THE EFFECTS OF MIDAZOLAM ON PROPOFOL-INDUCED ANESTHESIA - PROPOFOL DOSE REQUIREMENTS, MOOD PROFILES, AND PERIOPERATIVE DREAMS

This study examined the effects of midazolam on the doses of propofol required for the induction of hypnosis and the maintenance of propofol /nitrous oxide anesthesia. In addition, the effects of midazolam on th e time to patient recovery, perioperative mood profiles, incidence of perioperative dreams, patient satisfaction scores, and requirement for postoperative analgesics were assessed. This investigation was a pros pective, randomized, and double-blind study of female patients undergo ing dilatation and curettage. Patients received midazolam (30 mu g/kg, n = 30) or an equal volume of placebo (n = 30) immediately before the induction of anesthesia. Recall of dreams was assessed immediately po stoperatively, in the postanesthesia care unit (PACU), and on the day after surgery using a questionnaire designed for surgical patients. Mo od profiles were quantified using the Multiple Affect Adjective Check List-Revised, which was completed preoperatively and 1 h postoperative ly. The Client Satisfaction Questionnaire-8, an eight-item self-admini stered version of the Client Satisfaction Questionnaire, was used to a ssess patient satisfaction on the day after surgery. Our results indic ate that although the time to the loss of the lid reflex was significa ntly shorter in patients receiving midazolam (43.8 +/- 2.7 vs 74.7 +/- 7.6 s, P < 0.0003), there was no significant difference in the dose o f propofol required to induce hypnosis or maintain anesthesia. There w ere no group differences in postoperative sedation and orientation sco res, perioperative mood profiles, incidence of dreams, and patient sat isfaction scores. More patients who received midazolam requested analg esics in the PACU (11 vs 4, P < 0.05). In conclusion, midazolam did no t reduce the anesthetic dose requirement of propofol in patients under going anesthesia with nitrous oxide, nor did it accelerate patient rec overy. Our results call into question the benefit of coinducing anesth esia with propofol and midazolam. Implications: Midazolam, administere d immediately before anesthetic induction with propofol, did not decre ase the dose of propofol necessary for hypnosis, nor the maintenance o f surgical anesthesia, in female patients undergoing diagnostic dilata tion and curettage. In addition, midazolam did not alter patient recov ery characteristics, postoperative mood, incidence of perioperative dr eams, or patient satisfaction. The use of midazolam was associated wit h an increased need for postoperative analgesics. Our study calls into question the benefit of administering midazolam immediately before an aesthetic induction with propofol.