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Gastrointestinal bleeding

Gastrointestinal (GI) bleeding, arising from various etiologies, presents either as overt bleeding (hematemesis, melena, hematochezia) or occult bleeding, often linked to iron deficiency anemia. Classification is based on the bleeding site: upper GI bleeding (UGIB) occurs proximal to the ligament of Treitz (e.g., esophageal varices, peptic ulcers), while lower GI bleeding (LGIB) is distal (e.g., diverticula, malignancies, small bowel sources). Overt UGIB typically presents with hematemesis, though rapid bleeding can lead to hematochezia or melena. LGIB generally manifests as hematochezia, with melena suggesting small bowel or proximal colon involvement.

Initial management prioritizes hemodynamic stabilization, followed by endoscopic or angiographic localization and control of the bleed (endoscopic interventions, surgery, or angioembolization). For younger patients with minor hematochezia and no malignancy or IBD indications, sigmoidoscopy is an advisable first investigation. Regardless of presentation (overt or occult), identifying and addressing the underlying cause is imperative.

Last updated: December 3, 2024 254 views

  • Upper Gastrointestinal Bleeding (UGIB):
    • Accounts for approximately 70–80% of GI hemorrhages.
    • The bleeding source is proximal to the ligament of Treitz (the anatomical landmark where the duodenum ends and the jejunum begins).
  • Lower Gastrointestinal Bleeding (LGIB):
    • Represents about 20–30% of all GI hemorrhages.
    • The bleeding source is distal to the ligament of Treitz, typically in the colon.
  • Occult GI Bleeding:
    • Bleeding in small quantities, not visible macroscopically.
    • Requires chemical tests or microscopic examination for detection.
  • Overt GI Bleeding:
    • Macroscopically visible bleeding.
    • Accompanied by clinical symptoms such as anemia and tachycardia.
  • Obscure Gastrointestinal Bleeding:
    • GI bleeding that continues or recurs following an initial negative evaluation.
    • Characterized by the inability to initially find the bleeding source.

  • Etiologies of Upper Gastrointestinal Bleeding (UGIB):
    • Erosive/Inflammatory:
      • Peptic Ulcer Disease (about 30% of UGIB cases).
      • Esophagitis.
      • Erosive gastritis and/or duodenitis.
    • Vascular:
      • Esophageal or gastric varices.
      • Gastric antral vascular ectasia.
      • Dieulafoy lesion: difficult to visualize on endoscopy, treated with endoscopic hemostasis or mucosal excision.
    • Tumors:
      • Esophageal or gastric carcinoma.
    • Traumatic/Iatrogenic:
      • Hiatal hernias.
      • Mallory-Weiss syndrome.
      • Boerhaave syndrome.
    • Other Causes:
      • Portal hypertensive gastropathy.
      • Coagulopathies.
  • Etiologies of Lower Gastrointestinal Bleeding (LGIB):
    • Erosive/Inflammatory:
      • Diverticulosis (about 30% of LGIB cases).
      • Inflammatory bowel disease (IBD).
      • Invasive/inflammatory diarrhea (e.g., Shigella, EHEC).
    • Vascular:
      • Hemorrhoids.
      • Ischemia (e.g., ischemic colitis, mesenteric ischemia).
      • Arteriovenous malformation.
      • Rectal varices.
      • Angiodysplasia.
    • Tumors:
      • Colorectal or anal cancer.
      • Colonic polyps.
    • Traumatic/Iatrogenic:
      • Lower abdominal trauma.
      • Anorectal trauma (e.g., avulsion, impalement injuries).
      • Post-surgical anastomotic bleeding.
    • Other Causes:
      • Anal fissures.

  • Clinical Features of GI Bleeding:
    • Anemia Due to Chronic Blood Loss: Indicative of ongoing, slow bleeding.
    • Acute Hemorrhage with Significant Blood Loss: May lead to signs of circulatory insufficiency or hypovolemic shock.
    • Signs of Circulatory Insufficiency/Hypovolemic Shock:
      • Tachycardia, hypotension (manifesting as dizziness, collapse, or shock).
      • Altered mental status.

 

  • Features of Overt GI Bleeding:
    • Hematemesis:
      • Vomiting of blood, red or coffee-ground appearance.
      • Indicates upper GI tract bleeding (e.g., esophagus, stomach).
    • Melena:
      • Black, tarry stool with a strong offensive odor.
      • Typically due to upper GI tract bleeding, but can also occur with small bowel or right colon bleeding.
    • Hematochezia:
      • Bright red (fresh) blood passage through the anus, with or without stool.
      • Colonic bleeding: Maroon, jelly-like blood traces in stools.
      • Rectal bleeding: Streaks of fresh blood on stools.
      • Usually indicates lower GI tract bleeding (e.g., distal colon), but rapid upper GI tract bleeding may also cause hematochezia.
Note  
Both melena and hematochezia can be caused by either UGIB or LGIB. ملاحظة
Note  
Unexplained iron deficiency anemia (e.g., in men or postmenopausal women) should raise suspicion for GI bleeding. ملاحظة

