Perioperative warming with a thermal gown prevents maternal temperature loss during elective cesarean section. A randomized clinical trial.

BACKGROUND AND OBJECTIVES: Decrease in body temperature is common during general and regional anesthesia. Forced-air warming intraoperative during cesarean section under spinal anesthesia seems not able to prevent it. The hypothesis considers that active warming before the intraoperative period avoids temperature loss during cesarean. METHODS: Forty healthy pregnant patients undergoing elective cesarean section with spinal anesthesia received active warming from a thermal gown in the preoperative care unit 30min before spinal anesthesia and during surgery (Go, n=20), or no active warming at any time (Ct, n=20). After induction of spinal anesthesia, the thermal gown was replaced over the chest and upper limbs and maintained throughout study. Room temperature, hemoglobin saturation, heart rate, arterial pressure, and tympanic body temperature were registered 30min before (baseline) spinal anesthesia, right after it (time zero) and every 15min thereafter. RESULTS: There was no difference for temperature at baseline, but they were significant throughout the study (p<0.0001; repeated measure ANCOVA). Tympanic temperature baseline was 36.6±0.3°C, measured 36.5±0.3°C at time zero and reached 36.1±0.2°C for gown group, while control group had baseline temperature of 36.4±0.4°C, measured 36.3±0.3°C at time zero and reached 35.4±0.4°C (F=32.53; 95% CI 0.45-0.86; p<0.001). Hemodynamics did not differ throughout the study for both groups of patients. CONCLUSION: Active warming 30min before spinal anesthesia and during surgery prevented a fall in body temperature in full-term pregnant women during elective cesarean delivery.

[Use of forced-air to prevent intraoperative hypothermia]. / Uso da manta térmica na prevenção da hipotermia intraoperatória.

OBJECTIVE: Hypothermia is a life-threatening event during the perioperative period. No consensus has been reached about the best active warming approach for such cases. Furthermore there is no consensus on the most appropriate time to warm a hypothermic patient. This study aimed to assess the efficacy of a forced-air blanket to warm patients at 38 degrees C before and during surgery. Following utilization of the forced-air blanket, adverse effects were evaluated. METHODS: Patients submitted to orthopedic surgeries were divided into four groups of 15 patients. In the control group (Gcont), patients were not warmed with a forced-air blanket. In the preoperative group (Gpre), intraoperative group (Gintra), and total group (Gtotal), patients were warmed at 38 degrees C, during 30 minutes before anesthetic induction, after anesthetic induction up to 120 minutes and before and after the induction, respectively. Parameters evaluated were central (tympanic) temperature, peripheral (skin) temperature, operating room temperature, variations in the hemodynamic conditions and warming-induced adverse effects. RESULTS: Only Gtotal did not show significant variation in central temperature. Central temperatures of Gtotal patients were significantly higher (p <0.05) than those of other groups at 60 and 120 min after induction. In Gcont, Gpre and Gintra, patients were hypothermic at 60 min. CONCLUSION: The forced-air blanket is effective to prevent intraoperative hypothermia when applied for a period ranging from 30 min before anesthetic induction to 120 min after anesthetic induction. In the conditions of this study, adverse effects were not observed.