diarrhea can therefore cause potas-sium depletion and a metabolic acidosis.47–50. The answers are 47-c, 48-b, 49-d, 50-a. (Schwartz, 7/e, pp33–40.) Resting energy expenditure in the nonstressed patient is approxi-mately 10% greater than basal energy expenditure. The resting energyexpenditure increases directly proportional to the degree of stress. Studiesby Kinney and associates using indirect calorimetry have documented therelative degree of increase in resting energy expenditure for a variety ofclinical situations. The following table summarizes these results: Change in Energy Clinical Situation Expenditure Prolonged starvation Decreased 10–30% Skeletal trauma Increased 10–30% Sepsis Increased 30–60% Third-degree burns Ͼ 20% BSA Increased 50–100%
  41. 41. CRITICAL CARE:ANESTHESIOLOGY, BLOODGASES, RESPIRATORY CARE QuestionsDIRECTIONS: Each item below contains a question or incompletestatement followed by suggested responses. Select the one best response toeach question.51. The most common physio- 53. In a hemolytic reaction causedlogic cause of hypoxemia is by an incompatible blood transfu-a. Hypoventilation sion, the treatment that is mostb. Incomplete alveolar oxygen diffu- likely to be helpful is sion a. Promoting a diuresis with 250 mlc. Ventilation-perfusion inequality of 50% mannitold. Pulmonary shunt flow b. Treating anuria with fluid ande. Elevated erythrocyte 2,3-diphos- potassium replacement phoglycerate level (2,3-DPT) c. Acidifying the urine to prevent hemoglobin precipitation in the52. Generally accepted indications renal tubulesfor mechanical ventilatory support d. Removing foreign bodies, such asinclude Foley catheters, which may cause hemorrhagic complicationsa. PaO2 of less than 70 kPa and PaCO2 of e. Stopping the transfusion immedi- greater than 50 kPa while breathing ately room airb. Alveolar-arterial oxygen tension difference of 150 kPa while breath- 54. Which of the following inhala- ing 100% O2 tion anesthetics accumulates inc. Vital capacity of 40–60 mL/kg air-filled cavities during generald. Respiratory rate greater than 35 anesthesia? breaths/min a. Diethyl ethere. A dead space:tidal volume ratio b. Nitrous oxide (VD/VT) less than 0.6 c. Halothane d. Methoxyflurane e. Trichloroethylene 33 Terms of Use
  42. 42. 34 Surgery55. Major alterations in pul- 56. The curve depicted belowmonary function associated with plots the normal relationship ofadult respiratory distress syndrome arterial PO2 and percentage of(ARDS) include hemoglobin saturation with othera. Hypoxemia variables controlled at pH 7.4,b. Increased pulmonary compliance PaCO2 40 kPa, temperature 37°Cc. Increased resting lung volume (98.6°F), and hemoglobin 15 g/dL.d. Increased functional residual Which of the following statements capacity regarding this oxygen dissociatione. Decreased dead space ventilation relationship is true? 100 % Hb Saturation 50 50 100 PO2 torr a. Modest decrements of arterial PO2 have a major effect on alveolar oxy- gen uptake b. Modest decrements of hemoglobin saturation have a major effect on tissue oxygen uptake c. The curve shifts to the left with aci- dosis d. The curve shifts to the left follow- ing banked blood transfusion e. The curve is unaffected by chronic lung disease
  43. 43. Critical Care:Anesthesiology, Blood Gases, Respiratory Care 3557. A 64-year-old man afflicted 59. Which statement regardingwith severe emphysema, who re- transmission of viral illness throughceives oxygen therapy at home, is homologous blood transfusion isadmitted to the hospital because of true?upper gastrointestinal bleeding. a. The most common viral agentThe bleeding ceases soon after transmitted via blood transfusionadmission, and the patient in the United States is humanbecomes agitated and then disori- immune deficiency virus (HIV)ented; he is given intramuscular b. Blood is routinely tested for cyto-diazepam (Valium), 5 mg. Twenty megalovirus (CMV) because CMVminutes later he is unresponsive. infection is often fatal c. The most frequent infectious com-Physical examination reveals a stu- plication of blood transfusion con-porous but arousable man who has tinues to be viral meningitispapilledema and asterixis. Arterial d. Up to 10% of those who developblood gases are pH 7.17; PO2 42 posttransfusion hepatitis will de-kPa; PCO2 95 kPa. The best immedi- velop cirrhosis or hepatoma or bothate therapy would be to e. The etiologic agent in posttrans-a. Correct hypoxemia with high-flow fusion hepatitis remains undiscov- nasal oxygen eredb. Correct acidosis with sodium bicar- bonatec. Administer intravenous dexameth- asone, 10 mgd. Intubate the patiente. Call for neurosurgical consultation58. Dopamine is a frequently useddrug in critically ill patients be-causea. At high doses it increases splanch- nic flowb. At high doses it increases coronary flowc. At low doses it decreases heart rated. At low doses it lowers peripheral resistancee. It inhibits catecholamine release
