Closing Target - controlled Infusion with Propofol for Conscious Sedation in Patients Undergoing Epidural Anesthesia

Objective: To investigate the feasibility of target - controlled infusion (TCI) by feedback from bispectral index (BIS ) with propofol for sedation in patients under epidural anesthesia and compare the effectiveness with TCI. Methods:60 ASAI - Ⅱ pa-dents undergoing operation in lower abdomen or on lower extremity under epidural anesthesia were randomly divided into two groups of thirty each: feedback TCI group and TCI group. In feedback TCI group , target concentration of propofol was set at 1.8μg/mL, BIS value of 75 was set as the control variable. In TCI group, the target concentration of propofol was set at 1 .8μg/mL throughout anesthesia. The highest and lowest BIS and OAA/S and MAP and HR during operation, the standardized unit dose of propofol, doses of adjunctive drugs, time for orientation, amnesia and satisfactory degree were recorded and compared between groups. Results: The highest and the lowest values of BIS and MAP during operation were significantly different between the two groups( P 0.05). Total dose of propofol was statistilly lower in the feedback TCI group than that in TCI group (P 0.01), same was the standardized unit dose of propofol ( P 0. 01). Amnesia and satisfactory degree during operation were not significantly different between the two groups. Conclusions:BIS used as a feedback control is useful in propofol anesthesia with TCI. The feedback TCI for conscious sedation in patients under epidural anesthesia has the advantages of less propofol, appropriate sedation, rapid orientation and more stable blood pressure.