EFFICACY AND SAFETY OF NORADRENALINE IN MANAGING POST-SPINAL HYPOTENSION DURING CESAREAN DELIVERY

Abstract

Background: Spinal anesthesia is the primary anesthetic technique for Cesarean sections. The most common complication of spinal anesthesia in this setting is hypotension, occurring in over 70% of cases. Severe and prolonged hypotension may adversely affect both the mother and the fetus. The administration of vasopressors is prioritized in the management of this condition. Noradrenaline has been demonstrated to be equivalent or superior to other vasopressors, such as ephedrine or phenylephrine, and is characterized by low cost and high availability; however, there are limited evaluative studies in Viet Nam.

Objectives: To evaluate the efficacy and safety of Noradrenaline compared with Ephedrine in the management of post-spinal anesthesia hypotension.

Methods: A prospective, randomized, controlled, single-blind clinical trial was conducted on 70 parturients aged 18–40 years, ASA physical status II, with full-term singleton pregnancies, undergoing Cesarean section under spinal anesthesia at Le Van Thinh hospital from March to October 2025.

Results: The incidence of hypotension was 82.9% in the Noradrenaline group and 94.3% in the Ephedrine group

(p = 0.259); the incidence of severe hypotension was 28.6% in the Noradrenaline group and 51.4% in the Ephedrine group (p = 0.087). The lowest systolic blood pressure in the Noradrenaline group was 91.4 ± 10.5 (90 [87 – 95]) mmHg, which was significantly higher than that in the Ephedrine group (82.6 ± 11.4 (83 [77 – 89]) mmHg, p = 0.001). Hypotension occurred most frequently from the 2nd to the 5th minute in both groups (over 50%), with the Ephedrine group showing a significantly higher rate of hypotension at the 3rd and 4th minutes compared to the Noradrenaline group (p <0.01). While the number of hypotension episodes and reactive hypertension episodes showed no significant difference (p >0.05), Noradrenaline significantly limited the recurrence of severe hypotension compared to Ephedrine (0.0 [0.0 – 1.0] episodes vs. 1.0 [0 – 2.5] episodes, p = 0.021). The incidence of tachycardia showed little difference

(p = 0.092), but the total number of tachycardia episodes in the Ephedrine group was nearly six times higher than in the Noradrenaline group (p = 0.005). There were no significant differences in adverse effects such as nausea and vomiting, shivering, or pruritus between the two groups (p >0.05). While Apgar scores at 1-minute were comparable, the 5-minute Apgar score was higher in the Noradrenaline group (9 [9 – 10] vs. 9 [9 – 9], p = 0.005).

Conclusions: Compared to Ephedrine, Noradrenaline effectively controls hypotension, limits the severity and number of hypotensive episodes, causes less tachycardia, and is safe for both the mother and the newborn. As a readily available and suitable vasopressor, Noradrenaline shows promise as the preferred vasopressor for spinal anesthesia in cesarean sections.

Keywords: hypotension; spinal anesthesia; cesarean section; vasopressors