What to do next for a patient with an isolated episode of melena (black tarry stools) seen in general practice?

Management of an Isolated Episode of Melena in General Practice

For a patient presenting with an isolated episode of melena in general practice, the most appropriate next step is to refer for an urgent upper gastrointestinal endoscopy while initiating proton pump inhibitor therapy. 1

Initial Assessment and Risk Stratification

• Hemodynamic status evaluation is crucial:

  • Check vital signs (pulse, blood pressure) to identify shock (defined as pulse >100 beats/min and systolic BP <100 mmHg) 2
  • Assess for orthostatic changes and signs of ongoing bleeding
  • Measure hemoglobin level to determine severity of blood loss

• Risk factors that warrant immediate attention:

  • Age >60 years (mortality risk increases with age) 2
  • Presence of significant comorbidities (especially cardiovascular, renal, or liver disease)
  • Current use of anticoagulants or antiplatelet medications 1
  • Signs of hemodynamic instability

Immediate Management in General Practice

1. Start proton pump inhibitor therapy:

   • High-dose PPI (e.g., omeprazole 80mg bolus followed by 8mg/hour infusion if IV available, or high-dose oral PPI if not) 2
   • This reduces risk of continued bleeding while awaiting definitive diagnosis

2. Medication review and adjustment:

   • Discontinue NSAIDs immediately 1
   • For patients on antiplatelet therapy:
     • Do not discontinue aspirin if taken for secondary cardiovascular prevention 1
     • For dual antiplatelet therapy in patients with coronary stents, consult with cardiology before any changes 1

3. Referral pathway:

   • Hemodynamically unstable patient: Immediate hospital admission
   • Hemodynamically stable patient with isolated melena: Urgent referral for upper GI endoscopy (ideally within 24 hours) 2

Diagnostic Approach

• Upper GI endoscopy is the first-line diagnostic test as:

  • Melena most commonly originates from the upper GI tract 3
  • Early endoscopy (within 24 hours) improves outcomes 2
  • Allows for both diagnosis and potential therapeutic intervention

• If upper endoscopy is negative:

  • Consider colonoscopy, as right-sided colonic lesions can present with melena 4, 5
  • Diagnostic yield of colonoscopy after negative upper endoscopy is approximately 4.8%, with therapeutic intervention needed in 1.7% of cases 5

Special Considerations

• Medication-related risks:

  • For patients on anticoagulants: Evaluate risk-benefit ratio of continuing therapy 1
  • For patients on dual antiplatelet therapy: Consider cardiology consultation before any medication changes 1

• Follow-up recommendations:

  • Even after a single episode of melena resolves, endoscopic evaluation is still recommended to identify the source
  • Iron supplementation should be considered for patients with evidence of anemia 1
  • Age-appropriate cancer screening should be considered as GI malignancies can present with melena 1, 5

Key Pitfalls to Avoid

• Do not assume a self-limited episode requires no further evaluation - a single episode of melena warrants investigation even if bleeding has stopped
• Do not delay endoscopy in patients with significant risk factors (age >60, comorbidities)
• Do not routinely discontinue aspirin in patients taking it for secondary cardiovascular prevention 1
• Do not overlook the possibility of lower GI sources - approximately 24% of patients with melena have a non-diagnostic upper endoscopy 4

Remember that melena indicates significant blood loss (at least 50-100 mL) and warrants proper investigation even if it appears to be an isolated episode.