Phenylephrine
Alpha-1 adrenergic agonist vasopressor commonly used to treat maternal hypotension during neuraxial anesthesia in obstetrics.
Full Definition
Phenylephrine is a selective alpha-1 adrenergic receptor agonist that causes vasoconstriction and increases systemic vascular resistance. It is the preferred first-line vasopressor for treating maternal hypotension following spinal or epidural anesthesia during cesarean delivery. Unlike ephedrine, phenylephrine maintains placental blood flow and fetal acid-base status more effectively by avoiding beta-adrenergic stimulation. It can be administered as bolus doses or continuous infusion, with dosing adjusted based on maternal blood pressure response and fetal heart rate monitoring.
Usage
Usage note: Preferred over ephedrine in obstetrics due to better fetal outcomes; ensure distinction from epinephrine in emergency situations.
In Context
- "Prophylactic phenylephrine infusion was initiated to prevent spinal-induced hypotension." — Anesthetic management protocol
- "Bolus phenylephrine 100 mcg was administered for maternal hypotension with maintained fetal heart rate." — Intraoperative medication record