Effect of Bispectral Index versus End Tidal Anaesthetic Gas Concentration on Time to Tracheal Extubation for Isoflurane Based General Anaesthesia-A Prospective Observational Study.

Introduction: Modalities like Bispectral Index Monitoring (BIS) and End Tidal Anaesthetic Gas (ETAG) concentration guided anaesthesia have been used to study the intraoperative awareness but their efficacy for achieving early tracheal extubation has not been established. Aim: To compare the effect of BIS monitoring and ETAG concentration guided anaesthesia on time to tracheal extubation and haemodynamics for isoflurane based general anaesthesia. Materials and Methods: This prospective observational cohort study was conducted in the Department of Anaesthesiology at Mahatma Gandhi Memorial Government Medical College and MY Hospital, Indore, Madhya Pradesh, India, from June 2020 to June 2021. Total 60 patients with American Society of Anesthesiologists (ASA) status I and II who received isoflurane based general anaesthesia were included in study. Depending upon the modality being used by the anaesthesiologist to monitor and maintain the depth of anaesthesia, the patients were allocated in equal numbers into two group. Group B received BIS guided anaesthesia, where BIS value was kept between 40 and 60 and group E received ETAG concentration guided anaesthesia, where Minimum Alveolar Concentration (MAC) was kept between 0.7 to 1.3. Tracheal extubation time was recorded from stopping all anaesthetic agents upto the time of extubation. Unpaired t-test was applied for analysis of data. Results: The mean tracheal extubation time was significantly longer in the BIS group (21.14±2.23 minutes) as compared to ETAG group (15.20±1.27 minutes). All hemodynamic parameters i.e., pulse rate, mean arterial pressure and saturation remained within normal limits and were comparable between the two groups at all the time intervals. Conclusion: The tracheal extubation time is significantly longer in BIS guided anaesthesia as compared to ETAG guided anaesthesia. The ETAG monitoring promotes earlier extubation of patients as compared to BIS monitoring in isoflurane based general anaesthesia. [ABSTRACT FROM AUTHOR]