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Iran General Surgery Board Exam study materials
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Iran General Surgery Board Exam practice questions

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Question 1Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

During a laparoscopic cholecystectomy, the critical view of safety requires clearance of the hepatocystic triangle. Which arterial structure must be identified and preserved before clipping the cystic artery?

  1. The superior mesenteric artery, which arises from the anterior aorta
  2. The gastroduodenal artery, which lies posterior to the first part of the duodenum
  3. The left gastric artery, which supplies the lesser curvature of the stomach
  4. The right hepatic artery, which frequently gives the cystic artery and may run in a caterpillar hump configuration Correct answer.

Explanation

The cystic artery usually arises from the right hepatic artery within the hepatocystic triangle, and in a minority of patients the right hepatic artery itself forms a tortuous "caterpillar hump" loop close to the gallbladder neck. Failure to recognize this variant risks ligation of the right hepatic artery with biliary ischemia or stricture. The gastroduodenal, superior mesenteric, and left gastric arteries are not normally encountered in the hepatocystic triangle.

Question 2Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A patient with a high-output small bowel fistula loses several liters of succus entericus daily. Which acid-base and electrolyte disturbance is most characteristic?

  1. Hyperkalemic metabolic acidosis with hypernatremia
  2. Respiratory alkalosis with hypocalcemia
  3. Hypochloremic metabolic alkalosis with hypokalemia
  4. Hyperchloremic metabolic acidosis with hypokalemia Correct answer.

Explanation

Small bowel and pancreaticobiliary secretions are rich in bicarbonate and potassium, so external loss produces a normal-anion-gap metabolic acidosis with hypokalemia and volume depletion. Gastric outlet obstruction, by contrast, causes hypochloremic hypokalemic alkalosis from loss of hydrogen and chloride. Recognizing the site of loss determines whether bicarbonate or chloride replacement is needed.

Question 3Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which statement best describes the mechanism by which the kidney defends against metabolic alkalosis?

  1. Reduced chloride reabsorption with hyperchloremic compensation
  2. Increased renal bicarbonate reabsorption with enhanced hydrogen ion secretion
  3. Reduced bicarbonate reabsorption with increased urinary bicarbonate excretion Correct answer.
  4. Increased ammonia production with enhanced distal hydrogen secretion

Explanation

In metabolic alkalosis the kidney compensates by decreasing bicarbonate reabsorption and excreting excess bicarbonate in the urine, which returns the plasma bicarbonate toward normal. This correction requires adequate chloride and volume status; in chloride-depleted states the kidney cannot excrete bicarbonate and the alkalosis persists. Enhanced hydrogen secretion and ammoniagenesis would worsen, not correct, the alkalosis.

Question 4Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A 24-year-old man develops fever and a painful red streak along the forearm after a minor laceration. Which organism is the most likely cause of this ascending lymphangitis?

  1. Staphylococcus epidermidis
  2. Clostridium perfringens
  3. Streptococcus pyogenes Correct answer.
  4. Pseudomonas aeruginosa

Explanation

Ascending lymphangitis with a rapidly spreading erythematous streak is classically caused by beta-hemolytic streptococci, especially Streptococcus pyogenes, which spread along lymphatics. Staphylococcus aureus more often produces localized abscesses, while clostridial and pseudomonal infections have different clinical settings. Penicillin-based therapy is appropriate for streptococcal lymphangitis.

Question 5Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

During thyroid surgery, which nerve is at risk when the inferior thyroid artery is ligated close to the thyroid capsule, and what is the resulting deficit?

  1. The external branch of the superior laryngeal nerve, causing loss of pitch
  2. The hypoglossal nerve, causing tongue deviation
  3. The recurrent laryngeal nerve, causing hoarseness from vocal cord paresis Correct answer.
  4. The internal branch of the superior laryngeal nerve, causing loss of cough reflex

Explanation

The recurrent laryngeal nerve runs in the tracheoesophageal groove in close relation to the inferior thyroid artery and is at risk during ligation near the gland, producing vocal cord paresis and hoarseness. The external branch of the superior laryngeal nerve is at risk near the superior pole and affects pitch, while the hypoglossal nerve is distant from the thyroid bed. Bilateral recurrent laryngeal nerve injury can cause airway obstruction.

Question 6Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which of the following best explains why a patient with cirrhosis and portal hypertension develops esophageal varices?

