Comparison of the Effects of Norepinephrine and Phenylephrine Infusion in Preventing Hypotension during Spinal Anesthesia for Cesarean Delivery: A Randomized, Double-Blind Clinical Trial.

BACKGROUND

Hypotension following spinal anesthesia is one of the most common complications of cesarean delivery, posing significant risks to both maternal and fetal health. The use of vasopressors is a primary method for the prevention and management of hypotension.

Objective

This study aimed to compare the efficacy of norepinephrine and phenylephrine infusion in preventing hypotension in patients undergoing cesarean section under spinal anesthesia.

METHODS

In this randomized, double-blind clinical trial, 90 pregnant women at 37 weeks of gestation scheduled for elective cesarean delivery were randomly assigned to receive either norepinephrine (n=47) or phenylephrine (n=43). The initial infusion rate was set at 5 µg/min for norepinephrine (up to a maximum of 60 mL/min) and 0.5 mg/min for phenylephrine (up to a maximum of 60 mL/min). Hemodynamic parameters, including systolic blood pressure (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate, were assessed. Additionally, umbilical cord blood gas values (PACO2 and pH) at the time of birth were measured. Statistical analysis was performed using SPSS version 18 with descriptive statistics and independent t-tests or Mann-Whitney U tests (P≤0.05).

RESULTS

The findings revealed no statistically significant differences between the norepinephrine and phenylephrine groups regarding SBP and DBP, MAP, heart rate, and umbilical cord blood gas values (PACO2 and pH) at delivery (P≥0.05).

CONCLUSION

Norepinephrine and phenylephrine appear to have similar efficacy in preventing hypotension during cesarean delivery. Clinicians may select either drug based on the patient's clinical conditions and preferences.