Effect of intravenous midazolam on esophageal motility testing in normal human volunteers.

This study evaluates midazolam's immediate pharmacological impact on esophageal motility. Stationary esophageal motility in normal male volunteers was evaluated to obtain a baseline study. Immediately after the baseline study, each subject received midazolam 0.02 micrograms/kg intravenously, and underwent repeat manometry 5 min later. Midazolam produced a variety of motility changes. There was a decrease in upper esophageal sphincter resting pressures (p < 0.05). Median pressures increased in the esophageal body at 3 cm below the upper esophageal sphincter (p < 0.05). Lower esophageal sphincter residual pressure increased, and the percentage of relaxation decreased (p < 0.05). The most striking change was the induction of tracings consistent with nonspecific esophageal motility disorders (p < 0.01). On the basis of these results, we conclude that esophageal motility testing should not follow procedures in which midazolam is used, until the duration of its effects on the esophagus is known.