Use of priming principle in the induction dose requirement of propofol and its hemodynamic stability- A cross sectional study

Abstract

In anesthesia propofol induction is administered at a dose of 2mg/kg as a single bolus and when given at this dose the commonest problem faced by the anesthetist is the sudden drop in the blood pressure, as the hypotensive effect of propofol is proportional to the dose and rate of administration.To study the effect of auto co-induction (priming principle) in the requirement of induction dose of propofol and the resulting hemodynamic parameters. A prospective randomized double blinded study was conducted for a period of one year in the department of anesthesia at a government medical college hospital in TamilNadu. A total of 60 patients were selected for our study and were randomly allocated into two groups of 30 each. Group A is the study group (priming) and group B is the control group (non-priming group). In the priming group, three minutes after premedication the co induction agent was administered (25% of the calculated dose of propofol) and two minutes later the patient received propofol at a rate of 30mg/10 sec until loss of vocalization was achieved. The hemodynamic parameters along with the total dose requirement of propofol and BIS values were monitored at regular intervals after induction.The mean total dose of propofol required among the priming group patients was 78.2 mg compared to the total dose requirement in the non-priming group which was 92.5 mg and the mean difference was found to be statistically significant. A statistically significant fall in the heart rate and blood pressure was observed at 1 min and 3 mins after induction in non priming group compared to priming group. By applying priming principle the induction dose of propofol was reduced by 14.25% with a good hemodynamic stability.