Comparative Evaluation of Standard Propofol Induction with Propofol Priming and Midazolam-Propofol Co- Induction in Patients Undergoing General Anesthesia

Abstract

Background: Propofol has emerged as an induction agent of choice over the past two decades due to its quick, smooth induction and rapid recovery. The main concern for an anaesthesiologist is the hemodynamic instability caused by the standard induction dose of propofol (2–3 mg/kg).
Material & Methods: A prospective randomized, double blind control study was conducted where 120 patients (20-60 years) were divided into 3 groups. Group A received 0.4 mg/kg of propofol injection diluted with Normal Saline to make total amount to 5 ml (priming), Group B received 0.03 mg/kg midazolam injection diluted with Normal Saline to make a total amount of 5ml (co-induction) while as Group C received 5 ml of Normal Saline(control). We compared the total dose of propofol requirement for induction of anaesthesia in all the 3 groups, taking loss of verbal contact as the end point. Total dose and induction dose of propofol is different in all groups as 30 mg propofol is followed y 10 mg increments every 10 seconds till loss of verbal contact. and additionally, changes in haemodynamic status like blood pressure and heart rate at various intervals were studied and compared among the groups.
Results: The groups were similar in terms of age, sex, weight and American Society of Anaesthesiologists Physical Status. The dose of propofol required to induce anesthesia was1.77 mg/kg in propofol group, 1.46 mg/kg in midazolam group and 2.87 mg/kg in the control group. There were less hemodynamic changes in midazolam group compared to the other two.
Conclusion: Co-induction with midazolam is more effective than propofol priming and standard propofol induction in reducing the dose of propofol induced anaesthesia & associated with minimum hemodynamic alterations. From the present study we concluded that propofol priming and midazolam propofol co-induction significantly decreases the average induction dose of propofol with better hemodynamic stability and least adverse effects. However, the greater decrease in induction dose of propofol and better hemodynamics were seen with the midazolam- propofol co-induction.