Pressure ulcer

What is a pressure ulcer?

A pressure ulcer is an area of reddened skin that progresses to breakdown of skin and underlying tissue to form an erosion or ulcer, and is due to persistent pressure on the affected area. A pressure ulcer is also known as a bed sore, decubitus ulcer, pressure wound, and pressure ulceration.

What causes a pressure ulcer?

A pressure ulcer is caused by a lack of blood flow due to mechanical stress on the skin and tissues over a bony area that has been under pressure for a prolonged period. If the blood supply is cut off to an area of skin for more than 2–3 hours, the skin is deprived of oxygen and begins to die. In addition, when slowly sliding down a bed or chair, friction to the outer skin layer — such as from wrinkled bedding and clothing — contribute to skin injury and ulceration. Excessive exposure to moisture, such as sweat, blood, urine or faeces, also increases the likelihood of developing a pressure ulcer.

Who is at risk of a pressure ulcer?

People immobile due to illness or injury are at greatest risk of getting a pressure ulcer.

• They may be wheelchair-bound or bedridden, and are unable to change position without assistance eg, see Skin complications of paraplegia.
• They may have nerve damage from injury or illness, such as spina bifida, diabetes or stroke, and are unable to sense pain or the signals that normally make people move.
• Older people are at greater risk because their skin is thinner and more fragile.
• A pressure ulcer may develop underneath a plaster of Paris or fibreglass plaster (plaster ulcer).

What are the signs and symptoms of pressure ulcers?

Pressure ulcers are classified into stages according to wound severity.

Stage 1

• Skin is unbroken but shows a pink or reddened area
• May look like a mild sunburn
• Skin may be tender, itchy or painful

Stage 2

• Skin is red, swollen and painful
• Blisters may be present
• Upper layers of skin begin to die

Stage 3

• Ulcer has broken through the skin and wound extends down to deeper layers of skin tissue
• Crater-like ulceration is present
• Wound is prone to infection

Stage 4

• Sore extends past the skin and into fat, muscle and bone tissue
• Blackened dead tissue called eschar may be seen in deep open wounds

Early pressure changes between toes

Early pressure blisters over toes

Early pressure sore on back of shoulder

Extensive pressure ulcers over buttocks

Deep pressure sore over sacrum

Pressure sore

Most people with a pressure ulcer will feel some pain and itching. However, people who have impaired senses may not feel any pain even with a severe, deep sore.

What is the treatment for a pressure ulcer?

A pressure ulcer can be difficult to treat once it has gone beyond stage 2. In the early stages when the skin is still intact, a pressure ulcer usually heals by itself if the pressure has been removed. Once the skin is broken, the main aim is to prevent infection and protect the sore so that it can heal. Special dressings and honey preparations may be used to help the healing process. Dead tissue may be removed with a scalpel (debridement).

Therapeutic devices used to treat a pressure ulcer include:

• Topical negative pressure wound therapy (VAC®)
• Hydrotherapy debridement, using saline solution in a syringe or a water pressure jet
• Warming therapy, using radiant heat in a moist environment to maintain skin surface temperature of 37–38°C.

Deep pressure ulcers are very difficult to treat and often require surgical treatment to remove dead and decaying tissue.

• Healthy skin may be grafted onto the damaged area.
• Infection needs treatment with antibiotics.
• In severe or life-threatening situations, amputation of a limb may be necessary.

Can pressure ulcers be prevented?

Pressure ulcers can be prevented with intensive nursing care. Measures to prevent pressure ulcers include:

• Avoid and correct malnutrition if present (fluid, energy, protein, vitamins and minerals)
• Daily inspection of an immobile person's skin to detect early redness
• Frequent repositioning (every 2 hours)
• Maintaining skin hygiene
• Special foam, fibre and gels used as padding materials on chairs and beds to relieve the pressure on bony prominences
• Powered alternating-pressure mattresses and overlays.

Prevention of pressure ulcers is the best approach, as an established pressure ulcer can be painful and even life threatening. It may also lengthen hospital stay and markedly increase medical costs.