Deep Tissue Injury Research, Part II

More Than Skin Deep

Last month, we reviewed pressure ulcer research from 2014 as discussed by Amit Gefen, Ph.D., professor of biomedical engineering at Tel Aviv University, and Kara Kopplin, BSc, the Senior Director of Efficacy Research, Standards & Compliance for ROHO Inc. A key take-away from last year’s research — and a point critical to this year’s follow-through — is how tissue deformation occurs within the body, how it can cause tissue damage, and why deep tissue injury (DTI) presents such a challenge to today’s healthcare providers, in particular professionals in seating & wheeled mobility.

Due to factors that can include long periods of sitting, lack of sensation, difficulty in performing regular and sufficient weight shifts, and changes occurring within their bodies (such as the incursion of additional fat into the muscle tissue of spinal cord injury patients), wheelchair users are at increased risk for developing pressure ulcers. That’s been understood in the seating & wheeled mobility niche for a long time, and it’s the reason that wheelchair users are told to perform regular skin checks, and healthcare professionals and caregivers are taught to look for telltale signs of pressure ulcers, such as changes in skin color, temperature and texture. What’s much newer is the idea of tissue deformation and the DTIs that can develop insidiously, without those telltale signs that healthcare workers have been taught to watch for.

Getting Under Your Client’s Skin

Structurally, healthy skin is similar across individuals; it’s composed of (starting at the surface and going deeper) epidermis, dermis and subcutaneous fat layers. But when discussing pressure ulcers with Mobility Management at this year’s International Seating Symposium in Nashville, Tenn., Gefen pointed out that beneath the skin, every person is different.

“You can look at the skin of Kara and myself,” Gefen said, referring to his colleague, “and get similar pressure maps. But internally, it would be different. Because her pelvis and her bones are shaped differently than mine, and I have more muscle mass and less fat mass or whatever, the internal anatomy can be essentially different.”

That’s an important point because compared to ischemiacaused pressure ulcers, which wheelchair users have traditionally been taught to watch for by looking for reddened skin, etc., DTIs can be much more difficult to detect as they are forming.

Once DTIs are detectable, critical damage may already have occurred.

“Once you see [the DTI], it can also become a systemic problem,” Gefen said, “because the kidneys are overloaded with these muscle proteins that are going through the bloodstream. Everything now builds on this new knowledge, that tissue deformation is really the factor that you should look at.”

A Changing Conversation

Gefen added that the perspective on pressure ulcers is changing, thanks to a greater understanding of internal tissue deformation. He pointed to the National Pressure Ulcer Advisory Panel (NPUAP), headquartered in Washington, D.C., and the European Pressure Ulcer Advisory Panel.

“You could actually listen to a new conversation now, with new terminology,” he said. “When I was in these meetings a few years ago, they were all talking about preventing ischemia and optimizing blood flow and looking at pressure maps and saying well, if the pressures are too high, then blood vessels are collapsing, and then you have ischemia, and that’s not good. The other side of it, which is really scary, is they were saying some products work better than others, based only on the superficial information that they do decrease pressure.”

Gefen said research has shown that merely changing pressure at the skin/wheelchair cushion interface is not nearly enough to truly prevent the comprehensive damage caused by pressure ulcers.

And he said he realizes that recognizing the danger of DTI impacts so many existing processes and protocols, from HCPCS codes for skin-protection cushions to the funding attached to those codes, plus client risk assessment, design of future wheelchair cushions, the prescription of those cushions and efficacy evaluations.

“It’s changing already,” he said of pressure ulcer discussions. “I’m also the president of the European Pressure Ulcer Advisory Panel, and we’ve just launched, together with NPUAP, new guidelines for prevention and treatment, which were developed by an international group from Asia, the Americas and Europe. There’s a unified classification system now, and this classification system now includes DTIs worldwide.”

Gefen indicated this is one of the first steps in moving toward tackling a problem that can be so hard to predict and prevent because DTIs happen internally, and their formation is different for every patient. This means, for instance, that a long-term care facility’s practice of changing a resident’s position at regular intervals and checking for visual changes in the patient’s skin might not be enough — and that such facilities need to be educated appropriately.

“Sometimes you can’t see it,” Gefen says of DTIs. “You just break down. It’s all individual, so we have to rethink everything, basically, and this is a process which has started already.”

This article originally appeared in the September 2015 issue of Mobility Management.

About the Author

Laurie Watanabe is the editor of Mobility Management. She can be reached at

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