Objectives: To compare a forced air warming system with passive measur
es to avoid perioperative hypothermia. Design: Prospective open study.
Setting: University hospital, Sweden. Subjects: 28 Patients scheduled
for extensive thoracoabdominal operations under standard combined gen
eral and regional anaesthesia. Main outcome measures: Temperature meas
ured before, repeatedly under anaesthesia and during the operation for
up to three hours, and then up to eight hours postoperatively. Result
s: Three patients were excluded. In the 12 patients who had forced air
warming, temperature was preserved, and ranged from a mean (SD) of 36
.8 (0.7)degrees C, (95% confidence interval (CI) 36.4 to 37.2) at the
start to 36.9 (0.8)degrees C, (95% CI 36.5 to 37.3) after 3 hours. In
patients who had conservative passive heat preservation techniques the
mean temperature fell significantly perioperatively, from 36.8 (0.6)d
egrees C (95% CI 36.5 to 37.1) at the start to 35.1 (0.5)degrees C, (9
5% CI 34.9 to 35.3), after three hours of anaesthesia and surgery. Thi
s was a significant fall compared with the temperature in the study gr
oup (p < 0.001). Conclusion: Forced air warming intraoperatively can p
reserve normothermia during extensive thoracoabdominal operations.