Tintinalli's Emergency Medicine - Just the Facts, 3ed.

41. GASTROINTESTINAL BLEEDING

Mitchell C. Sokolosky

EPIDEMIOLOGY

images Acute upper gastrointestinal (UGI) bleeding.

images Lower GI bleeding has an annual incidence of 20 per 100,000.

images Both upper GI bleeding and lower GI bleeding are more common in males and the elderly.

PATHOPHYSIOLOGY

images UGI bleeding originates proximal to the ligament of Treitz.

images Peptic ulcer disease is the commonest cause of UGI bleeding followed by erosive gastritis and esophagitis, esophageal and gastric varices, and Mallory–Weiss tear.

images Predisposing factors for UGI bleeding include alcohol, salicylates, and NSAIDs.

images The most common cause of lower GI bleeding is diverticular disease, followed by colitis, adenomatous polyps, and malignancies.

images Lower GI bleeding may be due to an UGI source 10% to 14% of the time.

images It is estimated that 80% of lower GI bleeding will resolve spontaneously.

CLINICAL FEATURES

images Most patients will volunteer complaints of hematemesis (UGI source), hematochezia (bright red or maroon-colored bleeding usually from lower GI source), or melena (dark or black stools usually from UGI source).

images Hypotension and tachycardia suggests severe bleeding.

images Some patients will have more subtle presentations of hypotension, tachycardia, angina, syncope, weakness, and confusion.

images Vomiting and retching followed by hematemesis is suggestive of a Mallory–Weiss tear.

images A history of aortic graft should suggest the possibility of an aortoenteric fistula.

images Spider angiomata, palmar erythema, jaundice, and gynecomastia suggest underlying liver disease.

images Weight loss and changes in bowel habits are classic symptoms of malignancy.

DIAGNOSIS AND DIFFERENTIAL

images The diagnosis may be obvious with the finding of hematemesis, hematochezia, or melena.

images A careful ear, nose, and throat (ENT) examination can exclude swallowed blood as a source.

images A rectal examination is mandatory to detect the presence of blood, its appearance (bright red, maroon, or melanotic), and the presence of masses.

images Ingestion of iron or bismuth can simulate melena, and certain foods such as beets can simulate hematochezia; however, stool guaiac testing will be negative.

images Nasogastric (NG) tube placement may have both diagnostic (identify occult UGI source and assess for ongoing active bleeding) and therapeutic (prepare patient for endoscopy) benefits. A negative NG aspirate does not conclusively exclude a UGI source of bleeding. Concerns that NG tube passage may provoke bleeding in patients with varices are unwarranted.

images Guaiac testing of NG aspirate can yield both false-negative and false-positive results. Most reliable is gross inspection of the aspirate for bloody, maroon, or coffee-ground appearance, reserving guaiac testing to confirm that what appears to be blood actually is blood.

images In patients with significant GI bleeding, the most important laboratory test is the type and crossmatch of blood.

images Other important tests include a complete blood count, blood urea nitrogen (BUN), creatinine, electrolytes, glucose, coagulation studies, and liver function tests. The initial hematocrit level often will not reflect the actual amount of blood loss. UGI bleeding may elevate the BUN.

images UGI endoscopy is the diagnostic study of choice in the evaluation of UGI bleeding.

images Where available, angiography should be considered for the evaluation (detect site of bleeding) and management (embolization or infusion of vasoactive substances) of cases of severe lower GI bleeding.

images Scintigraphy has been used to localize the site of bleeding in obscure hemorrhage.

images Endoscopy is more accurate than angiography or scintigraphy, but the timing of colonoscopy is controversial for lower GI bleeding.

images Multidetector CT’s role in the emergent evaluation of lower GI bleeding remains in evolution.

EMERGENCY DEPARTMENT CARE AND DISPOSITION

images Emergency stabilization of the airway, breathing, and circulation takes priority.

images Oxygen, large-bore IVs, and monitors should be applied. Immediately replace volume loss with IV crystalloids.

images The decision to start blood should be based on clinical factors (continued active bleeding and no improvement in perfusion after infusion of 2 L of crystalloids) rather than initial hematocrit.

images An NG tube should be placed in all patients with significant bleeding, regardless of presumed source. Room temperature water is the preferred irrigant for gastric lavage if performed.

images Where available, early therapeutic endoscopy should be considered the treatment of choice for significant UGI bleeding. Endoscopic therapeutic interventions include injection therapy, coaptive therapy, endoscopic clips, and band ligation.

images Proton pump inhibitors should be considered for the treatment of bleeding peptic ulcers. Pantoprazole and esomeprazole, 80 milligram IV bolus followed by 8 milligram/h infusion, or lansoprazol, 60 milligram IV bolus followed by 6 milligram/h infusion, may be used.

images Octreotid, 25 to 50 microgram IV bolus followed by 25 to 50 microgram/h infusion, may be considered for patients with uncontrolled UGI bleeding awaiting endoscopy or when endoscopy is unsuccessful, con-traindicated, or unavailable.

images Histamine-2 antagonists are not beneficial in acute GI bleeding.

images Balloon tamponade with the Sengstaken-Blakemore tube or its variants can control documented variceal hemorrhage, but because of adverse reactions, it should be considered only a temporizing measure until therapeutic endoscopy.

images Emergency surgical intervention may be necessary with patients who do not respond to medical or endoscopic therapy.

images Patients with significant GI hemorrhage will require hospital admission and early referral to an endoscopist.

images Clinical features predicting adverse outcomes include initial hematocrit <30%, initial systolic BP <100 mm Hg, red blood in the NG lavage, history of cirrhosis or ascites on examination, and a history of vomiting red blood.


For further reading in Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7th ed., see Chapter 78, “Upper Gastrointestinal Bleeding,” by David T. Overton, and Chapter 79, “Lower Gastrointestinal Bleeding,” by Bruce M. Lo.




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