  1. Reduced splenic blood flow shunts blood directly into the azygos system
  2. Decreased nitric oxide production causes systemic hypertension and variceal rupture
  3. Splanchnic vasoconstriction reduces portal inflow and causes retrograde venous engorgement
  4. Increased hepatic sinusoidal resistance raises portal pressure, and portosystemic collaterals dilate at the gastroesophageal junction Correct answer.

Explanation

Cirrhosis increases intrahepatic resistance and splanchnic vasodilation increases portal inflow, so portal pressure rises and blood is diverted through portosystemic collaterals, prominently the left gastric and azygos veins at the gastroesophageal junction. These thin-walled varices then dilate and may rupture. Splanchnic vasoconstriction would lower rather than raise portal pressure.

Question 7Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which pharmacologic property makes ketamine useful for induction of anesthesia in a hypovolemic trauma patient?

  1. It produces reliable muscle relaxation for intubation
  2. It is a competitive antagonist at the GABA-A receptor
  3. It provides analgesia and preserves sympathetic tone and blood pressure Correct answer.
  4. It causes profound myocardial depression and vasodilation

Explanation

Ketamine is an NMDA receptor antagonist that provides amnesia and somatic analgesia while preserving sympathetic outflow, making it suitable for induction in hypovolemia. It does not produce muscle relaxation, and its cardiovascular profile contrasts with propofol, which causes vasodilation and hypotension. Its dissociative effects and emergence reactions are recognized side effects.

Question 8Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A patient with a strangulated inguinal hernia has a serum lactate of 5.4 mmol/L and metabolic acidosis. Which pathophysiologic process best explains these findings?

  1. Excessive bicarbonate ingestion with compensatory respiratory retention
  2. Anaerobic glycolysis from tissue hypoperfusion with impaired hepatic lactate clearance Correct answer.
  3. Increased renal ammoniagenesis from chronic kidney disease
  4. Primary hyperaldosteronism with renal hydrogen retention

Explanation

Strangulation obstructs venous outflow and arterial inflow, producing ischemic tissue that shifts to anaerobic glycolysis and generates lactate. Hypoperfusion also impairs hepatic lactate clearance, worsening lactic acidosis. The acidosis is a marker of irreversible ischemia and mandates urgent operative exploration.

Question 9Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which immunoglobulin class is most important for opsonization of encapsulated bacteria in the spleen, explaining the risk of overwhelming sepsis after splenectomy?

  1. IgG Correct answer.
  2. IgA
  3. IgM
  4. IgE

Explanation

IgG is the principal opsonizing antibody for encapsulated organisms and binds to Fc receptors on phagocytes, enabling splenic clearance. Splenectomy removes a major site of IgG-mediated opsonization and clearance, increasing susceptibility to Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis. Vaccination and prophylactic antibiotics address this deficit.

Question 10Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A patient with acute pancreatitis has a corrected calcium of 7.2 mg/dL and perioral numbness. Which mechanism best explains the hypocalcemia?

  1. Saponification of peripancreatic fat by liberated fatty acids binding calcium Correct answer.
  2. Excessive vitamin D synthesis with intestinal calcium absorption
  3. Increased renal tubular calcium reabsorption
  4. Primary hyperparathyroidism with bone resorption

Explanation

Pancreatic lipase releases fatty acids that bind calcium in a process of fat saponification, sequestering calcium in peripancreatic and retroperitoneal fat. Hypocalcemia in severe pancreatitis is a marker of extensive fat necrosis and poor prognosis. It may also be aggravated by hypoalbuminemia and vitamin D deficiency.

Question 11Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which nerve injury during inguinal hernia repair results in numbness over the anterior scrotum and medial thigh?

  1. The ilioinguinal nerve Correct answer.
  2. The lateral femoral cutaneous nerve
  3. The genitofemoral nerve
  4. The obturator nerve

Explanation

The ilioinguinal nerve runs through the inguinal canal and supplies sensation to the anterior scrotum or labium majus and the adjacent medial thigh, so it is at risk during open hernia repair. The genitofemoral nerve's genital branch supplies the cremaster and scrotum but injury is less often implicated in this specific sensory loss. The lateral femoral cutaneous and obturator nerves supply different territories.

Question 12Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which of the following is the primary fuel source for enterocytes of the small intestine?

  1. Glucose
  2. Ketone bodies
  3. Glutamine Correct answer.
  4. Long-chain fatty acids

Explanation

Enterocytes preferentially oxidize glutamine, which is the most abundant amino acid in blood and a key fuel for rapidly dividing intestinal epithelium. Glucose and long-chain fatty acids are used to a lesser extent, and ketone bodies are used by other tissues during fasting. Glutamine supplementation is therefore of interest in maintaining gut barrier function.

