Pressure sores: Can special mattresses and overlays prevent them?

It is important for people with an increased risk of developing pressure sores to move as often as possible – with help from others, if needed. Additionally, pressure-relieving aids like special mattresses and mattress overlays can lower the risk of getting pressure sores.

Pressure sores (also known as pressure ulcers, decubitus ulcers or bed sores) can be avoided. This kind of wound is particularly common in people who spend a lot of time lying down or in wheelchairs because they cannot move much or not at all. People can get pressure sores if they are not turned often enough or do not get enough help changing positions. Pressure sores can also develop during surgery or from wearing plaster casts, for example.

Pressure sores develop when skin is exposed to prolonged external pressure that restricts blood supply to the area. They typically affect areas of the body where bone is close to the skin surface, like the tailbone, hips and heels. The skin in these areas is thinner and pressure cannot spread out easily, so that blood vessels are compressed. If the pressure is not reduced, the tissue does not get enough oxygen and nutrients. The skin becomes even thinner and may start to die after some time, resulting in an open wound.

Pressure sores are very distressing. They can hurt a lot, particularly if you sit or lie on them. Germs may get into the wound too, causing it to become infected, and sometimes even leading to blood poisoning (sepsis). These sores usually heal very poorly and slowly, and treatment is often demanding, uncomfortable or painful. Pressure sores can be prevented, so it is important that as much as possible is done to try to stop them from developing in the first place.

Lowering the risk by relieving pressure

If people are at increased risk of getting a pressure sore, particular attention should be paid to relieving pressure. People who are in bed for long periods of time need to change position, be helped to move themselves, or be turned regularly so that they do not spend too much time lying on one side or on their back. It is especially important that weaker people, too, move as much as they can to stay as independent as possible.

Other options relieving pressure include mattress overlays and special mattresses or cushions. Pressure-relieving support surfaces aim to help in two main ways:

• Some aim to spread the pressure out so that it is not all concentrated on one small area of the body. Examples include special mattresses (made of foam or gel, for example) and special overlays (such as medical sheepskins) Overlays include woolen or skin overlays, or those made with substances such as silicone and gels.
• Other systems work by alternating pressure. This means that pressure of varying intensity is spread out alternately on certain areas of the body. This is done using mattresses or overlays, the various parts of which can be inflated to a higher or lesser degree.

In Germany, health or long-term care insurance will often cover the costs of the supplies you need at home, or provide special beds, for example. Your insurance company, doctor’s office or an advice center for carers will provide you with further information.

Research on pressure-relieving surfaces

What benefit have pressure-relieving surfaces, and are some products better than others? Researchers from the Cochrane Collaboration looked for trials that could answer these questions. The Cochrane Collaboration is an international network of researchers who work together to systematically gather the available information on the effectiveness of health care interventions. To do this, they analyze the results of clinical trials.

The most reliable kind of trial is called a randomized controlled trial (RCT). The voluntary participants in RCTs are randomly divided into different groups. One of the groups receives the treatment that is being tested, and the people in the other group (or groups) receive a fake treatment (placebo), no treatment or a different treatment. This makes it possible to find out what effect the treatment has on people’s health.

The Cochrane researchers looked for trials where pressure-relieving surfaces were used for people who were at increased risk of getting pressure sores. They found 53 of these trials, in which the various support surfaces were either compared with normal mattresses or with each other. This may sound like a lot of information, but because many different kinds of support surfaces were tested in these trials, there was only enough data to draw clear conclusions about some of them.

Foam mattresses, alternating pressure mattresses and special sheepskins lower the risk of pressure sores

The trials show that fewer people get pressure sores if mattresses made from special foam are used instead of ordinary hospital mattresses. These foam mattresses are a lot softer than ordinary mattresses. They mold to the body so that the body sinks somewhat into them when lying down. Nowadays they are often used in hospitals, nursing homes or at home. There is evidence in a few trials that alternating pressure mattresses can also prevent pressure sores. More research is needed however to find out how great their effect is, and whether some systems are better than others.

There were no trials of water beds and there is still not enough research about different types of cushions for beds or wheelchairs either. Special cushions like this include ones where bits are cut out for bony parts of the body. Others are filled with gel, so that the pressure can be spread out more equally. It is not known whether or not these are helpful or may even do harm.

If a bed is very soft, it could make it more difficult to move for some people. That is because it is not as easy to prop yourself up and change positions. People who are weak but would normally still be able to change positions on their own may move less when lying in bed as a result. It can therefore make sense to take these differences into account and to check exactly whether another mattress or overlay is needed.

Three trials indicate that Australian medical sheepskins used as mattress overlays can also lower the risk of developing pressure sores. Other skins have not been tested in trials like this.

Even though some overlays and mattresses can reduce the risk of developing pressure sores: they can only reduce the pressure on the body, they cannot take it away completely. Therefore moving and changing positions to relieve pressure remain the most important factors. In Germany, special outpatient nursing services and advisory centers offer training courses for relatives. Here they can learn how to best prevent pressure sores when caring for their loved ones at home. You can read more about how pressure sores develop and how they can be prevented here.

Author: German Institute for Quality and Efficiency in Health Care (IQWiG)

Next planned update: May, 2014. You can find out more about how our health information is updated here.

© IQWiG (Institute for Quality and Efficiency in Health Care)