What is the management for a massive lower gastrointestinal bleed?

Management of Massive Lower Gastrointestinal Bleeding

The management of massive lower gastrointestinal bleeding requires immediate hemodynamic stabilization followed by diagnostic procedures to localize the bleeding source, with endoscopic, radiological, or surgical interventions based on clinical status and findings. 1

Initial Assessment and Resuscitation

• Hemodynamic stabilization is the first priority:

  • Establish two large-bore IV access points for fluid and blood administration
  • Assess shock index (heart rate divided by systolic blood pressure) - a shock index >1 indicates instability
  • Initiate crystalloid fluid resuscitation concurrently with blood transfusion
  • Maintain mean arterial pressure >65 mmHg while avoiding fluid overload 1

• Blood transfusion strategy:

  • Use restrictive RBC thresholds (Hb trigger 70 g/L and target 70-90 g/L) for clinically stable patients
  • For patients with cardiovascular disease, use a higher threshold (Hb trigger 80 g/L and target 100 g/L) 2
  • Avoid overaggressive transfusion as restrictive strategies improve outcomes 1

• Coagulation management:

  • Interrupt anticoagulant therapy at presentation
  • For patients on warfarin with severe hemorrhage, reverse with prothrombin complex concentrate and vitamin K 2
  • For DOACs, primarily manage by withholding medication 2
  • Consider reversal agents for life-threatening hemorrhage on DOACs 1

Diagnostic Approach

1. Rule out upper GI source:

   • Up to 8% of patients presenting with hematochezia may have an upper GI source 1
   • Perform upper endoscopy first in patients with hemodynamic instability 3

2. Colonoscopy:

   • Should be performed within 24 hours of presentation after adequate colon preparation 3
   • Early colonoscopy (within 12 hours) is safe and effective, improving diagnostic yield and potentially reducing hospital stay 2
   • Consider colonic purge with PEG-based solution (5-8L) to clear the bowel for better visualization 2

3. CT Angiography (CTA):

   • Indicated when endoscopy is not feasible or fails to identify the source
   • Can detect bleeding rates as low as 0.3 mL/min 1
   • Provides information on bleeding location and potential culprit lesions 1

Therapeutic Interventions

Endoscopic Management

• For identified bleeding sources with high-risk stigmata (active bleeding, non-bleeding visible vessel, adherent clot), provide endoscopic hemostasis 3
• Treatment options based on etiology:
  • Angiodysplasia: Contact thermal probes or argon plasma coagulation 2
  • Diverticular bleeding: Endoscopic hemostasis with clips or thermal therapy 2
  • Consider tattoo marking of identified bleeding sources for potential future intervention 1

Interventional Radiology

• Technical success rates of embolization are high (93-100%) 2
• Consider when endoscopic management fails or is not feasible
• Complications include bowel ischemia (7-24%) and rebleeding (10-50% short-term) 2
• Empirical embolization may be considered in specific cases (e.g., tumor bleeding) but carries higher risks 2

Surgical Management

• Reserve for when endoscopic or radiological interventions fail 2
• Localization of the bleeding source is essential before surgery 2, 1
• Emergency subtotal colectomy is effective for unlocalised massive LGIB but has high morbidity and mortality 2
• Surgery should ideally be performed by colorectal surgeons who can perform on-table colonoscopy 2

Special Considerations

Anticoagulant Management

• Warfarin should be interrupted at presentation 2
• For severe hemorrhage, reverse warfarin with prothrombin complex concentrate and vitamin K 2
• DOACs are primarily managed by withholding medication 2
• Antiplatelet agents should be temporarily withheld in acute LGIB, despite potential cardiovascular risks 2

Monitoring and Follow-up

• High-risk patients should be admitted to a monitored setting for at least 24 hours 1
• Monitor for rebleeding, which occurs in 10-50% of cases after embolization 2
• Consider repeat colonoscopy if rebleeding occurs 3

Pitfalls and Caveats

1. Avoid proceeding to emergency laparotomy without localizing the bleeding source except in exceptional circumstances (e.g., aortoenteric fistula) 2

2. Beware of inappropriate blood transfusions - over 80% may be unnecessary according to UK audit data 2

3. Consider age and clinical signs when deciding between interventional radiology and surgery - older patients tend to be managed with IR rather than surgery 4

4. Don't delay treatment - shorter time to intervention is associated with better outcomes 2, 1