Pressure ulcers (pressure sores): prevention, stages and treatment

Pressure ulcers, also called pressure sores or bed sores, are areas of damage to the skin and tissue underneath. NICE Clinical Knowledge Summaries define them as localised damage to the skin and underlying tissue due to pressure, or pressure in combination with shear. Shear is the sideways dragging force that occurs when skin is held while the body slides, for example when someone slips down a bed or chair. Most occur over a bony prominence, but they can also be related to a medical device or other object pressing on the skin.

Severity ranges from patches of discoloured skin to extensive wounds filled with dead tissue involving muscle and bone. The NHS says that ulcers usually develop gradually, but can sometimes appear over a few hours, and that if left untreated they can worsen until they reach deeper layers. For that reason a patch of skin that looks only slightly different still deserves attention.

Anyone can be affected, but NICE guidance says all patients are potentially at risk, and it lists significantly limited mobility, significant loss of sensation, a previous or current pressure ulcer, nutritional deficiency, inability to reposition and significant cognitive impairment as examples of risk factors that trigger formal assessment. The NHS adds having been seriously ill in intensive care or recently had surgery, being underweight, having swollen, sweaty or broken skin, and having poor circulation or fragile skin.

NICE Clinical Knowledge Summaries add older age and conditions that reduce blood flow to the skin, such as diabetes and peripheral vascular disease. Risk is dynamic: NICE recommends reassessment when clinical status changes, for example after surgery, with a worsening underlying condition or a change in mobility. A person who is well and active may become high-risk within a day of an acute illness.

The NHS describes discoloured patches of skin that do not change colour when pressed, usually red on white skin and purple or blue on black or brown skin, a patch of skin that feels warm, spongy or hard, and pain or itchiness in the affected area. NICE specifically warns that non-blanchable redness may present as colour change or discolouration, particularly in darker skin tones, and recommends finger palpation or diascopy to check whether the area blanches.

Checking the skin is therefore about colour, temperature, firmness and moisture, not only visible redness. Heels, hips, base of the spine, shoulder blades, elbows and the back of the head are the commonest places. People who use wheelchairs also need to look at sitting bones and thighs, and those with oxygen tubing, splints or catheters need to check beneath devices.

• A patch that stays red, purple or blue after pressure is released.

• Skin that feels warmer, firmer or spongier than the surrounding area.

• New pain, tenderness or itch over a bony point.

• A blister or open area, however small.

NICE guidance sets out a package. Adults assessed as at risk should be encouraged to change position frequently and at least every 6 hours, and those at high risk at least every 4 hours, with help and equipment if they cannot move themselves. A high-specification foam mattress is advised for people at high risk, and a pressure-redistributing cushion for those who sit for long periods or use a wheelchair, with a plan to offload pressure from the heels. Skin massage or rubbing is not advised, and barrier preparations may be considered for skin at risk from moisture or incontinence.

The NHS adds to this for people cared for at home: check your skin every day, stay active if possible, eat a healthy balanced diet and do not smoke, and ask a GP for a risk assessment if you are being cared for at home and think you are at risk. NICE says nutritional supplements and fluids are not offered specifically to prevent ulcers where intake and hydration are adequate, which makes a nutritional assessment more useful than a blanket supplement.

The NHS says treatment depends on severity. Changing position and moving regularly is important to relieve pressure and stop new ulcers forming. Other treatments include specially designed mattresses and cushions, dressings to protect the ulcer and help it heal, creams and ointments, antibiotics if infected, and cleaning of the ulcer. Surgery to clean and close the ulcer may be needed if it is severe or other treatments have not worked.

NICE sets out more detail for adults: document the size and depth and classify the ulcer with a validated tool, offer a nutritional assessment, use a high-specification foam mattress and consider a dynamic surface if that is not enough, assess the need for debridement of dead tissue, and consider a dressing that keeps a warm, moist wound environment for deeper ulcers. Systemic antibiotics are offered for sepsis, spreading cellulitis or underlying bone infection, but not specifically to heal an ulcer or on the basis of a positive wound swab alone.

NICE Clinical Knowledge Summaries list pain, infection and increased mortality as complications. Infection can spread to the surrounding tissue (cellulitis), to bone (osteomyelitis) or to the bloodstream. The NHS advises asking for an urgent GP appointment or contacting NHS 111 if a person with a pressure ulcer has hot, swollen or red skin, pus coming out of the ulcer, a high temperature, or severe pain or pain that is getting worse.

Where an ulcer is not improving despite pressure relief and dressings, the question shifts to why: poor blood supply, ongoing pressure, unrecognised infection, poor nutrition or another diagnosis such as a venous or arterial ulcer. That is why wounds that fail to progress are reassessed rather than simply redressed.