  • General Management for All Patients:
    • Ensure patients are Nil Per Os (NPO).
    • Insert two large-bore peripheral IVs for potential fluid resuscitation and blood transfusion.
    • Obtain blood samples for laboratory studies (e.g., CBC, type and screen).
    • Conduct a focused history and examination, including digital rectal examination (DRE).
    • Risk stratify patients to guide further management.
    • Prior to hemostatic procedures consider:
      • Pretreatment (e.g., intravenous PPI).
      • Anticoagulant reversal for life-threatening bleeding.
      • Withholding antithrombotic agents.
    • Utilize endoscopy, colonoscopy, and transcatheter angiography for dual diagnostic and therapeutic purposes.
  • Stable Patients:
    • Implement a restrictive transfusion strategy (transfuse packed red blood cells if hemoglobin ≤ 7 g/dL).
    • Refer for endoscopy based on risk stratification and bleeding source.
  • Unstable Patients:
    • Follow an ABCDE approach.
    • Consider intubation for airway protection in patients with altered mental state or severe hematemesis.
    • Conduct urgent volume resuscitation for hemodynamic instability.
    • Implement a liberal transfusion strategy for hemorrhagic shock or massive bleeding.
    • Target normalization of vital signs before diagnostic testing.
    • Consult specialists to determine the optimal dual diagnostic/therapeutic intervention.
    • Ensure prompt hemostatic control via endoscopy, angioembolization, or surgery.

  • Approach to Low-Risk GI Bleeding:
    • Occult GI Bleeding:
      • Initial screening: Fecal occult blood test (FOBT), complete blood count (CBC), ± iron studies.
      • Nonurgent endoscopy if FOBT positive.
    • Scant Intermittent Hematochezia:
      • Initial screening for patients < 40 years without malignancy or IBD risk: Digital rectal exam (DRE) and sigmoidoscopy.
      • Colonoscopy for nondiagnostic sigmoidoscopy or unexplained red flag symptoms.
  • Approach to Overt GI Bleeding:
    • For Suspected UGIB:
      • Presenting signs/symptoms: Hematemesis, melena, hematochezia with instability.
      • First-line: Esophagogastroduodenoscopy (EGD).
      • If EGD negative: Colonoscopy or evaluation for small bowel bleeding.
    • For Suspected LGIB:
      • Presenting signs/symptoms: Hematochezia, melena with known right colon lesion.
      • First-line test: Colonoscopy after bowel preparation.
      • If colonoscopy negative: EGD or evaluation for small bowel bleeding.
    • Hemodynamically Unstable Patients:
      • First-line: EGD.
      • For hematochezia with moderate probability of UGIB: Nasogastric (NG) aspirate, then EGD.
      • Refractory instability: Angiography (e.g., computed tomography angiography, CTA) followed by source control.
  • Laboratory Studies:
    • CBC, coagulation panel, basic metabolic panel (BMP), blood type and crossmatching, liver chemistries for suspected variceal hemorrhage.
    • Elevated BUN/Cr ratio suggests brisk UGIB.
  • Nasogastric Aspirate (NG Aspirate):
    • Procedure: Instill and then aspirate saline via NG tube.
    • Findings: Positive for active UGIB if bright red blood or coffee grounds appear.
  • Endoscopy:
    • Upper endoscopy for visualization of the upper GI tract.
    • Colonoscopy for visualization of the colon.
    • Allows for bleeding source identification, diagnostic biopsies, and hemostatic interventions.
  • Angiography:
    • Indicated for suspected LGIB with hemodynamic instability or ongoing bleeding with negative endoscopy.
    • Options: Transcatheter angiography, CTA.
  • Evaluation of Small Bowel Bleeding:
    • Consider advanced endoscopic evaluation (e.g., push enteroscopy, video capsule endoscopy) and radiographic evaluation (e.g., CT enterography, tagged RBC scintigraphy).

  • Endoscopic Hemostasis:
    • Indications: High-risk endoscopic findings such as active bleeding, nonbleeding visible vessels, or adherent clots.
    • Modalities:
      • Injection Therapy: Using diluted epinephrine or normal saline.
      • Cauterization: Heater probes, electrocautery.
      • Mechanical Therapy: Band ligation, clips.
      • Polypectomy: For bleeding polyps, particularly in the colon.
  • Interventional Radiology (Angiography):
    • Indications:
      • Preferred in ongoing GI bleeding with hemodynamic instability unresponsive to resuscitation.
      • Alternative to colonoscopy in acute lower GI bleeding when bowel preparation is not feasible.
      • Consider for rebleeding or ongoing bleeding despite endoscopic measures.
    • Techniques:
      • Angioembolization.
      • Intraarterial vasopressin.
  • Surgery:
    • Indications:
      • Considered when other therapies fail.
      • For hemodynamically unstable patients with ongoing bleeding.
    • Procedure: Exploratory laparotomy and surgical hemostasis.
  • Treatment of Underlying Cause:
    • Following hemostasis, evaluate and treat the underlying cause of the bleeding.

  • Hypovolemic Shock:
    • Caused by significant blood loss leading to decreased blood volume and circulatory collapse.
  • Hepatic Encephalopathy (in Patients with Liver Cirrhosis):
    • Due to inadequate elimination of metabolic products by the liver.
    • Accumulation of neurotoxic metabolites (e.g., ammonia).
    • GI bleeding increases digestion of blood into protein, raising ammonia concentrations, thereby increasing the risk of hepatic encephalopathy.
  • Aspiration Pneumonia:
    • Occurs from aspiration of blood, leading to respiratory problems.
    • Common in patients with massive upper GI bleeding, particularly with esophageal involvement.
    • Higher risk in patients with altered mental states (e.g., dementia, hepatic encephalopathy).