[The dosage of sedative was reduced by patient-controlled sedation during epidural anesthesia].

The dosage of sedatives required for sedation was studied in patients who underwent total abdominal histerectomy under epidural anesthesia using patient-controlled sedation (PCS) and in those with anesthesiologist-controlled sedation (ACS). Patients in experimental groups received 1.0 or 1.5 mg bolus dose of midazolam by their request until desirable sedation was obtained using a computer-controlled device. In control group, anesthesiologists gave 1.5 mg bolus dose of midazolam and repeated until enough sedation was obtained. The total amount of midazolam was 12.15 +/- 3.90 mg (mean +/- SD) in ACS group and showed significant differences from experimental groups (PCS-1.0 group: 7.43 +/- 1.81 mg, PCS-1.5 group: 6.30 +/- 2.81 mg). The level of sedation showed wider variation in PCS groups than in ACS groups. The results suggest that PCS is a technique which allows reduction of sedatives in patients who undergo operation under local anesthesia.