Neonatal effects after vasopressor during spinal anesthesia for cesarean section: a multicenter, randomized controlled trial

Background: Placental transfer of ephedrine causes fetal effects when compared with phenylephrine. This study compared their drug effects on neonatal parameters after cesarean delivery under spinal anesthesia. Methods: Three-hundred-and-fifty-four women undergoing elective cesarean delivery who needed intravenous vasopressor following spinal anesthesia were randomized into two groups. Group E received boluses of ephedrine 6 mg, and Group P phenylephrine 100 mu g, titrated to maintain systolic blood pressure near baseline values. Neonatal heart rates at 10 and 30-45 min of age, oxygen saturation and capillary blood glucose at 30 min, and capillary blood lactate and urine metamphetamine were recorded. Results: Neonatal heart rate at 10 min was significantly higher (mean difference 4.0, 95%CI 0.6 to 7.3, P=0.02) in Group E versus Group P, but this was not clinically relevant. There was a linear correlation between neonatal heart rate at 10 min and ephedrine dose in Group E (r(2)=0.29, 95%CI 0.22, 0.74, p < 0.01). The decremental changes in neonatal heart rate at 10 and 30 min were significantly greater in Group E. Urine metamphetamine tests were positive in 19% of 44 neonatal urine samples. Neonatal heart rates at 30 min, oxygen saturation, capillary blood glucose and the incidence of tachycardia, respiratory problems or abnormal glucose, were not significantly different. Conclusions: Ephedrine, compared to phenylephrine as a vasopressor during cesarean delivery, was associated with higher neonatal heart rate in the early post-birth period, but without a significant difference in clinical outcomes in uncomplicated pregnancies. (C) 2017 Elsevier Ltd. All rights reserved.