Midazolam: an effective antiemetic after cardiac surgery--a clinical trial.

Cardiac surgery has been associated with a significant incidence of postoperative nausea and vomiting (PONV). To assess the antiemetic property of midazolam, we undertook this double-blinded, randomized trial in 200 patients undergoing cardiac surgery involving cardiopulmonary bypass, and we compared its efficacy with that of ondansetron in preventing PONV. Assessments on the occurrence of PONV were made at regular intervals for the first 24 h after tracheal extubation, along with sedation and pain scoring. We report a 6% incidence of nausea and no incidence of vomiting in the midazolam group, compared with a 21% incidence of PONV in the ondansetron group (P < 0.001). All 21 patients (18 women and 3 men) in the ondansetron group and none of the 6 patients (all women) in the midazolam group required a rescue antiemetic drug (P < 0.001). The sedation scores and postoperative pain scores were comparable in both groups. We conclude that midazolam, instituted as a continuous infusion in a dose of 0.02 mg. kg(-1). h(-1), is a more effective antiemetic than ondansetron in a dose of 0.1 mg/kg IV every 6 h for the prevention of PONV after cardiac surgery.