The effects on Apgar scores and neonatal outcomes of switching from a combination of phenylephrine and ephedrine to phenylephrine alone as a prophylactic vasopressor during spinal anesthesia for cesarean section

Abstract

BackgroundEphedrine, unlike phenylephrine, has a dose-related propensity to depress fetal pH during spinal anesthesia during cesarean section. A low arterial umbilical cord pH has a strong association with neonatal mortality and morbidity. The purpose of this retrospective study was to investigate influences of vasopressor change on Apgar scores and adverse neonatal outcomes in cesarean section.MethodsIn obstetric anesthesia, we changed the prophylactic vasopressor from a combination of phenylephrine and ephedrine to phenylephrine alone in 2000. We evaluated the impact of vasopressor change on Apgar scores (1 and 5 min), incidence of Apgar score < 7 (1 and 5 min), neonatal seizure, continuous positive airway pressure (CPAP), intermittent positive pressure ventilation (IPPV), intraventricular hemorrhage (IVH), periventricular leucomalacia (PVL), and hypoxic ischemic encephalopathy (HIE) in low-risk elective cesarean sections during a period when the combination of phenylephrine and ephedrine was used (2008-2009, two years) and the period of phenylephrine use alone (2011-2012, two years).ResultsThere were no differences in Apgar scores (1 and 5 min), the incidence of 5 min Apgar score < 7, neonatal seizure, CPAP, IPPV, IVH, PVL, and HIE between the two time periods. However, the incidence of 1 min Apgar < 7 was decreased during the period of phenylephrine use compared with the period of phenylephrine and ephedrine use (P = 0.002).ConclusionsConversion from a combination of phenylephrine and ephedrine to phenylephrine alone as a prophylactic anti-hypotensive drug during spinal anesthesia for cesarean section in low-risk pregnancy may be associated with a significant decrease in the incidence of 1 min Apgar < 7.

Comparing epidural surgical anesthesia and spinal anesthesia following epidural labor analgesia for intrapartum cesarean section: a prospective randomized controlled trial

“…Hypotension that occurred despite phenylephrine infusion was treated with a bolus of 100 µg phenylephrine if the patient's HR was ≥ 60 bpm. In contrast, if the HR was < 60 bpm, then a bolus of 10 mg ephedrine was administered [ 11 ].…”

A Prospective Single-Center Brazilian Study Investigating the Efficacy and Safety of Prophylactic Phenylephrine Infusion for the Management of Hypotension During Cesarean Section Under Spinal Anesthesia

“…In the present study, four neonates (2.8%) had Apgar scores of <7 at the first minute, and no neonates had Apgar scores of <7 at the fifth minute. Jeon et al [29], who included more than 3700 patients in their study, showed a significant increase in the incidence of neonates with Apgar scores <7 at the first minute in parturients who received ephedrine plus phenylephrine infusion but not with phenylephrine infusion alone.…”

Consensus on the Southeast Asian management of hypotension using vasopressors and adjunct modalities during cesarean section under spinal anesthesia

“…Cardiac output studies have shown that SA has a biphasic effect, in which cardiac output initially increases following a reduction in afterload from arterial vasodilatation and subsequently decreases due to a reduced preload [2]. Hypotension affects both the mother and fetus, including maternal nausea, vomiting, dizziness, rare loss of consciousness, cardiac arrest, and death [27]; and fetal symptoms, including low Apgar scores and low umbilical arterial pH (umbilical acidosis), have been shown to be associated with the duration and severity of hypotension [28]. Hypotension may be related to maternal and neonatal morbidity.…”