Master General Surgery
for DHA

What the DHA Tests in General Surgery

The DHA General Surgery exam tests your ability to recognise surgical presentations, prioritise life-threatening conditions, and apply evidence-based management. You must demonstrate knowledge of acute abdomen, trauma triage (ATLS principles), surgical infections, hernia types, breast lumps, colorectal emergencies, and biliary pathology. Questions often present a clinical scenario with vitals, lab values, and imaging findings, requiring you to choose the next best step in diagnosis or treatment. You must know specific criteria (e.g., Alvarado score for appendicitis, Ranson criteria for pancreatitis), first-line antibiotics (e.g., co-amoxiclav for cholangitis), and when to operate versus manage conservatively. Emphasis is on decision-making in emergency settings, recognition of complications (e.g., perforation, obstruction), and knowledge of common post-operative complications like anastomotic leak or DVT prophylaxis.

High-Yield Concepts

• Acute Appendicitis – Alvarado Score: Use the Alvarado (MANTRELS) score: Migration of pain, Anorexia, Nausea/vomiting, Tenderness in RLQ, Rebound pain, Elevated temperature (>37.3°C), Leukocytosis (>10,000/mm³), Left shift (>75% neutrophils). Score 7+ indicates high probability; proceed to CT or surgery. First-line treatment is laparoscopic appendicectomy; for uncomplicated appendicitis, co-amoxiclav 1.2 g IV or metronidazole + cefuroxime perioperatively.
• Acute Cholecystitis – Tokyo Guidelines 2018: Diagnosis requires one local sign (Murphy’s sign, RUQ mass/tenderness) plus one systemic sign (fever >38°C, elevated CRP, WBC >10,000/mm³) plus imaging (gallbladder wall >4 mm, pericholecystic fluid). Grade I (mild): early laparoscopic cholecystectomy within 72 hours; Grade II (moderate): urgent drainage if surgery delayed; Grade III (severe): organ dysfunction, requires ICU and percutaneous cholecystostomy.
• Acute Pancreatitis – Ranson Criteria & Management: Ranson criteria: at admission (age >55, WBC >16,000, glucose >11 mmol/L, LDH >350 IU/L, AST >250 IU/L) and at 48 hours (Hct drop >10%, BUN rise >1.8 mmol/L, calcium <2 mmol/L, PaO2 <60 mmHg, base deficit >4 mEq/L, fluid sequestration >6 L). Severe if ≥3 criteria. First-line: aggressive IV crystalloid (Hartmann’s), analgesia (morphine), enteral nutrition (nasojejunal if tolerated). Antibiotics only for infected necrosis (imipenem or meropenem).
• Inguinal Hernia – Nyhus Classification & Repair: Direct hernias (Nyhus type IIIA) protrude through Hesselbach’s triangle; indirect (type II) through deep ring. Emergency: irreducible, tender hernia with vomiting/obstruction suggests strangulation – urgent exploration, resection of non-viable bowel. Elective: Lichtenstein tension-free mesh repair (polypropylene mesh) is gold standard. Antibiotic prophylaxis (co-amoxiclav) only for high-risk patients (diabetes, recurrent hernia).
• Breast Lump – Triple Assessment: Triple assessment: clinical examination, imaging (mammogram for >35 years, ultrasound for <35 years), and core needle biopsy (CNB) for histology. BI-RADS categories: 4 or 5 require biopsy. First-line for early breast cancer (ER+): wide local excision + sentinel lymph node biopsy + radiotherapy, plus tamoxifen (premenopausal) or anastrozole (postmenopausal). For HER2+: add trastuzumab.
• Colorectal Obstruction – Management: Sigmoid volvulus: diagnosis by coffee-bean sign on AXR; first-line is endoscopic detorsion (rigid sigmoidoscopy) with rectal tube placement. Recurrence risk >50% – elective sigmoid resection. For obstructing left-sided colon cancer: Hartmann’s procedure (resection + colostomy) or emergency stenting as bridge to surgery. For right-sided obstruction: right hemicolectomy with primary anastomosis.
• Upper GI Bleed – Rockall Score: Rockall score: age (<60=0, 60-79=1, >80=2), shock (no shock=0, tachycardia=1, hypotension=2), comorbidity (none=0, major=2, renal/liver failure=3), endoscopic findings (Mallory-Weiss=0, ulcer with clot=1, active bleeding=2). Score ≥8 predicts high mortality. First-line: IV omeprazole 80 mg bolus then 8 mg/hour, endoscopic therapy (adrenaline injection + heater probe/clips) for active bleeding. If rebleeding: repeat endoscopy or interventional radiology (embolisation).
• Trauma – ATLS Primary Survey & Emergency Laparotomy: Primary survey: A (airway with C-spine control), B (breathing: tension pneumothorax needs needle decompression at 2nd ICS MCL), C (circulation: IV access, 2 large-bore cannulae; fluid resuscitation with 1 L crystalloid; if transient responder, activate massive transfusion protocol 1:1:1 PRBC:FFP:platelets). Indications for emergency laparotomy: haemodynamic instability with positive FAST, penetrating abdominal trauma with peritonitis, or evisceration. Damage control surgery: pack bleeding, temporary closure, ICU resuscitation.

Common Traps in General Surgery Questions

• Confusing Ranson criteria with Glasgow criteria for pancreatitis – Glasgow uses age >55, WBC >15, LDH >600, glucose >10, albumin <32, calcium <2, urea >16, PaO2 <60; Ranson has different time points.
• Thinking all right iliac fossa pain is appendicitis – remember to consider Meckel’s diverticulitis (rule of 2s: 2 feet from ileocecal valve, 2 inches long, 2% of population) in young adults.
• Forgetting that a non-tender, reducible inguinal hernia does not require urgent surgery – elective repair is appropriate; only strangulated or obstructed hernias are emergencies.
• Assuming a positive Murphy’s sign is pathognomonic for cholecystitis – it can be absent in gangrenous cholecystitis or in elderly/diabetic patients; always confirm with ultrasound.
• Misinterpreting a ‘clean’ abdominal XR in suspected obstruction – small bowel obstruction often shows only a few air-fluid levels; CT is more sensitive and should be the next step if clinical suspicion is high.

How to Revise General Surgery for the DHA

Focus on emergency surgical presentations: acute abdomen, trauma, and GI bleeding. Questions are scenario-based, often with vitals and lab values, requiring you to choose the next diagnostic step (e.g., CT abdomen vs. ultrasound) or management (e.g., when to operate vs. conservative). Prioritise memorising scoring systems (Alvarado, Ranson, Rockall, Glasgow) and their cut-offs. Know first-line antibiotics for common infections (e.g., co-amoxiclav for cholangitis, metronidazole for diverticulitis). Practise interpreting imaging findings: pneumoperitoneum on erect CXR, free fluid on FAST, dilated loops on AXR. Also review post-operative complications (e.g., anastomotic leak presents with tachycardia, oliguria, and peritonitis; management is return to theatre). Use single-best-answer format questions from past DHA-style banks to build speed.

Practise it: MedLumen has 110 General Surgery questions for the DHA, each with a full explanation and references.