What is the initial management for an active gastrointestinal (GI) bleed due to diverticulosis?

Initial Management of Active GI Bleeding with Diverticulosis

For active gastrointestinal bleeding due to diverticulosis, the initial management should include prompt resuscitation with intravenous fluids, blood transfusion targeting hemoglobin >7 g/dL, and urgent colonoscopy within 24 hours of presentation after adequate bowel preparation. 1, 2

Immediate Resuscitation Phase

1. Hemodynamic Stabilization:

   • Establish at least two large-bore IV catheters
   • Initiate crystalloid fluid resuscitation to restore hemodynamic stability
   • Maintain mean arterial pressure >65 mmHg while avoiding fluid overload
   • Target hemoglobin level >7 g/dL (restrictive transfusion strategy)
   • Monitor shock index (heart rate/systolic blood pressure) - value >1 indicates instability 1, 2

2. Coagulation Management:

   • Correct any coagulopathy if present
   • For patients on anticoagulants:
     • DOACs: Interrupt immediately
     • Warfarin: Withhold to facilitate hemostasis
     • Dual antiplatelet therapy: Continue aspirin but withhold P2Y12 inhibitor 2

Diagnostic Evaluation

1. Endoscopic Assessment:

   • Urgent colonoscopy within 24 hours after adequate bowel preparation 1, 2
   • Colonoscopy is the recommended first-line investigation as it can both identify the bleeding source and provide therapeutic intervention 3
   • Upper endoscopy should also be performed if a clear diagnosis of lower GI bleeding source is not possible (up to 15% of patients presenting with hematochezia have an upper GI source) 1

2. Alternative Diagnostic Modalities (if endoscopy unsuccessful):

   • CT angiography for patients with ongoing bleeding who are hemodynamically stable after resuscitation 1
   • Radionuclide scanning (technetium-99m-tagged red blood cell scan) if bleeding source not identified by colonoscopy 4
   • Angiography for active bleeding when other methods fail to identify the source 3

Therapeutic Interventions

1. Endoscopic Treatment:

   • If active bleeding is identified during colonoscopy, endoscopic interventions include:
     • Injection therapy with epinephrine
     • Thermal or mechanical methods (clips)
     • For severe cases: Over-the-scope clip method (OTSC) has shown effectiveness for diverticular bleeding 5

2. Interventional Radiology:

   • Angioembolization if endoscopic therapy fails or is not feasible
   • Intra-arterial vasopressin infusion can control bleeding in up to 91% of patients with diverticular disease 1

3. Surgical Management:

   • Indicated when:
     • Persistent hemodynamic instability despite aggressive resuscitation
     • Blood transfusion requirement greater than 6 units
     • Severe bleeding recurs after non-surgical therapies
     • Segmental bleeding source amenable to surgical cure 1, 6
   • Partial colectomy if bleeding site is localized; subtotal colectomy if localization not possible 3

Risk Stratification

Factors predicting severe diverticular hemorrhage include:

• Low initial hemoglobin
• INR ≥ 1.5
• Low initial diastolic blood pressure
• Elevated initial heart rate
• Use of blood pressure medications 6

Follow-up Management

• For patients with successful hemostasis, monitor for rebleeding
• Consider preventive strategies to reduce recurrence risk
• Resume anticoagulation 7 days after bleeding stops if indicated 2

Pitfalls and Caveats

• Diverticular bleeding resolves spontaneously in approximately 80% of patients, but can recur in up to 25% of cases 4
• Delaying colonoscopy beyond 24 hours reduces diagnostic yield
• Vasopressin infusion, while effective, may cause significant side effects including abdominal pain and is contraindicated in patients with coronary artery disease 1
• Failure to evaluate for upper GI source may miss up to 15% of bleeding sources 1

Remember that diverticular bleeding is the most common cause of lower GI bleeding, accounting for 20-40% of cases, and requires a systematic approach to management focusing on prompt resuscitation followed by diagnostic and therapeutic interventions 7, 5.