An air-fluidized bed is a highly specialized medical support surface designed to manage and treat severe skin and tissue breakdown. This technology works by suspending the patient on a fluid-like medium, which dramatically reduces the pressure exerted on the body’s contact points. It is often reserved for patients in critical care settings where standard mattresses are insufficient for adequate pressure relief. The primary function is to distribute the patient’s weight over the largest possible area, promoting the healing of existing wounds and preventing further damage.
The Process of Air Fluidization
The mechanism relies on a physical phenomenon known as fluidization, where a solid material is made to behave like a liquid. This is achieved by filling the bed’s basin with thousands of tiny, silicone-coated microspheres. A high-volume blower unit forces filtered, pressurized air upward through these beads. The upward flow of air suspends the microspheres, creating a dynamic, fluid-like support mass.
When a patient lies on the protective sheet covering the beads, their body immerses and is enveloped by the fluidized medium. This allows the surface to conform perfectly to the patient’s contours, maximizing the contact area. Spreading the total body weight across this large surface significantly reduces the pressure exerted on any single point, such as a bony prominence. This process lowers the interface pressure below the 32 millimeters of mercury (mmHg) threshold, which typically restricts blood flow to capillaries. The resulting environment supports tissue oxygenation and the wound healing process.
Clinical Indications for Use
These specialized support surfaces are reserved for severe clinical scenarios where other pressure-reducing equipment has been ineffective or is contraindicated. A primary indication is the presence of severe pressure injuries, particularly those classified as Stage III (full-thickness tissue loss) or Stage IV (deep tissue destruction). The intense pressure reduction is necessary to offload areas of deep tissue damage, allowing for granular tissue formation and wound closure. Patients who have undergone surgical repair of pressure injuries, such as myocutaneous flaps or skin grafts, also require this support to ensure the delicate surgical site is not compromised by pressure or shear forces.
The air-fluidized surface is also used for patients with extensive burns. The fluid-like support minimizes trauma to fragile skin and helps manage the large volume of exudate associated with burn wounds. The technology is also used for individuals with unstable spinal conditions or multiple trauma who require therapeutic immobilization. The conforming medium allows for full support without the need for frequent turning. Continuous air flow assists in managing the microclimate, keeping the skin dry and reducing the risk of maceration.
Key Structural Components
The function of the air-fluidized bed depends on the coordinated operation of several distinct structural elements. A powerful blower unit serves as the air source, drawing in ambient air, filtering it, and pushing it into the system. This pressurized air is directed into a sealed chamber, known as the plenum, positioned beneath the bead reservoir. The plenum collects the air and ensures it is delivered uniformly across the bed surface.
Above the plenum is a porous diffuser board, a plate containing numerous small holes that distribute the air evenly to suspend the microspheres. A thin, breathable filter sheet is positioned between the patient and the fluidized beads, preventing direct contact while allowing air to pass through. This sheet is waterproof yet vapor-permeable, helping to wick away moisture and manage the patient’s skin temperature. Many systems incorporate heating elements within the air pathway to warm the air before it reaches the patient, aiding in comfort and thermal regulation.