Background: Early recovery is a major goal after anaesthesia and various techniques have been used to monitor adequate depth of anaesthesia while ensuring rapid recovery. Our study attempts to compare bispectral index (BIS) with end tidal anaesthetic gas concentration (ETAG) guided protocols for anaesthesia depth for recovery after desflurane anaesthesia.
Methods: Eighty American Society of Anaesthesiologists (ASA) I & II patients were randomly divided into 2 groups of 40 each. Group B (40 patients) were monitored intraoperatively using BIS guided technique and Group E (40 patients) using ETAG guided technique. After induction, maintenance of anaesthesia was done with oxygen/nitrous oxide (50:50) and desflurane mixture. In group B, desflurane was titrated to maintain a BIS value of 40-60 and the display of ETAG values were hidden. In group E desflurane was titrated to MAC value of 0.7-1.2 and BIS values on the monitor were hidden. Time from discontinuation of desflurane till time to eye opening, response to verbal commands and tracheal extubation were recorded and hemodynamic variations in both groups were also noted. Results: Time to eye opening in BIS vs ETAG group was 7.44±1.52; 6.53±2.47(mins), Time to response to verbal commands (10.16 ± 2.02; 8.58 ± 3.27(mins) and time to tracheal extubation (11.43±2.15; 10.47±3.54(mins)) was comparable between both the groups. Conclusion: BIS and ETAG guided protocols are comparable for early recovery after desflurane anaesthesia and hemodynamic variations associated with both are similar.