Question 13Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A patient with a large duodenal perforation develops septic shock with a cardiac index of 5.2 L/min/m² and systemic vascular resistance of 480 dyn·s·cm⁻⁵. Which hemodynamic pattern is present?

  1. Obstructive shock with impaired ventricular filling
  2. Distributive shock with high cardiac output and low systemic vascular resistance Correct answer.
  3. Cardiogenic shock with low cardiac output and high systemic vascular resistance
  4. Hypovolemic shock with low cardiac output and high systemic vascular resistance

Explanation

Septic shock is distributive: inflammatory vasodilation lowers systemic vascular resistance, and the compensatory increase in cardiac output produces a high-output state. The low resistance and elevated index distinguish it from cardiogenic and hypovolemic shock, which typically show low output and high resistance. Fluid resuscitation and vasopressors target this physiology.

Question 14Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which change in pulmonary physiology predisposes a postoperative patient to atelectasis after upper abdominal surgery?

  1. Increased compliance of the chest wall from abdominal distension
  2. Elevated residual volume from bronchodilation
  3. Reduced functional residual capacity from diaphragmatic dysfunction and supine positioning Correct answer.
  4. Increased closing volume relative to tidal volume with enhanced surfactant production

Explanation

Upper abdominal incisions and pain impair diaphragmatic excursion, and supine positioning reduces functional residual capacity so that closing volume exceeds airway closing pressure, promoting alveolar collapse. This is compounded by anesthesia-related surfactant changes and mucus retention. Incentive spirometry and early mobilization aim to restore FRC.

Question 15Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which antibiotic mechanism is responsible for the bactericidal effect of gentamicin against gram-negative bacilli?

  1. Binding to the 50S subunit and blocking translocation
  2. Irreversible binding to the 30S ribosomal subunit with misreading of mRNA Correct answer.
  3. Inhibition of cell wall transpeptidation
  4. Inhibition of dihydrofolate reductase

Explanation

Aminoglycosides such as gentamicin bind irreversibly to the 30S ribosomal subunit, causing misreading of mRNA and production of abnormal proteins, which is bactericidal and oxygen-dependent. Cell wall inhibitors such as beta-lactams act at transpeptidation, and folate inhibitors are bacteriostatic. Aminoglycoside activity is enhanced when combined with a beta-lactam.

Question 16Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A patient with obstructive jaundice has a prolonged prothrombin time that corrects with parenteral vitamin K. Which mechanism explains this finding?

  1. Disseminated intravascular coagulation from biliary sepsis
  2. Hepatic failure with reduced synthesis of all clotting factors
  3. Impaired bile salt-dependent absorption of fat-soluble vitamin K Correct answer.
  4. Vitamin K deficiency causing reduced gamma-carboxylation of factors II, VII, IX, and X

Explanation

Bile is required for micellar absorption of fat-soluble vitamins, so cholestasis causes vitamin K deficiency and reduced gamma-carboxylation of factors II, VII, IX, and X. Because hepatic synthetic capacity is intact, parenteral vitamin K corrects the prothrombin time within hours, distinguishing this from hepatocellular failure. Failure to correct suggests underlying liver dysfunction.

Question 17Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which structural feature of the femoral canal explains why femoral hernias are prone to strangulation?

  1. Direct communication with the peritoneal cavity through a broad neck
  2. A narrow, rigid ring bounded by the inguinal ligament, lacunar ligament, and femoral vein Correct answer.
  3. Absence of surrounding fascial boundaries
  4. A wide, distensible ring allowing easy reduction

Explanation

The femoral ring is bounded anteriorly by the inguinal ligament, medially by the lacunar ligament, posteriorly by the pectineal ligament, and laterally by the femoral vein. This narrow, unyielding ring constricts the hernia neck, so femoral hernias have a high risk of incarceration and strangulation. This is why femoral hernia repair is generally urgent.

Question 18Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which mechanism underlies the hyperkalemia observed after massive transfusion of stored packed red blood cells?

  1. Increased renal potassium excretion from transfusion-related alkalosis
  2. Enhanced cellular potassium uptake from hypothermia
  3. Hypoaldosteronism induced by citrate anticoagulant
  4. Potassium leakage from red cells during storage with reduced cellular reuptake Correct answer.

Explanation

Stored red cells leak potassium into the supernatant over time, and massive transfusion can deliver a significant potassium load, particularly with older units. Hypothermia, acidosis, and reduced renal perfusion further impair potassium uptake and excretion. Citrate toxicity causes hypocalcemia rather than hypoaldosteronism.

