Influence of midazolam on induction dose of propofol

Patients & Methods: Fifty ASA Class 1 and 2 adult patients posted for elective surgery were randomly allocated to control and study groups with 25 patients in each groups. The control groups received 10ml of saline while the study group received 0.04mg kg^-1 of midazolam diluted to 10ml of saline over one minute. Three minutes later in both the groups, general anaesthesia was induced with propofol 10mg boluses every 15 seconds till endpoint is achieved. The endpoint was defined as first lack of response to command i.e the patient is unable to lift the hand when asked to do so. The dose at which end is achieved is noted. The results were analysed by chi-square test. Results: The dose of propofol required for induction in control group was 2.23mg Kg^-1 compared to study group which required 1.3mg kg ^-1. Thus a 42% reduction in induction dose is seen (p value 0.001 which is very significant). Fall in heart rate was less significant (p value 0.046) in study group when compared to control group (p value 0.001). Conclusion: Midazolam when used for co-induction helps in reduction of induction dose of propofol by almost 42% and helps maintain better hemodynamic stability, proving the synergy between the two drugs.