Pressure Sores



A chronic wound is a break in the skin or body surface that takes a long time to heal, does not heal, or keeps coming back. The most common chronic wounds are those caused by diabetes (leg and foot ulcers), arterial or venous (peripheral vascular) disease, persistent pressure on a bony part of the body, and with therapeutic irradiation for the treatment of tumours. Chronic wounds are particularly troublesome for the elderly who have likely to have a number of health problems. Chronic wounds are long lasting and resistant to treatment. They can worsen over time and cause distress for the individual.

Pressure sores (bedsores) form when a person has persistent pressure or rubbing over a bony prominent part of the body, such as the heels, hips, base of the spine and elbows. They start as discolouration of the skin, pain, itching and discomfort. Untreated, the skin breaks and damage spreads to the surrounding underlying tissues (muscle and bone). Immobile elderly people, patients with severe acute illnesses and in intensive care, orthopaedic patients, palliative care patients and people with neurological disabilities or spinal injuries are most likely to develop pressure sores.

Prevention of pressure sores is an important part of looking after people who are confined in their movements. Special mattresses and covers, constant repositioning of the patient, attending to nutrition and infections are some preventative measures used. Treatments to heal the wounds include dressings, applying topical treatments, heat, ultrasound and laser therapy.


With existing pressure sores, a variety of treatments are used to try to heal these wounds. These include using dressings, applying topical treatments and heat, ultrasound and laser therapy.

What is known

Electrical stimulation has been used for decades as a way of promoting healing of long-term wounds. In electromagnetic therapy a field effect is produced so that a wider area is treated. It is often termed Pulsed Electromagnetic Field therapy (PEMF).

Electromagnetic therapy (also called PEMF - pulsed electromagnetic field) is not a form of radiation or heating, but uses a field of electricity to try and promote healing.

What the synthesised research says

Electromagnetic therapy may be of benefit in the healing of pressure sores but the evidence from two small controlled trials is not strong.

The review is limited by few adequate studies to provide clear evidence for any benefit in using electromagnetic therapy to treat pressure ulcers. A beneficial or harmful effect cannot be ruled out because of methodological limitations of the trials and small numbers of participants.

How it was tested

The researchers made a thorough search of the medical literature and found two randomised trials comparing electromagnetic therapy with standard treatment or sham therapy where no electric current was used. These trials involved a total of 60 hospitalised people with progressing pressure sores. These were men with a spinal cord injury in one of the studies and men and women in the other study. Electromagnetic therapy was given for thirty minutes twice a day over either two or twelve weeks.  

Side effects and general cautions

The evidence is unreliable because of the small number of patients treated. The severity of pressure sores at the beginning of the trials was not well described. This was important to know because the more severe the pressure sore then the harder it is to heal.


Olyaee Manesh A, Flemming K, Cullum NA, Ravaghi H. Electromagnetic therapy for treating pressure ulcers. The Cochrane Database of Systematic Reviews 2006, Issue 2. Art. No.: CD002930. DOI: 10.1002/14651858.CD002930.pub3.


Pressure ulcers present on a continuum of tissue damage from persistently reddened, unbroken skin through to destruction of the muscle and bone. Pressure ulcers are treated by using wound dressings, relieving pressure on the wound, by treating concurrent conditions which may delay healing (poor nutrition, infection), and by the use of physical therapies such as electrical stimulation, laser therapy and electromagnetic ultrasound.

What is known

Low levels of ultrasound (not enough to generate heat) are sometimes used to treat pressure ulcers. It is not clear how ultrasound might affect healing, and ultrasound waves may have a positive or negative impact on the blood flow around the sore.

What the synthesised research says

There is currently no evidence of a benefit associated with therapeutic ultrasound in the healing of pressure ulcers. The possibility of a beneficial or a harmful effect cannot be ruled out. All the trials included in this review have involved small numbers of patients, differing regimens of therapeutic ultrasound, and differing follow up periods.

How it was tested

The researchers identified three trials carried out between 1985 and 1995 that met the inclusion criteria. The trials were all small, each involving 20 to 88 people with pressure ulcers.

Two trials compared ultrasound therapy delivered at approximately 3 MHz (three or five times a week) with sham therapy. The two studies involving only 128 patients in total found no evidence of a benefit of ultrasound on the healing rates of pressure ulcers.

The third trial compared a combination of ultrasound and ultraviolet light (given alternately for 5 days a week) to laser treatment (820 nm laser diode) and with standard wound care twice daily (cleansing with 0.05% chlorine solution, paraffin tulle dressing and pressure relief) in 20 patients with spinal cord injury. Treatment continued until healing occurred. There was no improvement in the number of ulcers healed following ultrasound treatment.

Side effects and general cautions

There were no reports of adverse effects. This review was originally published in The Cochrane Library, Issue 4, 2000. For this first update of the review, new searches were carried out in May 2005. No new study was identified. The reviewers’ conclusions remain unchanged.