Question 19Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which factor most strongly predicts poor wound healing by impairing collagen synthesis at the anastomosis?

  1. Mild postoperative anemia with hemoglobin of 10 g/dL
  2. Early ambulation on postoperative day one
  3. Use of a transverse abdominal incision
  4. Tissue hypoxia from hypovolemia and vasoconstriction Correct answer.

Explanation

Collagen synthesis by fibroblasts is oxygen-dependent, so hypovolemia, vasoconstriction, and tissue hypoxia impair healing and increase anastomotic leak risk. Anemia with adequate oxygen delivery is generally well tolerated, and early ambulation improves healing. Incision orientation affects strength but not collagen synthesis.

Question 20Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which statement about the blood supply of the colon is correct and relevant to left hemicolectomy?

  1. The marginal artery is absent in the left colon, making anastomoses unsafe
  2. The rectum is supplied entirely by the middle rectal arteries
  3. The superior mesenteric artery supplies the sigmoid colon directly
  4. The inferior mesenteric artery gives the left colic and sigmoid arteries, and the marginal artery anastomoses with the middle colic artery Correct answer.

Explanation

The inferior mesenteric artery supplies the distal transverse, descending, and sigmoid colon through the left colic and sigmoid branches, and the marginal artery of Drummond connects these with the superior mesenteric circulation. Preserving this collateral arcade at the splenic flexure is essential to avoid ischemia after ligation. The rectum has a dual supply from superior and middle rectal arteries.

Question 21Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which of the following best explains the osmotic diuresis seen after mannitol administration during neurosurgery?

  1. Mannitol is actively secreted into the proximal tubule
  2. Mannitol increases sodium reabsorption in the loop of Henle
  3. Mannitol is filtered but not reabsorbed, retaining water in the tubule lumen Correct answer.
  4. Mannitol stimulates antidiuretic hormone release

Explanation

Mannitol is freely filtered at the glomerulus and essentially not reabsorbed, so it exerts osmotic pressure within the tubule that prevents water reabsorption and increases urine output. This same osmotic effect reduces brain water content by drawing fluid from tissue. Its use requires monitoring of volume status and serum osmolality.

Question 22Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A patient with a history of gastric outlet obstruction from peptic ulcer disease has a serum bicarbonate of 38 mEq/L and a urine chloride of 8 mEq/L. Which finding is expected on physical examination?

  1. Warm extremities with wide pulse pressure
  2. Orthostatic hypotension with decreased skin turgor Correct answer.
  3. Hypertension with pulmonary edema
  4. Hyperreflexia from hypercalcemia

Explanation

Prolonged vomiting from gastric outlet obstruction causes loss of hydrogen and chloride, generating a chloride-responsive metabolic alkalosis with volume depletion. The low urine chloride confirms chloride depletion, and patients present with orthostatic hypotension, dry mucous membranes, and poor skin turgor. Saline administration corrects both the volume and the alkalosis.

Question 23Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which component of the innate immune response is most directly responsible for the rapid clearance of bacteria from the peritoneal cavity after contamination?

  1. Cytotoxic T lymphocyte-mediated killing of infected cells
  2. Memory B cells producing high-affinity IgG
  3. Mast cell degranulation with histamine release
  4. Resident macrophages and neutrophil recruitment with complement activation Correct answer.

Explanation

Resident peritoneal macrophages phagocytose bacteria and release cytokines that recruit neutrophils, while complement activation promotes opsonization and lysis. This innate response acts within minutes to hours, before adaptive immunity develops. Failure of these mechanisms, as with an adjuvant such as a foreign body or blood, permits abscess formation.

Question 24Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which mechanism explains the increased risk of venous thromboembolism in a patient with a hypercoagulable state from factor V Leiden?

  1. Increased fibrinolysis from elevated tissue plasminogen activator
  2. Resistance of factor Va to inactivation by activated protein C Correct answer.
  3. Reduced von Willebrand factor clearance
  4. Deficiency of antithrombin III with excessive thrombin generation

Explanation

Factor V Leiden is a point mutation that renders factor Va resistant to cleavage by activated protein C, prolonging thrombin generation and predisposing to venous thrombosis. It is the most common inherited thrombophilia and is distinct from antithrombin, protein C, or protein S deficiency. Perioperative prophylaxis is especially important in affected patients.

Question 25Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

Which of the following best describes the mechanism of action of octreotide in controlling bleeding from esophageal varices?

