Upper gastrointestinal bleeding from the stomach or duodenum may be the primary reason for intensive care unit admission or may be a subsequent complication in an already critically ill patient. Upper gastrointestinal bleeding carries a mortality rate of approximately 12%. After control of the airway as warranted, initial resuscitation, and placement of a nasogastric tube, attention must be turned to identifying the cause of the bleeding. Potential etiologies include vascular abnormalities (e.g., arteriovenous malformations, Dieulafoy’s lesions, or varices), traumatic injury (e.g., Mallory-Weiss tears), gastritis or duodenitis, and peptic ulcers.

Initial localization and control of bleeding may be achieved by endoscopy or angiography with embolization. Uncontrollable hemorrhage may require surgical intervention. Gastric acid potentiates bleeding by causing ongoing tissue damage, inhibiting platelet aggregation, and promoting clot lysis. Inhibition of gastric acid secretion may therefore be an important adjunct to prevent further bleeding. The efficacy of this strategy has been demonstrated in upper gastrointestinal bleeding from peptic ulcers. Intravenous proton pump inhibitor (PPI) therapy has been shown to reduce the risk of rebleeding from peptic ulcers (odds ratio 0.49) after initial hemostasis (e.g., by endoscopic therapy). Intravenous PPIs also reduce the need for surgery (odds ratio 0.61). It should be noted, however, that PPI therapy has not demonstrated any consistent mortality benefit. In addition, it should also be noted that H2-receptor antagonists have failed to show any benefit in preventing rebleeding.