What are the current guidelines for the evaluation and management of acute gastrointestinal bleeding?

Current Guidelines for Acute Gastrointestinal Bleeding

All patients presenting with GI bleeding must have immediate hemodynamic assessment using shock index (heart rate ÷ systolic blood pressure), with a shock index >1 defining instability and mandating urgent CT angiography rather than endoscopy. 1

Initial Assessment and Risk Stratification

Hemodynamic Evaluation

• Calculate shock index immediately upon presentation—a value >1 indicates hemodynamic instability requiring urgent intervention rather than routine endoscopy 2, 1
• Check for orthostatic hypotension, which signals significant blood loss and necessitates ICU admission 1
• Perform digital rectal examination to confirm blood presence and exclude anorectal pathology (accounts for ~16% of lower GI bleeding diagnoses) 2, 1

Laboratory Assessment

• Obtain complete blood count, coagulation studies (PT/INR), and blood type with cross-match immediately 1
• Correct coagulopathy promptly: transfuse fresh frozen plasma when INR >1.5 and platelets when platelet count <50 × 10⁹/L 1, 3

Risk Stratification Tools

For Lower GI Bleeding (Oakland Score): 2, 1

• Age: <40 (0 points), 40-69 (1 point), ≥70 (2 points)
• Male gender (1 point)
• Previous LGIB admission (1 point)
• Blood on digital rectal exam (1 point)
• Heart rate: <70 (0), 70-89 (1), 90-109 (2), ≥110 (3 points)
• Systolic BP: <90 (5), 90-119 (4), 120-129 (3), 130-159 (2), ≥160 (0 points)
• Hemoglobin: <70 g/L (22), 70-89 (17), 90-109 (13), 110-129 (8), 130-159 (4), ≥160 (0 points)

Score ≤8: Safe for discharge with outpatient investigation within 2 weeks (6% have underlying colorectal cancer) 2, 1, 3

Score >8: Requires hospital admission for inpatient colonoscopy 2, 1, 3

Management Algorithm Based on Hemodynamic Status

Hemodynamically UNSTABLE Patients (Shock Index >1)

Immediate Resuscitation

• Place at least two large-bore IV catheters for rapid volume expansion 1
• Initiate aggressive crystalloid resuscitation (normal saline or Ringer's lactate) 1, 3
• Use restrictive transfusion strategy: Hemoglobin trigger 70 g/L with target 70-90 g/L for patients without cardiovascular disease 1, 3
• For patients with cardiovascular disease: Hemoglobin trigger 80 g/L with target ≥100 g/L 1, 3

Diagnostic Approach

CT angiography (CTA) must be performed immediately as the first diagnostic test—NOT colonoscopy or endoscopy 1, 3

• CTA detects active bleeding at rates as low as 0.3 mL/min with 79-95% sensitivity 1, 3
• CTA requires no bowel preparation and provides the fastest, least invasive localization method 1, 3
• Colonoscopy is explicitly contraindicated when shock index >1 because it requires 4-6 liters of polyethylene glycol over 3-4 hours, sedation that worsens shock, and does not address massive bleeding 1, 3

Therapeutic Intervention

• Following positive CTA, proceed to catheter angiography with embolization within 60 minutes in centers with 24/7 interventional radiology 1, 3
• Transcatheter embolization achieves immediate hemostasis in 40-100% of cases 1, 3
• Always consider an upper GI source even with bright red rectal bleeding if hemodynamically unstable—10-15% of severe hematochezia originates from the upper GI tract 1, 3
• If CTA shows no lower GI source, perform upper endoscopy before considering surgery 1, 3

Surgical Intervention (Last Resort Only)

• Surgery is reserved only for patients who fail angiographic intervention or continue to deteriorate despite maximal resuscitation and angiographic attempts 1, 3
• Blind segmental resection without prior localization carries rebleeding rates up to 33% and mortality 33-57% 1, 3
• Emergency total colectomy mortality is 27-33% versus ~10% when bleeding is first localized radiologically 1, 3

Hemodynamically STABLE Patients (Shock Index ≤1)

For Lower GI Bleeding

• Calculate Oakland score to determine admission need 2, 1, 3
• Schedule colonoscopy on the next available inpatient list—NOT urgently within 24 hours, as urgent colonoscopy does not improve rebleeding, mortality, or length of stay 2, 1, 3
• Provide adequate bowel preparation with 4-6 liters of polyethylene glycol over 3-4 hours 2, 1
• Inadequate preparation leads to 70% repeat-procedure rates and missed lesions 1, 3

For Upper GI Bleeding

• Perform upper endoscopy within 24 hours (early endoscopy), NOT urgently within 12 hours, as urgent endoscopy does not improve outcomes 4, 5
• Administer erythromycin and proton pump inhibitor pre-endoscopy 5
• For peptic ulcer disease with high-risk stigmata (actively bleeding ulcers FIa/FIb), use combination therapy: epinephrine injection plus a second hemostasis modality (contact thermal or mechanical therapy) 4

Anticoagulation and Antiplatelet Management

Warfarin

• Interrupt warfarin immediately at presentation 1, 3
• For unstable hemorrhage: Reverse with 4-factor prothrombin complex concentrate AND vitamin K (dose <5 mg)—NOT fresh frozen plasma 1, 3
• Restart warfarin at 7 days after hemostasis for low thrombotic risk 1, 3
• For high thrombotic risk (e.g., mechanical mitral valve): Restart at 3 days after stable hemostasis 1, 3

Direct Oral Anticoagulants (DOACs)

• Interrupt DOAC therapy immediately at presentation 1, 3
• For life-threatening hemorrhage: Administer specific reversal agents (idarucizumab for dabigatran, andexanet alfa for factor Xa inhibitors) 1, 3
• Restart DOAC at maximum 7 days after hemorrhage 1

Aspirin

• For secondary cardiovascular prevention: Do NOT routinely stop aspirin; if stopped, restart within 3-5 days or as soon as hemostasis is achieved 1, 3, 4
• For primary prophylaxis: Permanently discontinue aspirin 1, 3

Dual Antiplatelet Therapy

• Continue aspirin 1, 3
• P2Y12 inhibitor may be temporarily held based on bleeding severity but should be restarted within 5 days 1

Post-Endoscopic Management

For Peptic Ulcer Disease

• Administer high-dose PPI therapy: 80 mg IV bolus followed by 8 mg/hour continuous infusion for 72 hours post-endoscopy 4
• Alternative: Twice-daily IV or oral PPI can be considered 4
• Initiate early enteral feeding for all UGIB patients 5

For Variceal Bleeding

• Administer prophylactic antibiotics and vasoactive medications for patients with cirrhosis 5
• Consider transjugular intrahepatic portosystemic shunt for high-risk patients or those with further bleeding 5

Critical Pitfalls to Avoid

• Never rush to colonoscopy in unstable patients—this delays definitive CTA localization and potential embolization 1, 3
• Never assume bright red rectal bleeding is always lower GI—up to 15% may originate from upper GI tract, especially with hemodynamic instability 1, 3
• Never perform colonoscopy without adequate bowel preparation—leads to 70% repeat-procedure rates 1, 3
• Never proceed to blind surgical resection without radiological localization—mortality 33-57% versus ~10% with localization 1, 3
• Do not use tranexamic acid in GI bleeding 5
• Mortality in lower GI bleeding is generally related to comorbidity rather than exsanguination, with overall in-hospital mortality 3.4% but rising to 20% in patients requiring ≥4 units of red cells 1, 3