MCQs General Surgery: case scenario

1. A pregnant woman in her 32nd wk of gestation is given magnesium sulfate for pre-eclampsia. The earliest clinical indication of hypermagnesemia is
a.Loss of deep tendon reflexes
b.Flaccid paralysis
c.Respiratory arrest
d.Hypotension
e.Stupor

2. Five days after an uneventful cholecystectomy, an asymptomatic middle-aged woman is found to have a serum sodium level of 120 meq/L. Proper management would be
a. Administration of hypertonic saline solution
b. Restriction of free water
c. Plasma ultrafiltration
d. Hemodialysis
e. Aggressive diuresis with furosemide

3. A 50-year-old patient presents with symptomatic nephrolithiasis. He reports that he underwent a jejunoileal bypass for morbid obesity when he was 39. One would expect to find
a.Pseudohyperparathyroidism
b.Hyperuric aciduria
c.“Hungry bone” syndrome
d.Hyperoxaluria
e.Sporadic unicameral bone cysts

4. Following surgery, a patient develops oliguria. You believe the patient is hypovolemic, but before increasing intravenous fluids you seek corroborative data. This would include
a. Urine sodium of 28 meq/L
b. Urine chloride of 15 meq/L
c. Fractional excretion of sodium less than 1
d. Urine/serum creatinine ratio of 20
e. Urine osmolality of 350 mOsm/kg 1 Terms of Use

5. A 45-year-old woman with Crohn’s disease and a small intestinal fistula develops tetany during the 2nd wk of parenteral nutrition. The laboratory findings include Ca 8.2 meq/L; Na 135 meq/L; K 3.2 meq/L; C1 103 meq/L; PO4 2.4 meq/L; albumin 2.4; pH 7.48; 38 kPa; P 84 kPa; bicarbonate 25 meq/L. The most likely cause of the patient’s tetany is
a.Hyperventilation
b.Hypocalcemia
c.Hypomagnesemia
d.Essential fatty acid deficiency
e.Focal seizure

6. A patient with a nonobstructing carcinoma of the sigmoid colon is being prepared for elective resection. To minimize the risk of postoperative infectious complications, your planning should include
a. A single preoperative parenteral dose of antibiotic effective against aerobes and anaerobes
b. Avoidance of oral antibiotics to prevent emergence of Clostridium difficile
c. Postoperative administration for 2–4 days of parenteral antibiotics effective against aerobes and anaerobes d. Postoperative administration for 5–7 days of parenteral antibiotics effective against aerobes and anaerobes e. Operative time less than 5 h

7. A 70-year-old man with aortic and mitral valvular regurgitation undergoes an emergency sigmoid colectomy and end colostomy for perforated diverticulitis. His postoperative course is complicated by a myocardial infarction and atrial fibrillation. Four weeks later, he has improved and requests elective colostomy closure. You would recommend
a. Discontinuation of antiarrhythmic and antihypertensive medications on the morning of surgery
b. Discontinuation of beta-blocking medications on the day prior to surgery
c. Control of congestive heart failure with diuretics and digitalis in severe cases
d. Administration of prophylactic antibiotics, other than ampicillin and gentamicin, for patients with valvular heart disease who are undergoing gastrointestinal procedures
e. Postponement of elective surgery for 6–8 wk after a subendocardial myocardial infarction

Items 8–9 A previously healthy 55-yearold man undergoes elective right hemicolectomy for a Dukes A cancer of the cecum. His postoperative ileus is somewhat prolonged, and on the fifth postoperative day his nasogastric tube is still in place. Physical examination reveals diminished skin turgor, dry mucous membranes, and orthostatic hypotension. Pertinent laboratory values are as follows: • Arterial blood gases: pH 7.56; PO2 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− 6

8. The values given above allow the descriptive diagnosis of
a. Uncompensated metabolic alkalosis
b. Respiratory acidosis with metabolic compensation
c. Combined metabolic and respiratory alkalosis
d. Metabolic alkalosis with respiratory compensation
e. “Paradoxical” metabolic respiratory alkalosis

