A COMPARATIVE STUDY ON THE TOTAL DOSE REQUIREMENTS AND HEMODYNAMIC ALTERATIONS WITH AND WITHOUT THE APPLICATION OF PRIMING PRINCIPLE AMONG PATIENTS INDUCED WITH PROPOFOL

Abstract

Background:- Propofol given at standard induction dose, is known to produce haemodynamic instability, especially hypotension. Application of “priming principle” helps to reduce the total dose of propofol. Objectives:- To study the total dose requirements of propofol and peri-intubation haemodynamic stability in patients undergoing surgery under GACV when priming principle is applied. Methodology:- This was an observational study among 54 ASA I and II patients undergoing surgery under GACV, who were randomly divided into three groups of 18 patients each. All patients received fentanyl 1 mcg/kg over 30 seconds followed by propofol. Group 1 patients received the total (100%) calculated dose of propofol. Group 2 and 3 patients received 20% and 40% of the dose respectively as priming dose, and the remaining was given 30 seconds later, until there was loss of eyelash reex. The total dose of propofol given, the heart rate, systolic and diastolic blood pressures, mean arterial pressures at various time intervals before, during and after induction and intubation, and complications observed were compared and statistically analysed using SPSS 2.0. Results:- The mean induction dose of propofol was signicantly lower in the priming groups (71.7 ± 17.2mg in group 2 and 80.0 ± 17.1mg in group 3) compared to group1 (107.9 ± 8.0mg). The fall in mean arterial pressure was signicantly lower in groups 2 and 3 (p<0.05) compared to group1 at one minute post-induction. Conclusion:-Application of priming principle reduces the induction dose of propofol and is associated with better peri-intubation haemodynamic stability.