Special Report: Pressure Ulcer Stages Revised by the National Pressure Ulcer Advisory Panel

  The National Pressure Ulcer Advisory Panel (NPUAP) has redefined pressure ulcer and revised the stages of pressure ulcers. The revision includes the original four stages and adds two stages that address deep tissue injury and unstageable pressure ulcers.

  The new descriptors represent the culmination of more than 5 years of work that began with the identification of deep tissue injury in 2001.

Pressure Ulcer Definition

  A pressure ulcer is localized injury to the skin and/or underlying tissue, usually over a bony prominence, as a result of pressure or pressure in combination with shear and/or friction. A number of contributing or confounding factors also are associated with pressure ulcers; the significance of these factors is yet to be elucidated.

Pressure Ulcer Stages

Suspected Deep Tissue Injury. Deep tissue injury may be characterized by a purple or maroon localized area of discolored intact skin or a blood-filled blister due to damage of underlying soft tissue from pressure and/or shear. Presentation may be preceded by tissue that is painful, firm, mushy, boggy, and warmer or cooler as compared to adjacent tissue.

  Further description. Deep tissue injury may be difficult to detect in individuals with dark skin tones. Evolution may include a thin blister over a dark wound bed. The wound may further evolve and become covered by thin eschar. Evolution may be rapid, exposing additional layers of tissue even with optimal treatment.

  Stage I. A Stage I pressure ulcer presents as intact skin with non-blanchable redness of a localized area, usually over a bony prominence. Darkly pigmented skin may not have visible blanching; its color may differ from the surrounding area.

  Further description. The area may be painful, firm, soft, and warmer or cooler as compared to adjacent tissue. Stage I ulcers may be difficult to detect in individuals with dark skin tones and may indicate “at risk” persons (a heralding sign of risk).

  Stage II. A Stage II pressure ulcer is characterized by partial-thickness loss of dermis presenting as a shallow open ulcer with a red-pink wound bed without slough. It also may present as an intact or open/ruptured serum-filled blister.

  Further description. A Stage II ulcer also may present 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.

  * Bruising indicates suspected deep tissue injury.

  Stage III. A Stage III pressure ulcer is characterized by full-thickness tissue loss. Subcutaneous fat may be visible but bone, tendon, or muscle is not exposed. Slough may be present but does not obscure the depth of tissue loss. Stage III ulcers may include undermining and tunneling.

  Further description. 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; Stage III ulcers in these locations 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 IV. A Stage IV pressure ulcer presents with full-thickness tissue loss with exposed bone, tendon, or muscle. Slough or eschar may be present on some parts of the wound bed. These ulcers often include undermining and tunneling.

  Further description. 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; Stage IV ulcers in these locations can be shallow. Stage IV ulcers can extend into muscle and/or supporting structures (eg, fascia, tendon, or joint capsule); osteomyelitis is possible. Exposed bone/tendon is visible or directly palpable.

  Unstageable. Full-thickness tissue loss in which the base of the ulcer is covered by slough (yellow, tan, gray, green or brown) and/or eschar (tan, brown or black) in the wound bed may render a wound unstageable.

  Further description. Until enough slough and/or eschar is removed to expose the base of the wound, the true depth (and therefore, the stage) cannot be determined. Stable (dry, adherent, intact without erythema or fluctuance) eschar on the heels serves as “the body’s natural (biological) cover” and should not be removed.

  The staging system was defined by Shea in 1975¹ and assigns a name to the amount of anatomical tissue loss. The original definitions were confusing to many clinicians and led to inaccurate staging of ulcers associated with or due to perineal dermatitis or deep tissue injury. The proposed definitions were refined by the NPUAP with input from an on-line evaluation of the face validity, accuracy, clarity, succinctness, utility, and discrimination of the definitions. This process was completed online and provided input to the Panel for continued work. The proposed final definitions were reviewed by a consensus conference; attendee comments were used to create the final definitions.

  For more information, email npuap@npuap.org or call (202) 521-6789.

This article was not subject to the Ostomy Wound Management peer-review process.

1. Shea JD. Pressure sores: classification and management. Clin Orthop Relat Res. 1975;112:89-100.