Clinical assessment and description of pressure sores can be quite difficult for the inexperienced observer; therefore, many classification schemes have been developed to define the severity of pressure ulcers. The National Pressure Ulcer Advisory Panel has recently updated its classification scheme for pressure ulcers.12 The goal of the revision was to clarify each stage and reduce the number of incorrectly staged ulcers or other types of wounds and skin lesions. This system consists of 4 stages of ulceration but is not intended to imply that all pressure sores follow a standard progression from stage I to stage IV or that healing pressure sores follow a standard regression from stage IV to stage I to a healed wound. Rather, the system is designed to describe the degree of tissue damage observed at the specific time of examination and is meant to facilitate communication among the various disciplines involved in the study and care of these patients.
(Suspected) Deep Tissue Injury: This is the most recent addition to the staging system. This stage is described as a “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.”12 This stage may be difficult to detect in individuals with dark skin.
Stage I: This classification represents intact skin with signs of impending ulceration. Initially, this presents as blanchable erythema indicating reactive hyperemia. When tissue becomes temporarily ischemic, relief of pressure causes hyperemia, which is probably a protective mechanism of increased blood flow designed to oxygenate the tissues and remove potentially harmful products of metabolism. Reactive hyperemia should resolve within 24 hours of the relief of pressure. Warmth and induration also may be present. Continued pressure creates erythema that does not blanch with pressure and may well represent the first outward sign of tissue destruction. Finally, the skin may appear white from ischemia.
Stage II: This classification represents a partial-thickness loss of skin involving epidermis and dermis that appears as an open shallow ulcer with a pink wound bed.
Stage III: This classification represents a full-thickness loss of skin with extension into subcutaneous tissue but not through the underlying fascia. This lesion presents as an ulcer that may include undermining and tunneling of adjacent tissue. Bone, tendon, and fascia are not exposed.
Stage IV: This classification represents full-thickness tissue loss with extension into muscle, bone, tendon, or joint capsule. Slough or eschar may be present in the wound. Osteomyelitis with bone destruction and dislocations or pathologic fractures may be present. Sinus tracts and severe undermining are commonly present.
Unstageable: An unstageable ulcer is defined as full-thickness tissue loss in which the base of the ulcer is covered by slough or eschar such that the full depth of the wound cannot be appreciated. Only when the slough or eschar is removed can the depth of the ulcer be evaluated and correctly staged.
Staging of wound depth is only a small part of the initial assessment. Ulcer location, size of the skin opening, and presence of any surrounding maceration or induration must be accurately recorded. The presence of multiple pressure ulcers prompts the search for interconnecting tracts with overlying skin bridging that may not be readily apparent. Also note the presence or absence of foul odors, wound drainage, and soilage from urinary or fecal incontinence. This provides information regarding the level of bacterial contamination and the need for debridement or diversionary procedures