9. The most appropriate therapy for the patient described would be
a. Infusion of 0.9% NaC1 with supplemental KC1 until clinical signs of volume depletion are eliminated
b. Infusion of isotonic (0.15 N) HC1 via a central venous catheter
c. Clamping the nasogastric tube to prevent further acid losses
d. Administration of acetazolamide to promote renal excretion of bicarbonate
e. Intubation and controlled hypoventilation on a volumecycled ventilator to further increase PCO2

10–11 A 23-year-old woman is brought to the emergency room from a halfway house, where she apparently swallowed a handful of pills. The patient complains of shortness of breath and tinnitus, but refuses to identify the pills she ingested. Pertinent laboratory values are as follows: • Arterial blood gases: pH 7.45; PO2 126 kPa; PCO2 12 kPa • Serum electrolytes (meq/L): Na+ 138; K+ 4.8; C1− 102; HCO3− 8

10. The patient’s acid-base disturbance is best characterized by which of the following descriptions?
a. Acute respiratory alkalosis, compensated
b. Chronic respiratory alkalosis, compensated
c. Metabolic acids, compensated
d. Mixed metabolic acidosis and respiratory alkalosis e. Mixed metabolic acidosis and respiratory acidosis

11. The most likely cause of the disturbance in this patient is an overdose of
a. Phenformin
b. Aspirin
c. Barbiturates
d. Methanol
e. Diazepam (Valium)

12. A 65-year-old man undergoes a technically difficult abdominoperineal resection for a rectal cancer during which he receives three units of packed red blood cells. Four hours later in the intensive care unit he is bleeding heavily from his perineal wound. Emergency coagulation studies reveal normal prothrombin, partial thromboplastin, and bleeding times. The fibrin degradation products are not elevated but the serum fibrinogen content is depressed and the platelet count is 70,000/µL. The most likely cause of the bleeding is a. Delayed blood transfusion reaction
b. Autoimmune fibrinolysis
c. A bleeding blood vessel in the surgical field
d. Factor VIII deficiency
e. Hypothermic coagulopathy

13. A 78-year-old man with a history of coronary artery disease and an asymptomatic reducible inguinal hernia requests an elective hernia repair. You explain to him that valid reasons for delaying the proposed surgery include
a. Coronary artery bypass surgery 3 mo earlier
b. A history of cigarette smoking
c. Jugular venous distension
d. Hypertension
e. Hyperlipidemia

14. A 68-year-old man is admitted to the coronary care unit with an acute myocardial infarction. His postinfarction course is marked by congestive heart failure and intermittent hypotension. On the fourth hospital day, he develops severe midabdominal pain. On physical examination, blood pressure is 90/60 mm Hg and pulse is 110 beats/min and regular; the abdomen is soft with mild generalized tenderness and distention. Bowel sounds are hypoactive; stool hematest is positive. The next step in this patient’s management should be which of the following?
a.Barium enema
b.Upper gastrointestinal series Angiography
c.Ultrasonography
d.Celiotomy

15. A 30-year-old woman in the last trimester of pregnancy suddenly develops massive swelling of the left lower extremity from the inguinal ligament to the ankle. The correct sequence of workup and treatment should be
a. Venogram, bed rest, heparin
b. Impedance plethysmography, bed rest, heparin
c. Impedance plethysmography, bed rest, vena caval filter
d. Impedance plethysmography, bed rest, heparin, warfarin (Coumadin)
e. Clinical evaluation, bed rest, warfarin 5

16. A 20-year-old woman is found to have an activated partial thromboplastin time (APTT) of 78/32 on routine testing prior to cholecystectomy. Further investigation reveals a prothrombin time (PT) of 13/12 (patient/control), a template bleeding time of 13 min, and a platelet count of 350 × 100/µL. Which one of the following characteristics of this woman’s coagulopathy is true?
a. Infusion of purified factor VIII is usually required to normalize its concentration prior to surgery
b. Infusion of cryoprecipitate will not be followed by an improvement in coagulation
c. Most of these patients are, or become, seropositive for HIV
d. Epistaxis or menorrhagia is uncommon
e. Lack of platelet aggregation in response to ristocetin is a common feature of this disease

17. The chief surgical risk to which patients with polycythemia vera are exposed is that due to
a.Anemic disturbances
b.Hemorrhage
c.Infection
d.Renal dysfunction
e.Cardiopulmonary complications

