alternatingpressure

Alternating pressure refers to a system that cyclically changes the surface pressure supporting a person, typically by inflating and deflating an arrangement of air cells. It is commonly used to prevent and treat pressure ulcers in individuals with limited mobility. The term is most closely associated with alternating pressure mattresses and overlays, which distribute body weight and relieve prolonged pressure on vulnerable areas.

Mechanism: A pump and control unit alternately fill and evacuate air from a matrix of interconnected cells. As one region is inflated, it raises and relieves pressure on adjacent areas, then the pattern reverses. Cycles are timed to support tissue perfusion and accommodate body shape. There are mattresses with built‑in alternating pressure cells and overlays that can be placed on existing beds.

Applications: Alternating pressure devices are used in acute care, long‑term care, and home settings for people at risk of pressure ulcers or with existing ulcers. They are also employed in seating cushions for long‑term wheelchair users to reduce ischial pressure. Some systems offer additional features such as low‑air‑loss ventilation or integrated monitoring.

Benefits and limitations: Alternating pressure can reduce sustained tissue deformation and improve blood flow, potentially lowering ulcer risk. It is not a substitute for regular repositioning, skin inspection, nutrition, or moisture management. Practical considerations include device noise, energy use, weight limits, and maintenance. Proper hygiene and the use of skin‑safe, latex‑free materials are important to minimize irritation and moisture buildup.

History and standards: The technology developed as part of wound prevention and rehabilitation efforts and is widely used in care settings. Devices are evaluated under safety and efficacy standards, with clinicians selecting products based on patient needs, risk level, and facility protocols.