Comparison of Colloid (Hydroxyethyl Starch) Preloading and Coloading for the Prevention of Hypotension During Cesarean Section Under Spinal Anesthesia: A Prospective Randomized Study

Objective: This study aimed to compare the effects of hydroxyethyl starch (6% HES 130/0.4) administered as preload or coload on the incidence of maternal hypotension and neonatal outcomes in elective cesarean sections performed under spinal anesthesia.Methods: This prospective, randomized trial included 162 parturients aged 18–45 years with American Society of Anesthesiologists physical status II and a gestational age greater than 36 weeks undergoing elective cesarean delivery under spinal anesthesia. Participants received 500 mL of HES either 30 minutes before spinal anesthesia (preload group) or at the onset of cerebrospinal fluid flow (coload group). Maternal hemodynamic parameters were monitored throughout the procedure. Umbilical cord blood gas analysis, Apgar scores at 1 and 5 minutes, and total ephedrine consumption were recorded.Results: The incidence of maternal hypotension was 51.1% in the preload group and 48.9% in the coload group, with no statistically significant difference between groups (p = 0.83). Systolic arterial pressure at the onset of hypotension was 86.41 ± 8.63 mmHg in the preload group and 82.20 ± 9.14 mmHg in the coload group (p = 0.19). Total ephedrine requirement and umbilical cord blood gas parameters were comparable between groups. While 1-minute Apgar scores were similar, the 5-minute Apgar score was significantly higher in the preload group (p = 0.01).Conclusion: Colloid preload and coload administration were associated with comparable effects on maternal hypotension, vasopressor requirements, and neonatal outcomes in cesarean deliveries performed under spinal anesthesia.