What is the management approach for a patient with overt or occult gastrointestinal (GI) bleeding?

Management of Overt and Occult Gastrointestinal Bleeding

For overt GI bleeding with hemodynamic instability (shock index >1), perform CT angiography immediately to localize the bleeding source, followed by visceral angiography with embolization within 60 minutes if CTA is positive. 1, 2

Initial Assessment and Resuscitation

Hemodynamic evaluation is the critical first step:

• Calculate shock index (heart rate ÷ systolic blood pressure) immediately—a value >1 indicates instability requiring urgent intervention 1
• Place two large-bore IV catheters for rapid volume expansion 1
• Initiate crystalloid resuscitation to restore hemodynamic stability 1

Transfusion strategy should be restrictive:

• Use hemoglobin threshold of 7 g/dL with target range 7-9 g/dL for most patients 1, 2
• For patients with cardiovascular disease, use threshold of 8 g/dL with target ≥10 g/dL 1

Key clinical predictors to assess include:

• Age >65 years, presence of shock, comorbid illnesses (cardiovascular, renal, liver disease), low initial hemoglobin, fresh red blood in emesis/nasogastric aspirate/rectal examination, and transfusion requirement all predict increased risk of rebleeding and mortality 3, 4

Diagnostic Algorithm Based on Hemodynamic Status

For Hemodynamically Unstable Patients (Shock Index >1)

CT angiography is the first-line diagnostic test:

• CTA detects bleeding at rates as low as 0.3-0.5 mL/min and provides anatomical localization superior to nuclear medicine studies 3
• If CTA is positive, proceed immediately to visceral angiography with embolization within 60 minutes in centers with 24/7 interventional radiology 1, 2
• Angiography detects bleeding at 0.5 mL/min and allows simultaneous therapeutic embolization 3

Critical pitfall to avoid:

• Always consider an upper GI source even with hematochezia in unstable patients—11-15% of presumed lower GI bleeds are actually upper GI sources, particularly with brisk bleeding, hemodynamic compromise, or elevated BUN/creatinine ratio 2, 4
• Perform upper endoscopy immediately if CTA shows no source in unstable patients 2

For Hemodynamically Stable Patients

Upper and lower endoscopy are first-line diagnostic procedures:

• Upper endoscopy should be performed within 24 hours for suspected upper GI bleeding 1, 4
• Colonoscopy after adequate bowel preparation (4-6 liters polyethylene glycol over 3-4 hours) for suspected lower GI bleeding 3, 2
• Both procedures offer diagnostic and therapeutic capabilities 4, 5

For post-polypectomy bleeding specifically:

• Colonoscopy (not CTA) should be first-line even in unstable patients, as the bleeding source is likely already known 3

Management of Obscure Bleeding (Negative Initial Endoscopy)

Video capsule endoscopy is the next diagnostic modality after negative upper and lower endoscopy:

• VCE has diagnostic yield of 50-72% in obscure overt GI bleeding 3
• Timing is critical: VCE performed within 48 hours of bleeding has diagnostic yield of 87-91.9%, but drops to <50% if performed beyond 3 days 3
• VCE permits examination of the entire small bowel in 79-90% of patients 3

Alternative imaging if VCE is contraindicated or negative:

• Nuclear medicine red cell scintigraphy has sensitivity of 60-93% for intermittent or slow bleeding 3
• Repeat CTA is unlikely to be beneficial unless bleeding becomes more brisk 3
• Mesenteric angiography within 24 hours of negative CTA is rarely positive in stable patients 3

Limitations of VCE to consider:

• Capsule retention occurs in 2% of patients 3
• No therapeutic capability and difficulty localizing lesions 3

Endoscopic Therapy

For identified bleeding sources requiring intervention:

• Use dual modality therapy (epinephrine plus one other method such as clips, thermal coagulation, or sclerosant) extrapolating from peptic ulcer bleeding literature 3, 2
• CO2 insufflation should be used in poorly prepared colons to reduce gas explosion risk with diathermy or argon plasma coagulation 3

For recurrent bleeding after initial endoscopic therapy:

• Perform second endoscopic treatment 6, 7
• If bleeding persists or recurs after second attempt, proceed to interventional radiology or surgery 6

Management of Anticoagulation

For patients on warfarin with unstable GI hemorrhage:

• Interrupt warfarin immediately and reverse with prothrombin complex concentrate plus vitamin K 1, 2
• For low thrombotic risk patients, restart warfarin 7 days after hemorrhage 1

For patients on aspirin with established cardiovascular disease:

• Do not stop aspirin for secondary prophylaxis in lower GI bleeding 7
• Restart aspirin soon after bleeding ceases (within 7 days, ideally 1-3 days) with PPI therapy 6, 7

Occult GI Bleeding Management

For occult bleeding (iron deficiency anemia or guaiac-positive stools without visible blood):

• In men and postmenopausal women, assume GI source until proven otherwise due to malignancy risk 8
• Perform upper and lower endoscopy as initial evaluation 8, 9
• If negative, proceed to VCE for small bowel evaluation 9
• Computed tomographic enterography should be performed if obstruction is suspected before VCE or after negative VCE 9

Surgical Intervention

Surgery is reserved for specific circumstances:

• Hemodynamic instability persisting despite resuscitation 2
• Transfusion requirement exceeding 6 units 2
• Severe recurrent bleeding 2
• Critical caveat: Exhaust all radiologic and endoscopic localization attempts before emergency laparotomy, as operative mortality is 10% 2