Propofol anesthesia with target-controlled-infusion controlled by feedback from BIS

Objective Target-controlIed-infusion(TCI) system makes administration of intravenous anesthetics simpler, more accurate and adjustable. Bispectral index (BIS) is generally accepted as a measurement of depth of sedation and anesthesia. The aim of this study was to evaluate the usefulness of BIS as a feedback control in propofol anesthesia with TCI for patients undergoing laparoscopic cholecystectomy. Methods Forty ASA Ⅰ - Ⅱ patients (12 male, 28 female) aged between 20-70 yr were randomly allocated to one of two groups of twenty each: feedback TCI group and TCI group. In feedback TCI group, BIS value of 50 was set as the control variable. A bolus of 3 μg·kg-1 fentanyl was given Ⅳ 3 min before induction. The target concentration of propofol was set at 3 μg·ml-1 throughout anesthesia. Real time BIS, the highest and lowest systolic and diastolic pressure during operation, doses of adjunctive drugs, time for emergence and orientation, awareness during operation and the standardized unit dose of propofol were recorded and compared between groups. Results Total dose of propofol was statistically 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) . Better hemodynamic stability was achieved in feedback TCI group with less vasoconstrictors used during operation. Furthermore time for emergence after discontinuation of infusion was significantly shorter in feedback TCI group than that in TCI group, but there was no significantly difference in time for regaining orientation between the two groups. The highest and the lowest values of BIS during operation, the BIS values at emergence and at regaining orientation were not significantly different between the two groups. Fentanyl decreased BIS significantly in both groups. Conclusions BIS used as a feedback control is useful in propofol anesthesia with TCI. Propofol anesthesia with TCI controlledby feedback from BIS for laparoscopic cholecystectomy has the advantages of less propofol, rapid emergence, more stable blood pressure and more accurate adjustment of depth of anesthesia.