  1. Beta-adrenergic blockade reducing cardiac output
  2. Splanchnic vasoconstriction that reduces portal venous inflow and pressure Correct answer.
  3. Inhibition of gastric acid secretion with reduced fibrinolysis
  4. Direct sclerosing effect on variceal endothelium

Explanation

Octreotide is a somatostatin analog that constricts splanchnic arterioles, reducing portal venous inflow and thereby lowering portal pressure and variceal bleeding. It is used as a bridge to definitive endoscopic or radiologic therapy. Its action is hemodynamic, not a direct sclerosant effect.

Question 26Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A 34-year-old man is admitted with a deep laceration over the anterior forearm. On examination he cannot flex the distal phalanx of the index finger at the interphalangeal joint, while sensation over the thenar eminence is intact. Which nerve has most likely been injured?

  1. Radial nerve in the spiral groove
  2. Median nerve, specifically its anterior interosseous branch Correct answer.
  3. Posterior interosseous nerve
  4. Ulnar nerve at the cubital tunnel

Explanation

The anterior interosseous nerve arises from the median nerve just distal to the pronator teres and supplies the flexor pollicis longus, the radial half of the flexor digitorum profundus, and the pronator quadratus. Because it is purely motor and gives no cutaneous branches, injury produces isolated loss of distal interphalangeal flexion of the index finger with preserved sensation. The main median trunk would additionally cause sensory loss over the palmar digits.

Question 27Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A 58-year-old woman with small bowel obstruction has been vomiting for 3 days. Serum chemistry shows Na 132 mEq/L, K 2.9 mEq/L, Cl 88 mEq/L, and HCO3 34 mEq/L. Which acid-base and electrolyte disturbance best fits these values?

  1. Respiratory alkalosis with compensatory metabolic acidosis
  2. Hyperchloremic normal anion gap metabolic acidosis
  3. Hypokalemic, hypochloremic metabolic alkalosis with paradoxic aciduria Correct answer.
  4. High anion gap metabolic acidosis from lactic acidosis

Explanation

Prolonged vomiting of gastric contents removes hydrogen and chloride while the kidney excretes bicarbonate to defend volume, generating a hypochloremic metabolic alkalosis with hypokalemia. Volume depletion activates aldosterone, so sodium is reabsorbed in exchange for hydrogen and potassium, producing an acidic urine despite systemic alkalosis. The normal anion gap and low chloride distinguish this from organic acidosis.

Question 28Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A 62-year-old man undergoes emergency laparotomy for perforated sigmoid diverticulitis and receives 6 units of stored packed red cells. Two hours later he develops confusion, a petechial rash, and oozing from the wound, with platelets falling from 210,000 to 60,000/µL and a rising creatinine. Which pathophysiologic process best explains this picture?

  1. Dilutional coagulopathy from crystalloid resuscitation alone
  2. Heparin-induced immune thrombocytopenia from intraoperative prophylaxis
  3. Immediate IgE-mediated hemolysis of donor red cells
  4. Microvascular platelet-fibrin thrombi causing consumptive thrombocytopenia and organ ischemia Correct answer.

Explanation

This is transfusion-associated microangiopathy, in which widespread platelet-fibrin thrombi in the microcirculation consume platelets and fragment red cells. The resulting ischemia produces renal injury and neurologic change, while the consumption causes thrombocytopenia and bleeding. It is distinct from simple dilution, which does not cause a petechial rash or rising creatinine.

Question 29Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A 45-year-old man is started on total parenteral nutrition after a massive bowel resection. On day 4 he becomes tachycardic and confused, and an electrocardiogram shows a prolonged QT interval. Which deficiency is most likely responsible?

  1. Thiamine deficiency
  2. Magnesium depletion Correct answer.
  3. Essential fatty acid deficiency
  4. Zinc deficiency

Explanation

Refeeding drives phosphate, potassium, and magnesium into cells, and magnesium depletion is a classic cause of refractory hypokalemia, QT prolongation, and arrhythmia during parenteral nutrition. Magnesium is required for normal membrane repolarization, so it must be monitored and replaced. Confusion and tachycardia accompany the electrolyte shift.

Question 30Basic Sciences as Applied to Surgery (anatomy, physiology, pathophysiology, surgical pathology, microbiology, pharmacology, immunology, fluid/electrolyte and nutrition)

A 70-year-old woman with a strangulated femoral hernia undergoes resection of ischemic bowel. Postoperatively she develops fever, leukocytosis, and hypotension, and blood cultures grow a gram-negative anaerobe. Which innate immune receptor pathway most directly recognizes bacterial lipopolysaccharide to trigger the systemic inflammatory response?

