What is the initial workup and management for a patient with a gastrointestinal (GI) bleed?

Initial Workup and Management of Gastrointestinal Bleeding

All patients presenting with GI bleeding require immediate hemodynamic assessment using shock index (heart rate ÷ systolic BP), with a shock index >1 indicating instability that demands urgent CT angiography before any endoscopic intervention. 1, 2

Immediate Assessment and Resuscitation

Hemodynamic Evaluation

• Calculate shock index immediately (heart rate divided by systolic blood pressure) to stratify patients as stable (≤1) or unstable (>1). 1, 2
• Place at least two large-bore IV catheters (18-gauge or larger) for rapid volume expansion. 2, 3
• Initiate fluid resuscitation with crystalloids to restore hemodynamic stability. 2, 3

Risk Stratification for Stable Patients

• For stable lower GI bleeding, use the Oakland score to determine disposition (age, gender, previous LGIB admission, digital rectal exam findings, heart rate, systolic BP, hemoglobin). 1, 2
• Patients with Oakland score ≤8 points and no other admission indications can be safely discharged for urgent outpatient investigation. 1
• Patients with Oakland score >8 points require hospital admission for colonoscopy. 1

Blood Transfusion Strategy

• Use restrictive transfusion thresholds: hemoglobin trigger of 70 g/L (7 g/dL) with target 70-90 g/L for hemodynamically stable patients without cardiovascular disease. 1, 2
• For patients with cardiovascular disease, use hemoglobin trigger of 80 g/L (8 g/dL) with target ≥100 g/L. 1, 2
• This restrictive strategy improves survival and reduces rebleeding in cirrhotic patients. 1

Diagnostic Algorithm Based on Hemodynamic Status

For Hemodynamically Unstable Patients (Shock Index >1)

Step 1: CT Angiography First

• Perform CT angiography immediately as the fastest, least invasive means to localize bleeding before planning any intervention. 1, 2
• CTA has 79-95% sensitivity and 95-100% specificity for active bleeding. 1
• CTA can detect bleeding rates as low as 0.3-1.0 mL/min. 1

Step 2: Consider Upper GI Source

• If CTA is negative, perform upper endoscopy immediately because hemodynamic instability with hematochezia may indicate upper GI bleeding (up to 8% of cases). 1, 2
• Bright red rectal bleeding with shock suggests brisk upper GI bleeding. 1

Step 3: Interventional Management

• Following positive CTA, proceed to catheter angiography with embolization within 60 minutes in centers with 24/7 interventional radiology. 1, 2
• Surgery should only be considered after every effort at radiological and endoscopic localization has failed, except in exceptional circumstances. 1

For Hemodynamically Stable Patients

Step 1: Perform Digital Rectal Examination

• Digital rectal examination detects approximately 40% of rectal carcinomas and confirms bleeding characteristics. 1, 3

Step 2: Upper vs. Lower Endoscopy Decision

• For suspected upper GI bleeding (hematemesis, melena, elevated BUN/creatinine ratio, history of peptic ulcer disease or portal hypertension): perform upper endoscopy within 24 hours. 1, 4
• For suspected lower GI bleeding (hematochezia without hemodynamic instability): perform colonoscopy within 24 hours after adequate bowel preparation. 1

Step 3: If Initial Endoscopy Negative

• Consider video capsule endoscopy for small bowel evaluation (55-65% diagnostic yield). 1
• Push enteroscopy can evaluate proximal 60 cm of jejunum. 1

Laboratory Workup

Essential Initial Tests

• Complete blood count to assess hemoglobin and hematocrit. 2
• Coagulation studies (PT/INR) to evaluate for coagulopathy. 2
• Blood type and cross-match for patients with severe bleeding or hemodynamic instability. 2
• BUN/creatinine ratio (elevated ratio suggests upper GI source). 1
• Liver function tests if variceal bleeding suspected. 2

Correction of Coagulopathy

• Correct INR >1.5 with fresh frozen plasma or prothrombin complex concentrate. 1, 2
• Correct platelet count <50,000/µL with platelet transfusion. 1, 2

Management of Anticoagulation and Antiplatelet Therapy

Warfarin Management

• Interrupt warfarin immediately at presentation in patients with major GI bleeding. 1, 2
• For unstable hemorrhage, reverse with prothrombin complex concentrate and vitamin K (fresh frozen plasma if PCC unavailable). 1, 2
• Restart warfarin at 7 days after hemorrhage in patients with low thrombotic risk. 1, 2

Direct Oral Anticoagulants

• Temporarily withhold DOACs at presentation in patients with major lower GI bleeding. 5

Aspirin Management

• Do NOT stop aspirin in patients taking it for secondary cardiovascular prevention. 5, 6
• If aspirin is stopped, restart within 5 days or as soon as hemostasis is achieved. 5, 6
• Permanently discontinue aspirin only if used for primary prophylaxis. 7

Dual Antiplatelet Therapy

• Continue aspirin; the P2Y12 receptor antagonist can be temporarily interrupted based on bleeding severity and ischemic risk. 5, 6
• If P2Y12 inhibitor is stopped, restart within 5 days to prevent thrombotic complications. 7, 5

Special Considerations for Variceal Bleeding

Initial Medical Management

• Administer octreotide (50 mcg IV bolus, then 50 mcg/hour continuous infusion for 2-5 days). 1
• Start prophylactic antibiotics (ceftriaxone 1 g IV every 24 hours, maximum 7 days) to reduce infections, rebleeding, and mortality. 1
• Maintain hemoglobin >7 g/dL (4.5 mmol/L) and mean arterial pressure >65 mmHg during resuscitation, but avoid fluid overload. 1

Endoscopic Intervention

• Perform urgent endoscopy within 12 hours following stabilization. 1
• Consider erythromycin 250 mg IV 30-120 minutes before endoscopy to optimize visualization (check QT interval first). 1

Critical Pitfalls to Avoid

• Failing to consider upper GI source in hemodynamically unstable patients with hematochezia leads to delayed diagnosis and increased mortality. 1, 2
• Performing colonoscopy before CT angiography in unstable patients delays definitive diagnosis and treatment. 1
• Over-transfusing patients increases portal pressure in cirrhotics and worsens outcomes. 1
• Stopping aspirin in patients on secondary cardiovascular prevention increases thrombotic risk without clear bleeding benefit. 5, 6
• Proceeding to emergency laparotomy without radiological/endoscopic localization results in higher mortality (10% operative mortality). 1

Mortality Risk Factors

• Overall in-hospital mortality is 3.4%, but rises to 18% for inpatient-onset bleeding and 20% for patients requiring ≥4 units of red cells. 1, 3
• Mortality is primarily related to comorbidities rather than exsanguination. 3, 7
• Age and comorbid conditions (coronary artery disease, cirrhosis, COPD) are the strongest predictors of mortality. 1