Intraoperative Forced Air-Warming During Cesarean Delivery Under Spinal Anesthesia Does Not Prevent Maternal Hypothermia

Abstract

BACKGROUND: Prewarming and intraoperative warming with forced air-warming systems prevent perioperative hypothermia and shivering in patients undergoing elective cesarean delivery with epidural anesthesia. We tested the hypothesis that intraoperative lower body forced air-warming prevents hypothermia in patients undergoing elective cesarean delivery with spinal anesthesia. METHODS: Thirty healthy patients undergoing cesarean delivery with spinal anesthesia were randomly assigned to forced air-warming or control groups (identical cover applied with forced air-warming unit switched off). A blinded investigator assessed oral temperature, shivering, and thermal comfort scores at 15-min intervals until discharge from the postanesthetic care unit. Umbilical cord blood gases and Apgar scores were also measured after delivery. RESULTS: The maximum core temperature changes were similar in the two groups (-1.3 degrees C +/- 0.4 degrees C vs -1.3 degrees C +/- 0.3 degrees C for the forced air-warming group and control group, respectively; P = 0.8). Core hypothermia (< or =35.5 degrees C) occurred in 8 of 15 patients receiving forced air-warming and in 10 of 15 unwarmed patients (P = 0.5). The incidence and severity of shivering did not significantly differ between groups. Umbilical cord blood gases and Apgar scores were similar in both groups (P = NS). CONCLUSIONS: We conclude that intraoperative lower body forced air-warming does not prevent intraoperative hypothermia or shivering in women undergoing elective cesarean delivery with spinal anesthesia.