Pressure ulcers 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 I pressure ulcers 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). In the sense that an ulcer is a defect of the skin into the dermis, stage I pressure ulcers are actually a misnomer. However, if the cause of the ulcer is not relieved, these will progress and form proper ulcers. Stage I pressure ulcers differ from reactive hyperemia (increased bloodflow 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.
Symptoms of Stage I Pressure Ulcers
In addition to the aforementioned non-blanchable erythema, stage I pressure ulcers may also differ in temperature (warmer or cooler), consistency (firmer or softer) or may be more tender than adjacent tissue.
Figure 1: Stage I pressure ulcer development
Pressure ulcers 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.
- Immobility or limited mobility
- Spinal cord injury
- Diseases that affect blood flow such as diabetes or atheroscelerosis
- Fragile skin
- Urinary or fecal incontinence
- Poor nutrition or dehydration
- Decreased mental awareness
- Neurological disease
Infection is the most common major complication of pressure ulcers. 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.
Treatment of Stage I Pressure Ulcers
The key factors to consider in a treating a stage I pressure ulcer 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 I pressure ulcer 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:
- Turn patients every two hours.
- Keep the skin clean and dry.
- Avoid massaging bony prominences.
- Provide adequate intake of protein and calories.
- Maintain current levels of activity, mobility and range of motion.
- Use positioning devices to prevent prolonged pressure bony prominences.
- Keep the head of the bed as low as possible to reduce risk of shearing.
- Keep sheets dry and wrinkle free.
Merck Sharp & Dohme Corp. Pressure Ulcers. The Merck Manual. http://www.merckmanuals.com/professional/dermatologic_disorders/pressure.... Updated October 2008. Accessed August 21, 2012.
National Pressure Ulcer Advisory Panel. Pressure Ulcer Prevention Points. National Pressure Ulcer Advisory Panel. http://www.npuap.org/resources/educational-and-clinical-resources/pressu.... Accessed August 21, 2012.
Salcido R. Pressure Ulcers and Wound Care. Medscape Reference. http://emedicine.medscape.com/article/319284-overview#aw2aab6b2. Updated January 18, 2012. Accessed August 21, 2012.
Image copyright Medetec (www.medetec.co.uk). Used with permission.