Table 2

National Pressure Ulcer Staging System

Pressure Ulcer StagePrevious NPUAP Staging Definitions2007 NPUAP Definitions2007 NPUAP Descriptions to Accompany Revised Definitions
Deep Tissue InjuryA pressure-related injury to subcutaneous tissues under intact skin. Initially, these lesions have the appearance of a deep bruise, and they may herald the subsequent development of a Stage III–IV pressure ulcer, even with optimal treatment.Purple or maroon localized area of discolored intact skin or blood-filled blister due to damage of underlying soft tissue from pressure and/or shear.
  • The area may be preceded by tissue that is painful, firm, mushy, boggy, warmer, or cooler, as compared to adjacent tissue.
  • Deep tissue injury may be difficult to detect in individuals with dark skin tones.
  • The area may rapidly evolve to expose additional layers of tissue, even with optimal treatment.
Stage IAn observable pressure-related alteration of intact skin whose indicators as compared to an adjacent or opposite area on the body may include changes in one or more of the following parameters: skin temperature (warmth or coolness), tissue consistency (firm or boggy feel), sensation (pain, itching), and/or a defined area of persistent redness in lightly pigmented skin; in darker skin tones, the ulcer may appear with persistent red, blue, or purple hues.Intact skin with nonblanchable redness of a localized area, usually over a bony prominence.
  • The area may be painful, firm, soft, warmer, or cooler, as compared to adjacent tissue.
  • Stage I may be difficult to detect in individuals with dark skin tones.
  • May indicate at-risk persons (a heralding sign of risk).
Stage IIPartial thickness skin loss involving the epidermis and/or dermis. The ulcer is superficial and presents clinically as an abrasion, blister, or shallow crater.Partial thickness loss of dermis presenting as a shallow open ulcer with a red, pink wound bed without slough. May also present as an intact or open/ruptured serum-filled blister.Presents as a shiny or dry shallow ulcer without slough or bruising. This stage should not be used to describe skin tears, tape burns, perineal dermatitis, maceration, or excoriation.
Stage IIIFull thickness skin loss involving damage or necrosis of subcutaneous tissue that may extend down to, but not through, underlying fascia. The ulcer presents clinically as a deep crater with or without undermining of adjacent tissue.Full thickness tissue loss. Subcutaneous fat may be visible, but bone, tendon, or muscle are not exposed. Slough may be present but does not obscure the depth of tissue loss. May include undermining and tunneling.
  • The depth of a Stage III pressure ulcer varies by anatomical location. The bridge of the nose, ear, occiput, and malleolus do not have subcutaneous tissue, and Stage III ulcers can be shallow. In contrast, areas of significant adiposity can develop extremely deep Stage III pressure ulcers.
  • Bone/tendon is not visible or directly palpable.
Stage IVFull thickness skin loss with extensive destruction; tissue necrosis; or damage to muscle, bone, or supporting structure (such as tendon, or joint capsule).Full thickness tissue loss with exposed bone, tendon, or muscle. Slough or eschar may be present on some parts of the wound bed. Often includes undermining and tunneling.
  • The depth of a Stage IV pressure ulcer varies by anatomical location. The bridge of the nose, ear, occiput, and malleolus do not have subcutaneous tissue, and these ulcers can be shallow.
  • Stage IV ulcers can extend into muscle and/or supporting structures (e.g., fascia, tendon, or joint capsule), making osteomyelitis likely to occur.
  • Exposed bone/tendon is visible or directly palpable.
UnstagableFull thickness tissue loss in which actual depth of the ulcer is completely obscured by slough (yellow, tan, gray, green, or brown) and/or eschar (tan, brown, or black) in the wound bed.Until enough slough and/or eschar is removed to expose the base of the wound, the true depth, and therefore stage, cannot be determined. Stable (dry, or adherent, intact without erythema or fluctuance) eschar on the heels serves as the “the body’s natural (biological) cover” and should not be removed.
©

2007 NPUAP

From: Chapter 12, Pressure Ulcers: A Patient Safety Issue

Cover of Patient Safety and Quality
Patient Safety and Quality: An Evidence-Based Handbook for Nurses.
Hughes RG, editor.

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