Master Adult Health (Surgery)
for AMC Cat 1

What the AMC Cat 1 Tests in Adult Health (Surgery)

Adult Health (Surgery) on the AMC Cat 1 exam tests the ability to recognise and manage common surgical presentations in adults, including acute abdomen, trauma, perioperative care, and surgical oncology. Candidates must demonstrate knowledge of diagnostic criteria (e.g., Alvarado score for appendicitis), first-line investigations (e.g., CT KUB for ureteric colic), and evidence-based management (e.g., laparoscopic cholecystectomy within 72 hours for acute cholecystitis). Emphasis is on decision-making for emergency versus elective surgery, recognition of complications (e.g., anastomotic leak, compartment syndrome), and understanding of surgical sepsis (e.g., source control in cholangitis). The exam also tests core perioperative principles: DVT prophylaxis (e.g., LMWH per Caprini score), fluid balance, and antibiotic prophylaxis (e.g., cefazolin for clean-contaminated cases).

High-Yield Concepts

• Acute Appendicitis – Alvarado Score & Management: Alvarado score ≥7 warrants urgent appendicectomy; score 5-6 requires CT abdomen. First-line: laparoscopic appendicectomy within 24 hours of diagnosis. Antibiotics (e.g., co-amoxiclav 1.2g IV) if perforated. Key cut-off: neutrophils >75% on WCC.
• Acute Cholecystitis – Tokyo Guidelines & Timing: Diagnosis: Murphy sign, raised CRP, US showing thickened gallbladder wall (>4mm) or pericholecystic fluid. Grade I (mild) → laparoscopic cholecystectomy within 72 hours; Grade II (moderate) → early surgery after resuscitation; Grade III (severe) → percutaneous cholecystostomy if unfit.
• Bowel Obstruction – Differentiation & Initial Management: Small bowel obstruction (SBO): CT shows transition point, no gas in colon. Large bowel obstruction (LBO): dilated colon, often due to tumour. First-line: NGT decompression, IV fluids (Hartmann's), CT with IV contrast. Emergency surgery if strangulation (e.g., closed-loop, peritonitis).
• Perioperative DVT Prophylaxis – Caprini Score: Caprini score ≥5 (high risk): enoxaparin 40mg SC daily + mechanical prophylaxis. Score 3-4 (moderate): enoxaparin 40mg SC daily. Contraindications: active bleeding, recent haemorrhagic stroke. Continue for 28 days after major cancer surgery.
• Surgical Site Infection (SSI) – Antibiotic Prophylaxis: For clean-contaminated wounds (e.g., colorectal): cefazolin 2g IV + metronidazole 500mg IV within 60 minutes before incision. Redose if surgery >3 hours or blood loss >1500mL. No routine antibiotics for clean procedures (e.g., hernia repair) unless high risk.
• Acute Limb Ischaemia – Rutherford Classification & Management: Rutherford I (viable): urgent duplex → angioplasty. Rutherford IIa (marginally threatened): emergent revascularisation (thrombectomy/bypass). Rutherford IIb (immediately threatened): emergency surgery within 6 hours. Rutherford III (irreversible): amputation. Key: check for compartment syndrome post-reperfusion.
• Trauma – ATLS Primary Survey & Massive Transfusion: Primary survey: A (airway with C-spine), B (breathing, tension pneumothorax → needle decompression), C (circulation, pelvic binder if unstable). Massive transfusion protocol: 1:1:1 ratio of PRBC:FFP:platelets. Target: Hb >80 g/L, platelets >50, INR <1.5, ionised Ca >1.0 mmol/L.
• Surgical Jaundice – Obstructive vs Hepatocellular: Obstructive: raised ALP, GGT, bilirubin; US shows dilated bile ducts. First-line: MRCP then ERCP with sphincterotomy/stenting. If gallstone-related, cholecystectomy after ERCP. Hepatocellular: raised ALT/AST, normal ducts. Cut-off: bilirubin >40 µmol/L with dilated ducts = urgent referral.

Common Traps in Adult Health (Surgery) Questions

• Confusing Alvarado score with RIPASA score; RIPASA is validated for Asian populations but AMC expects Alvarado.
• Ordering CT abdomen with oral contrast for acute pancreatitis; CT is indicated only at 48-72 hours if severe, not on admission.
• Giving IV antibiotics for uncomplicated diverticulitis without abscess; current guidelines recommend oral co-amoxiclav or metronidazole+ciprofloxacin for mild cases.
• Failing to recognise that a positive Murphy sign on US does not rule out cholecystitis if the gallbladder is contracted and stone-impacted.
• Assuming all post-operative fevers are wound infections; atelectasis on day 1-2 is more common, and UTI or line sepsis should be considered after day 3.
• Forgetting to check capillary lactate and compartment pressure in a patient with acute limb ischaemia post-revascularisation; missed compartment syndrome is a common pitfall.

How to Revise Adult Health (Surgery) for the AMC Cat 1

Focus on acute surgical presentations with clear management algorithms: appendicitis, cholecystitis, bowel obstruction, and trauma. Questions often present a clinical vignette with a single best answer requiring you to choose the next step in management (e.g., 'What is the most appropriate next investigation?'). Prioritise knowing the Tokyo Guidelines for cholecystitis, ATLS protocols for trauma, and Caprini scores for DVT prophylaxis. Practise interpreting CT findings (e.g., transition point, pneumoperitoneum) and lab values (e.g., lactate, WCC, CRP). Expect 1-2 questions on perioperative complications (e.g., anastomotic leak presenting with peritonitis on day 5). Use the AMC MCQ bank to drill time-sensitive decisions, and memorise key cut-offs: Alvarado ≥7, CRP >150 in cholecystitis, lactate >2 mmol/L in ischaemia.

Practise it: MedLumen has 90 Adult Health (Surgery) questions for the AMC Cat 1, each with a full explanation and references.