Comparison of hypertonic saline (3%), normal saline (0.9%), and hydroxyethyl starch (6%) for prevention of hypotension during spinal anesthesia for cesarean section

Abstract

Aim The aim of this study was to compare the efficacy of hypertonic saline (HS) (3%) (4 ml/kg), normal saline (NS) (0.9%) (13 ml/kg), and hydroxyethyl starch (HES) (6%) in the prevention of hypotension after spinal anesthesia for cesarean section. Patients and methods Sixty healthy parturients scheduled for elective cesarean delivery under spinal anesthesia were included in this randomized prospective study. The patients were randomly assigned to receive 4 ml/kg of HS (3%) (group HS: n=20), 13 ml/kg of NS (0.9%) (group NS: n=20), or 500 ml of HES (6%) (group HES: n=20) before spinal anesthesia. Blood pressure and heart rate were measured before preloading, after preloading, and after spinal injection throughout the procedure. Hypotension was treated with intravenous boluses of 5 mg of ephedrine. Serum sodium levels were measured before and after fluid preloading and after 30 and 90 min. The neonatal outcome was assessed using the APGAR scoring system. Results Two patients (10%) in the HS group, six patients (30%) in the HES group, and 13 patients (65%) in the NS group experienced hypotension, thus the incidence of hypotension was significantly lower in the former two groups. The total dose of ephedrine required by the HS and the HES group was significantly lower compared with that required by the NS group. The heart rate showed no significant differences among the three groups throughout the procedure. Serum sodium concentrations showed no significant differences between the three groups before preloading, after preloading, and after 30 and 90 min. There were no significant changes in each group during the study period. The neonatal outcome was excellent in all three groups. Conclusion HS (3%) at a dose of 4 ml/kg is a safe, inexpensive, and effective preloading fluid in parturients undergoing cesarean section under spinal anesthesia for the prophylaxis against hypotension. HS (3%) can be recommended for fluid preloading in situations in which excess free water administration is not required.