What is the approach to managing lower gastrointestinal (GI) bleeding?

Management of Lower Gastrointestinal Bleeding

For patients with lower gastrointestinal bleeding (LGIB), initial assessment should focus on hemodynamic status using shock index (heart rate/systolic BP), with immediate fluid resuscitation for unstable patients, followed by risk stratification using the Oakland score to guide management decisions regarding hospitalization and timing of interventions. 1, 2, 3

Initial Assessment and Risk Stratification

• Immediately assess hemodynamic status using shock index (heart rate/systolic BP), with a shock index >1 indicating instability requiring urgent intervention 2, 3
• Calculate the Oakland score for stable patients, which includes age, gender, previous LGIB admission, digital rectal examination findings, heart rate, systolic blood pressure, and hemoglobin level 3
• Patients with an Oakland score ≤8 points can be safely discharged for urgent outpatient investigation 3
• Patients with an Oakland score >8 points should be admitted to hospital for colonoscopy 3
• The BLEED classification system (ongoing bleeding, low systolic blood pressure, elevated prothrombin time, erratic mental status, unstable comorbid disease) can help identify patients at high risk of adverse in-hospital outcomes 4

Resuscitation and Blood Transfusion

• For hemodynamically unstable patients, initiate aggressive fluid resuscitation concurrently with diagnostic evaluation 1, 2
• Use restrictive transfusion thresholds (Hb trigger 70 g/L, target 70-90 g/L) for patients without cardiovascular disease 2, 3
• Use higher threshold (Hb trigger 80 g/L, target ≥100 g/L) for patients with cardiovascular disease 2, 3
• Correct coagulopathy or thrombocytopenia with fresh frozen plasma or platelets, respectively 1

Diagnostic Approach

For Hemodynamically Unstable Patients:

• Consider an upper GI source in patients with severe hematochezia and hypovolemia (accounts for 10-15% of such cases) 1, 3
• Perform CT angiography immediately to localize bleeding before any intervention 2, 3
• Following positive CTA, proceed to catheter angiography with embolization within 60 minutes for hemodynamically unstable patients 2, 3

For Hemodynamically Stable Patients:

• Perform colonoscopy as the first-line diagnostic procedure after adequate bowel preparation 1, 5
• Urgent colonoscopy should be performed within 24 hours of presentation for better identification of bleeding source 1, 5
• If colonoscopy is negative and bleeding persists, consider:
  • Radionuclide imaging ([99Tcm] pertechnetate-labeled red blood cell scanning) which can detect bleeding at rates of 0.1-0.5 mL/min 1
  • A positive red blood cell scan should be followed by urgent angiography within 1 hour 1
• If upper and lower GI sources are ruled out, evaluate the small bowel with enteroscopy or video capsule endoscopy 1

Management of Identified Bleeding Sources

• Provide endoscopic hemostasis therapy to patients with high-risk endoscopic stigmata including active bleeding, non-bleeding visible vessel, or adherent clot 5
• The endoscopic hemostasis modality (mechanical, thermal, injection, or combination) should be guided by the etiology of bleeding and access to the bleeding site 5
• Consider repeat colonoscopy with endoscopic hemostasis for patients with evidence of recurrent bleeding 5
• For patients with continued bleeding despite endoscopic intervention, consider angiographic embolization 4, 1
• Surgical intervention is indicated when:
  • Hypotension and shock persist despite resuscitation
  • Continued bleeding (>6 units of packed red blood cells transfused) without diagnosis despite comprehensive evaluation
  • Active bleeding from a segmental lesion amenable to surgical cure 4

Management of Medications

• For patients on warfarin with unstable GI hemorrhage:

  • Interrupt warfarin therapy immediately at presentation
  • Reverse anticoagulation with prothrombin complex concentrate and vitamin K
  • For low thrombotic risk, restart warfarin 7 days after hemorrhage
  • For high thrombotic risk, consider low molecular weight heparin therapy at 48 hours after hemorrhage 2, 3

• For patients on antiplatelet therapy:

  • Discontinue aspirin permanently if used for primary prophylaxis
  • For secondary prevention, aspirin should not be routinely stopped; if stopped, restart as soon as hemostasis is achieved
  • For dual antiplatelet therapy, if P2Y12 receptor antagonist is stopped, reinstate within 5 days 2, 3, 5

Common Pitfalls and Caveats

• Failure to consider an upper GI source in patients with severe hematochezia can lead to delayed diagnosis and treatment 1, 3
• Delayed colonoscopy may reduce diagnostic yield, particularly for identifying stigmata of recent hemorrhage 1
• Overreliance on radionuclide imaging without confirmatory tests before surgery can lead to incorrect localization 1
• Mortality in LGIB is generally related to comorbidity rather than exsanguination, with in-hospital mortality of 3.4% overall but rising to 18% for inpatient-onset LGIB and 20% for patients requiring ≥4 units of red cells 2, 3