Selecting the right bed can improve both the patient and your bottom line

Fancy or plain, you have to know what works

(This is the first of a two-part series on specialty bed usage in wound care and prevention. Next month, we will feature advice on making the most of Medicare reimbursement for specialty beds in the home care setting.)

If you’re looking for just the right bed to prevent pressure sores for your patients, you’d better have lots of time or knowledge. According to one estimate, more than 1,600 therapeutic support surfaces and specialty beds are on the market. They range from the simplest of foam pads costing a few dollars to huge air-fluidized beds costing hundreds of dollars per day.

Selecting the wrong support surface for patients with post-surgical wounds or for those who have or are at risk for pressure ulcers can slow the healing process or even lead to additional wounds. And, of course, it can be very costly. One health care consultant told Wound Care that a client hospital had spent $330,000 per quarter for special beds and mattresses. A nursing study1 reported that the use of specialty beds adds approximately $175 to $275 per day to the cost of patient care in hospitals.

"The selection of the proper support surface can have a great impact on the success or failure of wound care," says Ben Peirce, RN, CWCN, clinical manager of the Wound Care Program for Columbia Home Care–Southeast Florida in Ft. Lauderdale.

When a support surface is well-matched to a patient’s condition, it promotes faster wound healing, improves patient comfort, decreases hospitalization time, decreases nursing time spent at the bedside, and ultimately decreases costs, adds Timothy M. Demers, LPN, a nurse consultant with Hill-Rom Home Care in Charleston, SC. "You don’t want a patient with a stage I ulcer on a bed that costs $100 a day," he says.

Thorough patient assessment

The process of selecting support surfaces for wound care patients begins with a thorough assessment of their overall condition. Wounds must be accurately staged because the information will influence selection criteria, says Demers. But just as important to the decision process is taking a more holistic view of the patient. All risk factors need to be carefully considered, including pressure on the skin, dressings in use, general health status, mental acuity, mobility, nutrition, compliance, and medication.

"It’s not safe to assume just because a patient has a stage I ulcer, he needs a static device," Demers says. "A patient whose wounds are not healing may be the result of factors other than the support surface." For example, immobile patients with stage I pressure ulcers may need a more advanced support surface than patients with similar wounds who are able to reposition themselves.

Knowing the cause or causes of the wound (pressure, shear, friction, or moisture) is also important. Each force acts upon tissue in distinct ways and thus should influence the choice of support surfaces. (For more information, see story on the forces that cause wounds, p. 39.)

When pressure relief is the paramount concern, objective measures are available for evaluating a support surface. Tissue under constant compression from pressure against a support surface can close down capillaries, which can lead to ischemia and necrosis. Generally, capillary closure occurs at about 32 mm Hg, though patients with compromised nutrition and health can succumb to wounds with capillary pressures that are significantly lower.2

Spreading the weight

How much or how little pressure a surface exerts on the body is a function of how efficiently it spreads weight across its surface, says Peirce. Ultimately, relief of the interface pressure at the capillary level is paramount, especially at bony prominences where pressure ulcers often occur, such as the pelvis, heel, and sacrum.

Peirce cautions that some surfaces appear to conform to the body very well, but if pressure actually measured at sensitive areas isn’t below capillary closing pressure, it will not be effective at preventing wounds from occurring or keeping them from deteriorating.

Effective low-pressure beds usually fall into the category of low air-loss beds or air-fluidized beds. Also, some of the newer static devices are considered low-pressure surfaces. Sometimes, simple high-density foam mattresses are adequate. (For details, see story, above right.)

Shear forces are often a problem for people who elevate the head of the bed more than 30 degrees. This allows the spine to slide down while the skin sticks to the sheets, closing off blood supply to the area. The effectiveness of a surface at reducing shear forces depends on its coefficient of friction (slipperiness). Nylon or silk sheets, for example, are more slippery than cotton sheets and reduce shear injuries. Unlike pressure relief, there is no objective numerical measure to apply to specialty beds that aid in quantifying shear severity or reduction. For minimal shear and friction problems, high density foam mattresses provide some protection. Low air-loss beds and air-fluidized beds provide additional defense.

Excessive and concentrated moisture build-up can lead to maceration in which the skin softens and becomes highly prone to breakdown and deterioration caused by pressure, shearing, or friction. Incontinent patients are at high risk for wounds resulting from maceration. Support surfaces for these cases must allow moisture to escape or be carried away.

Clinicians have the option of using water permeable mattress covers, which are relatively inexpensive, or higher-priced dynamic surfaces, such as air-loss and air-fluidized beds, which blow a stream of air under the patient, evaporating excess moisture.

Demers suggests asking the following basic questions when searching for the proper support surface:

1. Pressure: Does the product distribute the patient’s body weight evenly and adjust to any movement?

2. Shear and friction: If the patient’s head is elevated, moves, or slides down a lot, how does the product help to prevent shearing and friction? 

3. Maceration: Is the cover permeable to moisture? Does the support surface allow air to escape near the patient’s skin?

Show me the proof

But how do you know if a bed or support surface does all its manufacturer advertises? Ask for proof, suggests Demers. "If a company claims their product substantially reduces pressure, ask for clinical studies and research data to support the assertions," he says. "If they can’t back it up, be very cautious." 

Supplier follow-up also should be taken into consideration when shopping for specialty beds or mattresses, regardless of whether the setting is a hospital, nursing facility, or the patient’s home. Don’t settle for a company that simply drops off the product. "Find out if they’ll check in occasionally to see how the patient is doing and how much healing has occurred, and if they offer clinical support if required," says Demers. "Find out how the distributor will support you if the patient isn’t healing. Will the supplier educate the patient and caregivers about the bed’s operations? These are all important factors."

Guidelines help clear the smoke’

Peirce suggests referring to guidelines on managing tissue loads issued by the federal Agency for Health Care Policy and Research (AHCPR). "The guidelines help to clear the smoke and clarify what’s out there and how to match patient needs with the right product," he says. The AHCPR offers a flowchart for narrowing down the support surface decision.(See "Management of Tissue Loads: AHCPR Guidelines," p. 40.) 

Whatever support surface they choose, clinicians strongly agree that nothing substitutes for turning patients regularly. Patients should be repositioned every two hours if at all possible, says Kim Bookout, RN, BSN, CETN, skin and wound management program manager at Columbia Home Care in Houston. "This can be big problem in the home, because caregivers often are under the misconception that turning isn’t important since the patient has a special bed," Bookout says.

1. Mahon D, Jensen V, Plamer S, Peterson M, Vowell, V. Reducing specialty bed use. Nurs Econ 1995; 13:174-177.
2. Jay R. Pressure and shear: Their effects on support surface choice. Ostomy Wound Mgmt 1995; 41:36-45. n