Treatment of pressure ulcers with noncontact normothermic wound therapy: healing and warming effects

This study compared healing rates in stage III and IV pressure ulcers treated with noncontact normothermic wound therapy or moist dressings. Periwound temperature changes with noncontact normothermic wound therapy were evaluated.

This 8-week, prospective, randomized clinical trial evaluated linear rate of healing of the wound edge and periwound temperature changes during the 1-hour warming treatment and for 15 minutes after warming.

Forty subjects referred from primary care providers, home care providers, acute care facilities, and long-term care facilities were enrolled in the study. Twenty-nine subjects completed the trial (14 received standard care, and 15 received noncontact normothermic wound therapy).

Ulcers were measured with acetate tracings, digital and Polaroid photography, and Pressure Sore Status Tool evaluations. The linear rate of healing was determined with use of computerized planimetry. Periwound temperatures were recorded with use of a Cole Parmer thermometer YSI 400 series.

Subjects were evaluated weekly. Subjects randomly assigned to noncontact normothermic wound therapy received 3 treatments daily, during which the dressing was warmed to 38 degrees C for 1 hour. Subjects in the standard care group were treated with dressings that were moisture retentive and provided absorption as needed.

The two groups were statistically similar with regard to baseline and wound characteristics. The linear rate of healing was significantly faster in the group treated with noncontact normothermic wound therapy (Mann-Whitney U test = 47, P =.01). On average, periwound temperatures increased 2.4 degrees C at the end of warming (1 hour), a significant increase above baseline values (P =.001).

The healing rate was significantly increased with noncontact normothermic wound therapy treatment. Periwound temperature increased significantly after 1 hour of warming, achieving levels approximating normothermia. Healing effects associated with noncontact normothermic wound therapy may be related to several mechanisms, including improvements in perfusion, oxygen supply, and cellular activity in response to warming.