Convection heating in pediatric general surgery – a comparison of warming alternatives in a mannequin study

Background: Numerous methods of patient warming are used to prevent intraoperative hypothermia in children. Commercially available forced air warming blankets are effective, but are single-use items. We tested a custom-designed heat dissipation unit (HDU) against one such commercially available blanket.

Methods: Air temperatures at various points around a mannequin under simulated operating conditions were recorded using thermistors and thermal imaging. The only variable changed was the heating method: a forced air blanket or a customized HDU with two draping techniques – cotton drapes with and without a plastic ‘undersheet’.

Results: The three methods produced similar temperature increases and plateaux across the 11 thermistor points measured. There were no significant differences between temperatures at 1 h. A plastic sheet did not appear to enhance the effectiveness of the HDU in this study. Thermal imaging photography suggested more uniform heating of the mannequin with the HDU arrangements.

Conclusions: The custom-built HDU compares favorably in our mannequin study with a Bair Hugger forced air warming blanket. As it is reusable, it offers considerable potential savings.