PLAB 2 Acute Abdominal Pain Station: How to Approach, Mark Scheme & Free Practice

Hold these differentials in your head

Bracket the deadly causes first. If you fail to consider any of these in your reasoning out loud, the clinical-management domain will suffer.

• Acute cholecystitis
  Constant right upper quadrant pain after a fatty meal, radiating to the right shoulder blade, with fever, vomiting and a positive Murphy's sign. Previous milder self-limiting episodes after fatty food point to underlying gallstones.
• Acute appendicitis
  Central colicky pain migrating to the right iliac fossa over 12 to 24 hours, with anorexia, low-grade fever and localised tenderness at McBurney's point. The classic surgical abdomen of a younger patient.
• Acute pancreatitis
  Severe epigastric pain boring through to the back, eased by sitting forward, with profuse vomiting. Ask about gallstones and alcohol - the two dominant causes - and always request an amylase or lipase to rule it in or out.
• Renal colic
  Severe colicky loin-to-groin pain in a patient who cannot lie still, often with haematuria. Contrast this with the peritonitic patient, who lies rigid - the restlessness itself is a discriminating feature.
• Ruptured abdominal aortic aneurysm
  Sudden severe abdominal or back pain with collapse or hypotension, classically in a man over 60 who smokes. Rapidly fatal - actively rule it out in any older patient with abdominal pain and haemodynamic compromise.
• Ectopic pregnancy
  Lower abdominal pain with a missed or abnormal period, sometimes shoulder-tip pain or dizziness, in any woman of childbearing age. <strong>Always ask about the last menstrual period and request a pregnancy test</strong> - assuming she cannot be pregnant is a safety-critical fail.
• Peptic ulcer disease and perforation
  Epigastric burning related to meals, on a background of NSAID use, smoking or previous dyspepsia. Sudden severe generalised pain with a rigid, board-like abdomen signals perforation and needs an urgent erect chest X-ray for free air.

Step-by-step approach

This is the structure that scores. You do not need to follow it verbatim, but every numbered block below maps to a cluster of marks in the rubric.

1. 1. Open and acknowledge the pain

   This patient is hurting. The first thirty seconds decide your interpersonal-skills score.

   • Wash hands, greet, introduce yourself with name and grade, confirm the patient's full name and age.
   • Acknowledge what you can see: "I can see you're in a lot of pain - I'm sorry, we'll get on top of that."
   • Offer analgesia early - "Before we go any further, would you like something for the pain?" is a weighted mark and basic kindness.
   • Ask permission to ask some questions while the pain relief is arranged.

2. 2. SOCRATES the pain

   Every letter is a mark, and in abdominal pain the answers do most of your diagnostic work.

   • Site - ask them to point. Right upper quadrant, epigastrium, loin and right iliac fossa each open a different differential.
   • Onset - sudden or gradual, and what they were doing. Ask specifically what brought it on - a fatty meal is a weighted mark in a gallstone story.
   • Character - constant or colicky. A constant pain that was previously colicky suggests inflammation has set in.
   • Radiation - right shoulder blade (gallbladder), through to the back (pancreas, aorta), loin to groin (renal colic), shoulder tip (diaphragmatic irritation, think ectopic).
   • Associated symptoms - nausea, vomiting, fever, sweating, anorexia, bowel habit, urinary symptoms.
   • Time course - continuous or intermittent, getting better or worse, and any similar previous episodes - recurrent post-prandial attacks are a weighted mark.
   • Exacerbating and relieving factors - movement, deep breathing, food, position, simple analgesia.
   • Severity - 1 to 10 now and at its worst.

3. 3. Screen the red flags

   A short, deliberate sweep that shows the examiner you are ruling out the killers, not just describing the pain.

   • Jaundice - yellowing of the skin or eyes, dark urine and pale stools - a stone in the bile duct changes the whole plan.
   • Fever, rigors, feeling hot and sweaty - infection or sepsis.
   • Weight loss and appetite - malignancy screen, brief but scored.
   • Collapse, dizziness or back pain in an older patient - do not let a ruptured AAA hide behind "renal colic".
   • Last menstrual period, possibility of pregnancy and contraception in every woman of childbearing age. This is safety-critical - ask it even when the pain is nowhere near the pelvis.
   • Blood in vomit or stool, black tarry stools.

4. 4. Complete the history

   Round out the background before you turn to the examiner.

