Ten minutes after spinal anaesthesia for elective Caesarean section with hyperbaric bupivacaine, a parturient develops hypotension to 85/50 mmHg with a heart rate of 96 bpm. According to current obstetric anaesthesia practice, which vasopressor is the preferred first-line agent?

• A Ephedrine bolus
• B Adrenaline bolus
• C Phenylephrine infusion or bolus ✓
• D Noradrenaline bolus

Explanation

Alpha agonists such as phenylephrine are now first-line for spinal hypotension in Caesarean section because they restore maternal blood pressure with less fetal acidosis. Ephedrine crosses the placenta readily, stimulates fetal beta receptors, increases fetal metabolic oxygen demand, and is associated with greater umbilical arterial pH depression when used in large cumulative doses. Adrenaline is reserved for refractory collapse, and noradrenaline is an emerging alternative, not standard first-line.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.