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.