Comparison of phenylephrine and ephedrine for treating hypotension after spinal anesthesia for cesarean section: A Randomized double-blind clinical trial

Background and objectives: Hypotension following spinal anesthesia (SA) for cesarean delivery can have important consequences for parturient and may affect neonatal outcome. The objective of this study was to compare intravenous bolus doses of phenylephrine and ephedrine to treat hypotension after SA for cesarean section and the effect of vasopressors on fetal outcome in terms of Apgar score. Methodology: Two hundred parturient fulfilling inclusion criteria were randomly allocated into two groups of hundred each. Lumbar puncture was done in sitting position and 10 mg, 0.5% hyperbaric bupivacaine was given intra-thecally to every patient. All patients were placed supine with 15 degree left lateral tilt position. If hypotension occurred after SA (systolic blood pressure less than 90 mm Hg or decrease in systolic blood pressure more than 20% of base line whichever is lower) was treated with either 100/ig phenylephrine in Group A or 6 mg ephedrine in Group B boluses given intravenously. Results: Single intravenous bolus dose of phenylephrine 100 jug was effective in treating hypotension in 92% parturient while ephedrine 6mg remained effective in 78% parturient, which was statistically significant (p= 0.0009). There was no difference in the mean Apgar scores (p = 0.76) at 1 minute and (p = 0.09) at 5 min between the two groups. Incidence of bradycardia (heart rate < 50 beats/mints.) was significantly higher in Group A as compared to Group B (p=0.038). Conclusion: Intravenous bolus dose of phenylephrine 100 μg and ephedrine 6mg were both effective in treating hypotension after SA for elective cesarean section. Mean Apgar scores of the neonates at 1 and 5 min were comparable between the two groups.