Authors: Mohta M et al.
Anesthesia & Analgesia. 141(4):736–739, October 2025.
Summary
This randomized, double-blind trial compared prophylactic phenylephrine administered as titrated boluses versus variable-rate infusion for prevention of postspinal hypotension during elective cesarean delivery under spinal anesthesia. While international consensus guidelines recommend prophylactic phenylephrine infusion, infusion pumps may not be universally available, particularly in resource-limited settings. This study examined whether a carefully titrated bolus strategy could achieve comparable hemodynamic control.
One hundred ASA II parturients undergoing elective cesarean delivery were randomized to receive either prophylactic phenylephrine boluses or a prophylactic variable-rate infusion, initiated immediately after spinal anesthesia and continued until delivery. Both strategies were titrated to maintain systolic blood pressure near baseline. The primary outcome was total phenylephrine requirement, with secondary outcomes including hemodynamic stability, maternal side effects, and neonatal outcomes.
Total phenylephrine requirements did not differ significantly between the bolus and infusion groups. Hemodynamic trends, including systolic blood pressure and heart rate over the first 15 minutes after spinal anesthesia, were also comparable. The incidence of hypotension, hypertension, bradycardia, nausea, and atropine rescue did not differ significantly between groups. Neonatal outcomes, assessed by Apgar scores and umbilical cord blood gases, were similarly unaffected by the phenylephrine administration strategy.
The main operational difference was physician workload. Patients receiving bolus phenylephrine required significantly more physician interventions compared with those receiving infusions. Despite this, bolus administration achieved equivalent maternal and neonatal outcomes when titrated appropriately by experienced clinicians.
Key Points
Prophylactic phenylephrine boluses and variable-rate infusion provided comparable blood pressure control during elective cesarean delivery under spinal anesthesia.
Total phenylephrine requirements were similar between the two strategies.
Maternal hemodynamic stability and neonatal outcomes did not differ between groups.
Bolus administration required more frequent physician interventions than infusion.
Titrated bolus phenylephrine is a viable alternative when infusion pumps are unavailable.
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