Comparison between Bispectral Index-guided Propofol Induction and Clinically-guided Induction in Adult Hypertensive Patients Undergoing Elective Laparoscopic Surgery: A Randomised Controlled Study

Abstract

Introduction: Traditional clinical endpoints for propofol induction often led to unintentional overdose, leading to haemodynamic instability, delayed recovery, and other complications. Bispectral Index monitoring could potentially prevent undesired haemodynamic changes like hypotension. Aim: To compare BIS-guided propofol induction with clinically guided propofol induction. Materials and Methods: A randomised controlled study was conducted in the Department of Anaesthesiology at Apollo Hospitals, Guwahati, Assam, India, between December 7, 2020 and December 6, 2021, on adult hypertensive patients undergoing elective laparoscopic surgeries. The Clinical Group (n=30) received propofol induction based on clinical guidance, and the Bispectral index group (n=30) underwent Bispectral Index (BIS) guided induction. Demographic variables, the dose of drug required for BIS 50, and the total amount of drug consumed were recorded. After the administration of each dose, Systolic BP (SBP), Diastolic BP (DBP), Mean Arterial BP (MAP), Heart Rate (HR), and SpO2 were recorded. Frequencies and percentages were used to describe qualitative data, whereas the mean and standard deviation were used to express quantitative data. Parametric tests included unpaired t-tests for comparison between groups. A p-value of <0.05 was considered statistically significant. Results: Total 60 patients with 30 in each group, were studied. There was a steady fall in SBP, DBP, and MAP with successive incremental doses of 0.5 mg in both groups. Mean SBP was comparable between the two groups at dosages of 1 mg/ kg, 1.5 mg/kg, and 2 mg/kg. At 2.5 mg/kg, the clinical group had a significantly lower SBP (p=0.0001). Mean DBP was comparable in both groups at doses of 2 mg/kg and 2.5 mg/ kg but significantly lower in the BIS group at 1 mg/kg and at 1.5 mg/kg (p=0.003, p=0.01). Mean MAP was comparable at doses of 2 and 2.5 mg/kg but significantly lower in the BIS group at doses of 1 mg/kg and 1.5 mg/kg (p=0.007, p=0.02). Mean HR was comparable between the two groups at doses of 1 and 1.5 mg/kg. HR showed an increase in group CL and a gradual drop in group BIS with incremental doses. Mean HR was significantly lower in the group BIS at doses of 2 mg/kg and 2.5 mg/kg (p=0.001, p=0.001). The BIS group required a substantially lower total dose of propofol compared to the CL group (158.63±30.57 mg vs. 118.23±28.53 mg, p=0.0001). Conclusion: BIS-guided propofol induction leads to more stable haemodynamics during induction. It helps to titrate propofol administration, which, in turn, reduces the frequency of propofol overdose and its subsequent adverse effects on haemodynamic stability. The total dose of propofol consumed is also reduced.