Comparison of Phenylephrine and Ephedrine in Treatment of Spinal Induced Hypotension in Emergency Cesarean Section

Open Access

Abstract

Background: Spinal-induced hypotension is a common complication during emergency cesarean section, affecting up to 70% of parturients and potentially impacting maternal and fetal outcomes. Phenylephrine and ephedrine are widely used vasopressors to manage hypotension, yet their comparative efficacy and safety remain under investigation. Objective: This study aimed to compare the efficacy and safety of phenylephrine versus ephedrine in managing spinal-induced hypotension during emergency cesarean sections. Methods & Materials: This observational comparative study was conducted at the Department of Anaesthesia and ICU, Kurmitula General Hospital (KGH), Dhaka, Bangladesh, from January-2025 to June 2025. A total of 60 patients aged 18–40 years who underwent emergency cesarean section under spinal anesthesia were enrolled in this study and the enrolled patients were divided equally into two groups with 30 patients in each. Group-1 received intravenous phenylephrine (initial dose 100 mcg, titrated as needed), and Group-2 received intravenous ephedrine (initial dose 5 mg, titrated as needed). Maternal hemodynamics, neonatal Apgar scores, and adverse effects were recorded. Hypotension was defined as systolic blood pressure (SBP) <90 mmHg or ≥20% decrease from baseline. Data were analyzed using Statistical Package for Social Sciences (SPSS) version-23.0. Results: A total of 60 parturients undergoing emergency cesarean section under spinal anesthesia were included, with 30 patients in each group. The mean age was 27.8 ± 4.2 years in the phenylephrine group and 28.1 ± 4.6 years in the ephedrine group (p=0.78). Mean height (155.6 ± 5.4 vs. 156.3 ± 5.1 cm; p=0.62) and weight (63.8 ± 7.5 vs. 64.9 ± 7.1 kg; p=0.54) were similar. ASA physical status was comparable, with ASA I comprising 12 (40%) vs. 11 (36.7%) and ASA II 18 (60%) vs. 19 (63.3%) in the phenylephrine and ephedrine groups, respectively. Indications for cesarean delivery were evenly distributed between the groups: failure to progress in 9 (30%) vs. 10 (33.3%), cephalopelvic disproportion in 8 (26.7%) vs. 7 (23.3%), previous cesarean in 7 (23.3%) vs. 6 (20%), and other indications in 6 (20%) vs. 7 (23.3%) in the phenylephrine and ephedrine groups, respectively.. Phenylephrine provided significantly higher systolic blood pressure at all measured time points (5 min: 112.4 ± 8.6 vs. 105.2 ± 9.3 mmHg); (p=0.003) and lower maternal heart rates (10 min: 82.7 ± 7.6 vs. 94.3 ± 9.1 bpm;( p<0.001) compared with ephedrine. Neonatal outcomes, including one- and five-minute Apgar scores, were similar between the groups (p>0.05). Adverse effects were infrequent; bradycardia occurred more often in the phenylephrine group (16.7% vs. 3.3%, (p=0.09), while nausea and vomiting were slightly more common in the ephedrine group without statistical significance (P>0.05). Conclusion: Phenylephrine provides superior systolic blood pressure stability and lower maternal heart rates compared with ephedrine during spinal-induced hypotension in emergency cesarean sections, with similar neonatal outcomes and overall safety. These findings support phenylephrine as the preferred vasopressor in obstetric anesthesia for managing spinal-induced hypotension.