Prophylaxis of upper gastrointestinal hemorrhage in patients requiring mechanical ventilation.

Because approximately 20% of patients receiving mechanical ventilation have upper gastrointestinal bleeding, these patients were prophylatically treated with either antacids, cimetidine, or a placebo in a double-blind randomized fashion. The authors did not titrate gastric acidity because it is a time-consuming process that requires a nasogastric tube. When gastrointestinal bleeding developed in 9 of the 36 patients entered in the study, the treatment code was broken to assess the efficacy of prophylaxis and the frequency of complications. In the antacid group, 5 of the 11 patients were unable to ingest and tolerate their antacids (p less than 0.05 when compared to the control and cimetidine groups). Gastrointestinal bleeding did not occur in any of the six subjects receiving antacids but did occur in one of the 11 subjects receiving cimetidine, in 5 of the 14 control patients, and in 3 of the 5 patients who were unable to tolerate antacids. These differences were not significant. When groups were rearranged, though, there was a significant difference between them. Only 1 of 17 patients receiving medication (antacids or cimetidine) bled, whereas 8 of 19 patients receiving no medications bled (p less than 0.01). The average number of risk factors was not significantly different in the treatment groups. The authors conclude that prophylactic therapy (cimetidine or antacids) given without titration is associated with a lower frequency of upper gastrointestinal hemorrhage than when no medication is given. The authors also conclude that more subjects are able to tolerate cimetidine than antacids.