Comparison of Maternal and fetal effects of Ephedrine, Mephentermine and Phenylephrine for treatment of hypotension during spinal anaesthesia for Caesarean delivery

The objective was Ephedrine, Mephentermine, and Phenylephrine was compared in the treatment of maternal hypotension following spinal anesthesia for elective cesarean delivery. The Design was Randomized, double-blind trial and Setting in Obstetric suite at a university-affiliated hospital. The Patients were sixty healthy patients electively scheduled for cesarean delivery under spinal anesthesia. The Interventions in Patients were randomly assigned to receive either Ephedrine (n = 20) in 6 mg intravenous (IV) bolus injections, or Mephentermine (n=20) in 6 mg intravenous (IV) bolus injections, or Phenylephrine (n = 20) in 100 μg IV bolus injections to maintain systolic blood pressure (SBP) above 90 mmHg. In Results were Maternal arterial blood pressure, heart rate, Umbilical artery blood pH were measured, and neonatal Apgar scores were assessed. In the Ephedrine group, umbilical artery pH was 7.4±0.2 (mean±SD). In the Mephentermine group, umbilical artery pH was 7.3±0.1. In the Phenylephrine group, umbilical artery pH was 7.4 ± 0.1.There were significant differences between the groups in mean umbilical artery pH, although all values obtained were within normal limits. There were no significant differences between the groups in the maternal parameters or the neonatal Apgar scores. In Conclusions Mephentermine is as effective as Phenylephrine and ephedrine in the treatment of maternal hypotension, and when used in small incremental bolus injections, it appears to have no adverse neonatal effects in healthy parturients.