Efficacy and safety of priming principle in propofol induction

Introduction: Reduction in induction dose of Propofol may help in reducing adverse hemodynamic events and anaesthetic cost. In this study the ‘priming principle’ was used during induction with Propofol and dose requirements and hemodynamic changes were assessed. Methods: Eighty ASA I and II patients of both gender, aged between 18 to 55 years planned for elective surgical procedure under general anaesthesia were randomly allocated into equal numbers as two groups: Group P (Priming), Group NP (Non-priming). The calculated propofol dose was 2 mg/Kg. Inj Fentanyl 1 µg/Kg was given to all patients. Standard ASA monitoring and BIS were used. Group P received 20% of the calculated Propofol dose and after 2 minutes the remaining drug was given. In group NP bolus Propofol was given. In both groups propofol was administered at the rate of 30 mg in 10 seconds till loss of verbal response. Inj Suxamethonium 2 mg/Kg was used for intubation. Total dose of propofol, BIS values after propofol administration, hemodynamic parameters including heart rate, blood pressure were recorded before and after induction, 1 minute and 5 minutes after intubation. Results: Both groups were comparable in demographics and baseline hemodynamic parameters. The total dose of propofol was significantly less (39.8%) in Group P than Group NP (67.0 ± 17.9 mg; 111.3 ±17.6 mg; p<0.01). The BIS values at end point were comparable. In group NP heart rate was significantly high and blood pressure values were low in all time points after induction. Discussion: The priming principle significantly reduced induction dose of Propofol with less incidence of hypotension. This principle can be useful where minimal hemodynamic fluctuations during induction is warranted.