What are the diagnosis and treatment options for gastrointestinal (GI) bleeds?

Diagnosis and Treatment of Gastrointestinal Bleeding

Initial Assessment and Hemodynamic Stabilization

Calculate the shock index (heart rate ÷ systolic blood pressure) immediately upon presentation—a shock index >1 defines hemodynamic instability and mandates urgent CT angiography rather than endoscopy as the first diagnostic step. 1, 2

Resuscitation Protocol

• Place at least two large-bore intravenous catheters and initiate aggressive fluid resuscitation with crystalloids to restore hemodynamic stability 3
• Use restrictive transfusion thresholds for most patients: hemoglobin trigger of 70 g/L with target range 70-90 g/L 1, 2, 3
• For patients with cardiovascular disease, use higher thresholds: hemoglobin trigger of 80 g/L with target ≥100 g/L 1, 2, 3
• Correct coagulopathy immediately: transfuse fresh frozen plasma for INR >1.5 and platelets for platelet count <50,000/µL 1

Risk Stratification for Lower GI Bleeding

For hemodynamically stable patients with suspected lower GI bleeding, calculate the Oakland score to guide disposition 1, 3:

• Oakland score ≤8 points: Safe for discharge with urgent outpatient investigation 1
• Oakland score >8 points: Requires hospital admission for colonoscopy 1

The Oakland score incorporates: age, gender, previous LGIB admission, digital rectal examination findings, heart rate, systolic blood pressure, and hemoglobin level 1

Diagnostic Approach Based on Hemodynamic Status

Hemodynamically Unstable Patients (Shock Index >1)

Perform CT angiography (CTA) immediately as the first-line investigation—this provides the fastest and least invasive means to localize bleeding before planning any therapeutic intervention. 4, 1, 2

• CTA has sensitivity of 79-95% and specificity of 95-100% for detecting active bleeding at rates of 0.3-1.0 mL/min 4
• Do not perform colonoscopy in unstable patients with shock index >1, as CTA can identify upper GI, small bowel, or lower GI sources and is rapidly accessible without bowel preparation 4, 1
• Following positive CTA, proceed to catheter angiography with embolization within 60 minutes in centers with 24/7 interventional radiology to maximize success rates 1, 2, 3

Critical pitfall: Always consider an upper GI source in patients with hemodynamic instability, even with bright red rectal bleeding—up to 11% of presumed lower GI bleeds originate from the upper GI tract 4, 1, 2. If CTA identifies no lower GI source, perform upper endoscopy immediately 4

Hemodynamically Stable Patients

• Perform digital rectal examination to confirm blood in stool and exclude anorectal pathology 1, 3
• For suspected upper GI bleeding: Perform upper endoscopy within 24 hours of presentation after adequate resuscitation 3
• For suspected lower GI bleeding: Perform colonoscopy within 24 hours after adequate bowel preparation 3
• Nasogastric tube placement is not recommended in suspected upper GI bleeding—it does not reliably aid diagnosis, does not affect outcomes, and causes complications in one-third of patients 4

When Initial Investigations Are Negative

If upper and lower endoscopy are negative but bleeding continues 4, 3:

1. Video capsule endoscopy (VCE) should be the next diagnostic modality for overt-obscure GI bleeding 4

   • Highest diagnostic yield (87-91.9%) when performed within 48 hours of bleeding episode 4
   • Diagnostic yield drops to <50% if performed beyond 3 days 4
   • Capsule retention occurs in 2% of patients 4

2. Nuclear medicine studies may be considered when CTA, angiography, or colonoscopy are negative, particularly for intermittent or slow bleeding (sensitivity 60-93%) 4

3. Repeat CTA is unlikely to be beneficial unless bleeding becomes more brisk 4

Therapeutic Interventions

Endoscopic Therapy

• For post-polypectomy bleeding, colonoscopy (not CTA) should be the first-line investigation and treatment 4
• Use dual modality therapy (epinephrine plus one other method) for endoscopic hemostasis, extrapolating from peptic ulcer bleeding literature 4
• Most cases of lower GI bleeding stop spontaneously and do not require intervention 4

Angiographic Embolization

• Indicated following positive CTA in hemodynamically unstable patients 1, 2
• Should be performed within 60 minutes for unstable patients in centers with 24/7 interventional radiology 1, 2

Surgical Intervention

• Reserved only for patients who fail angiographic intervention or continue to deteriorate despite all attempts at localization and intervention 1
• Diagnostic laparotomy is mandatory only in unstable patients not responding to aggressive resuscitation AND after failure of other localization methods 1
• Avoid laparotomy unless every effort has been made to localize bleeding through radiological and endoscopic modalities 1

Management of Anticoagulation and Antiplatelet Therapy

Warfarin Management

• Interrupt warfarin immediately at presentation in patients with unstable GI hemorrhage 1, 2, 3
• Reverse anticoagulation with prothrombin complex concentrate and vitamin K for unstable bleeding 1, 2, 3
• For patients with low thrombotic risk: Restart warfarin 7 days after hemorrhage 1, 2, 3
• For patients with high thrombotic risk: Consider low molecular weight heparin at 48 hours after hemorrhage 2

Antiplatelet Management

• Aspirin for primary prophylaxis: Permanently discontinue 1, 2
• Aspirin for secondary prevention: Do not routinely stop; if stopped, restart as soon as hemostasis is achieved 1, 2
• Dual antiplatelet therapy: If P2Y12 receptor antagonist is stopped, reinstate within 5 days to prevent thrombotic complications 2

Mortality and Prognostic Factors

Mortality in GI bleeding is generally related to comorbidity rather than exsanguination, with overall in-hospital mortality of 3.4% 1, 2, 3. However, mortality rises significantly to:

• 18% for inpatient-onset lower GI bleeding 1, 2
• 20% for patients requiring ≥4 units of red blood cells 1, 2

Clinical predictors of poor outcome include: age >65 years, shock, comorbid illness, low hemoglobin, melena, fresh red blood in emesis or on rectal examination 3