A method for determining the heat transfer and water vapour permeability of patient support systems

The formation of pressure ulcers can be exacerbated by a breakdown in the i ntegrity of the patient's skin caused by poor maintenance of the skin micro climate. Patient support systems (PSSs-specialised beds, mattresses, chairs , cushions and pads) play an important role in the dissipation of heat and moisture away from the skin/support interface which is necessary in order t o maintain the physiological skin microclimate. This paper reports a laboratory method and theory for the simultaneous meas urement of the heat and water vapour dissipating properties of PSSs. The re sults demonstrate that the method is extremely selective, exhibiting very s ignificant differences between the PSSs tested. It also shows that assessin g PSS covers independently does not necessarily indicate the overall perfor mance of the complete PSS. (C) 2000 IPEM. Published by Elsevier Science Ltd . All rights reserved.