Comparison of hemodynamic effects of intravenous etomidate versus thiopentone during induction and intubation using entropy-guided hypnosis levels in coronary artery bypass surgery cases

Abstract

Background: Most of the induction agents cause hypotension. Accurate assessment of the depth of anesthesia using various monitors contributes to tailor drug administration, thus maintaining anesthetic depth and improving hemodynamic stability. Aim: The aim of this study is to compare the hemodynamic responses during induction and intubation between etomidate and thiopentone and to compare their doses, using entropy-guided hypnosis levels, in patients of coronary artery bypass surgery (CABG). Methodology: After ethics committee clearance, 60 patients for CABG were randomly allocated into the etomidate or thiopentone group, based on induction agents. Anesthesia was induced using intravenous etomidate or thiopentone titrated to state entropy (SE) level of 40–60. Heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressures, response entropy, and SE were recorded before, during, and after induction of anesthesia. Statistical analysis was done using descriptive and inferential statistics using Chi-square test, Students paired and unpaired t-test. Results: Stable hemodynamics was maintained with both etomidate and thiopentone. There was 33.3% and 34% less dose requirement in the etomidate and thiopentone groups, respectively. Minimal drug side effects and lesser complications were observed with equipotent doses, using entropy to guide equivalent hypnosis levels. Conclusion: The use of etomidate and thiopentone titrated to entropy leads to reduced etomidate and thiopentone dosage translating into increased hemodynamic stability during induction with adequate anesthetic depth.