  1. NOD-like receptor activation by muramyl dipeptide
  2. Mannose receptor binding of terminal mannose residues
  3. Toll-like receptor 3 recognition of double-stranded RNA
  4. Toll-like receptor 4 signaling through the MyD88 adaptor Correct answer.

Explanation

Lipopolysaccharide is bound by CD14 and presented to Toll-like receptor 4, which signals through the MyD88 adaptor to activate NF-kB and produce proinflammatory cytokines. This pathway is central to gram-negative septic shock. The other receptors recognize different microbial structures and do not mediate the lipopolysaccharide response.

Question 31Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A 45-year-old man is scheduled for elective open cholecystectomy. According to the ASA Physical Status classification, a patient with well-controlled type 2 diabetes mellitus and no other systemic disease is classified as:

  1. ASA II Correct answer.
  2. ASA III
  3. ASA IV
  4. ASA I

Explanation

ASA II designates a patient with mild systemic disease that is well controlled and does not limit activity, such as diabetes or hypertension under good control. ASA I is reserved for a completely healthy patient, and ASA III requires a disease that limits activity or is poorly controlled.

Question 32Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

Which preoperative laboratory finding most strongly predicts an increased risk of postoperative pulmonary complications after major abdominal surgery?

  1. Serum albumin of 3.9 g/dL
  2. Hemoglobin of 11.5 g/dL
  3. FEV1 of 55% of predicted Correct answer.
  4. Serum creatinine of 1.0 mg/dL

Explanation

Reduced forced expiratory volume in one second reflects obstructive ventilatory impairment and correlates with postoperative atelectasis, pneumonia, and prolonged ventilation after upper abdominal incisions. Mild anemia, near-normal albumin, and normal creatinine do not carry comparable pulmonary risk.

Question 33Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A patient on chronic warfarin therapy for a mechanical mitral valve requires an elective inguinal hernia repair. Which perioperative anticoagulation plan is most appropriate?

  1. Stop warfarin and bridge with therapeutic-dose low molecular weight heparin until surgery Correct answer.
  2. Stop warfarin five days before surgery without any bridging therapy
  3. Continue warfarin at full dose through the operation
  4. Switch to aspirin 325 mg daily until the day of surgery

Explanation

Patients with mechanical heart valves at high thromboembolic risk require bridging with therapeutic-dose heparin after warfarin is stopped and until the INR normalizes, because the thrombotic risk of a bare interruption outweighs bleeding risk. Aspirin is inadequate thromboprophylaxis for a mechanical valve.

Question 34Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A 62-year-old man undergoes elective right hemicolectomy. On postoperative day 4 he develops fever, tachycardia, and diffuse abdominal tenderness with a rising white cell count. Which complication should be suspected first?

  1. Anastomotic leak Correct answer.
  2. Superficial surgical site infection
  3. Deep vein thrombosis
  4. Atelectasis

Explanation

An anastomotic leak typically presents around postoperative days 3 to 7 with fever, tachycardia, ileus, and peritonitis, and it is the most feared cause of early deterioration after colorectal resection. Superficial wound infection usually remains localized, and atelectasis rarely produces diffuse peritonitis.

Question 35Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

Which intervention is a core element of enhanced recovery after surgery (ERAS) protocols for elective colorectal surgery?

  1. Prolonged preoperative fasting from midnight
  2. Routine nasogastric decompression until return of bowel function
  3. Early oral intake and early mobilization after surgery Correct answer.
  4. Routine mechanical bowel preparation with oral antibiotics for all patients

Explanation

ERAS pathways emphasize early feeding and early ambulation to reduce catabolism, insulin resistance, and length of stay. Routine prolonged fasting, indiscriminate mechanical bowel preparation, and routine nasogastric tubes are discouraged because they add morbidity without benefit.

Question 36Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A 70-year-old woman with a body mass index of 42 kg/m² and type 2 diabetes undergoes elective laparoscopic ventral hernia repair. Which factor most increases her risk of surgical site infection?

  1. Obesity and diabetes Correct answer.
  2. Female sex
  3. Use of nonabsorbable mesh
  4. Laparoscopic approach

Explanation

Obesity increases wound tension, dead space, and operative time, while diabetes impairs neutrophil function and microvascular perfusion, and both are established independent risk factors for surgical site infection. Female sex and laparoscopy are not recognized independent risk factors in this context.

