Pressure injuries are localized areas of tissue necrosis that typically develop when soft tissue is compressed between a bony prominence and an external surface for a long period of time. Stage 1 pressure injuries are characterized by superficial reddening of the skin (or red, blue or purple hues in darkly pigmented skin) that when pressed does not turn white (non-blanchable erythema). If the cause of the injury is not relieved, these will progress and form proper ulcers. Stage 1 pressure injuries differ from reactive hyperemia (increased blood flow to an area after a period of ischemia) in that reactive hyperemia will typically resolve itself within 3/4 the time of ischemia and will blanche when pressure is applied.
In addition to the aforementioned non-blanchable erythema, stage 1 pressure injuries may also differ in temperature (warmer or cooler), consistency (firmer or softer) or may be more tender than adjacent tissue.
Pressure injuries are accepted to be caused by three different tissue forces:
In most cases, this pressure is caused by the force of bone against a surface, as when a patient remains in a seated or supine position for an extended period. When this pressure exceeds the tissue capillary pressure, it deprives the surrounding tissues of oxygen and can lead to tissue necrosis if left untreated.
This force is typically a result of the skin of a patient staying in one place as the deep fascia and skeletal muscle slide down, which can pinch off blood vessels and in turn lead to ischemia and tissue necrosis.
Friction is the opposing force to the shear force. This can cause microscopic and macroscopic tissue trauma, specifically when the patient is being moved across the support surface.
In addition, moisture from incontinence, perspiration or exudate can increase the coefficient of friction between the skin and the surface, making it more susceptible to friction damage. Increased moisture also can weaken the bonds between epithelial cells, resulting in skin maceration, which also makes the skin more susceptible to pressure, shear, and friction damage.
Infection is the most common major complication of pressure ulcers/injuries. If the ulcer progresses far enough, it can lead to osteomyelitis (infection of the underlying bone) or sinus tracts, which themselves can be either superficial or connect to deeper structures.
The key factors to consider in a treating a stage 1 pressure injury are identifying the cause of the wound and determining how best to prevent it from worsening, including an evaluation of the nutritional status of the patient. The presence of a stage 1 pressure injury should be a signal to take preventive action.
The following precautions can help minimize the risk of developing pressure ulcers in at-risk patients and to minimize complications in patients already exhibiting symptoms:
Merck Sharp & Dohme Corp. Pressure Ulcers. The Merck Manual. http://www.merckmanuals.com/professional/dermatologic_disorders/pressure.... Updated July 2017. Accessed June 21, 2018.
National Pressure Injury Advisory Panel. Prevention and Treatment of Pressure Ulcers/Injuries: Clinical Practice Guideline. The International Guideline 2019.
Salcido R. Pressure Ulcers and Wound Care. Medscape Reference. http://emedicine.medscape.com/article/319284-overview#aw2aab6b2. Updated June 11, 2018. Accessed June 21, 2018.
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