ABSTRACT
Introduction: Priming refers to administration of asubanaesthetic dose (priming dose) of an agent prior to itsactual anaesthetic dose. The “priming principle” is a methodto reduce the total dose requirements of a drug. This studywas undertaken to study the effect of priming principle oninduction dose requirements of propofol.Material and Methods: Sixty (60) patients with AmericanSociety of Anaesthesiologists (ASA) I and ASA II grades,of both sexes, aged 18-55 years, and undergoing electivesurgical procedures under general anaesthesia were randomlyallocated into two equal groups with 30 patients each. GroupI (control) received calculated induction dose of injection(inj.) propofol 2mg/kg. Group II (study) received 20% of totalcalculated induction dose of propofol 2 mg/kg as a primingdose and remaining dose after 60 seconds titrated till loss ofthe eyelash reflex.Results: The control group consumed a higher dose of inj.propofol (2 mg/kg) as compared with the study group (1.34± 0.28 mg/kg), i.e., there was 33% reduction of the total dosein the study group. The hemodynamic changes in HR, SBP,DBP, MAP and RPP at 30 minutes before induction, justbefore induction, immediately after intubation and 5 minutesafter induction were similar in both groups (P > 0.05) .Thehemodynamic changes in HR, SBP, DBP, MAP and RPP atone minute after induction were statistically significant inboth the groups (P< 0.05). Incidence of pain and apnea wascomparable in both groups but hypotension was seen in 4patients in control group and none in study group.Conclusion: The priming technique effectively reduced thetotal induction dose requirements of propofol and favourablyreduced extent of hypotension following induction withpropofol.