Bispectral index monitoring in sevoflurane and remifentanil anesthesia. Analysis of drugs management and immediate recovery

BACKGROUND: Recent studies have suggested that electroencephalogram bispectral index (BIS) monitoring can improve recovery after anaesthesia and save money by shortening patients postoperative stay. The aim of the study is to evaluate the management of drugs and to measure immediate recovery after anaesthesia with or without BIS monitoring. METHODS: We studied 90 patients undergoing abdominal surgery randomly allocated to one of two groups of 45 each with or without BIS monitoring. Standard monitoring (EKG, arterial oxygen saturation and non-invasive blood pressure) was applied. All groups were monitored with BIS, using electrodes (Zipprep, Aspect Medical Systems) applied to the forehead. In the group 2 the BIS value was blinded to the anaesthesiologist. The BIS value was displayed using Spacelabs Medical BIS Ultraview Monitor. After obtaining baseline values for the BIS index (group 1) and haemodynamic data (all groups) anaesthesia was induced with a bolus dose of remifentanil and TPS, and vecuronium. The anaesthesia was maintained with Remifentanil and Sevoflurane. At standard times BIS, haemodynamic and respiratory parameters were recorded. Recovery times were measured by a study coordinator. Drug consumption was calculated. RESULTS: In group 1 the consumption of Sevoflurane decreased by 40 % while the consumption of remifentanil decreased by 10 % as compared to group 2. The use of vecuronium did not change in the 2 groups. In group 1 the time elapsed from cessation of anaesthetics to orientation decreased significantly. The difference was 5 min, from 11 to 6 min. CONCLUSIONS: BIS monitoring decrease both sevoflurane and remifentanil consumption, when compared to anaesthesia without BIS, with an immediate recovery after sevoflurane and remifentanil anaesthesia.