Effect of Dexmedetomidine Premedication on Sevoflurane Requirement using BIS during General Anaesthesia in Laparoscopic Cholecystectomy

Abstract

Background: Dexmedetomidine is a highly selective α2-adrenoreceptor agonist with sedative, anxiolytic and analgesic properties without any respiratory depression. It decreases the requirement of volatile anaesthetics with better hemodynamic stability in surgical patients. We avoided the risk of awareness under anaesthesia by using Bispectral index. Aims: To evaluate the efficacy of Dexmedetomidine pre-medication on Sevoflurane requirement and to assess the haemodynamic stability during elective laparoscopic cholecystectomy surgeries. Methods: Randomized double-blind control study. Design: Forty eight patients were randomly allocated into two groups. Group A received saline infusion and Group 2 received Dexmedetomidine infusion in a dose of 1µg/kg over 15 min before induction. Vital parameters and bispectral index were noted throughout the surgery. Patients were induced and intubated as per the standard protocol and maintained with Oxygen & Nitrous oxide (1 litre Oxygen + 2 litre Nitrous oxide) with Sevoflurane concentration adjusted to achieve BIS values of 45–55. Demographic profile, hemodynamic parameters total Sevoflurane consumption were noted. Statistical Analysis: Statistical analysis was performed using SPSS software version 22.0. Percentage analysis was done for qualitative data. Parametric data were compared using an unpaired t-test. Nonparametric data were compared with Fisher’s exact test or Chi-square test. Results: Mean Sevoflurane consumption in Group A and Group B were 0.379 ± 0.10, 0.169 ± 0.05 ml/min respectively with P<0.001 which was statistically significant. A 55.4% reduction in Sevoflurane consumption was found in patients receiving Dexmedetomidine premedication. Conclusions: Dexmedetomidine premedication is useful to reducing Sevoflurane consumption during general anesthesia and it provides better haemodynamic stability.