In the Hot Seat

Thinking Outside the Chair When Assessing Pressure Sore Risk

A quick inventory of where a person with mobility limitations sits on a daily basis will garner a list much longer than just two items — a wheelchair and a bed. Yet when assessing risk for decubitus ulcers, the wheelchair and bed are the first and often the last places considered. Decubitus ulcers form as a result of long-term pressure that compresses tissue among the bone and an outer surface — but what that surface may be varies between individuals. No scientific data can pinpoint exactly which surface is to blame, so evaluating all surfaces is the best approach.

Often seating surfaces other than wheelchairs and beds can present more of a problem simply because they are overlooked. Does your inventory include a commode chair, a shower chair, a tub bench, a combination commode/shower chair, a transfer board, a kitchen chair, a couch, a minivan seat, a bus seat, a high chair, a car seat and the floor? All of these surfaces — and certainly an endless array of additional surfaces — can cause pressure sores.


Did You Know? Tilt-in-space shower/commode combination chairs employ gravity to position individuals who would otherwise require straps to sit upright. Some of these chairs actually have a lot of the same standard features as wheelchairs, including adjustable footrests; flip-back, padded, removable arms; and dual-locking casters. Tilt-in-space chairs are available in pediatric and adult sizes and can benefit quadriplegics and those with cerebral palsy.

"When pressure sores develop, most of the time it's the wheelchair cushion that's blamed," says Elizabeth Stevens, an OTR/L at Invacare, Elyria, Ohio. "But there are so many other offenders."

Dan Eilerman, a PT at Varilite, Seattle, agrees. Pressure sores "can really be caused by just about any surface that you're sitting on," he says. "It doesn't have to be your wheelchair or your commode chair. You can transfer into your car and drive for 30 minutes and tend to slump like we all do, and as you slide, it can certainly create shearing forces" — contributing forces for skin integrity issues.

Determining Risk IQ

Anyone with limited mobility can get a pressure sore, but for individuals with a spinal cord injury or anyone older than 70, the risk is compounded, says Stevens.

Among these groups, two important factors send up the risk flag: decreased or lost sensation and/or the inability to shift weight easily.

"Any time you have a person who has decreased sensation or decreased mobility or that has had previous pressure sores," says Dan Lipka, M.Ed, NRRTS past president, OTR/L, ATS, RTS at Miller's Assistive Technologies, Akron, Ohio, "potentially any surface can provide some degree of risk."

That is to say, a hard surface, such as a plastic tub bench, may work fine for many "because they're still ambulatory and maybe they're in there for 10 minutes sitting on it and they can change their position and they're not risking compromising their circulation to one set area," says Stevens.

But couple medical predispositions with that hard surface, and the risk greatly increases. Individuals who are at risk may be accustomed to shifting their weight while in a wheelchair, but oftentimes those practices are disregarded when it comes to bathroom equipment or other surfaces. And for some, weight shifting may not be an option on any surface.

Spinal cord injury clients have another mark against them: the amount of time skin is in contact with a hard surface. "It's the folks … like your spinal cord injured patients," says Stevens. "Sometimes when it comes to their bowel and bladder program, it can take up to an hour, it could take up to all day … and if you're sitting on a hard plastic surface with no sensation and you don't have that feedback to tell you to move your bottom or to get off your sacrum … you're putting yourself at an increased risk."

Another inherent danger of seating surfaces, particularly bathroom equipment, involves transferring from one surface to another, says Eilerman. "Probably the second leading cause [for pressure sores] is the fact that pressure sores start from shear forces and a break in the skin and … oftentimes that is done in transferring." Equipment such as commode chairs, shower chairs and transfer boards are prime surfaces for creating shear forces because a client is transferring onto a hard surface between surfaces that are not always level. And spinal cord injury patients, says Eilerman, who "have no sensation on that skin surface … may not even realize that they have created a shear injury to their skin."

Shear forces pose an additional threat for the elderly because their skin is not as durable, healing times are slower and incontinence creates moist skin, which is prone to shearing forces, Eilerman says.

Bowel Programs: The Mechanics of Risk for SCI Clients

A Little Padding Goes a Long Way

Without the support of Medicare and many insurance companies, which generally do not pay for bathroom equipment, the choices available for items such as commode chairs and bath chairs can be limited.

As a result, individuals frequently use the most basic of equipment, and padding — an essential element for redistributing pressure — is commonly left off.

"Anytime that you have someone that's going to be on that surface for a lot longer period of time without the ability to shift their weight or without the ability to feel when they're starting to get some discomfort," says Stevens, "that's when it becomes more important that they have that padded surface and even a contoured surface as long as it doesn't interfere too much with their transfers."

Of course, padded surfaces will not eliminate the risk of pressures sores, says Darren Hammond, MPT, CWS, The ROHO Group, Belleville, Ill., but a little padding is better than no padding at all.

Other design elements that help to redistribute pressure include contoured surfaces that adhere to the body's shape, a larger surface area, and footplates and legrests that reposition the lower extremities.

