The Impact of Fentanyl and Morphine on Maternal Hemodynamics in Spinal Anesthesia for Cesarean Section

Background: Spinal anesthesia is considered the method of choice for elective cesarean sections; however, it is not without maternal-fetal risks. Materials and Methods: This study compared the effects on maternal hemodynamics of intrathecal administration of fentanyl or morphine in parturients undergoing spinal anesthesia with 0.5% hyperbaric bupivacaine, with doses varied between 7.5 and 11 mg, depending on the patient's height. Data from a cohort of 170 parturients were analyzed. The administered doses were intrathecal morphine at 0.1 mL (100 µg, solution of 1 mg/mL) or fentanyl at 0.25 mL (25 µg, solution of 50 µg/mL). This study included 80 patients in the fentanyl (F) group and 90 in the morphine (M) group. Results: Group F showed significantly higher post-intervention systolic blood pressure values than group M (95.30 ± 12.99 mmHg vs. 90.58 ± 14.75 mmHg, p = 0.032). The incidence of vomiting was significantly less frequent in group F compared to group M (1, 1.3% vs. 10, 11.1%, p = 0.011). The total dose of ephedrine required for hypotension correction was significantly lower in the F group (12.75 ± 13.26 mg vs. 17.72 ± 16.73 mg, p = 0.035). Conclusions: The addition of fentanyl as an adjuvant alongside the local anesthetic in cesarean section is associated with enhanced hemodynamic stability compared to morphine, requiring lower doses of ephedrine and contributing to increased patient safety during elective cesarean surgery.