Target-Controlled Infusion of Alfentanil and Propofol for Total Abdominal Hysterectomy

Abstract

Background: Alfentanil has been shown to act synergistically if combined with propofol, with or without nitrous oxide, or if combined with potent inhalation anesthetics. The goal of this study was to determine the dosing rate and target plasma concentration of propofol to supplement nitrous oxide in the presence of varying concentrations of alfentanil and to determine the optimal combination of propofol and alfentanil. Methods: Sixty patients undergoing a total abdominal hysterectomy (TAH) were anesthetized with nitrous oxide, and given a target-controlled infusion (TCI) of alfentanil [target plasma concentrations of 0 (A0 group), 50 ng/ml (A50 group), and 100 ng/ml (A100 group)], and propofol at rates varied up and down depending on the bispectal index (BIS). The mean target concentration (Tc) and infusion rate of propofol according to changes of concentrations of alfentanil were determined. Recovery time (from infusion stop to eye opening) and side effects were compared. Results: Induction time and recovery time were shortened in the A50 group and A100 group compared with the A0 group (P 0.05). The infusion rate and mean target concentration of propofol were significantly lower in the A100 group (7.5 mg/kg/h, 3.4g/ml) than the A0 (12.6 mg/kg/h, 4.5g/ml) and A50 (10.2 mg/kg/h, 4.0g/ml) groups (P 0.01). Side effects did not differ among the three groups. Conclusions: The optimal blood propofol and plasma alfentanil concentration, with respect to satisfactory intraoperative anesthetic conditions and speed of recovery, are 4.0g/ml and 50 ng/ml or 3.4g/ ml and 100 ng/ml in TAH patients.