IM15.{1-3,6} | GI Bleeding Foundations and Stabilisation — Summary & Reflection

KEY TAKEAWAYS

GI bleeding is classified by anatomical source: upper GI (UGIB) — proximal to the ligament of Treitz, presenting as haematemesis and/or melaena — versus lower GI (LGIB) — distal, presenting as haematochezia. The BUN:creatinine ratio >20:1 and coffee-ground nasogastric aspirate support an upper source. Key upper causes: peptic ulcer disease (NSAID/H. pylori), oesophageal varices (portal hypertension — treat with octreotide/terlipressin + band ligation + prophylactic antibiotics), Mallory–Weiss tear. Key lower causes: diverticular disease (commonest acute LGIB in elderly), haemorrhoids, colorectal carcinoma, IBD, angiodysplasia.

Pathophysiology of haemorrhagic shock: sympathoadrenal compensation maintains BP until ~20–30% blood volume loss; beyond this, lactic acidosis, coagulopathy, and hypothermia create the lethal triad which is self-amplifying. Acute Hb is an unreliable early indicator of blood loss.

Stabilisation sequence: airway → O₂ → two large-bore IV cannulae → blood draw → crystalloid bolus → blood products. Transfusion threshold: Hb <7 g/dL (restrictive, standard); Hb <8 g/dL in cardiovascular disease. FFP if INR >1.5; platelets if <50 × 10⁹/L in active bleeding. Target MAP ≥65 mmHg and UO ≥0.5 mL/kg/hour. Resuscitate first — endoscopy only after haemodynamic stability.

REFLECT

Think about the clinical scenario in the opening hook — the 3 AM presentation with haematemesis and haemodynamic shock. Now that you have worked through this module, what would you do differently from the panicked house officer in the opening scene? If you had 60 seconds with that patient before any investigation could be organised, what are your first three actions and why does the order matter? How does understanding the pathophysiology of haemorrhagic shock — particularly the lethal triad — change the way you think about the timing of endoscopy versus resuscitation? Reflect also on the transfusion decision: why is a restrictive threshold not 'under-treating' the patient — what does the evidence actually say about outcomes with liberal versus restrictive strategies?