What is the definition and management of upper and lower gastrointestinal (GI) bleed?

Upper and Lower Gastrointestinal Bleeding: Definition and Management

Gastrointestinal bleeding is anatomically defined as upper GI bleeding when originating from a source proximal to the ampulla of Vater, mid GI bleeding from the ampulla of Vater to the terminal ileum, and lower GI bleeding when originating from the colon. 1

Definitions

Upper GI Bleeding

• Bleeding from a source proximal to the ampulla of Vater (within reach of EGD)
• Common manifestations: hematemesis, melena, or hematochezia with hemodynamic instability
• Common causes:
  • Peptic ulcer disease
  • Gastritis/esophagitis
  • Varices
  • Mallory-Weiss tears
  • Dieulafoy's lesion
  • Gastric antral vascular ectasia
  • Cameron's erosions in hiatal hernias 2, 3

Lower GI Bleeding

• Bleeding from the colon (distal to the terminal ileum)
• Typically presents as hematochezia (bright red blood per rectum)
• Common causes:
  • Diverticulosis (most common cause in adults)
  • Angiodysplasia
  • Hemorrhoids
  • Ischemic colitis 2, 4

Mid GI Bleeding

• Bleeding from the ampulla of Vater to the terminal ileum
• Often presents as obscure GI bleeding after negative EGD and colonoscopy
• Best investigated by capsule endoscopy and double-balloon enteroscopy
• Common causes:
  • Angiodysplasias (especially in patients >40 years)
  • NSAID-induced enteropathy
  • Dieulafoy's lesion (younger patients)
  • Crohn's disease (younger patients) 2

Management Approach

Initial Assessment and Resuscitation

1. Hemodynamic stabilization:

   • Maintain hemoglobin >7 g/dL (>8 g/dL for patients with cardiovascular disease)
   • Maintain mean arterial pressure >65 mmHg
   • IV fluid resuscitation while avoiding fluid overload 1

2. Risk stratification:

   • Assess vital signs, hemoglobin/hematocrit
   • Perform digital rectal examination
   • Consider Glasgow-Blatchford score for upper GI bleeding 1, 3

Diagnostic Approach

For Upper GI Bleeding:

1. Urgent upper endoscopy (EGD):

   • Should be performed within 24 hours of presentation
   • Provides both diagnostic and therapeutic capabilities 3

2. If endoscopy fails to identify source:

   • CT Angiography
   • If negative, proceed to video capsule endoscopy 1

For Lower GI Bleeding:

1. Initial evaluation:

   • Rule out upper GI source (10-15% of severe hematochezia cases have upper GI source)
   • Ano-proctoscopy or flexible sigmoidoscopy as initial diagnostic procedure 2, 1

2. Colonoscopy:

   • Should be performed within 24 hours after adequate bowel preparation
   • Complete colonoscopy indicated when risk factors for colorectal cancer exist or initial evaluation inconclusive 1, 4

3. If colonoscopy is negative or not feasible:

   • CT Angiography (can detect bleeding at rates of 0.3-1.0 mL/min)
   • Nuclear medicine labeled red cell scan (can detect bleeding as low as 0.05-0.1 mL/min)
   • Mesenteric angiography 1

For Mid GI/Obscure Bleeding:

1. Video capsule endoscopy:

   • High diagnostic yield when performed within 48 hours of bleeding
   • Contraindicated in suspected GI obstruction (risk of retention ~2%) 1

2. CT Enterography:

   • First-line imaging for suspected small bowel bleeding in stable patients
   • Particularly useful when patients are at risk for capsule retention 1

3. Deep enteroscopy:

   • For therapeutic intervention of small bowel lesions 1

Therapeutic Interventions

Endoscopic Therapy:

• For active bleeding, non-bleeding visible vessel, or adherent clot:

  • Mechanical methods (clips)
  • Thermal methods (coagulation)
  • Injection therapy (epinephrine)
  • Combination therapy 4

• For variceal bleeding:

  • Endoscopic variceal ligation
  • Sclerotherapy
  • EUS-guided glue injection 1

Pharmacologic Therapy:

• Proton pump inhibitors:

  • Should be initiated upon presentation with upper GI bleeding
  • High-dose treatment for first 72 hours post-endoscopy (highest rebleeding risk) 3

• For variceal bleeding:

  • Vasoactive drugs (octreotide, terlipressin)
  • Prophylactic antibiotics 1, 5

Interventional Radiology:

• Angiographic embolization:

  • When bleeding site localized by CTA but requires intervention
  • Technical success rates 93-100%, clinical success rate 67%
  • Option when endoscopic hemostasis fails 1

• TIPS (Transjugular Intrahepatic Portosystemic Shunt):

  • For severe portal hypertension when endoscopic treatment fails 1

Surgical Intervention:

• Reserved for failed endoscopic and radiologic interventions
• Source of bleeding should be carefully localized before resection 4

Follow-up and Prevention

1. Iron supplementation:

   • For patients discharged with anemia (response rate 80-90%) 1

2. Medication management:

   • Avoid NSAIDs in patients with history of GI bleeding
   • For patients on antithrombotics, carefully weigh bleeding vs. thrombotic risks
   • Patients with high-risk cardiovascular disease should not stop aspirin for secondary prophylaxis 4

3. H. pylori testing and eradication:

   • Essential for patients with peptic ulcer bleeding 1, 6

4. Follow-up endoscopy:

   • Routine second-look endoscopy not recommended
   • Gastroenterology follow-up within 2 weeks if discharged 1

Common Pitfalls to Avoid

1. Failing to consider upper GI source in patients presenting with hematochezia and hemodynamic instability
2. Delaying endoscopy beyond 24 hours in high-risk patients
3. Using barium or iodinated contrast studies that may interfere with subsequent procedures
4. Overlooking common sources of bleeding (Cameron's erosions, fundic varices, angiodysplasias)
5. Neglecting to optimize renal status before contrast studies
6. Inappropriate transfusion strategies (overtransfusion can worsen bleeding outcomes)