18. A victim of blunt abdominal trauma requires a partial hepatectomy. He is rapidly transfused with 8 units of appropriately crossmatched packed red blood cells from the blood bank. He is noted in the recovery room to be bleeding from intravenous puncture sites and the surgical incision. His coagulopathy is likely due to thrombocytopenia and deficiencies of which clotting factors?
a. II only
b.II and VII
c.V and VIII
d.IX and X
e.XI and XII

19. Following celiotomy, normal bowel motility can ordinarily be presumed to have returned
a. In the stomach in 4 h, the small bowel in 24 h, and the colon after the first oral intake
b. In the stomach in 24 h, the small bowel in 4 h, and the colon in 3 days
c. In the stomach in 3 days, the small bowel in 3 days, and the colon in 3 days
d. In the stomach in 24 h, the small bowel in 24 h, and the colon in 24 h
e. In the stomach in 4 h, the small bowel immediately, and the colon in 24 h

20. A 65-year-old woman has a life-threatening pulmonary embolus 5 days following removal of a uterine malignancy. She is immediately heparinized and maintained in good therapeutic range for the next 3 days, then passes gross blood from her vagina and develops tachycardia, hypotension, and oliguria. Following resuscitation, an abdominal CT scan reveals a major retroperitoneal hematoma. You should now
a. Immediately reverse heparin by a calculated dose of protamine and place a vena cava filter (e.g., a Greenfield filter)
b. Reverse heparin with protamine, explore and evacuate the hematoma, and ligate the vena cava below the renal veins
c. Switch to low-dose heparin
d. Stop heparin and observe closely
e. Stop heparin, give fresh frozen plasma (FFP), and begin warfarin therapy

21. Which of the following surgical interventions is least likely to provide acceptable prolongation of life for patients with AIDS?
a. Splenectomy for AIDS-related idiopathic thrombocytopenic purpura
b. Colonic resection for perforation secondary to cytomegalovirus infection
c. Cholecystectomy for acalculous cholecystitis
d. Tracheostomy for ventilatordependent patients with respiratory failure
e. Gastric resection for a bleeding gastric lymphoma or Kaposi’s sarcoma

22. An elderly diabetic woman with chronic steroid-dependent bronchospasm has an ileocolectomy for a perforated cecum. She is taken to the ICU intubated and is maintained on broad-spectrum antibiotics, renal-dose dopamine, and a rapid steroid taper. On postoperative day 2 she develops a fever of 39.2°C (102.5°F), hypotension, lethargy, and laboratory values remarkable for hypoglycemia and hyperkalemia. The most likely diagnosis of this acute event is
a.Sepsis
b.Hypovolemia
c.Adrenal insufficiency
d.Acute tubular necrosis
e.Diabetic ketoacidosis

23. A cirrhotic patient with abnormal coagulation studies due to hepatic synthetic dysfunction requires an urgent cholecystectomy. A transfusion of fresh frozen plasma is planned to minimize the risk of bleeding due to surgery. The optimal timing of this transfusion would be
a.The day before surgery
b.The night before surgery
c.On call to surgery
d.Intraoperatively
e. In the recovery room

24. On postoperative day 3, an otherwise healthy 55-year-old man recovering from a partial hepatectomy is noted to have scant serosanguineous drainage from his abdominal incision. His skin staples are removed, revealing a 1.0cm dehiscence of the upper midline abdominal fascia. Which of the following actions is most appropriate?
a. Removing all suture material and packing the wound with moist sterile gauze
b. Starting intravenous antibiotics
c. Placing an abdominal (Scultetus) binder
d. Prompt resuturing of the fascia in the operating room
e. Bed rest

 

