Objectives: To compare a forced air warming system with passive measures to avoid perioperative hypothermia.
Design: Prospective open study.
Setting: University hospital, Sweden.
Subjects: 28 Patients scheduled for extensive thoracoabdominal operations under standard combined general and regional anaesthesia.
Main outcome measures: Temperature measured before, repeatedly under anaesthesia and during the operation for up to three hours, and then up to eight hours postoperatively.
Results: 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) degrees C (95% CI 36.5 to 37.1) at the start to 35.1 (0.5) degrees C, (95% CI 34.9 to 35.3), after three hours of anaesthesia and surgery. This was a significant fall compared with the temperature in the study group (p < 0.001).
Conclusion: Forced air warming intraoperatively can preserve normothermia during extensive thoracoabdominal operations.