PROPHYLACTIC PHENYLEPHRINE INFUSION VERSUS RESCUE BOLUSES: EFFECT ON THE PHYSICIAN INTERVENTION AND FLUID ADMINISTRATION

Phenylephrine Infusion Versus Rescue Boluses

Abstract

Objective: To compare the effect of prophylactic phenylephrine infusion on the fluid management and physician intervention as compared with rescue boluses of phenylephrine alone.
Study Design: Randomized controlled trial.
Place and Duration of Study: Anesthesiology department, Combined Military Hospital, Rawalpindi; from Feb to Jul 2016.
Material and Methods: A total of 70 patients were randomly divided into two groups, 35 in each. After a preload of 10ml/kg of ringer lactate; spinal anesthesia was given with 12 mg 0.75% hyperbaric bupivacaine. Group A given prophylactic phenylephrine infusion at the rate of 0.75ug/kg/minute for 5minutes after initiation of spinal anesthesia. Group B was given 50ug rescue bolus of phenylephrine when hypotension occurred.
Results: The two groups did not differ in their demographic profile and mean fluid pre-load. The mean preload was 691.4ml (±110.1) in group A versus 721.4ml (±89.3) in group B, p-value 0.215. The total fluid administered in group A was lower than group B, 1634.2ml (±232.5) versus 1777.1 ml (±328.1); p-value 0.039. An average of 0.23 (±0.49) number of physician interventions were done in hypotensive patients in group A versus 1.26 (±1.29) in group B; p-value 0.06, which is statistically insignificant. The groupA received a much higher dose of phenylephrine, mean dose 287.2ug ± 48.8 versus 64.2ug ± 64.8; p value<0.001. The mean rescue phenylephrine bolus dose in group A was 15.7ug (±31.5) in group A versus 64.2 ± 64.8ug, p-value<0.001; which is statistically insignificant.
Conclusion: Prophylactic phenylephrine infusion with crystalloid preload was found associated with reduced number of rescue boluses and rescue phenylephrine dose and lesser total intraoperative fluid administration, when compared to preload with rescue boluses.