Question 37Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A trauma patient becomes hypotensive and oliguric six hours after massive transfusion. Which finding best supports the diagnosis of transfusion-related acute lung injury (TRALI) rather than transfusion-associated circulatory overload (TACO)?

  1. Normal pulmonary capillary wedge pressure with bilateral infiltrates and fever Correct answer.
  2. Improved oxygenation after diuretic administration
  3. Hypertension with a positive fluid balance
  4. Elevated brain natriuretic peptide and jugular venous distension

Explanation

TRALI produces noncardiogenic pulmonary edema with normal filling pressures, bilateral infiltrates, fever, and often hypotension, typically within six hours of transfusion. TACO instead shows elevated filling pressures, hypertension, jugular venous distension, and a positive fluid balance.

Question 38Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A patient with a serum albumin of 2.1 g/dL and 15% weight loss is scheduled for major pancreatic resection. Which preoperative measure is most appropriate?

  1. Immediate surgery without delay
  2. Seven to ten days of preoperative nutritional support, preferably enteral Correct answer.
  3. Routine total parenteral nutrition for four weeks
  4. Cancellation of surgery until albumin exceeds 4 g/dL

Explanation

Severe malnutrition with hypoalbuminemia and substantial weight loss warrants a short course of preoperative nutritional repletion, and enteral feeding is preferred when the gut works. A four-week delay for parenteral nutrition or an arbitrary albumin target is not justified, and proceeding immediately worsens complication rates.

Question 39Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

Which statement about normal wound healing by primary intention is correct?

  1. Fibroblasts deposit collagen and angiogenesis begins during the proliferative phase Correct answer.
  2. Neutrophils are the predominant cell in the wound after the first week
  3. Wound strength reaches approximately 80% of uninjured skin by three weeks
  4. Collagen synthesis peaks in the first 24 hours after wounding

Explanation

During the proliferative phase, roughly days 4 to 21, fibroblasts migrate into the wound, synthesize collagen, and stimulate angiogenesis and granulation tissue formation. Wound strength is only about 20% at three weeks and collagen accumulation continues for weeks to months.

Question 40Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A 58-year-old man with cirrhosis (Child-Pugh class C, MELD 22) is evaluated for elective umbilical hernia repair. Which approach is most appropriate?

  1. Proceed with elective repair under general anesthesia
  2. Optimize liver function and consider repair only for complications such as incarceration or rupture Correct answer.
  3. Perform repair under local anesthesia without further workup
  4. Delay surgery indefinitely regardless of symptoms

Explanation

Child-Pugh class C cirrhosis carries very high perioperative mortality, so elective surgery is generally deferred while medical optimization and transplant evaluation proceed. Repair is reserved for complicated hernias such as incarceration, strangulation, or rupture with ascites leak.

Question 41Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

Which measure is most effective for preventing ventilator-associated pneumonia in a surgical intensive care unit?

  1. Elevating the head of the bed to 30 to 45 degrees Correct answer.
  2. Routine prophylactic antibiotics
  3. Daily chest radiographs
  4. Scheduled circuit changes every 48 hours

Explanation

Semirecumbent positioning reduces aspiration of oropharyngeal and gastric secretions and is a cornerstone of ventilator-associated pneumonia prevention bundles. Routine radiographs, prophylactic antibiotics, and frequent circuit changes do not prevent this complication and may cause harm.

Question 42Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A patient develops high fever, hypotension, and a rapidly spreading erythema with crepitus 48 hours after an appendectomy. Which initial management step is most important?

  1. Oral antibiotics and outpatient follow-up
  2. Antifungal therapy alone
  3. Urgent surgical debridement with broad-spectrum antibiotics Correct answer.
  4. Observation with serial abdominal examinations

Explanation

Crepitus with systemic toxicity suggests necrotizing soft tissue infection, a surgical emergency requiring immediate radical debridement plus broad-spectrum antibiotics covering anaerobes and gram-negatives. Delay for observation or oral therapy markedly increases mortality.

Question 43Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A patient with severe sepsis from a perforated viscus is resuscitated. Which parameter best reflects adequate initial resuscitation according to current sepsis guidance?

  1. Mixed venous oxygen saturation of 50%
  2. Lactate clearance and mean arterial pressure of at least 65 mmHg Correct answer.
  3. Central venous pressure of 12 mmHg
  4. Urine output of 0.2 mL/kg/h

Explanation

Current sepsis bundles emphasize dynamic measures such as lactate clearance, mean arterial pressure of at least 65 mmHg, and adequate urine output rather than a fixed central venous pressure target. A single static pressure value is a poor indicator of fluid responsiveness.