   • Past medical history - previous similar episodes, gallstones, ulcers, pancreatitis.
   • Previous abdominal surgery - adhesions change the differential and the plan.
   • Medications - the combined pill, NSAIDs, steroids, anticoagulants all matter here. Allergies.
   • Family history - gallstones and gallbladder surgery run in families and it is a scored question.
   • Social history - smoking, alcohol in units, diet, and who is at home if admission is on the cards.

5. 5. Ideas, concerns and expectations

   One short question that earns interpersonal marks and often reveals the real fear - appendicitis, cancer, an operation.

   • "Is there anything in particular you were worried this might be?"
   • "Was there anything you were hoping we would do today?"
   • Listen, acknowledge, do not dismiss - then fold the answer into your explanation later.

6. 6. Request examination findings from the examiner

   State out loud exactly what you would examine - the examiner only gives findings you explicitly ask for. Mention a chaperone before you examine.

   • Vital signs - blood pressure, heart rate, respiratory rate, temperature, oxygen saturation. A fever with tachycardia raises the stakes immediately.
   • General inspection - jaundice, pallor, distress, how the patient is lying (still and rigid versus writhing).
   • Abdominal examination - tenderness, guarding, rebound, masses, bowel sounds, hernial orifices.
   • Murphy's sign if the story points to the gallbladder - ask for it by name, it is a weighted mark.
   • A urine pregnancy test in any woman of childbearing age - request it alongside the examination, not as an afterthought.

7. 7. Request investigations

   Order tests that discriminate between your differentials, and say why.

   • Bedside - urine dipstick and urine pregnancy test, ECG if the pain is upper abdominal in an older patient.
   • Bloods - FBC and CRP for infection, LFTs for the biliary tree, amylase or lipase to exclude pancreatitis, U&Es, glucose. Group and save if surgery is likely.
   • Abdominal ultrasound - the first-line imaging for suspected gallstone disease, looking for stones, a thickened gallbladder wall and duct dilatation.
   • Erect chest X-ray if perforation is on the differential, CT if the diagnosis remains unclear or an aneurysm is suspected.

8. 8. Explain the diagnosis in plain English

   Translate every term. The patient should leave the conversation able to repeat the diagnosis to a relative.

   • "I think the most likely cause is inflammation of the gallbladder - a small pouch under the liver that stores bile. Small stones can form there and one has probably blocked it, which is why fatty food set the pain off."
   • Mention one or two alternatives you are checking for - an ulcer, the pancreas - so the patient knows the tests have a purpose.
   • Pause and check understanding before moving to the plan.

9. 9. Outline management and safety-net

   Cover the admission decision, immediate treatment, the definitive plan and explicit safety-netting.

   • Admit under the surgical team. Do not send home with oral antibiotics - this is the safety-critical decision of the station.
   • Nil by mouth, IV fluids, IV analgesia (for example morphine, titrated) and an antiemetic.
   • IV antibiotics per local policy - co-amoxiclav is a reasonable example.
   • Definitive treatment: laparoscopic cholecystectomy, ideally during the same admission or within a week, per NICE guidance for acute cholecystitis.
   • Lifestyle advice - a low-fat diet and gradual weight management reduce further attacks while awaiting surgery.
   • Safety-net explicitly: worsening pain, yellowing of the skin or eyes, persistent vomiting or fever must be reported to staff immediately.
   • Check understanding, invite final questions, thank the patient and close.

Common pitfalls

• Not offering analgesia early - assessing a patient in visible pain for six minutes before mentioning pain relief loses a weighted interpersonal mark and looks unkind.
• Forgetting the last menstrual period and pregnancy test in a woman of childbearing age - this is a safety-critical omission even when the story sounds classically biliary.
• Never asking what brought the pain on - the fatty-meal trigger is a weighted data-gathering mark and the single best clue in a gallstone history.
• Skipping the jaundice screen - yellowing, dark urine and pale stools distinguish simple cholecystitis from a duct stone, and the duct question changes the whole plan.
• Not requesting amylase - stating "bloods" is not enough; you must name the test that excludes pancreatitis.
• Agreeing to send the patient home with oral antibiotics because she asks about her children - acknowledge the concern, offer to involve family, but the admission stands.
• Examining without mentioning a chaperone - one sentence protects the mark.
• Using jargon ("cholecystitis", "Murphy's positive", "USS") without translation - explain the gallbladder in plain English before naming the condition.

Frequently asked questions