Abstract No. : ABS1022: Effect of use of Entropy Monitoring on Consumption of Sevoflurane Inhalational Agent in patients undergoing off-Pump Coronary Artery Bypass Graft Surgery

Abstract

Background & Aims:Assessing depth of anaesthesia using entropy is resourceful as it allows for accurate hypnotic drug administration and decreased anaesthetic drug consumption. This study was performed to evaluate the effect of entropy monitoring on sevoflurane consumption in patients undergoing off-pump coronary artery bypass graft (OPCABG) Surgery.Methods:60 patients of American Society of Anesthesthesiologists grade II and III between 40-70 years of age, of either sex planned for OPCABG surgery were randomly allocated to two groups. In the control group B, sevoflurane was titrated according to changes in clinical parameters and in the study group A, sevoflurane was titrated to maintain state entropy values between 40-60 accordingly. Response entropy and state entropy values were continuously recorded in both the groups but were displayed on the monitor only in the study group. The entropy values, sevoflurane consumption andrecovery times were compared.Results:Sevoflurane consumption and recovery time were significantly reduced in the study group A than the control group B (p-value <0.001); Sevoflurane consumption was 7.03±0.67 ml/h vs 12.42±0.68 ml/h; recovery time 6.47±0.65 h vs 12.05±1.11 h). Response and state entropy values were lower in the control group than the study group (p < 0.001). Systolic blood pressure during skin incision, sternotomy and at the time of completion of all grafts were significantly lower in study group.Conclusion:Monitoring the depth of anaesthesia using entropy monitoring leads to significant reduction in sevoflurane consumption. Significantly faster recovery rate from surgery could be associated with more accurate hypnotic and analgesic drug administration.