Makindo Medical Notes

🩺 OSCE Melaena

Candidate Instructions 📋

You are the medical student in the Acute Medical Unit. A 58-year-old man has been referred by his GP with a history of black stools. Take a focused history and outline your initial management plan. You do not need to perform a physical examination. You have 8 minutes.

Key Learning Points 🔑

• Melaena = black, tarry stools due to digested blood, usually from an upper GI source.
• Causes include peptic ulcer disease, varices, gastritis, Mallory-Weiss tear, malignancy.
• Always assess for haemodynamic stability 🚨 (shock, syncope, dizziness).
• History must screen for red flags + medication use (NSAIDs, anticoagulants).

History Framework 📝

• Presenting Complaint: Colour, consistency, duration of black stools. Any fresh blood?
• Associated Symptoms: Haematemesis, dizziness, presyncope, abdominal pain, weight loss, dyspepsia.
• Red Flags: Syncope, shock, known liver disease, weight loss, dysphagia.
• Past Medical History: PUD, cirrhosis, varices, IHD, CKD.
• Drug History: NSAIDs, aspirin, anticoagulants, steroids.
• Social History: Alcohol intake 🍺, smoking 🚬 (risk of cirrhosis, ulcers, malignancy).
• Family History: Malignancy, peptic ulcer disease.

Role-Player Prompts 👨‍⚕️

• Stools black & tarry for 3 days, very smelly.
• Felt dizzy when standing, almost fainted.
• No vomiting blood, but occasional epigastric pain.
• Takes ibuprofen regularly for knee pain, and aspirin after an MI.
• Past history: hypertension, no known liver disease.
• Smokes 20/day, drinks 25 units/week.
• No family history of bowel cancer.

Differential Diagnosis ⚖️

• Peptic ulcer disease (most likely here)
• Gastric/duodenal erosions
• Variceal bleed
• Mallory-Weiss tear
• Upper GI malignancy
• Swallowed blood (e.g., epistaxis)

Investigations 🔬

• Bedside: Obs, ECG, stool inspection.
• Bloods: FBC (Hb), U&E (urea ↑ in upper GI bleed), LFTs, clotting, group & save, crossmatch.
• Imaging: Not first-line unless unstable, then urgent endoscopy when stabilised.
• Endoscopy: Gold standard to diagnose & treat (banding, clipping, adrenaline injection).

Management 🚑

• Immediate: ABCDE, insert large-bore IV access, monitor vitals, give O₂ if hypoxic.
• Resuscitation: IV fluids ± blood products (use restrictive transfusion threshold Hb <70 g/L unless cardiovascular disease).
• Pharmacological: IV PPI (omeprazole) if ulcer suspected; terlipressin + antibiotics if varices suspected.
• Endoscopy: Arrange urgent OGD within 24 hours (sooner if unstable).
• Definitive: Endoscopic therapy (clipping, adrenaline, band ligation), surgery or radiology embolisation if ongoing bleeding.
• Secondary Prevention: Stop NSAIDs/aspirin if possible, eradicate H. pylori, alcohol reduction advice, PPI prophylaxis.

Examiner’s Marking Guide 📋

• Introduces self, gains consent, clarifies “black stools”.
• Asks about haemodynamic compromise (dizziness, syncope, collapse).
• Explores drug history (NSAIDs, anticoagulants).
• Identifies need for resuscitation, IV access, bloods, crossmatch.
• Mentions urgent endoscopy and PPI therapy.

References 📚

• NICE CKS: Upper GI bleeding
• NICE NG184: Acute GI bleeding