• Answers 1. The answer is a. States of magnesium excess are characterized by generalized neuromuscular depression. Clinically, severe hypermagnesemia is rarely seen except in those patients with advanced renal failure treated with magnesium-containing antacids. Hypermagnesemia is produced intentionally, however, by obstetricians who use parenteral magnesium sulfate (MgSO4) to treat preeclampsia. MgSO4 is administered until depression of the deep tendon reflexes is observed, a deficit that occurs with modest hypermagnesemia (over 4 meq/L). Greater elevations of magnesium produce progressive weakness, which culminates in flaccid quadriplegia and in some cases respiratory arrest from paralysis of the chest bellows mechanism. Hypotension may occur because of the direct arteriolar relaxing effect of magnesium. Changes in mental status occur in the late stages of the syndrome and are characterized by somnolence that progresses to coma.
• 2. The answer is b. Acute severe hyponatremia sometimes occurs following elective surgical procedures. It is usually the result of the combination of appropriate postoperative stimulation of antidiuretic hormone and injudicious administration of excess free water in the first few postoperative days. Totally sodium-free intravenous fluids (e.g., dextrose and water) should be given with great caution postoperatively, since occasionally the resulting hyponatremia can be associated with sudden death from a flaccid heart or with severe permanent brain damage. The condition is usually best treated by withholding free water and allowing the patient to reequilibrate spontaneously. At levels below 115 meq/L, seizures or mental obtundation may mandate treatment with hypertonic sodium solutions. This must be done with extreme care because the risk of fluid overload with acute pulmonary or cerebral edema is high. 16
• 3. The answer is d. Any patient who has lost much of the ileum (whether from injury, disease, or elective surgery) is at high risk of developing enteric hyperoxaluria if the colon remains intact. Calcium oxalate stones will develop in at least 10% of these patients. The condition results from excessive absorption of oxalate from the colon through two related synergistic mechanisms: unabsorbed fatty acids combine with calcium, which prevents the formation of insoluble calcium oxalate and allows oxalate to remain available for colonic absorption; and unabsorbed fatty acids and bile acids also increase the permeability of the colon to the oxalate.
• 4. The answer is c. When oliguria occurs postoperatively, it is important to differentiate between low output caused by the physiologic response to intravascular hypovolemia and that caused by acute tubular necrosis. The fractional excretion of sodium (FENa) is an especially useful test to aid in this differentiation. Values of FE < 1% in an oliguric setting indicate aggressive sodium reclamation in the tubules; values above this suggest tubular injury. The fractional excretion is a simple calculation: (urine Na × serum creatinine) ÷ (serum sodium × urinary creatinine). In the setting of postoperative hypovolemia, all findings would reflect the kidney’s efforts to retain volume: the urine sodium would be below 20 meq/L, the urine chloride would not be helpful except in the metabolically alkalotic patient, the serum osmolality would be over 500 mOsm/kg, and the urine/serum creatinine ratio would be above 40.
• 5. The answer is c. Magnesium deficiency is common in malnourished patients and patients with large gastrointestinal fluid losses. The neuromuscular effects resemble those of calcium deficiency—namely, paresthesia, hyperreflexia, muscle spasm, and ultimately tetany. The cardiac effects are more like those of hypercalcemia. An electrocardiogram therefore provides a rapid means of differentiating between hypocalcemia and hypomagnesemia. Hypomagnesemia also causes potassium wasting by the kidney. Many hospital patients with refractory hypocalcemia will be found to be magnesium deficient. Often this deficiency becomes manifest during the response to parenteral nutrition when normal cellular ionic gradients are restored. A normal blood pH and arterial PCO2 rule out hyperventilation. The serum calcium in this patient is normal when Surgery adjusted for the low albumin. Hypomagnesemia causes functional hypoparathyroidism, which can lower serum calcium and thus result in a combined defect.