  44. 44. 36 SurgeryItems 60–61 60. Proper management would now call for A 68-year-old hypertensiveman undergoes successful repair a. Administration of a diuretic to increase urine outputof a ruptured abdominal aortic b. Administration of a vasopressoraneurysm. He receives 9 L Ringer’s agent to increase systemic bloodlactate solution and 4 units of pressurewhole blood during the operation. c. Administration of a fluid challengeTwo hours after transfer to the sur- to increase urine outputgical intensive care unit, the follow- d. Administration of a vasodilutinging hemodynamic parameters are agent to decrease elevated systemicobtained: vascular resistance e. A period of observation to obtain• Systemic blood pressure (BP): more data 90/60 mm Hg• Pulse rate: 110 beats/min 61. The patient then has an• Central venous pressure (CVP): improvement in all hemodynamic 7 mm Hg parameters. However, 6 h later he develops ST segment depression,• Pulmonary artery pressure: and a 12-lead cardiogram shows 28/10 mm Hg anterolateral ischemia. New hemo-• Pulmonary capillary wedge pres- dynamic parameters are obtained: sure: 8 mm Hg • Systemic BP: 70/40 mm Hg• Cardiac output: 1.9 L/min • Pulse rate: 100 beats/min• Systemic vascular resistance: 35 Woods units (normal is 24–30 • Central venous pressure (CVP): Woods units) 18 cm H2O• PaO2: 140 kPa (FiO2: 0.45) • Pulmonary capillary wedge pres- sure (PCWP): 25 mm Hg• Urine output: 15 mL/h (specific gravity: 1.029) • Cardiac output: 1.5 L/min• Hematocrit: 35% • Systemic vascular resistance: 25 Woods units The single best pharmacologic intervention would be a. Sublingual nitroglycerin b. Intravenous nitroglycerin c. A short-acting beta blocker d. Sodium nitroprusside e. Dobutamine
  45. 45. Critical Care:Anesthesiology, Blood Gases, Respiratory Care 3762. A 56-year-old man undergoes 64. A 73-year-old woman with aa left upper lobectomy. An epidural long history of heavy smokingcatheter is inserted for postopera- undergoes femoral artery–poplitealtive pain relief. Ninety minutes artery bypass for resting pain in herafter the first dose of epidural mor- left leg. Because of serious underly-phine, the patient complains of ing respiratory insufficiency, sheitching and becomes increasingly continues to require ventilatorysomnolent. Blood gas measurement support for 4 days after her opera-reveals the following: pH 7.24; tion. As soon as her endotrachealPaCO2 58; PaO2 100; HCO3− 28. Ini- tube is removed, she begins com-tial therapy should include plaining of vague upper abdominala. Endotracheal intubation pain. She has daily fever spikes tob. Intramuscular diphenhydramine 39°C (102.2°F) and a leukocyte (Benadryl) count of 18,000/µL. An upperc. Epidural naloxone abdominal ultrasonogram reveals ad. Intravenous naloxone dilated gallbladder, but no stonese. Alternative analgesia are seen. A presumptive diagnosis of acalculous cholecystitis is made.63. If end-diastolic pressure is You would recommendheld constant, increasing which of a. Nasogastric suction and broad-the following will increase the car- spectrum antibioticsdiac index? b. Immediate cholecystectomy witha. Peripheral vascular resistance operative cholangiogramb. Pulmonary wedge pressure c. Percutaneous drainage of the gall-c. Heart rate bladderd. Systemic diastolic pressure d. Endoscopic retrograde cholan-e. Viscosity of the blood giopancreatography (ERCP) to visualize and drain the common bile duct e. Provocation of cholecystokinin re- lease by cautious feeding of the patient
  46. 46. 38 SurgeryItems 65–67 A 32-year-old man undergoes a distal pancreatectomy, splenectomy,and partial colectomy for a gunshot wound to the left upper quadrant ofthe abdomen. One week later he develops a shaking chill in conjunctionwith a temperature spike to 39.44°C (103°F). His blood pressure is 70/40mm Hg with a pulse of 140 beats/min and his respiratory rate is 45breaths/min. He is transferred to the ICU where he is intubated and aSwan-Ganz catheter is placed.65. Which of the following would be most consistent with this patient’spreintubation arterial blood gas measurement? pH PaCO2 PaO2 a. 7.31 48 61 b. 7.52 28 76 c. 7.45 40 77 d. 7.40 30 72 e. 7.40 48 9466. Which of the following is consistent with the expected initial Swan-Ganz catheter readings?a. Cardiac output: 7.0 L/minb. Peripheral vascular resistance: 1660 dynesc. Pulmonary artery pressure: 50/20 mm Hgd. Pulmonary capillary wedge pressure: 16 mm Hge. Central venous pressure: 18 mm Hg67. Initial therapy for this patient would includea. Furosemideb. Propranololc. Sodium nitroprussided. Broad-spectrum antibioticse. Laparotomy

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