TEMPERATURE-MODULATED PRESSURE ULCERS - A PORCINE MODEL

Objective: A reliable porcine model was developed to facilitate invest igations of pressure ulcer formation, healing, and prevention. In the present study, it was specifically used to study the relationship betw een applied temperature, applied pressure, and time of application in the formation of cutaneous and deep tissue injuries. Design: An appara tus and procedure were created to simultaneously apply 12 metal discs (each with a diameter of 51mm) on the dorsal aspect of the swine, all at an equal pressure of 100mmHg, for a 5-hour period, while servo-cont rolling disc temperatures at either 25, 35, 40, or 45 degrees C. Resul ts: The severity of the resultant tissue injuries correlated with an i ncrease in applied temperature. No damage was observed in the superfic ial or deep tissues underlying the shes of the 25 degrees C pressure a pplicators. In general, only deep tissue damage resulted from the appl ication of a 35 degrees C temperature, whereas the application of high er temperatures caused both cutaneous and subdermal damage (the extent of necrosis being greater at the 45 degrees C sites), There was a hig h degree of reproducibility of these results among a large population of shes per temperature (n = 64) and number of animals investigated (n = 16). Furthermore, subsequent healing (monitored up to 4 weeks) was uniform for the degree of induced damage. Insights into pressure ulcer formation were also sought via systematic examination of histological sides and postmortem visual assessment over the 4-week period. Conclu sion: It was concluded that this animal model of temperature-modulated pressure ulcers has the potential for significant use in all major ar eas of this field, ie, wound formation, healing, and prevention. (C) 1 995 by the American Congress of Rehabilitation Medicine and the Americ an Academy of Physical Medicine and Rehabilitation