Pocket Medicine

GASTROENTEROLOGY

GASTROINTESTINAL BLEEDING

Definition

•  Intraluminal blood loss anywhere from the oropharynx to the anus

•  Classification: upper = above the ligament of Treitz; lower = below the ligament of Treitz

•  Signs: hematemesis = blood in vomitus (UGIB); hematochezia = bloody stools (LGIB or rapid UGIB); melena = black, tarry stools from digested blood (usually UGIB, but can be anywhere above and including the right colon)

Etiologies of upper GI bleed (UGIB)

•  Peptic ulcer disease (50%): H. pylori, NSAIDs, gastric hypersecretory states

•  Varices (10–30%): esophageal ± gastric, 2° to portal HTN. If isolated gastric → r/o splenic vein thrombosis.

•  Gastropathy/gastritis/duodenitis (15%): NSAIDs, ASA, alcohol, stress, portal hypertensive

•  Erosive esophagitis/ulcer (10%): GERD, XRT, infectious (CMV, HSV or Candida if immunosuppressed), pill esophagitis (bisphosphonate, NSAIDs; ± odynophagia)

•  Mallory-Weiss tear (10%): GE junction tear due to retching against closed glottis

•  Vascular lesions (5%)

Dieulafoy’s lesion: superficial ectatic artery usually in cardia → sudden, massive UGIB

AVMs, angioectasias, hered. hemor. telangiectasia: submucosal, anywhere in GI tract

Gastric antral vascular ectasia (GAVE):  “watermelon stomach,” tortuous, dilated vessels; a/w cirrhosis, atrophic gastritis, CREST syndrome

Aortoenteric fistula: AAA or aortic graft erodes into 3rd portion of duodenum; p/w “herald bleed”; if suspected, diagnose by endoscopy or CT

•  Neoplastic disease: esophageal or gastric carcinoma, GIST

•  Oropharyngeal bleeding and epistaxis → swallowed blood

Etiologies of lower GI bleed (LGIB)

•  Diverticular hemorrhage (33%): 60% of diverticular bleeding localized to right colon

•  Neoplastic disease (19%): usually occult bleeding, rarely severe

•  Colitis (18%): infectious, ischemic, radiation, inflammatory bowel disease (UC >> CD)

•  Angiodysplasia (8%): most commonly located in ascending colon and cecum

•  Anorectal (4%): hemorrhoids, anal fissure, rectal ulcer

•  Other: postpolypectomy, vasculitis

Clinical manifestations

•  UGIB > LGIB: N/V, hematemesis, coffee-ground emesis, epigastric pain, vasovagal, melena

•  LGIB > UGIB: diarrhea, tenesmus, BRBPR, hematochezia (11% UGIB; Gastro 1988;95:1569)

Initial management

•  Assess severity: tachycardia (can be masked by bB use) suggests 10% volume loss, orthostatic hypotension 20% loss, shock >30% loss

•  Resuscitation: placement of 2 large-bore (18-gauge or larger) intravenous lines Volume replacement: NS or LR to achieve normal VS, UOP, & mental status

•  Transfuse: blood bank sample for type & cross; use O-neg if emerg; transfuse as needed; for UGIB (esp. w/ portal HTN) use more restrictive Hb goal (eg, 7 g/dL) (NEJM 2013;368:11)

•  Reverse coagulopathy: FFP & vit K to normalize PT; plts to keep count >50,000

•  Triage: consider ICU if unstable VS or poor end organ perfusion

Intubation for emergent EGD, if ongoing hematemesis, shock, poor resp status, Δ MS

? OutPt management if SBP ≥110, HR <100, Hb ≥13 () or ≥12 (), BUN <18,  melena, syncope, heart failure, liver disease (Lancet 2009;373;42)

Workup

•  Historywhere (anatomic location) & why (etiology)

acute or chronic, prior GIB, # of episodes, other GI dx

hematemesis, vomiting prior to hematemesis (Mallory-Weiss), melena, hematochezia

abdominal pain, wt loss, anorexia, Δ in stool caliber

gastric irritants (ASA/NSAIDs), antiplatelet drugs, anticoagulants, known coagulopathy

alcohol (gastropathy, varices), cirrhosis, known liver disease, risk factors for liver disease

abdominal/rectal radiation, history of cancer, prior GI or aortic surgery

•  Physical examVS most important, orthostatic Ds, JVP

localizable abd tenderness, peritoneal signs, masses, LAN, signs of prior surgery

signs of liver disease (hepatosplenomegaly, ascites, etc.)

rectal exam: masses, hemorrhoids, anal fissures, stool appearance, color, occult blood

pallor, jaundice, telangiectasias (alcoholic liver disease or hered. hemor. telangiectasia)

•  Lab studies: Hct (may be normal in first 24 h of acute GIB before equilibration)

↓ 2–3% → 500 mL blood loss; low MCV → Fe deficient and chronic blood loss; plt, PT,

PTT; BUN/Cr (ratio >36 in UGIB b/c GI resorption of blood ± prerenal azotemia); LFTs

Diagnostic studies

•  Nasogastric tube can aid localization: fresh blood → active UGIB; coffee grounds → recent UGIB; nonbloody bile → ? lower source, but does not exclude active UGIB (~15% missed);  occult blood testing of no value

•  UGIB: EGD w/in 24 h for dx and poss Rx; ↓ LOS & need for surgery, consider erythro 250 mg IV 30 min prior → empty stomach of blood → ↑ Dx/Rx yield (Am J Gastro 2006;101:1211)

•  LGIB: first r/o UGIB before attempting to localize presumed LGIB (10–15% actually UGIB, 3–5% small bowel), then colonoscopy (identifies cause in >70%); consider rapid purge w/ PEG solution 4 L over 2 h; no clear benefit of colonoscopy w/in 12 vs. 36–60 h (AJG 2010;105;2636); CT angio promising (Radiology 2010;262:109)

•  Unstable or recurrent UGIB & LGIB:
tagged RBC scan: can localize bleeding rates ≥0.1 mL/min for surg but unreliable arteriography: can localize if bleeding rates ≥0.5 mL/min and can Rx (coil, vaso, glue) emergent exploratory laparotomy (last resort)

Obscure GIB (Gastro 2007;133:1694; GIE 2010;72:471)

•  Definition: continued bleeding (melena, hematochezia) despite  EGD & colo; 5% of GIB

•  Etiologies: Dieulafoy’s lesion, small bowel angiodysplasia, ulcer or cancer, Crohn’s disease, aortoenteric fistula, Meckel’s diverticulum (2% of pop., remnant of vitelline duct w/ ectopic gastric mucosa), hemobilia

•  Diagnosis: repeat EGD w/ push enteroscopy/colonoscopy when bleeding is active

If , video capsule to evaluate small intestine (Gastro 2009;137:1197)

If still , consider 99mTc-pertechnetate scan (“Meckel’s scan”), enteroscopy (single-balloon, double-balloon or spiral), tagged RBC scan and arteriography