Predominant effects of midazolam for conscious sedation: benefits beyond the early postoperative period

Abstract

Conscious sedation with intravenous sedative-hypnotic drugs has the advantage of relaxing patients before invasive procedures. Preoperative anxiety has been suggested to correlate with postoperative comfortableness. In this study, we chose midazolam and droperidol as well-established intravenous sedative-hypnotic drugs. We evaluated the preoperative anxiolytic effect on postoperative memories and emotions up to the first postoperative morning. In a prospective, double blind study, 120 patients requiring epidural anesthesia were randomly assigned to one of three groups to receive saline, midazolam (0.04mg/kg), or droperidol (0.1mg/kg). Cardiovascular and respiratory measurements, observer's assessment of alertness/sedation scale, level of anxiety and discomfort of the patients, pain during the infiltration of local anesthetics, and incidence of adverse effects were recorded. Amnesia, anxiety, and discomfort during the epidural procedure were re-assessed between 12 and 20h postsurgery. Patients who received sedatives were significantly more sedated (P<0.0001), but the pain score was significantly higher in the droperidol group (P=0.0007) at epidural catheterization. On the first postoperative morning, patients receiving midazolam had a significantly lower pain score (P<0.0001) with less anxiety and discomfort. Patients in both the midazolam and droperidol groups showed a significant decrease in blood pressure (P<0.0167), but no respiratory impairment. No adverse effects were experienced throughout the study period. Conscious sedation with intravenous midazolam 0.04mg/kg significantly decreased the anxiety and discomfort scores of the patients on the day following surgery but had no effect on these immediately following the epidural catheterization procedure.