What is the appropriate workup and initial management for a patient presenting with nausea, vomiting and melena (dark tar‑colored stool)?

Workup and Management of Nausea, Vomiting, and Melena

This patient requires immediate hospital admission for hemodynamic stabilization, urgent esophagogastroduodenoscopy (EGD) within 24 hours, and high-dose proton pump inhibitor therapy, as melena with nausea and vomiting indicates upper gastrointestinal bleeding with significant mortality risk that demands early specialist intervention. 1

Immediate Resuscitation (Priority #1)

Establish two large-bore IV lines in the anticubital fossae and begin aggressive fluid resuscitation with normal saline while simultaneously assessing hemodynamic stability—this takes absolute priority before any diagnostic procedures. 1

• Check pulse, blood pressure, and orthostatic vital signs immediately 1, 2
• Hemodynamic instability is defined as heart rate >100 bpm and systolic BP <100 mmHg—this combination with active bleeding carries approximately 80% risk of ongoing bleeding or death 1
• Insert urinary catheter and monitor hourly urine output (target >30 mL/hour indicates adequate resuscitation) 1
• Infuse 1-2 liters of normal saline initially in hemodynamically compromised patients 1
• If shock persists after 2 liters, add plasma expanders as this indicates ≥20% blood volume loss 1

Blood Transfusion Thresholds

• Transfuse red blood cells to maintain hemoglobin >7 g/dL 1, 3
• Use higher threshold of >9 g/dL in patients with massive bleeding or cardiovascular comorbidities 1, 3
• If active hematemesis with shock is present, transfuse immediately 1

Risk Stratification

High-Risk Features Requiring Aggressive Management

• Age >65 years (mortality rates significantly higher, reaching up to 30% in patients >90 years) 1, 3
• Significant comorbidities (cardiovascular disease, renal insufficiency, liver disease, advanced malignancy)—virtually all fatalities occur in patients with such conditions 1
• Hemodynamic instability despite resuscitation 1
• Specifically assess for cirrhosis, as variceal bleeding mortality approaches 30% versus 10% for nonvariceal sources 3

Anticoagulation Assessment

• If patient is on apixaban or other direct oral anticoagulants (DOACs), correct coagulopathy as the first therapeutic step in hemodynamically stable patients 1
• DOACs markedly raise the risk of gastrointestinal bleeding from any pre-existing lesion 1

Diagnostic Workup

Esophagogastroduodenoscopy (EGD)

Perform EGD within 24 hours of admission in hemodynamically stable patients—this is the initial procedure of choice with both diagnostic and therapeutic capabilities. 1, 4

• Critical pitfall: Do not perform endoscopy before adequate resuscitation—this is a critical error that increases mortality 1
• Keep patient fasted until hemodynamically stable 1
• Endoscopy should be performed by experienced endoscopists capable of therapeutic interventions for ulcers and varices 1
• In severely bleeding patients, consider endotracheal intubation before endoscopy to prevent pulmonary aspiration 1
• Use cap-fitted endoscopy to examine blind areas (high lesser curve, under incisura angularis, posterior duodenal bulb) to improve diagnostic yield 1

If Initial EGD is Negative

• Perform colonoscopy, as approximately 10-15% of patients presenting with melena have a lower-GI origin of bleeding 1
• Obtain random duodenal biopsies for celiac disease 1
• Consider capsule endoscopy to identify small intestinal bleeding lesions 1
• Proceed to double-balloon enteroscopy for therapeutic intervention if a lesion is identified 1

Most Likely Etiologies by Frequency

Upper GI Sources (Most Common)

• Peptic ulcer disease: 35-50% of cases (most common nonvariceal cause, associated with H. pylori or chronic NSAID use) 3, 5
• Mallory-Weiss tears: approximately 15% (from forceful vomiting, which fits this patient's nausea/vomiting presentation) 3, 2
• Gastroduodenal erosions: 8-15% (commonly associated with NSAID use, stress, or metabolic conditions) 3
• Esophageal varices: 5-10% overall, but cause 66-70% of massive hematemesis cases—critical to identify early due to 30% mortality 3
• Esophagitis: 5-15% 3

Lower GI Sources (When Upper Endoscopy Negative)

• Diverticulosis: 20-41% of lower-GI melena in older adults 1
• Angiodysplasia: 3-40% of lower-GI bleeding, up to 80% of obscure bleeding in patients >40 years 1
• Ischemic colitis: 10-21% 1
• Colorectal cancer/polyps: 6-27% 1

Rare but Critical Causes to Consider

• Aortoenteric fistula (especially in patients with prior AAA repair—life-threatening) 1, 3
• Dieulafoy lesion (1-2% of cases, large caliber artery in stomach wall) 1, 3
• Cameron's erosions in large hiatal hernias (commonly overlooked) 1

Post-Endoscopy Management

Following Successful Endoscopic Therapy

• Initiate high-dose proton pump inhibitor therapy 1
• Address underlying causes: H. pylori eradication, acid suppression, counsel regarding NSAID use 1
• Monitor for rebleeding (defined as fresh hematemesis/melena with shock, CVP fall >5 mmHg, or hemoglobin reduction >20 g/L over 24 hours) 3

Special Considerations for Cirrhotic Patients

• Early TIPS placement should be considered in Child-Pugh class C (score 10-13) or class B with active bleeding despite vasoactive agents 3

Nausea and Vomiting Management

• Treat according to NCCN antiemesis guidelines 6
• For persistent nausea/vomiting, titrate dopamine receptor antagonists (prochlorperazine, haloperidol, metoclopramide) to maximum benefit and tolerance 6
• Consider adding 5HT3 receptor antagonists, anticholinergic agents, antihistamines, corticosteroids, or continuous infusion of antiemetics 6