Assessment of pressure injuries
For a structured assessment framework, see Assessing patients with an ulcer or wound. Service providers generally require that pressure injuries are reported on a risk or incident management system.
A classification system is used to stage a pressure injury based on the depth and type of tissue damage. There are currently six pressure injury stages; for diagrams and photographs, see #lwg2-c08-s3__tlwg2-c08-tbl2. Pressure injury development may not progress through consecutive stages; full thickness pressure injury (ie stage III or IV) can occur without any preceding external signs if caused by deep tissue ischaemia.
Pressure injury stages are:
- Stage I—intact skin with nonblanchable erythema1. In patients with dark skin the pressure injury may be a different colour from the surrounding skin.
- Stage II—partial thickness loss of dermis. A shallow wound with a red/pink wound bed but no slough or bruising. Can also present as an intact or ruptured serum-filled blister.
- Stage III—full thickness tissue loss. Subcutaneous fat may be visible, but bone, muscle or tendon is not visible or palpable. Slough (if present) does not obscure the depth of tissue loss. Undermining or tunnelling can be present.
- Stage IV—full thickness tissue loss with exposed or palpable bone, muscle or tendon. May have slough or eschar on areas of the wound bed. Undermining or tunnelling is often present.
- Unstageable (depth unknown)—full thickness tissue loss where the wound bed is covered by nonviable tissue (slough, necrosis, eschar) that obscures the depth of the wound. Until enough nonviable tissue is removed, the stage of the pressure injury cannot be determined2.
- Suspected deep tissue injury (depth unknown)—an area of intact skin, purple or maroon in colour, or a blood-filled blister. Indicates damage to underlying soft tissue from pressure or shear. Deep tissue injury can be difficult to detect in patients with dark skin tones.
This classification system is used for initial assessment of pressure injuries. It is not used for staging pressure injury healing, or to describe skin tears, moisture or incontinence associated lesions, or mucous membrane injury.
Stage III or IV pressure injuries can form a cavity, including undermining, tunnelling, sinus, or fistula. Assess cavities using a sterile probe, or with careful palpation (wear sterile gloves), to determine the depth and extent of the cavity. Exposed bone can indicate osteomyelitis.
Assess the pressure injury characteristics using the TIME framework (see Wound characteristics summarised using the TIME acronym).
Infection is suggested by profuse, purulent or malodorous discharge; increasing pain; signs of inflammation; or wound increasing in size—see Ulcer and wound infection. Patients with pressure injury are at risk of systemic infection, which requires urgent medical review and management.
Vascular assessment is recommended for patients with pressure injury of the lower limb or extremities.