Surgery: Prioritise Physiology Before Anatomy
Surgery items test the acute abdomen, trauma resuscitation, perioperative care, fluid and transfusion strategy, and the initial approach to common elective conditions such as hernia, thyroid and breast disease. Examiners reward a structured sequence: resuscitate, diagnose, decide on operative versus non-operative management, and recognise the patient who is deteriorating despite normal-looking observations.
Core rules
- Trauma. Follow ABCDE with catastrophic haemorrhage control first. Permissive hypotension is acceptable in penetrating trauma without head injury; massive transfusion follows a balanced 1:1:1 red cell, plasma and platelet strategy.
- Acute abdomen. Use pain migration and peritoneal signs. Visceral pain is poorly localised and midline; parietal irritation produces sharp, localised guarding.
- Ischaemia. Pain out of proportion to examination, atrial fibrillation or vascular disease suggests mesenteric ischaemia; lactate is often elevated and CT angiography is the test.
- Perioperative. Antibiotic prophylaxis within 60 minutes of incision, VTE risk assessment, glycaemic control, and correction of volume and electrolyte deficits before elective surgery.
- Burns. Parkland formula 4 mL/kg per percent total body surface area in the first 24 hours, half in the first 8 hours; titrate to urine output 0.5–1 mL/kg/h rather than to the formula alone.
Worked example
A 19-year-old man has 18 hours of anorexia and periumbilical pain that has migrated to the right lower quadrant. Temperature is 38.0°C, there is tenderness at McBurney's point with guarding, and the white cell count is 14 × 10⁹/L. The migration from midline visceral pain to localised parietal pain is the discriminating feature, giving a working diagnosis of acute appendicitis. A pregnancy test is mandatory in any woman of childbearing age; ultrasound is preferred in children and pregnancy, CT in adults. Management is intravenous crystalloid, preoperative antibiotics covering gram-negative and anaerobic organisms, and laparoscopic appendectomy.
Traps that cost marks
- Withholding analgesia for fear of masking the examination; adequate analgesia does not obscure peritoneal signs.
- Diagnosing gastroenteritis in a patient with focal right lower quadrant tenderness and leukocytosis.
- Forgetting the pregnancy test, which changes imaging and management.
- Over-resuscitating burns and causing compartment or pulmonary oedema.