Efficacity of Noradrenaline Boluses in Preventing Post-Spinal Hypotension during Elective Cesarean Sections: A Prospective Study

Background: Post-spinal hypotension is a common complication during scheduled cesarean sections, with potential adverse effects on both the mother and fetus. Norepinephrine, known for its vasopressor effects and minimal impact on heart rate, has been proposed as an alternative to ephedrine. However, there is limited data regarding the use of very low concentrations of norepinephrine in this context. Objective: To evaluate the effectiveness of diluted norepinephrine at 4 μg/ml in managing post-spinal hypotension during scheduled cesarean sections. Methods: A prospective, double-blind, randomized study was conducted from February 15, 2024, to July 30, 2024, involving 100 women undergoing cesarean section under spinal anesthesia. Participants were randomly assigned to receive either norepinephrine (Group N) or ephedrine (Group E) boluses. Blood pressure, heart rate, and neonatal Apgar scores were recorded. The primary outcome was the number of boluses required to restore normal blood pressure. Results: The norepinephrine group required significantly fewer boluses to restore blood pressure compared to the ephedrine group (2.1 ± 0.9 vs. 3.2 ± 1.1; p = 0.041). One bolus corrected hypotension more frequently in the norepinephrine group (80% vs. 60%; p = 0.038). The frequency of tachycardia was higher in the ephedrine group (p = 0.032). No significant difference in the Apgar score was observed between the two groups. Conclusion: The administration of diluted norepinephrine at 4 μg/ml in bolus is an effective alternative to ephedrine in managing post-spinal hypotension during cesarean sections. Norepinephrine provides faster blood pressure stabilization, requires fewer boluses, and has fewer adverse effects, particularly regarding tachycardia. Further multicenter studies with larger sample sizes and additional neonatal parameters are needed to confirm these findings.