• 6. The answer is c. Many clinical and experimental studies have looked at the optimum bowel preparation and preoperative regimen for elective colonic surgery to reduce the postoperative infectious complications of wound infection, intraabdominal abscess, and anastomotic leakage. Currently, a postoperative rate of wound infection of only 5% can be attained by combining mechanical cleansing, oral antibiotics, and perioperative parenteral antibiotics. The type of mechanical cleansing does not matter as long as it is effective. Preoperative oral antibiotics may be administered one or more days prior to surgery and should cover aerobes and anaerobes (e.g., neomycin-erythromycin). Parenteral antibiotics effective against aerobes and anaerobes (e.g., cefoxitin) should be administered on call to the operating room as a single dose and no more than 24 h postoperatively. Both antibiotic regimens yield maximum prophylaxis without fostering resistant transformation of microbes. Procedures that require operative time greater than 3 h or that involve the extraperitoneal rectum are associated with an increased risk of infectious complications.
• 7. The answer is c.There are several recommended interventions in cardiac patients who are undergoing noncardiac surgery. The two factors that correlate best with postoperative lifethreatening or fatal cardiac complications are myocardial infarction (transmural or subendocardial) and uncontrolled congestive heart failure. Hence, delay of elective surgery for 6 mo after myocardial infarction and preoperative control of congestive heart failure with diuretics and digitalis, in severe cases, will have the greatest effect in decreasing the risks of surgery. A patient’s cardiac medications should be continued preoperatively, including during the morning of surgery, to maintain adequate therapeutic levels. This is especially true for beta blockers, which can manifest withdrawal rebound hypertension and tachycardia approximately 24 h after discontinuation. Patients with prosthetic valves or valvular heart disease should be given prophylactic antibiotics to prevent seeding of their valves during episodes of significant bacteremia. This most commonly occurs during gastrointestinal or genitourinary procedures. Ampicillin and gentamicin cover the flora frequently encountered, including enterococci and gram-negative organisms.
• 8. The answer is d. Both the arterial pH and the PCO2 are elevated in the patient presented in the question; the disturbance is alkalosis with hypoventilation. The PCO2 typically increases by 0.5–1.0 pKa for each meq/L increase in serum bicarbonate. These findings suggest that the hypoventilation is compensatory rather than a primary phenomenon. This assumption is further supported by the absence of clinical lung disease.
• 9. The answer is a. The development of a clinically significant metabolic alkalosis in a patient requires not only the loss of acid or addition of alkali, but renal responses that maintain the alkalosis. The normal kidney can tremendously augment its excretion of acid or alkali in response to changes in ingested load. However, in the presence of significant volume depletion and consequent excessive salt and water retention, the tubular maximum for bicarbonate reabsorption is increased. Correction of volume depletion alone is usually sufficient to correct the alkalosis, since the kidney will then excrete the excess bicarbonate. HCl infusion is usually unnecessary and can be dangerous. Acetazolamide is unlikely to be effective in the face of distal Na+ reabsorption (in exchange for H+ secretion). Moreover, to the extent that acetazolamide causes natriuresis, it will exacerbate the volume depletion.
• 10. The answer is d. The patient presented in the question is in a state of metabolic acidosis as shown by a markedly increased anion gap of 28 meq unmeasured anions per liter of plasma. However, the respiratory response is greater than can be explained by a compensatory response, since the patient is mildly alkalemic. The disturbance cannot be pure respiratory alkalosis, since the serum bicarbonate does not drop below 15 meq/L as a result of renal compensation and the anion gap does not vary by more than 1–2 meq/L from its normal value of 12 in response to a respiratory disturbance. The renal response to hyperventilation involves wasting of bicarbonate and compensatory retention of chloride; it does not involve a change in the concentration of “unmeasured” anions, such as albumin and organic acids.

