Exposure treatment of the burned patient--a computer simulation of the thermal environment and its effect on evaporation and heat loss.

The influence of the thermal environment on evaporation and heat loss from burned tissue has been studied in order to optimise conditions for treatment of severely burned patients. Diffusion resistances have been defined to describe movement of water vapour through the skin and away from the body surface. These have been evaluated from experiments on a water phantom and from data on evaporation rates from burned tissue and normal skin. Results show that the diffusion resistance for burned tissue is less than one tenth of that for normal skin, but changes substantially during the development of an eschar. Evaporation is promoted by a high skin temperature and a low relative humidity, but not by raising the ambient air temperature. Blowing warm dry air over a burn wound will enhance evaporation and reduce heat loss, encouraging the rapid formation of a dry eschar to provide a barrier against infection. Selective irradiation of burned tissue with low levels of radiant energy can be used to compensate for local heat losses, and allow the air temperature in the treatment room to be kept at a level comfortable for the patient and nursing staff.