A 58-year-old man with a 10-year history of cirrhosis presents with hematemesis and melena. On examination, he is hemodynamically unstable with BP 90/60 mmHg and HR 110/min. After initial resuscitation and correction of coagulopathy, what is the investigation of choice to confirm the source of bleeding and guide immediate therapeutic intervention?

## Investigation of Choice in Acute Upper GI Bleeding **Key Point:** Upper gastrointestinal endoscopy (OGD) is the gold standard investigation of choice in acute upper GI bleeding, particularly in haemodynamically unstable patients with suspected variceal bleeding. ### Why Endoscopy is Optimal 1. **Diagnostic accuracy**: Directly visualizes the bleeding source (varices, peptic ulcer, Mallory-Weiss tear, erosions) 2. **Therapeutic capability**: Allows immediate intervention—variceal ligation, sclerotherapy, injection of cyanoacrylate, or hemoclip placement 3. **Timing**: Should be performed within 12 hours of presentation (ideally <6 hours in variceal bleeding) 4. **Prognostic value**: Identifies stigmata of recent hemorrhage (active bleeding, visible vessel, adherent clot) ### Clinical Context in This Case - **Cirrhosis + hematemesis** → variceal bleeding is the leading diagnosis - **Haemodynamic instability** → requires urgent intervention, not just diagnosis - Endoscopy allows **simultaneous diagnosis and treatment**, reducing mortality from 40% to <15% when combined with variceal ligation **High-Yield:** In variceal bleeding, endoscopy within 12 hours combined with vasoactive drugs (terlipressin/octreotide) and prophylactic antibiotics (ceftriaxone) is the standard of care [cite:Harrison 21e Ch 297]. ### Procedural Prerequisites - Correct coagulopathy (INR <1.5, platelet >50,000) - Airway protection if encephalopathy or altered consciousness - IV access, resuscitation, and blood products available **Clinical Pearl:** Even in unstable patients, brief stabilization followed by urgent endoscopy is superior to prolonged resuscitation without definitive diagnosis.