Prevention of maternal hypothermia after scheduled cesarean delivery under spinal anesthesia with active warming of intravenous fluids: an exploratory double-blind randomized controlled trial (CESAR-RESOL2)

Background Maternal hypothermia frequently occurs after cesarean delivery under spinal anesthesia. We assessed whether active fluid warming would decrease the incidence of postoperative hypothermia as compared with no active warming in this context. Methods In this randomized double-blind controlled trial, patients undergoing scheduled cesarean delivery with spinal anesthesia and intrathecal morphine were randomized to active intravenous fluid warming (intervention group, n = 35) or no active warming (control group, n = 35). Maternal temperature was continuously monitored with a zero-heat-flux sensor. Primary endpoint was the proportion of maternal hypothermia (temperature < 36 °C) upon post-anesthesia care unit arrival. Results Postoperative hypothermia occurred in 58.8% of the patients in the intervention group vs. 80.0% in the control group (RR = 0.74, 95% CI 0.53 to 1.02; P = 0.056). Mean maternal temperature upon post-anesthesia care unit arrival was significantly higher in the intervention group (35.8 °C ± 0.6 versus 35.4 °C ± 0.6, respectively; P = 0.005). No significant differences were observed regarding shivering, thermal discomfort, or neonatal outcomes. Conclusions Active fluid warming reduces the incidence of hypothermia after cesarean delivery, although the study was underpowered to detect a significant difference.