Comparative Study between Preloading with Fluids Vs Phenylephrine in the Management of the Hypotensive Effects of Propofol in Patients Undergoing Rapid Sequence Intubation

Introduction: The induction of general anaesthesia with propofol has been associated with a decrease in systolic arterial blood pressure. Various strategies have been attempted to prevent this hypotension with inconclusive evidence. Ketamine, ephedrine, atropine, glycopyrolate, dopamine, dobutamine etc have been administered in various studies to prevent this hypotension with various results.

Aims and Objective: Present study was undertaken to compare, the effect of preloading with crystalloid (Ringer lactate) and the effect of prophylactic administration of intravenous phenylephrine against the hypotensive effects of induction of anesthesia with propofol in rapid sequence intubation.

Material and Methods: After taking ethical committee clearance and written informed consent from every patients randomly selected 60 patients aged between 18-50 years, ASA grade I-II, Mallampati class I-II posted for elective surgical procedure requiring general anaesthesia were included in  the a prospective, randomized, single blind study study. Group R-Patients (30) who received Inj Propofol (2.5mg/kg) & 10-15 ml /kg Ringer lactate 10 minutes prior to induction of anaesthesia and  Group P –Patient who received inj propofol (2.5mg/kg) & inj phenylephrine 0.1 mg intravenously before induction of anaesthesia. Haemodynamic parameters (HR, SBP, DBP and MAP) were monitored & recorded in following specific time intervals: Before the starting of anaesthesia (baseline value), Just before intubation and  1, 2, 3, 4, 5, 10 minute after intubation.

Results: All the patients of two study groups were comparable with respect to sex, age, height, weight. No significant differences were observed between the groups (p value >0.05). During the entire process of intubation up to 10 minutes, heart rate was significantly lower in Group P compared to Group R. However the mean heart rate was within the physiological limit. In group P the systolic, diastolic, mean arterial pressure all significantly increased in the first two reading than reading taken just before in the intubation. Then the pressure gradually tends to normalise for upto 10 minutes.

Conclusion: Phenylephrine infusion in the dose of 100 microgram is effective in obtunding hypotension caused by propofol induction with minimal side effects and is a better option than crystalloid infusion.