Clinical comparison of prophylactic phenylephrine infusion vs. bolus regimens on maternal hemodynamics and neonatal outcomes during cesarean section

Abstract

Background and Objective: Phenylephrine bolus or infusion is used to maintain arterial blood pressure during the subarachnoid block (SAB) for cesarean section. The objective was to assess the clinical efficacy of prophylactic phenylephrine infusion or bolus doses for maternal hemodynamics maintenance and its effect on fetal outcomes. Materials and Methods: Sixty parturients were randomized to receive either a continuous prophylactic IV infusion of phenylephrine (n = 30, group A) at a dose of 0.50 μg.kg−1.min−1 or phenylephrine (n = 30, Group B) 50 μg bolus dose after the systolic blood pressure (SBP) fell by 20% from the baseline. The changes in hemodynamics, ill effects, neonatal APGAR scores, and fetal acidosis were recorded at different time intervals. Results: SBP was significantly higher over time in group A. Group A showed a significant fall in heart rate from baseline after giving SAB and remained significantly low throughout the intraoperative period (P 20% from the baseline; however, hypotension was observed in 21 patients in group B (P 20% of baseline value, were noted in 3 out of 30 patients in the Group A. There was also a statistically nonsignificant trend toward a less frequent incidence of nausea and vomiting in the group A (P < 0.29). There was no significant difference between the two groups in APGAR scores at 1 and 5 min after delivery (P < 0.56, 0.13). The incidence of neonatal acidosis was similar in the two groups. Conclusion: Prophylactic phenylephrine infusion is superior to therapeutic phenylephrine bolus dose for control of hemodynamics.

Keywords

• apgar
• cesarean section
• neonatal outcome
• phenylephrine
• subarachnoid block
• umbilical arterial blood