Comparison of Crystalloid Preloading and Coloading for Prevention of Spinal-induced Hypotension in Cesarean Delivery: A Randomized Controlled Trial at a Tertiary Facility in Ghana

Abstract

BACKGROUND: Spinal anesthesia is the recommended technique for cesarean section. It is easy to perform and provides a reliable, safe, effective, and fast sensory and motor block of high quality. Hypotension, which can be deleterious to both mother and  baby, is however a common side effect. Preloading has not been shown to consistently prevent spinal-induced hypotension. AIM: The aim of this study was to compare coloading with preloading using crystalloids for preventing spinal anesthesia-induced hypotension in parturients undergoing scheduled cesarean delivery. MATERIALS AND METHODS: A single-blinded, randomized, and controlled study was conducted on 88 patients at term scheduled for elective cesarean delivery under spinal anesthesia at the Korle-Bu Teaching Hospital. Parturients were randomly assigned to receive a preload of 12.5 mL/kg of Ringer’s Lactate (Group P) before the spinal anesthetic or a coload of 12.5 mL/kg of Ringers Lactate (Group C) at the time of the spinal procedure. Blood pressure, heart rate, incidence and timing of nausea and vomiting, and amount and frequency of vasopressor used were recorded for the first 10 minutes post-spinal anesthesia. Neonatal Apgar scores were determined at 1 and 5 minutes after birth. RESULTS: The two groups were comparable with respect to age, weight, height, gestational age, ASA classification, baseline hemodynamic  measurements, time to onset of hypotension, and time to delivery of baby post-spinal anesthesia. Post-spinal anesthesia changes in the heart  rate, systolic blood pressure and mean arterial blood pressure were also comparable between the two groups. None of the patients in both groups experienced nausea or vomiting without hypotension. Although the cumulative dose of ephedrine to treat hypotension in the preload group was  higher compared to the coload group, the difference was not statistically significant (16.3 vs. 12.4; p-value = 0.110). CONCLUSION: Preloading and coloading with 12.5 mL/kg of Ringer’s Lactate are comparable but neither is effective alone for preventing spinal-induced hypotension in the obstetric population. A vasopressor regimen is required to improve efficacy of the fluid load for preventing spinal-induced hypotension.