Warming Efficacy Of Regional Heating With Different Skin Thickness Of The Body

Many active external warming devices have been developed for medical treatment of perioperative hypothermia. Previous efficacy assessments for warming systems have generally compared different devices. This study compares the warming efficacy of regional heating at different sites of the body, and its relation to the thickness of subcutaneous adipose tissue. A total of 13 participants (men, 19-21 years) participated in 3 study groups, in each of which a resistive heating pad was placed on 1 of 3 sites of the body: the upper back, the lower back, and the abdomen. All participants were placed in a cold room with an ambient temperature adjusted to 21 +/- 1 degrees C to simulate an operating theater. Skin temperature distributions around the body, skin temperatures beneath the heating pad, and verbal analog score (VAS) values were recorded before and after warming. The subcutaneous adipose thickness of each site was measured using a skinfold technique. Subjective VAS values and body skin temperatures around the designated sensor areas revealed that warming efficacies varied depending on where the heating pad was placed. Efficacy was lowest when the heating pad was placed on the abdomen, where subcutaneous adipose was thickest. The VAS of the abdomen was signifficantly lower than that obtained from either the lower back or the upper back (p < 0: 05). These results suggest that the warming efficacies of regional heating could vary with subcutaneous adipose thickness. The influence of the subcutaneous adipose layer on heat transfer warrants further investigation for warming applications.