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

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 (F) or morphine (M) in pregnant women undergoing spinal anesthesia with 0.5% hyperbaric bupivacaine, with doses varied between 7.5 mg - 11 mg, depending on the patient's height. Data from a cohort of 170 pregnant women were analyzed. The administered doses were intrathecal M at 0.1 mL (100 µg, solution of 1 mg/mL) or F at 0.25 mL (25 µg, solution of 50 µg/mL). The study included 80 patients in group F and 90 in group M. Results: The group F showed significantly higher post-intervention systolic blood pressure values than the 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 F as an adjuvant alongside the local anesthetic in cesarean section is associated with better hemodynamic stability compared to M, requiring lower doses of ephedrine, and thus increasing patient safety during elective cesarean surgery.