Baba-Akbari Sari A, Flemming K, Cullum NA,Wollina U. Therapeutic ultrasound for pressure ulcers. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD001275. DOI: 10.1002/14651858.CD001275.pub2.


The prevention of pressure ulcers involves a number of strategies to, for example, repositioning the person or using pressure relieving cushions or mattresses and optimising the person’s fluid levels, circulation and nutrition. Decreased calorie intake, loss of body fluid, and a drop in the amount of protein in the blood may decrease the tolerance of skin and underlying tissue to pressure, friction and shearing force, increasing risk of skin breakdown and reducing wound healing.

What is known

Having a poor nutritional state or being dehydrated can weaken the skin and make a person more likely to develop pressure ulcers. Dietary supplements, including zinc and vitamin C, and additional nutrition may be useful to prevent or treat pressure ulcers.

Nutrition can be provided normally by mouth or through a tube up the nose and into the stomach (tube feeding), or by gastrostomy. This food is normally digested. Nutrition can also be provided via a tube into a vein (intravenous infusion) or by intramuscular injection (parenteral feeding that does not involve the digestive system).

What the synthesised research says

It was not possible to draw any firm conclusions on the effect of nutritional interventions on the prevention or treatment of pressure ulcers.

These conclusions were based on eight trials, four looking at prevention and four at treatment of pressure sores.

Elderly people recovering from acute critical illness appeared to develop fewer pressure ulcers when given two daily supplement drinks per day over two to three weeks (in one trial).

There was a trend for fewer pressure ulcers in people receiving a supplement in three trials involving 302 participants who were people recovering from hip fractures (1990 to 2003). They were randomly assigned to receive mixed nutritional supplements or normal diet. Follow up times varied from 14 days to six months.

For treatment of existing pressure ulcers: one trial examined mixed nutritional supplements, one trial examined zinc, another the effect of proteins, and two studies compared ascorbic acid with standard care. Whether nutritional deficiencies have an effect on clinically relevant outcomes such as pressure ulcers remains unclear.

How it was tested

The researchers thoroughly searched the medical literature and found eight trials that met the inclusion criteria. Most of the studies were small and of poor methodological quality.


Nutritional supplements included supplements of protein alone, mixed supplements of protein, vitamins, carbohydrate and fats.

In the one trial during the acute phase of a critical illness, one trial randomised 672 elderly people to receive two oral supplements per day in addition to the normal diet or normal diet. They were followed up for 15 days or until discharge. Patients in the nutritional intervention group had a lower risk of developing pressure ulcers and were less dependent than the comparison group. Severe redness of the skin (erythema) was prevalent in both groups.

In three small trials of mixed supplements for people recovering from hip fractures (302 patients) there were smaller numbers of ulcers in the supplement group but the trials were far too small to determine whether these differences were due to chance or a true effect. Follow-up times varied from 14 days to six months.


These trials were undertaken between 1971 and 1995.

Vitamin C: given as 500 mg ascorbic acid twice daily.

The findings are contradictory. One trial involving people with pressure ulcers in surgical wards randomly assigned 20 patients to receive either vitamin C or a non-active treatment (placebo). Healing was twice as effective in the patients given a supplement of vitamin C compared with placebo. Vitamin C was given over four weeks.

The second trial involved people mainly in nursing homes. Eighty-eight patients with pressure ulcers received vitamin C with or without ultrasound or a low dose (10 mg ascorbic acid) with or without ultrasound for 12 weeks. Most patients had nutritional deficiencies on admission. Patients on low-dose vitamin C had better clinical outcomes at 12 weeks.


One small trial involved 12 institutionalised patients randomly assigned to a high protein or a very high protein dietary formula given by nasogastric tube. On both diets, ulcer size decreased over eight weeks but the improvement was greater in the very high protein group. The average decrease in ulcer size was 42% in the high protein group compared with 73% in the very high protein group.


In one trial with 14 patients with pressure ulcers were randomly assigned to receive either zinc sulphate (200 mg three times daily) or non-active treatment (placebo). After 12 weeks the patients switched the groups. Only three people completed the trial and no benefits with zinc were found but the trial is far too small to detect important effects.

Side effects and general cautions

Most trials were small with short follow-up times, insufficient to detect true effects of the interventions. Many of the people in the trials had nutritional deficiencies which improved with additional nutritional supplements.

In one trial, patients did not tolerate tube feeding at night over a long period and ethical aspects are important. This raises ethical issues.

The benefit to the individual in terms of pain and discomfort of a reduction in area (rather than complete healing) is not known.


Langer G, Schloemer G, Knerr A, Kuss O, Behrens J. Nutritional interventions for preventing and treating pressure ulcers. The Cochrane Database of Systematic Reviews 2003, Issue 4. Art. No.: CD003216. DOI: 10.1002/14651858.CD003216.