Classification
The definitions of the four pressure ulcer stages are revised periodically by the National Pressure Ulcer Advisory Panel (NPUAP) in the United States. Briefly, however, they are as follows:
The definitions of the four pressure ulcer stages are revised periodically by the National Pressure Ulcer Advisory Panel (NPUAP) in the United States. Briefly, however, they are as follows:
Stage I is the most superficial, indicated by non blanchable redness that does not subside after pressure is relieved. This stage is visually similar to reactive hyperemia seen in skin after prolonged application of pressure. Stage I pressure ulcers can be distinguished from reactive hyperemia in two ways: a) reactive hyperemia resolves itself within 3/4 of the time pressure was applied, and b) reactive hyperemia blanches when pressure is applied, whereas a Stage I pressure ulcer does not. The skin may be hotter or cooler than normal, have an odd texture, or perhaps be painful to the patient. Although easy to identify on a light-skinned patient, ulcers on darker-skinned individuals may show up as shades of purple or blue in comparison to lighter skin tones.
Stage II is damage to the epidermis extending into, but no deeper than, the dermis. In this stage, the ulcer may be referred to as a blister or abrasion.
Stage III involves the full thickness of the skin and may extend into the subcutaneous tissue layer. This layer has a relatively poor blood supply and can be difficult to heal. At this stage, there may be undermining damage that makes the wound much larger than it may seem on the surface.
Stage IV pressure ulcerStage IV is the deepest, extending into the muscle, tendon or even bone.
Unstageable pressure ulcers are covered with dead cells, or eschar and wound exudate, so the depth cannot be determined.