"Most commode chairs, although not all … are a very hard surface that is not at all shaped like the person's body is," says Lipka. "Not only that, but it's a fairly small surface area. And as you know, pressure sores … are most commonly believed to be occurring from high pressures over small areas, particularly over bony prominences of the pelvis."

"Some of those seats are so small, they'll hit a user about mid-thigh," agrees Stevens. "It's that old adage like that guy that used to be in the circus and he'd lay across a bed of nails and you'd get all of this pressure of his body weight, but he was able to lay over the bed of nails because he had a lot of surface area. But if he was just to lay his whole body over just one nail, that's a lot of force over a tiny little surface area. So, he would be impaled. … If you think about that with a seating surface, too, it's like the most I can maximize that [surface area], the most I'll spread out that force coming down and hopefully prevent pressure sores from those real delicate areas."

Footrests and legrests aid positioning, which is very important in devices like wheeled shower chairs, says Eilerman. "If you've got someone that their feet are hanging down, not supported, you're putting a lot of pressure on their seating surface as opposed to allowing some pressure to go through the feet." Adjustable footrests can help support the weight properly and place the upper body in the correct position for pressure relief.

With all surfaces, inspection is key. Stevens suggests inspecting for rough or sharp edges, which can cause skin trauma and increase the risk of pressure sore formation.

Hold the Seat Accountable

To prevent pressure sore formation for those at an increased risk, Hammond recommends three essential features for bathroom equipment or alternate seating surfaces: adjustability, padding and security.

Adjustable devices make for a level transfer, says Hammond, by preventing an individual from transferring from a low surface to a high surface and vice versa. A level transfer means less shear force that can cause a tear in the skin's surface.

Padding is vital to weight distribution, but also important is the integrity of the fabric, says Hammond. Ripped or cracked material can cause pressure sores.

If the equipment moves, make sure it can be locked into place, advises Hammond. Check for locking brakes on wheeled equipment. Since a tub bench is used in a slippery environment, it should have suction cups to secure it to a surface and prevent sliding. Commode chairs commonly come with brackets that mount the device to a wall or the actual commode to prevent slipping during transfers.

To prevent shearing, evaluate transfer techniques between all surfaces, as well. Many shear force injuries happen during transferring as a result of improper technique. "I don't know that I can quote anything to say that, you know, 28 percent of all spinal cord injuries patients that use transfer boards get pressure sores," says Eilerman. "Is it a problem though? Absolutely." Eilerman says that in a perfect situation no sliding would occur during transfers.

Hammond agrees. He says that transfer boards are "basically like a pit stop in that it covers a gap between two surfaces." The proper technique for using a transfer board is to lift the whole body, move it and then sit down on the transfer board.

The key to assessing any surface is education. The more that each member of the caregiving team knows about pressure sore risks, the easier it is to prevent pressure sores from forming. "Allied health care professionals, like OTs, PTs and nurses, we tend to concentrate more on pressure sores being developed in the bed and in the wheelchair," says Hammond. "But we have to be more aware to educate our clients that they can incur [a pressure sore] sitting in a car without a cushion, sitting in a La-Z-Boy chair, sitting on a park bench [or] laying [on] the floor when they're playing with their kids."


Bowel Programs: The Mechanics of Risk for SCI Clients

After a spinal cord injury, damage can occur to the nerves responsible for getting messages from the brain to the areas that control bowel movements. According to the United Spinal Association, an injury above the T-12 level can cause the sphincter muscle to remain tight and bowel movements to occur on a reflex, or automatic, basis. Damage below the T-12, on the other hand, can cause a flaccid bowel, meaning bowel movements may leak out because the sphincter does not close tightly.

Inability to control the sphincter can result in impaction, a condition where solid waste remains in the body, according to the University of Miami/Jackson Memorial Medical Center. Impaction, which can be deadly if untreated, may require surgery.

A successful bowel program can help prevent unplanned bowel movements and bowel problems such as impaction, constipation and diarrhea. Methods of facilitating a bowel program may include manual removal, digital stimulation, suppositories and mini-enemas.

Despite the obvious benefits, bowel programs take a lot of time — time that could contribute to the formation of pressure sores. Dan Eilerman, PT at Varilite, says bowel programs require sitting on a commode or commode chair as often as three or four times a week for an extended period of time. The United Spinal Association estimates that bowel programs require 30-60 minutes to complete, though Eilerman says many programs could take up to an hour, sometimes an hour and a half.

Padding, legrests, increased surface area and frequent weight shifting help to relieve the pressure caused by commode chairs. "Sometimes [clients] forget about the sitting surface when they're doing their bowel program," says Darren Hammond, MPT, CWS, at The ROHO Group. "And if the person themselves are not educated, they don?t realize that sometimes when they're sitting on those types of surfaces, they still have to do pressure relief — just like if they're sitting in their wheelchair for a prolonged period of time."

This article originally appeared in the February 2006 issue of Mobility Management.

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