Management of Melena (Black, Tarry Stools)
Immediately assess hemodynamic stability by calculating the shock index (heart rate ÷ systolic blood pressure), and if <1, proceed with upper endoscopy as the primary diagnostic test; if >1 or the patient is unstable, resuscitate aggressively and consider urgent intervention. 1, 2
Immediate Assessment and Resuscitation
Calculate the shock index immediately upon presentation – a value <1 defines hemodynamic stability, while >1 indicates active bleeding requiring ICU admission and urgent intervention rather than routine workup. 1, 2
Check orthostatic vital signs in patients who appear stable, as orthostatic hypotension indicates significant blood loss requiring ICU admission even if supine vitals seem reassuring. 2
Establish two large-bore IV lines in the anticubital fossae and begin aggressive fluid resuscitation with 1-2 liters of normal saline if the patient shows any signs of hemodynamic compromise. 2
Transfuse packed red blood cells to maintain hemoglobin >7 g/dL in stable patients, or >8-9 g/dL in patients with cardiovascular disease, massive bleeding, or anticipated delay in therapeutic intervention. 3, 1, 2
Diagnostic Approach Based on Stability
For Hemodynamically Stable Patients (Shock Index <1):
Perform esophagogastroduodenoscopy (EGD) as the initial diagnostic procedure, as the upper gastrointestinal tract is the most common source of melena (duodenal ulcer, gastric ulcer, esophagitis, or varices). 3, 4, 5
Insert a nasogastric tube to protect the airway, decompress the stomach, and help confirm upper GI bleeding before endoscopy. 3
If EGD is nondiagnostic, proceed with colonoscopy after adequate bowel preparation, as 4.8% of melena cases have a lower GI source (right-sided arteriovenous malformations, colitis, large polyps, tumors, or ulcers). 6
Consider small bowel evaluation with capsule endoscopy or push enteroscopy if both EGD and colonoscopy are negative, as small bowel sources account for approximately 5-10% of melena cases. 3, 4
For Hemodynamically Unstable Patients (Shock Index >1):
Perform CT angiography immediately as the first diagnostic step in unstable patients, as it provides the fastest and least invasive means to localize bleeding with 79-95% sensitivity. 2
Proceed to catheter angiography with embolization within 60 minutes if CT angiography is positive and interventional radiology is available 24/7. 2
Reserve urgent surgery only for patients with persistent hemodynamic instability despite aggressive resuscitation, transfusion requirement exceeding 6 units, or failed angiographic intervention. 2
Post-Endoscopy Management
If endoscopic therapy is performed for ulcer bleeding, administer high-dose omeprazole (80 mg IV bolus followed by 8 mg/hour infusion for 72 hours) to reduce rebleeding, transfusion requirements, and hospital stay. 3
Monitor vital signs every 4-6 hours minimum after endoscopy, watching for fresh melena, hematemesis, drop in blood pressure, or rise in pulse rate, which indicate rebleeding requiring immediate notification. 3, 1
Allow oral intake 4-6 hours after endoscopy if the patient remains hemodynamically stable, as prolonged fasting is unnecessary in stable patients. 3
Anticoagulation Management
Interrupt warfarin immediately at presentation and reverse with fresh frozen plasma and vitamin K if the patient has active bleeding. 3, 1, 2
Document the patient's anticoagulation status (warfarin, aspirin, other antiplatelet agents) as this affects bleeding risk and management decisions. 1
Critical Pitfalls to Avoid
Do not assume all melena originates from the upper GI tract – approximately 15% of apparent lower GI bleeding actually originates from massive upper GI bleeding with rapid transit time, and 5% originates from the small bowel. 7, 4
Do not delay resuscitation for diagnostic evaluation in unstable patients, as this is a critical error that increases mortality. 2, 7
Do not minimize the significance of melena – mortality for hospitalized patients who develop GI bleeding can reach 18%, and patients requiring ≥4 units of transfusion have approximately 20% mortality risk, primarily related to comorbidities. 1, 2
Do not perform repeat endoscopy routinely after initial endoscopic treatment unless there is clinical evidence of rebleeding or concerns about suboptimal initial therapy. 3
Do not proceed to surgery without repeat endoscopy in patients who rebleed after initial stability, as further endoscopic therapy has outcomes at least as good as urgent surgery. 3