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ACNP III - Exam 2 > Lower GI Bleeding > Flashcards

Flashcards in Lower GI Bleeding Deck (7):

What classifies a lower GI bleed?

GI bleeding that originates distal to the ligament of Treitz


What causes lower GI bleeding?

  • Diverticulosis – 40% of cases and the primary cause of severe LGIB in patients > 60 years of age
  • Vascular ectasias - most common in patients older than 70 years of age with chronic renal failure; painless bleeding ranging from chronic occult blood loss to acute hematochezia
  • Benign Tumors/Neoplasms – chronic, occult blood loss normally- rarely causes  massive lower tract bleeding
  • Inflammatory bowel disease – ulcerative colitis and Crohn’s disease
  • Anorectal disease – hemorrhoids, rectal ulcers anal fissures; rarely results in significant blood loss
  • Ischemic colitis – usually seen in the elderly who have a history of atherosclerosis; signs/symptoms: abdominal cramping, bloody diarrhea or hematochezia
  • Other: radiation-induced colitis or infectious colitis (E. coli, Shigella spp., etc.)


What are the clinical manifestations associated with a lower GI bleed?

  • Hematochezia (bright red blood), occasionally melena
  • Chronic blood loss:
    • Skin pallor
    • Tachycardia
    • Postural hypotension
  • Acute blood loss:
    • Altered mental status
    • Hypotension
    • Shock
    • Gross evidence of rectal blood loss
  • Rule out vaginal or urethral bleeding in females


What lab/diagnostic tests are done to diagnose a lower GI bleed?

  • NGT- to rule out upper GI source
  • CBC – r/o anemia, may be normal in early acute massive bleeds due to hemoconcentration
  • Iron studies
  • Fecal occult blood test- if patient stable and questionable GI blood loss
  • Anoscopy and sigmoidoscopy
  • Colonoscopy- within 6-24 hours in patients with significant LGIB after colon had been cleaned
  • Arteriography, or nuclear medicine tagged RBC scan (scintigraphy), or CT angiography
  • Small intestine push enteroscopy- used in recurrent bleeding of unknown origin; consists of a long, small diameter endoscope that is able to reach jejunum
  • Capsule endoscopy may be indicated for identification of distal small intestinal bleeding.


How do you manage a patient with lower GI bleeding?

1. Rapid assessment and resuscitation precedes all diagnostic evaluation in an unstable patient with acute severe LGIB

  • Place 2 large bore IV lines and/or pulmonary artery catheter
  • Administer lactated Ringer’s or 0.9NS and/or PRBCs as indicated
  • Monitor vital signs, MAP, PCWP, CVP
  • Titrate infusion rate to maintain perfusion

2. Once stability is attained:

  • Evaluate for immediate risk of re-bleeding and/or complications, underlying source of bleeding.

3. Discontinue NSAIDS or Aspirin, treat cause of bleeding

4. IV proton pump inhibitors:

  • Pantoprazole 80mg IV bolus, followed by continuous infusion 8mg/hr

5. Type and Cross 

  • Have blood products ready 

6. Proceed to diagnostic studies (Colonoscopy, Nuclear Medicine radionuclide tagged scan, CT angiography)


When are the requirements for using a nuclear medicine radionuclide tagged RBC scan for lower GI bleeding?

  • Requires a rate of bleeding of 0.1mL/minute to be localized
  • The MOST sensitive imaging modality for GI bleeding
  • Disadvantages: patients must be actively bleeding during scan due to short half-life of technetium-99m Sulphur colloid; if no bleeding is found on tagged RBC scan, the likelihood that bleeding will be found on an angiography is low


When are the indications for using a CT Angiography for lower GI bleeding?

It requires the rate of bleeding to be at least 0.5 mL/minute to reliably show extravasation of contrast into the bowel lumen to identify a bleeding site; diagnostic, NO therapeutic capability

  • Used in cases where colonoscopy has been unable to locate site of bleeding
  • Contraindicated in patients with iodine allergy or renal insufficiency
  • Useful in planning definitive therapy, through endoscopy, arteriography or surgery