Question 44Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

Which patient has the highest risk of aspiration pneumonitis during induction of general anesthesia?

  1. A patient with well-controlled asthma
  2. A patient with a full stomach and small bowel obstruction Correct answer.
  3. A patient receiving regional anesthesia
  4. A fasting patient undergoing elective knee arthroscopy

Explanation

A full stomach combined with bowel obstruction creates a large residual gastric volume and elevated intragastric pressure, so rapid sequence induction with cricoid pressure is required. Fasting elective patients and those receiving regional anesthesia do not carry this risk.

Question 45Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A patient with a history of anaphylaxis to penicillin requires prophylaxis before colorectal surgery. Which antibiotic choice is most appropriate?

  1. Cefazolin plus metronidazole
  2. Vancomycin plus metronidazole
  3. Cefazolin alone
  4. Clindamycin plus gentamicin Correct answer.

Explanation

For documented severe penicillin anaphylaxis, clindamycin combined with an aminoglycoside provides gram-positive and gram-negative coverage for colorectal prophylaxis. Cephalosporins carry cross-reactivity risk in severe reactions, and vancomycin with metronidazole lacks adequate gram-negative coverage.

Question 46Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A patient with a body mass index of 50 kg/m² requires emergency laparotomy. Which perioperative measure most reduces the risk of venous thromboembolism?

  1. Aspirin 81 mg daily
  2. Graduated compression stockings alone
  3. Weight-adjusted low molecular weight heparin plus intermittent pneumatic compression Correct answer.
  4. Early discharge on postoperative day 1

Explanation

For high-risk obese patients undergoing major abdominal surgery, guidelines recommend combined pharmacologic prophylaxis with weight-adjusted low molecular weight heparin and mechanical compression. Mechanical prophylaxis alone or aspirin is insufficient in this risk category.

Question 47Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A 30-year-old man sustains a stab wound and arrives with a systolic pressure of 70 mmHg, cold extremities, and a hemoglobin of 7 g/dL. Which initial resuscitation strategy is most appropriate?

  1. Immediate vasopressor infusion without volume resuscitation
  2. Permissive hypotension with early balanced blood product transfusion Correct answer.
  3. Aggressive crystalloid infusion to normalize blood pressure before transfusion
  4. Rapid transfusion of packed red cells alone without plasma

Explanation

Damage control resuscitation favors permissive hypotension until hemorrhage is controlled, together with early balanced transfusion of red cells, plasma, and platelets in a 1:1:1 ratio to avoid dilutional coagulopathy. Large crystalloid boluses worsen acidosis and coagulopathy.

Question 48Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

Which statement about surgical wound classification is correct?

  1. A contaminated wound is an operation on infected tissue with pus
  2. A dirty wound is an elective operation with no viscus entry
  3. A clean wound involves acute inflammation without pus
  4. A clean-contaminated wound involves entry into a hollow viscus under controlled conditions Correct answer.

Explanation

Clean-contaminated surgery enters a hollow viscus, such as the biliary or gastrointestinal tract, under controlled conditions without unusual contamination. Dirty or infected wounds involve existing infection or pus, while clean wounds are elective and uninfected.

Question 49Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

A patient on chronic corticosteroids for rheumatoid arthritis is scheduled for major abdominal surgery. Which perioperative management is most appropriate?

  1. Abruptly discontinue steroids on the morning of surgery
  2. Give stress-dose hydrocortisone and taper to maintenance over 24 to 48 hours Correct answer.
  3. Double the oral dose for one week preoperatively
  4. Withhold all steroids until the patient is discharged

Explanation

Chronic corticosteroid use suppresses the hypothalamic-pituitary-adrenal axis, so patients need stress-dose hydrocortisone during major surgery, tapered back to their maintenance dose as the stress response resolves. Abrupt withdrawal risks adrenal crisis and hemodynamic collapse.

Question 50Preoperative, Perioperative and Postoperative Care (risk assessment, anesthesia coordination, wound healing, surgical infections, critical care, complications, enhanced recovery)

Which finding on preoperative assessment most strongly predicts difficult mask ventilation during induction of anesthesia?

  1. Body mass index of 45 kg/m² with a beard and edentulous airway Correct answer.
  2. Mallampati class I
  3. Full cervical spine extension
  4. Thyromental distance of 7 cm

Explanation

Obesity, a beard, and absence of teeth are recognized independent predictors of difficult mask ventilation because they impair the seal and upper airway patency. A Mallampati class I, adequate thyromental distance, and full neck extension all suggest an easy airway.