Cytoprotection and stress ulceration.

The stomach possesses many mechanisms for protection against stress ulceration. The gastric microcirculation, prostaglandins, mucus secretion, epithelial cell renewal, and muscle tone are factors involved in gastric cytoprotection. Therapy is partially directed at augmenting these natural physiologic defense mechanisms to prevent and promote healing of stress ulceration. Drugs such as sucralfate, carbenoxalone, colloidal bismuth, and prostaglandins are used. Stress ulceration is an important cause of upper gastrointestinal tract hemorrhage in postoperative and critically ill patients in the intensive care unit setting. Preventive therapy includes neutralization of gastric acid by antacids, suppression of gastric acid secretion by H2-receptor blockers, administration of cytoprotective agents, and correction of the underlying stress state. Active bleeding requires accurate diagnosis by gastroscopy. Additional therapy may be necessary, including intra-arterial administration of vasopressin and occasionally surgery. Dieulafoy's lesion is an unusual stress-related cause for upper gastrointestinal bleeding. The area of mucosal injury is minute but underneath lies a large submucosal gastric artery. It can cause massive bleeding and is often missed at initial gastroscopy. The pathogenesis of Dieulafoy's lesion is complex and the mainstay of therapy has been surgical. Ligation of the vessel, wedge resection, or proximal gastric resection is performed. Therapeutic endoscopy with endoscopic cauterization or injection has changed the approach to this lesion.