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DOI: http://dx.doi.org/10.21088/ijaa.2349.8471.51218.5

Abstract

  Background: MAC is most common method of titration of volatile anesthetics and BIS is used to measure the hypnotic effect of anesthetics. This study was undertaken to evaluate and compare the BIS value produced by different inhalational agents at their 1 MAC end tidal concentration. Method: 200 patients of ASA I ­ II of either sex between 20­50 years , for laparoscopic cholecystectomy were divided into 4 groups of 50 each and received either halothane, isoflurane, sevoflurane or desflurane. General anesthesia was administered using fentanyl, propofol, inhalational agents and vecuronium and maintained with 67% nitrous in oxygen. After achieving and maintaining 1 MAC for 15 min, BIS value were recorded for next 15 min at an interval of 1 min .Collected data was analyzed using ANOVA test. Results: At 1 MAC end tidal concentration mean BIS value for halothane was 57.0±3.51, for isoflurane 51.57±3.84, for sevoflurane value was 49.621± 3.82, and for desflurane BIS value 42.11±4.68, and difference among groups were statistically significant. Conclusion: At 1MAC, BIS values are agent specific and BIS value of halothane > isoflurane > sevoflurane > desflurane. 

Keywords : Bispectral Index; MAC; Halothane; Isoflurane; Sevoflurane; Desflurane.

Corresponding Author : Dr. Namita Arora, Associate Professor, Dept. of Anaesthesiology and Intensive Care, Post Graduate Institute of Medical Education and Research & Dr. Ram Manohar Lohia Hospital, New Delhi, Delhi 110001, India.