Dressings for preventing pressure ulcers: how do they work?

Pressure ulcers (PUs) negatively affect quality of life (QoL) and cause problems for patients, such as pain, distress and often specific difficulties with treatments used to manage the wound. Thus, it is important to implement appropriate prevention strategies in order to achieve high-quality care, thereby reducing the burden of PUs on patients, the healthcare system and society as a whole. PU development arises due to the adverse effects of pressure, shear, friction and moisture at the skin/surface interface. Preventive interventions typically include risk assessment, reducing pressure and minimising shear and friction. More recently, certain wound dressings, as a potential additional protective strategy for preventing PUs, have been introduced. This review explores the mechanisms of action of dressings for preventing PUs. Findings from the review indicate that decreasing frictional forces transmitted to the patient's skin is achieved by use of a dressing with an outer surface made from a low friction material. Furthermore, the ability of dressings to absorb and redistribute shear forces through good adhesion to the skin, high loft and lateral movement of the dressing layers is important in reducing shear forces. This is achieved when the dressing reduces pressure transmitted to the patient's tissues by the propriety of high loft/thickness and padding that allows a degree of cushioning of bony prominences. Further, dressings may reduce humidity at the skin/dressing interface, i.e., the dressing is absorbent and/or permits moisture to evaporate quickly. As part of an established PU prevention protocol, dressings may help decrease PU incidence.