[Comparison of midazolam and hydroxyzine as premedicants for combination of spinal and epidural anesthesia with midazolam sedation].

Midazolam 4 mg i.m. (Group M, n = 15) was compared with hydroxyzine 50 mg i.m. (Group H, n = 13) in a randomized double-blind study, as premedicants for patients undergoing simple total hysterectomy under combination of spinal and epidural anesthesia with midazolam sedation. Reduction of anxiety and amnesic effects about procedure under regional anesthesia with sufficient patient co-operation were greater following midazolam. The doses for intraoperative sedation of midazolam and pentazocine were the same in both groups. Mean doses of midazolam 2 mg and pentazocine 6 mg were required to induce sleep. Maintenance doses of midazolam and pentazocine were 3.7 and 11.4 mg.hr-1, respectively. No patient had recall of surgical procedure. Midazolam did not delay the postoperative resedation which lasted about 2 hours. The decrease in O2 saturation by pulse oxymetry is significant in Group M (4.5%) than Group H (2.7%). Nevertheless two patients in each group required oxygen 2 liter.min-1 via a nasal catheter. These results indicate that premedication by midazolam is more effective for procedures under regional anesthesia.