Lower GI Bleeding Flashcards
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
