Is the bispectral index useful in predicting fast-track eligibility after ambulatory anesthesia with propofol and desflurane?

Abstract

This study was designed to test the hypothesis that outpatients with higher electroencephalographic (EEG) Bispectral Index (BIS) values at the end of anesthesia achieve a modified Aldrete score of 10 and satisfy fast-track eligibility criteria more rapidly after ambulatory surgery. Sixty consenting women undergoing laparoscopic tubal ligation procedures were studied. After premedication with midazolam 2 mg IV, anesthesia was induced with propofol 2 mg/kg IV, fentanyl 1.5 microg/kg IV, and succinylcholine 1 mg/kg IV and was initially maintained with either desflurane 4% (n = 31) or a propofol infusion 100 microg kg(-1) min(-1) (n = 29), in combination with nitrous oxide 65% in oxygen. Subsequently, the inspired desflurane concentrations (2%-6%) and propofol infusion rates (50-150 microg.kg(-1) min(-1) were varied to maintain a clinically acceptable depth of anesthesia. The average BIS value during the 3-min interval immediately before the discontinuation of the maintenance anesthetics was recorded. Emergence times and modified Aldrete scores were assessed from the end of anesthesia until patients were considered fast-track-eligible. The BIS values at the end of anesthesia were significantly correlated with the time to reach fast-track eligibility in both the desflurane (r = -0.68) and propofol (r = -0.76) groups. We concluded that the EEG-BIS value at the end of anesthesia is useful in predicting fast-track eligibility after laparoscopic tubal ligation procedures with either a desflurane- or propofol-based anesthetic technique. In outpatients receiving either desflurane and propofol anesthesia for laparoscopic tubal ligation surgery, the times to achieve criteria for bypassing the recovery room (i.e., fast-tracking) correlated with the electroencephalographic-Bispectral Index values at the end of anesthesia.