 

• 11. The answer is b.The acid-base disturbance in the patient described in the previous question demonstrates the value of extracting all available information from a small amount of rapidly retrievable data, e.g., arterial blood gases. Salicylates directly stimulate the respiratory center and produce respiratory alkalosis. By building up an accumulation of organic acids, salicylates also produce a concomitant metabolic acidosis. Characteristically both disturbances exist simultaneously following massive ingestion of salicylates. If sedative agents have been taken as well, the respiratory alkalosis (and even the respiratory compensation) may be absent. Phenformin and methanol overdoses also produce “high-anion-gap” metabolic acidosis, but without the simultaneous respiratory disturbance. In the case presented, the patient’s history of tinnitus in conjunction with her mixed metabolic acidosis–respiratory alkalosis is essentially pathognomonic of salicylate intoxication.
• 12. The answer is c. Whenever significant bleeding is noted in the early postoperative period, the presumption should always be that it is due to an error in surgical control of blood vessels in the operative field. Hematologic disorders that are not apparent during the long operation are most unlikely to surface as problems postoperatively. Blood transfusion reactions can cause diffuse loss of clot integrity; the sudden appearance of diffuse bleeding during an operation may be the only evidence of an intraoperative transfusion reaction. In the postoperative period, transfusion reactions usually present as unexplained fever, apprehension, and headache—all symptoms difficult to interpret in the early postoperative period. Factor VIII deficiency (hemophilia) would almost certainly be known by history in a 65-year-old man, but if not, intraoperative bleeding would have been a problem earlier in this long operation. Severely hypothermic patients will not be able to form clots effectively, but clot dissolution does not occur. Care should be taken to prevent the development of hypothermia during long operations through the use of warmed intravenous fluid, gas humidifiers, and insulated skin barriers.
• 13. The answer is c. (Goldman, J Cardiothorac Anesth 1:237, 1987.) The work of Goldman and others has served to identify risk factors for perioperative myocardial infarction. The highest likelihood is associated with recent myocardial infarction: the more recent the event, the higher the risk 21 up to 6 mo. It should be noted, however, that the risk never returns to normal. A non-Q-wave infarction may not have destroyed much myocardium, but it leaves the surrounding area with borderline perfusion; hence the particularly high risk of subsequent perioperative infarction. Evidence of congestive heart failure, such as jugular venous distention, or S3 gallop also carries a high risk, as does the frequent occurrence of ectopic beats. Old age and emergency surgery are risk factors independent of these others. Coronary revascularization by coronary artery bypass graft (CABG) tends to protect against myocardial infarction. Smoking, diabetes, hypertension, and hyperlipidemia (all of which predispose to coronary artery disease) are surprisingly not independent risk factors, although they may increase the death rate should an infarct occur. The value of this information and data derived from further testing is that it identifies the patient who needs to be monitored invasively with a systemic arterial catheter and pulmonary arterial catheter. Most perioperative infarcts occur postoperatively when the “third-space” fluids return to the circulation, which increases the preload and the myocardial oxygen consumption. This generally occurs around the third postoperative day.
• 14. The answer is c. Acute mesenteric ischemia may be difficult to diagnose. The condition should be suspected in patients with either systemic manifestations of arteriosclerotic vascular disease or low cardiac output states associated with a sudden development of abdominal pain that is out of proportion to the physical findings. Lactic acidosis and an elevated hematocrit reflecting hemoconcentration are common laboratory findings. Abdominal films show a nonspecific ileus pattern. The cause may be embolic occlusion or thrombosis of the superior mesenteric artery, primary mesenteric venous occlusion, or nonocclusive mesenteric ischemia secondary to low cardiac output states. A mortality of 65–100% is reported. The majority of affected patients are at high operative risk, but since early diagnosis followed by revascularization or resectional surgery or both is the only hope for survival, celiotomy must be performed once the diagnosis of arterial occlusion or bowel infarction has been made. Initial treatment of nonocclusive mesenteric ischemia includes measures to increase cardiac output and blood pressure and the direct intraarterial infusion of vasodilators such as papaverine into the superior mesenteric system. The patient presented in the question is at risk for both occlusive and nonocclusive mesenteric ischemic disease. If his clinical status permits, angiographic studies should be performed before the operation to establish the diagnosis and to determine whether embolectomy, revascularization, or nonsurgical management is indicated as initial treatment.
• 15. The answer is b. This patient has a left iliofemoral vein thrombosis, as evidenced by sudden massive swelling of her entire left lower extremity. Noninvasive venous testing should be quite helpful as the venous obstruction extends above the knee; therefore, venography and x-ray exposure are unnecessary. Heparin is the preferred agent because it does not cross the placenta, while warfarin does. The vena caval filter is not indicated because there is no contraindication to heparin therapy and there has not been any evidence of pulmonary embolus.
• 16. The answer is e. von Willebrand disease has an autosomal dominant pattern of inheritance that affects both men and women. The deficiency of factor VIII activity is generally less severe than in classic hemophilia and tends to fluctuate even in an untreated patient. However, the bleeding tendency is compounded by abnormal platelet function. This is responsible for the common occurrence of epistaxis and menorrhagia. In 70% of patients, platelets fail to aggregate in response to the diagnostic reagent ristocetin. Transfusion of cryoprecipitate provides factor VIII R:WF (the von Willebrand factor), whereas infusions of high-purity concentrates of factor VIII:C are not effective. These patients do not generally require treatment unless they need surgery or are severely injured; therefore, they have not usually received the contaminated concentrates responsible for the 80% prevalence of HIV seropositivity among hemophiliacs.
• 17. The answer is b. Intraoperative and postoperative hemorrhage is a significant problem in the patient with polycythemia vera. Despite thrombocytosis, these patients have a hemorrhagic tendency generally ascribed to a qualitative deficiency of the platelets. Elective surgery should be postponed until the hematocrit and platelet count reach normal levels. Alkylating agents, such as busulfan or chlorambucil, are effective in this regard. In the emergency situation, phlebectomy should be performed prior to operation and also an especially careful hemostatic technique should be employed. Infection is also a problem in patients with polycythemia vera, but hemorrhagic problems are the more frequently encountered complications.
• 18. The answer is c. When large amounts of banked blood are transfused, the recipient becomes deficient in factors V and VIII (the “labile” factors) and an acquired coagulopathy ensues. Since banked blood is also deficient in platelets, thrombocytopenia may also develop.

