Surgery
Core concepts
Surgical questions test triage and sequence more than operative detail. Know the acute abdomen differential by quadrant and by onset: appendicitis (migratory pain, McBurney point, Rovsing), cholecystitis (right upper quadrant, Murphy sign, ultrasound), pancreatitis (epigastric radiation to back, lipase >3× normal), bowel obstruction (crampy pain, vomiting, distension, air-fluid levels), perforation (rigid abdomen, free air), and mesenteric ischemia (pain out of proportion to exam). Understand ATLS-style priorities - airway, breathing, circulation, disability, exposure - and when to operate emergently versus observe.
Traps
Examiners frequently present a "classic" picture in an atypical patient: the elderly or diabetic patient with appendicitis may lack fever or classic migration; the pregnant patient with appendicitis has a displaced appendix. Another trap is choosing imaging before resuscitation in an unstable patient - the unstable trauma patient goes to the operating room, not the CT scanner. Distinguish strangulation risk (fever, tachycardia, peritoneal signs, leukocytosis) from simple obstruction; the former mandates urgent surgery. Finally, remember that normal amylase does not exclude pancreatitis and that lipase is preferred.
Worked rule of thumb
For any acute abdomen stem, ask two questions in order: (1) Is the patient hemodynamically stable? If not, resuscitate and operate or intervene without delay. (2) Are there signs of peritonitis or strangulation? If yes, surgical consultation is immediate. Example: a 70-year-old with crampy abdominal pain, vomiting, distension, and a tender, tympanitic abdomen plus fever and tachycardia has obstruction with possible strangulation - fluids, nasogastric decompression, labs, and urgent surgical evaluation, not a period of observation.