What is the management approach for acute diverticular bleeding?

Management of Acute Diverticular Bleeding

For acute diverticular bleeding, initiate immediate hemodynamic resuscitation targeting hemoglobin >7 g/dL (7-9 g/dL range), followed by urgent colonoscopy within 12-24 hours after rapid bowel preparation in stable patients, or CT angiography immediately in unstable patients (shock index >1), with endoscopic hemostasis as first-line treatment when bleeding source is identified. 1, 2, 3

Initial Resuscitation and Hemodynamic Stabilization

Immediate Assessment:

• Calculate shock index (heart rate ÷ systolic blood pressure) at presentation—a value >1 defines hemodynamic instability requiring urgent intervention rather than routine endoscopy 2, 3
• Place at least two large-bore intravenous catheters for rapid volume expansion 2
• Maintain mean arterial pressure >65 mmHg while avoiding fluid overload 1

Transfusion Strategy:

• Use restrictive red blood cell transfusion with hemoglobin threshold of 7 g/dL, targeting 7-10 g/dL range for patients without cardiovascular disease 1, 2
• For patients with cardiovascular disease, use higher threshold (Hb trigger 8 g/dL, target ≥10 g/dL) 2
• Monitor hourly urine output targeting >30 mL/hour in severe cases 1

Coagulopathy Management:

• For patients on warfarin with unstable bleeding, interrupt warfarin immediately and reverse with prothrombin complex concentrate and vitamin K 2, 3
• Restart warfarin 7 days after hemorrhage in patients with low thrombotic risk 2, 3
• Transfuse fresh frozen plasma for INR >1.5 and platelets for platelets <50,000/µL 3

Diagnostic Approach Based on Hemodynamic Status

For Hemodynamically Stable Patients (Shock Index ≤1):

Colonoscopy as First-Line:

• Perform urgent colonoscopy within 12-24 hours of presentation after hemodynamic stabilization 1, 2
• Administer rapid bowel preparation with 4-6 liters of polyethylene glycol solution over 3-4 hours before colonoscopy 1
• Use CO2 insufflation to reduce gas explosion risk in poorly prepared colons 1

For Hemodynamically Unstable Patients (Shock Index >1):

CT Angiography First:

• Perform CT angiography immediately to localize bleeding before any intervention—this provides the fastest and least invasive means to identify the bleeding source 2, 3
• Following positive CTA, proceed to catheter angiography with embolization within 60 minutes in centers with 24/7 interventional radiology 2, 3
• Critical pitfall: Always consider an upper GI source in patients with hemodynamic instability, even with hematochezia—failure to do so leads to delayed diagnosis 2, 3

Endoscopic Treatment Options

When a bleeding diverticulum is identified during colonoscopy, multiple therapeutic options are available:

Preferred Techniques:

• Endoscopic band ligation shows superior outcomes with lower early rebleeding rates (6%) compared to clipping (33%) 1
• Other options include endoscopic clipping, injection therapy (epinephrine), thermal therapies, and hemostatic powders 1, 4

Technical Considerations:

• Identification of stigmata of recent hemorrhage (visible vessel or adherent clot) allows for targeted endoscopic hemostasis 5, 6
• Over-the-scope clip (OTSC) method has demonstrated effectiveness in severe diverticular bleeding, especially in cases of rebleeding after first-line conventional procedures 7

Angiographic Intervention

Indications:

• Consider angiography when endoscopic visualization or treatment fails 1
• Use for ongoing severe bleeding with hemodynamic instability when colonoscopy is not feasible 1

Technical Success:

• Technical success rates for embolization are 93-100% regardless of embolic agent used 1
• Superselective embolization is the preferred therapeutic option when endoscopy fails 5

Surgical Management

Indications for Surgery:

• Ongoing bleeding despite endoscopic and angiographic interventions 1
• Recurrent severe diverticular bleeding episodes 1
• Patients who remain unstable despite aggressive resuscitation and failure of all localization/intervention methods 3

Surgical Approach:

• Segmental colectomy is the preferred surgical option when the bleeding source is localized 1
• Mortality rate: 5-10% with rebleeding rate of 14% at 1 year 1
• Important caveat: Emergency surgical resection carries significantly higher mortality (33%) compared to other treatment modalities 8

Natural History and Risk Factors

Spontaneous Resolution:

• Diverticular hemorrhage resolves spontaneously in approximately 70-90% of patients 4, 5
• However, about 50% of patients require blood transfusion 7

Risk Factors for Rebleeding:

• History of prior diverticular bleeding 1
• Chronic kidney disease 1
• Failure to identify and treat the bleeding point 1

Management Algorithm Summary

1. Immediate resuscitation: Assess shock index, establish IV access, initiate restrictive transfusion strategy 1, 2
2. Risk stratification: Shock index >1 = unstable; ≤1 = stable 2, 3
3. Unstable patients: CT angiography → angiographic embolization → surgery if failed 1, 2, 3
4. Stable patients: Urgent colonoscopy (12-24 hours) → endoscopic hemostasis (preferably band ligation) → angiography if failed → surgery as last resort 1, 2
5. ICU admission criteria: Orthostatic hypotension, hematocrit decrease ≥6%, transfusion requirement >2 units, continuous active bleeding, or persistent hemodynamic instability 3

Critical Context on Mortality: Mortality in diverticular bleeding is generally related to comorbidity rather than exsanguination, with overall in-hospital mortality of 3.4%, rising to 20% in patients requiring ≥4 units of red cells 3. This underscores the importance of early intervention and appropriate risk stratification.