Air Mattresses for Pressure Sores: How They Work

How pressure sores form, in brief

Skin and the tissue under it need a steady blood supply. When a bony area presses on a firm surface for a long time, blood vessels are squeezed shut and the tissue starves of oxygen. Friction, shear (skin dragged as the body slides) and moisture from sweat or urine make this worse. Older adults, people with poor nutrition, diabetes, reduced feeling, or who cannot move on their own are at higher risk. Damage can begin within hours in fragile skin.

The aim of any pressure-relieving surface is to spread the load, reduce the time any one area is squeezed, and manage moisture and heat. But no mattress replaces turning, skin checks and good care; see preventing bedsores at home and pressure ulcers: stages and care.

What an air mattress is

An air mattress for pressure care is made of a series of air cells, usually tubes running across the bed, connected to an electric pump. It replaces or lies on top of the standard mattress. There are two main kinds.

Alternating pressure mattress. The pump inflates and deflates groups of cells in a cycle, commonly every few minutes. Typically alternate cells are inflated while the others are partly deflated, so that pressure moves from one part of the body to another. This gives areas of skin a rest from pressure. It is widely used for people at medium to high risk and for those who cannot be turned often.

Static (low air loss or constant low pressure) mattress. The cells stay inflated to a set level, moulding around the body to spread the load. Some have tiny holes that let air flow under the skin to reduce moisture. These are used for people at lower to medium risk, or in combination with regular turning.

You may also see bubble mattresses, which are thin, bubble-patterned overlays with a small pump. They are inexpensive, but they give limited pressure relief. They may reduce risk slightly for some people but are not enough for those with existing sores or high risk. See choosing an anti-bedsore mattress for a comparison.

Mattresses may be:

• Overlay: a layer placed on top of an existing mattress.
• Replacement: a full mattress with air cells inside, used on the bed frame or a hospital bed.
• Hybrid: foam base with air cells on top, which gives a safety margin if air is lost.

Who may need an air mattress

A doctor or nurse should assess risk. Air mattresses are often considered for people who:

• spend most of the day or night in bed or a chair;
• cannot turn or reposition themselves;
• already have a pressure sore or very red skin that does not fade when pressed;
• have thin or fragile skin, low body weight or poor nutrition;
• have reduced feeling, for example after stroke or spinal injury;
• have diabetes or poor circulation;
• are incontinent so that their skin is often wet;
• are confused or too ill to ask for a change.

For someone who walks and moves freely, an air mattress is not needed. A mattress that is too soft or unstable can make it hard for a person to move and get out of bed, and may increase fall risk, so use only if the need is clear.

What an air mattress cannot do

• It does not replace turning. Many people still need repositioning every few hours, as the care team advises; see positioning a bedridden parent.
• It does not treat an existing sore on its own. Wounds need medical care.
• It does not solve poor nutrition, dehydration, wet skin or friction.
• It does not work if it is switched off, under-inflated or wrongly set.
• It does not suit every person, and some feel unstable or hot on it.

Setting up an air mattress

1. Check the box and manual. Make sure all parts are present, and read the instructions. Note the weight limit. 2. Place on the bed. Put the mattress on a flat, firm bed base, with the pump hose at the foot end if the design suggests. The surface should be clean and free of sharp objects. 3. Connect the hose to the pump, checking that it is not kinked or trapped under the bed. Hang the pump on the foot board or place it on a stable surface; do not let it rest on the floor in a damp place. 4. Plug in and inflate. It may take 10 to 30 minutes to reach pressure. Check the pump display or indicators. 5. Set the pressure according to the patient's weight, following the manual. Many have a dial or switch for weight or comfort. Too hard means less pressure relief; too soft means the person may "bottom out" and rest on the base. 6. Do the hand check. Slide your flat hand under the mattress below the patient's buttocks. You should be able to feel a few centimetres of air between your hand and the patient. If you feel the patient resting on your hand, increase the pressure or check for leaks. A nurse can demonstrate. 7. Use a single, thin layer of linen, and keep sheets smooth and loose. Thick, tightly tucked layers or plastic sheets reduce the effect. Use breathable, absorbent cover pads for incontinence; see bed linen and fabrics for sensitive older skin. 8. Fit rails only after checking they work with the mattress; see bed rails guide. Air mattresses can compress and change the gap between rail and mattress.

Using it day to day

• Keep the pump on. Do not unplug it to save power. If the mattress deflates, the patient can end up on the hard base within an hour or two.
• Check the display and alarm lights each shift. Most pumps alarm if pressure is low or the power fails.
• Do a hand check daily and whenever the patient's weight, position or the room temperature changes.
• Keep pets, sharp objects and cigarettes away. Do not put hot water bottles, heating pads or needles on the mattress.
• Do not sit on the mattress edge or place heavy objects on it; transfers to the edge can be unstable, so use a firm chair for sitting; see bed transfer techniques.
• Keep turning and checking skin. See preventing bedsores at home.
• Move the patient carefully, lifting rather than dragging.
• Use the CPR or emergency deflate function, if present, if the patient needs resuscitation.
• Keep the hose clear of the wheels of the bed and of moving beds.

Noise, heat and comfort

Pumps hum or click, which some patients find soothing and others find distressing, particularly at night. Place the pump so that the noise is away from the patient's head, and use a pump with a quiet setting if available. Some mattresses feel warm; low-air-loss models reduce this. In hot weather, use thin cotton sheets, light clothing and fans (not directed straight at the patient); see keeping a bedridden parent cool in Indian summers.

Power cuts and failures

An air mattress depends on electricity. In many Indian cities power cuts are common.

• Check how the mattress behaves. Some models hold air for several hours after power is lost, others deflate quickly. Ask the supplier.
• Use a backup, such as an inverter or battery connected to the pump. Check that the pump uses a plug type that suits the supply. Do not use a large load on a small inverter.
• Have a plan. If power fails for long, turn the patient more often and keep them on their sides, using pillows to protect bony areas, until the pump is running again. Do not leave the patient lying on an uninflated mattress for hours.
• Know how to lock the air in: some mattresses have valves that can hold air.
• Keep a spare foam mattress or overlay for emergencies.

See hospital beds and power cuts for planning.

Cleaning and care

• Follow the maker's cleaning instructions, which generally say to wipe the cover with a mild detergent or an approved disinfectant, rinse and dry.
• Clean after every spill, and daily around the area of use.
• Do not use harsh solvents or sharp tools.
• Check the cover for tears, and replace worn covers.
• Check cells and hoses for holes by listening for leaks and checking the pressure.
• Keep the pump's filter clean, as instructed.
• Never fold the mattress in storage without deflating as directed.
• Service the pump annually, or as advised.

Common mistakes

• Using a mattress rated for too low a weight.
• Setting the pressure by guessing rather than by the weight setting and hand check.
• Putting several thick layers of linen or plastic over the mattress.
• Forgetting to check the pump, so a deflated mattress goes unnoticed.
• Stopping repositioning because "we have an air mattress".
• Using a child's inflatable airbed from a shop; these are not designed for pressure care.
• Using bubble mattresses for high-risk patients.
• Placing the mattress on a sagging bed base.

When to ask a professional

A nurse or doctor should assess your parent's risk, check the skin and say what type of mattress is needed. A tissue viability nurse or wound care specialist is ideal for existing sores. A physiotherapist or occupational therapist can advise on positioning and transfers. Seek urgent advice for skin that is broken, black, blistered, very painful or hot, for a sore that smells or oozes, and for any fever or confusion.