Emergency Treatment for Acute Haematochezia
Immediately stratify the patient by hemodynamic stability using shock index (heart rate/systolic BP), and if unstable (shock index >1) or actively bleeding, proceed directly to CT angiography after initial resuscitation to localize bleeding before planning intervention. 1
Initial Assessment and Resuscitation
Begin by calculating the shock index (heart rate divided by systolic blood pressure). A shock index >1 defines hemodynamic instability and triggers an aggressive pathway 1.
For Unstable Patients (Shock Index >1):
- Initiate aggressive resuscitation with IV access and fluid replacement
- Reverse anticoagulation immediately if on warfarin using prothrombin complex concentrate and vitamin K 1
- Interrupt warfarin therapy at presentation in all cases 1
- Proceed to CT angiography as the fastest, least invasive method to localize bleeding before planning endoscopic or radiological therapy 1
Critical pitfall: If CT angiography shows no source in an unstable patient, consider upper GI bleeding and perform immediate upper endoscopy, as hemodynamically unstable lower GI bleeding may actually originate from the upper tract 1, 2
Blood Transfusion Strategy
Use restrictive transfusion thresholds to reduce mortality:
- Hemoglobin trigger of 70 g/L with target 70-90 g/L post-transfusion for stable patients
- Hemoglobin trigger of 80 g/L with target 100 g/L for patients with cardiovascular disease 1, 3
This restrictive approach is strongly recommended based on moderate quality evidence and improves outcomes.
Diagnostic and Therapeutic Interventions
For Hemodynamically Unstable or Active Bleeding:
- CT angiography first - provides rapid localization 1
- Catheter angiography with embolization should follow positive CTA as soon as possible, ideally within 60 minutes in centers with 24/7 interventional radiology 1, 4
- Upper endoscopy if CTA negative (to exclude upper GI source) 1, 2
For Stable Patients with Major Bleeding:
- Admit to hospital for colonoscopy 1
- Use Oakland score for risk stratification: scores ≤8 indicate minor self-terminating bleeds suitable for urgent outpatient investigation rather than admission 1
Antiplatelet and Anticoagulation Management
Aspirin management depends on indication:
- Primary prevention: permanently discontinue 1
- Secondary prevention: do NOT routinely stop; if stopped, restart as soon as hemostasis achieved 1
Dual antiplatelet therapy requires cardiology consultation for individualized risk-benefit assessment 1
Low molecular weight heparin for venous thromboembolism should be considered at 48 hours after hemorrhage; warfarin restarted at 7 days for low thrombotic risk patients 1
Surgical Considerations
No patient should proceed to emergency laparotomy unless every effort has been made to localize bleeding radiologically and/or endoscopically, except under exceptional circumstances 1, 5. This strong recommendation reflects that mortality in lower GI bleeding relates primarily to comorbidity rather than exsanguination, and blind surgery carries significant morbidity.
Key Clinical Pearls
- In-hospital mortality is 3.4% overall but rises to 18% in patients who develop bleeding while hospitalized and 20% in those requiring ≥4 units transfusion 1
- Most lower GI bleeding (80%) stops spontaneously, but rebleeding occurs in 25% of cases 4
- The diagnostic pathway must balance speed with accuracy - unstable patients need immediate localization via CTA, while stable patients benefit from colonoscopy after adequate preparation 1, 3