Pressure Injuries: Staging and Prevention

A pressure injury is localized damage to the skin and/or underlying tissue, as a result of pressure or pressure in combination with shear. It usually occurs over a bony prominence but may also be related to a medical or other device. Injury can be present beneath intact skin. Mechanism: sustained loading of soft tissue reduces blood flow and perfusion, so oxygen and nutrients run short and waste products accumulate, eventually leading to cell death. Muscle tolerates reduced perfusion far worse than skin, which is why the visible skin can look better than the tissue beneath it. Shear, which compresses and distorts tissue between a bone and a surface, and an adverse microclimate (heat and moisture at the skin) add to the injury. Damage can start at different depths. The surface may conceal deeper injury. Staging uses the visible or directly palpable tissue and whether the wound depth is obscured. Only pressure injuries are staged; other wounds use their own classification. - Stage 1: intact skin with a localized area of non-blanchable erythema. In darkly pigmented skin it may look different,...