A prospective, randomized, double-blind, comparative study of phenylephrine and ephedrine in treating hypotension during cesarean section under spinal anesthesia: Vasoconstrictors for Hypotension During CS

Introduction: Hypotension may affect 70-75% of patients undergoing cesarean section (CS) under spinal anesthesia (SA) and may have detrimental effects on both the mother and the fetus. Our study attempts to compare the effectiveness of phenylephrine and ephedrine in treating SA-induced hypotension in CS and their impact on the fetus. Methods: Forty adult pregnant female patients undergoing elective CS under SA were randomly divided into two groups to receive phenylephrine 100 µg IV bolus and ephedrine 6 mg IV bolus when the systolic blood pressure (SBP) dropped below 20% of the baseline. After delivery of the fetus, the umbilical artery blood sample was taken for blood gas analysis. Apgar score was recorded at 1 and 5 minutes post-delivery. Results: Significant differences were observed in heart rate (HR), SBP, and diastolic blood pressure (DBP), with HR being lower and SBP and DBP being higher in the Phenylephrine group. No significant difference was seen in the Apgar scoring, but uterine artery pH was significantly higher in the Phenylephrine group. Conclusion: Phenylephrine and ephedrine are equally effective in treating SA-induced hypotension in patients undergoing CS. Neonates of patients receiving phenylephrine had significantly higher pH than those receiving ephedrine, although the eventual neonatal outcome, as assessed by Apgar scoring, remained equally good with both drugs.