Prevention of Acute Stress Bleeding with Sucralfate, Antacids, or Cimetidine , A Controlled Study with Pirenzepineas a Basic Medication MICHAEL TRYBA, M.D. FELIX ZEVOUNOU, M.D. MARIA TOROK, M.D. MICHAEL ZENZ, M.D. Hannover, Federal Republic of Germany in a prospective, controlled, randomized study of a prophylaxis for stress bleeding, 100 high-risk patients in an Intensive care unit re- celved, on a daily basis, 1 g of sucralfate every four hours, an ant- acid every two hours, or 2 g of cimetldlne intravenously. All patlents also received 50 mg of plrenzepine by Intravenous infuslon each day. Gastric pH was determined every eight hours. Bleeding was defined as macroscoplcally visible bleedlng. The lntragastric pH was less than 4 slgnlflcantly more often in patients treated with su- cralfate than In patients treated with the other agents, but stress blesdlng occurred only In patients treated with clmetldlne (n = 2) or antacids (n = 2). In the latter two treatment groups, the probablllty of bleedlng correlated wlth the Incidence of pH values below 4. No side effects of sucralfate thempy were observed. The results lndi- cate that prophylactic treatment of stress bleedlng wlth plrenzeplne and sucralfate Is at least as effective as combined treatment with pirenzeplne and clmetldlne or antacids. From the Depamnents of Anesthesiology and Bi- ometry, Hat-mover School of Medicine, Hannover, Federal Republic of Germany. Requests for re- prints should be addressed to Dr. Michael Tryba, Department of Anesthesiology IV, Hannover School of Medicine, Podbielskistr 380, D-3000 Hannover 51, Federal Republic of Genany. Stress hemorrhage from acute mucosal lesions of the upper gastrointes- tinal tract constitutes a serious risk to patients in intensive care units. In those at particularly high risk, hemorrhage has been observed in more than 50 percent of cases [1,2]. A number of factors contribute to the development of acute mucosal lesions of the stomach and the duodenum in patients who are critically ill. Under physiologic conditions, the intact mucosa is able to protect itself against potentially injurious agents such as hydrogen ions, pepsin, and bile acids. However, disturbances of the micro-circulation due to hypovo- lemia, hypotension, or hypoxia lead to a breakdown of the gastric muco- sal barrier [3,4]. Hydrogen ions and pepsin have been shown to be impor- tant causes of hemorrhage [5], and current efforts to prevent stress bleeding are directed at attenuating these factors. The attainment of a pH of 3.5 or more is regarded as sufficient [1,6-g] to eliminate acid as an aggressive factor since the concentration of free hydrogen ions is low in this case. Also, at a pH of more than 3.5, the proteolytic activity of pepsin is markedly reduced. The widespread use of measures to increase intragastric pH in patients who are critically ill has resulted in a decisive decrease in both the inci- dence and the severity of stress hemorrhage. Prospective studies have shown that antacids [6,6], HP-receptor antagonists [l ,lO,l 11,and pirenze- pine [12,13] are effective in preventing acute stress bleeding. It has also been found that these drugs are more effective in combination than when given alone [14-161. Continuous elevation of intragastric pH is, however, associated with August 30, lgs5 The Amerkan Journal ol Medklne Volunw 79 (suppi X) 55