Ephedrine and Phenylephrine Use during Cesarean Delivery: Which to choose?

A Review of the Impact of Phenylephrine Administration on Maternal Hemodynamics and Maternal and Neonatal Outcomes in Women Undergoing Cesarean Delivery

Ashraf S. Habib, MBBCh, MSc, MHS, FRCA

Anesth Analg 2011

Phenylephrine is effective for the management of spinal anesthesia-induced hypotension in parturients undergoing cesarean delivery under spinal anesthesia. While ephedrine was previously considered the vasopressor of choice in obstetric patients, phenylephrine is increasingly being used. This is largely due to studies suggesting improved fetal acid base status with the use of phenylephrine as well as the low incidence of hypotension and its related side effects with prophylactic phenylephrine regimens. This review highlights the effects of phenylephrine compared with ephedrine on many important aspects. Here is the conclusion.

Both ephedrine and phenylephrine are effective in managing spinal anesthesia-induced hypotension.

Phenylephrine may be associated with a lower incidence of IONV (Intraoperarive Nausea and Vomiting), and higher umbilical artery pH and base excess compared with ephedrine. However, the difference in pH is small and unlikely to be clinically relevant in low-risk deliveries.

Administration of phenylephrine as a prophylactic infusion is more effective in reducing the incidence of hypotension and IONV compared with bolus administration. However, phenylephrine use is associated with a decrease in maternal cardiac output. The clinical significance of this reduction in healthy low-risk parturients is unclear. Studies suggest that such changes do not appear to have any consequences in healthy mothers. The optimum phenylephrine administration regimen is unclear. Studies addressing the use of phenylephrine in high-risk pregnancies, such as those complicated by placental insufficiency, preeclampsia, and growth restriction, are needed.