Comparison of mean fall in systolic blood pressure in patients undergoing cesarean section under spinal anesthesia treated with norepinephrine bolus versus infusion.

Abstract

Objective: To compare systolic blood pressure fall, lightheadedness, bradycardia incidence and Apgar scores between norepinephrine bolus and prophylactic infusion treatments. Study Design: Cross-sectional Analytical study. Setting: Bahawal Victoria Hospital. Period: January to December 2025. Methods: Involving 68 eligible participants undergoing cesarean section under spinal anesthesia. Patients were allocated into Group A (therapeutic bolus, n=34) or Group B (prophylactic infusion, n=34). Intraoperative hemodynamic variables, maternal side effects, and neonatal Apgar scores at one and five minutes were strictly documented and analyzed using SPSS version 23.0. Results: Baseline demographics were comparable. The mean systolic blood pressure reduction observed immediately post-block was significantly greater in the bolus group (11.76±7.97 mmHg) versus infusion (9.35±4.55 mmHg; p=0.007). Bradycardia occurred significantly more frequently among patients in Group A (20.6%) compared to Group B (2.9%; p=0.027). Neonatal Apgar scores at one and five minutes were significantly higher in the infusion group (p<0.001) respectively. Conclusion: Prophylactic norepinephrine infusion ensures better hemodynamic stability with fewer bradycardia episodes and enhanced neonatal results compared to therapeutic bolus administration. Based on findings, continuous infusion should be the preferred protocol for optimizing overall maternal and clinical safety during obstetric spinal anesthesia.