 

• 19. The answer is b. The misconception that the entire bowel does not function in the early postoperative period is still widely held. Intestinal motility and absorption studies have clarified the patterns by which bowel activity resumes. The stomach remains uncoordinated in its muscular activity and does not empty efficiently for about 24 h after abdominal procedures. The small bowel functions normally within hours of surgery and is able to accept nutrients promptly, either by nasoduodenal or percutaneous jejunal feeding catheters or, after 24 h, by gastric emptying. The colon is stimulated in large measure by the gastrocolic reflex but ordinarily is relatively inactive for 3–4 days.
• 20. The answer is a.In a heparinized patient with significant life-threatening hemorrhage, immediate reversal of heparin anticoagulation is indicated. Protamine sulfate is a specific antidote to heparin and should be given as 1 mg for each 100 U heparin if hemorrhage begins shortly after a bolus of heparin. For a patient (such as this) in whom heparin therapy is ongoing, the dose should be based on the half-life of heparin (90 min). Since protamine is also an anticoagulant, only half the calculated circulating heparin should be reversed. The protaminization should be followed by placement of a percutaneous vena cava filter (Greenfield filter). In this critically ill patient, exploration of the retroperitoneal space would be surgically challenging and meddlesome. 21. The answer is d. (Diettrich, Arch Surg 126:860–865, 1991.) Patients who have AIDS frequently present with problems that potentially require surgical care. The involvement of surgeons with these patients will increase as more effective treatments are developed and the AIDS patient’s survival is prolonged. AIDS patients not only suffer from common surgical illnesses, they also develop problems especially associated with their altered immune status, such as bleeding from gastrointestinal lymphomas or Kaposi’s lesions, bowel ischemia, perforation from parasitic or viral infection, acalculous cholecystitis, and retroperitoneal and intraabdominal masses due to massive lymphadenitis. With the exception of tracheostomy, experience has demonstrated that surgery can be performed with acceptable morbidity and mortality and that it seems to provide comfort and prolong quality life. Though it may facilitate nursing care, tracheostomy does not reverse or slow the pulmonary failure once the patient has become ventilator dependent.
• 22. The answer is c. Acute adrenal insufficiency is classically manifested as changing mental status, increased temperature, cardiovascular collapse, hypoglycemia, and hyperkalemia. The diagnosis can be difficult to make and requires a high index of suspicion. Its clinical presentation is similar to that of sepsis; however, sepsis is generally associated with hyperglycemia and no significant change in potassium. The treatment for adrenal crisis is hydrocortisone 100 mg intravenously, volume resuscitation, and other supportive measures to treat any new or ongoing stress. Then, 200–400 hydrocortisone mg is administered over the next 24 h, followed by a taper of the steroid as tolerated.
• 23. The answer is c.Transfusions with fresh frozen plasma (FFP) are given to replenish clotting factors. The effectiveness of the transfusion in maintaining hemostasis is dependent on the quantity of each factor delivered and its half-life. The half-life of the most stable clotting factor, factor VII, is 4–6 h. A reasonable transfusion scheme would be to give FFP on call to the operating room. This way the transfusion is complete prior to the incision with circulating factors to cover the operative and immediate postoperative period.
• 24. The answer is c.Serosanguineous drainage is classically associated with fascial dehiscence. A reasonable approach to this problem is to remove several sutures and gently explore the wound to determine the extent of the dehiscence. A small fascial dehiscence (1–2 cm) can be treated conservatively with local wound care and an abdominal binder to support the fascia. A larger dehiscence requires reoperation for formal reclosure of the fascia. High-risk patients with a large fascial dehiscence may be treated with an abdominal binder and modified bed