What is Pressure ulcers - Meaning and definition

Published by Roberto Wenk. Reviewed by Alison Ramsey. Last updated date: January 27, 2019.

Prevention and staging

Pressure ulcers result from ischemia — skin can withstand 30-60 minutes of poor perfusion, but not longer — due to pressure closing the microarterioles, particularly at pressure points: heels, sacrum, and elbows.
Intrinsic risk factors for the ulcer development are limited mobility, conditions that reduce tissue oxygenation, cachexia, and age-related changes in skin.
Extrinsic risk factors are physical forces, such as friction, moisture, and shear.

Ulcer progression
Stage I The heralding lesion of skin ulceration is non-blanchable erythema.
Stage II Partial-thickness skin loss involving epidermis, dermis, or both. The ulcer is superficial and looks like an abrasion or shallow crater or blister.
Stage III Full thickness skin loss involving subcutaneous tissue. The ulcer may extend down to, but not through, the underlying fascia. The ulcer looks like a deep crater, with or without undermining of adjacent tissue.
Stage IV The ulcer is deep enough to include necrosis and damage to underlying muscle, bone, and/or other supporting structures, such as tendon or joint capsule. Undermining of adjacent skin and sinus tracts may also be present.

Prevention of ulcers is the highest level of care; bedbound patients need to be turned regularly and/or they need a pressure-reducing surface.
Skin should be protected from friction, moisture, and shear.
High-risk areas should have either a thin film or hydrocolloid dressings applied.

Pressure-reducing surfaces
There are 3 groups of support surfaces that have demonstrated effectiveness; some need to be ordered by the physician.
1. Air or water mattress overlays are ideal for most patients to prevent pressure ulcers. Order for patients at risk for pressure ulcers.
2. Low-air-loss beds can be used for high-risk patients, or patients with existing ulcers to prevent worsening and/or healing.
3. Air-fluidized beds are reserved for patients needing maximum pressure reduction and pressure relief. However, patients frequently describe them as overly confining.

Adapted from Ferris F, von Gunten CF. Fast facts and concepts #40. Pressure ulcer management: staging and prevention. Internet. January 21, 2016.

Published by Roberto Wenk. Reviewed by Alison Ramsey. Last updated date: January 27, 2019.

Debridement and dressings

The first step in deciding how to manage pressure ulcers is an assessment of whether or not the wound is likely to heal.
- If the patient has a prognosis of months to years, adequate nutrition, and blood flow to the tissue, then healing is possible.
- If the patient has a prognosis of days to weeks, anorexia/cachexia, and/or the wound has inadequate perfusion, then symptom control alone is appropriate and uncomfortable/burdensome treatments are not appropriate.

Debridement
Necrotic tissue must be removed under adequate analgesia for ulcer healing; surgical debridement is the fastest and most effective method when there is healthy surrounding tissue.
Debridement gels on the ulcer, under an occlusive dressing, are available for ulcers that don't require surgery or when surgical debridement is incomplete. These products come with or without enzymes to encourage autolytic or enzymatic debridement.
For minimally necrotic ulcers, occlusive dressings promote autolysis.

A commonly prescribed form of mechanical debridement is the use of saline, wet-dry dressings. This treatment actually retards healing by pulling off new epithelial cells as part of healthy granulation tissue; its use for the treatment of skin ulcers should be abandoned.
Note: If the patient is close to dying, and/or the wound will never heal, then debridement should not be attempted.

Dressings
Living tissue requires moisture for transport of oxygen and nutrients. A moist ulcer environment promotes the migration of fibroblasts and epithelial cells; growth factors are present in the serous exudate that speed healing. In contrast, a dry environment is conducive to necrosis and eschar.
Ulcer healing is delayed if there is bacterial infection within the wound bed. Erythema, purulent exudate, and fever are signs of infection. Cleansing and application of topical antibiotics may be sufficient for superficial infection with minimal surrounding erythema. Systemic antibiotics are indicated for deep/surrounding tissue infection, or if ulcer healing is delayed.

Cleanse wounds that are expected to heal with non-cytotoxic fluids. Cytotoxic fluids (e.g., betadine) will kill granulation tissue.
Clinical pearl of wisdom: don't cleanse an ulcer with any fluid you wouldn't put in your eye if you want the ulcer to heal.

There are 6 classes of dressings distinguished by the wear time and whether you want to add or remove fluid in order to maintain the ideal moist, interactive ulcer-healing environment.
A dry ulcer needs to have moisture added through a hypotonic gel (donates water).
In a wet ulcer, a hypertonic gel or foam is used to remove water.

- Polyurethane foams. Most absorptive; used under a covering secondary dressing.
- Alginates. Works to desiccate an overly wet wound. Prevents maceration of surrounding skin from excess fluid; is hemostatic and may reduce risk of infection
- Hydrogels. Used for wounds with larger volumes of exudate; requires a secondary dressing to secure.
- Hydrocolloid wafers. Self-adhesive. Promotes autolysis, angiogenesis and granulation. Remains in place for 5-7 days. Often used to “seal” a wound that is otherwise clean in order to promote healing.

Adapted from Ferris F, von Gunten CF. Fast facts and concepts #41. Pressure ulcer management: debridement and dressings. Internet. January 21, 2016.

Pressure ulcers

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