Pressure sores, pressure ulcers, pressure wounds, decubitus ulcers bedsores all names of what we commonly include as skin breakdown. These wounds and their terms have been around for a long time – so what is new?
Here is a new term – Deep Tissue Injury (DTI). In several articles published in Mobility Management in 2014 there is new light on tissue deformation and how this internal deformation can cause Deep Tissue Injuries that can be even more insidious than traditional pressure ulcers. DTI is harder to identify and observe than the typical pressure ulcer. Research by Amit Gefen, Ph.D. and professor of biomedical engineering at Tel Aviv University has adopted an unconventional, but very effective approach to understanding the forces from within the body that eventually lead to skin breakdown.
Using computational modeling, Dr. Gefen is finding how the bones of the body and the soft tissues interact to create a chronic wound field. Dr. Gefen explained that the computer simulations show how loads develop in tissues, not only on the surface of tissues, but also internally, where you can’t look. Also using open style MRI equipment Dr. Gefen was able scan subjects while sitting upright. When sitting directly on the surface of the MRI machine, Dr. Gefen found that the muscle is deformed to at least 50 percent of its original thickness.
Further analysis in looking at the cellular level we learn what exactly happens to the cells that kills them. These deformations are basically compromising the control of transport through the plasma membrane of the cell so after an amount of time, the walls of the cell (plasma membranes) become permeable.
Hence, that deformation eventually causes tissue damage from within where it is almost impossible to detect using normal methods. To protect the tissues, it is necessary to minimize tissue deformation, according to Gefen. Minimizing tissue deformation is not the same as minimizing interface pressures. To look at interface pressures one is basically just looking at the skin. You cannot really tell what is going on inside the body.
Healthy skin is similar from one person to another. Our outer skin is the epidermis. Going deeper is the dermis and subcutaneous fat layers. Wheelchair users are at a greater risk of developing pressure sores due to factors such as sitting for long periods, lack of sensation and insufficient and/or irregular weight shifts. For these reasons wheelchair users, caregivers and healthcare professionals are taught to look for the signs of pressure ulcers developing, such as changes in skin color, temperature and texture.
There is significantly greater difficulty in detecting the formation of DTIs. When they are detected, critical damage may already have occurred.
Greater awareness of internal tissue deformation is emerging as National Pressure Ulcer Advisory Panel (NPUAP) and the European Pressure Ulcer Advisory Panel are now developing new guidelines for prevention and treatment. There is now a universal classification system that includes DTIs.
Deep tissue injuries happen internally. Therefore they may not cause the reddened or warmer skin that has always been the sure indication of a developing pressure ulcer. Tissue deformation puts the tissue at risk since we now know that the more serious pressure ulcers start from the inside. The highest tissue loads are at the bone/soft tissue interface.
For example the ischial tuberosity (IT) are rather pointed bones depressing the soft tissue of the buttocks and deforming the tissues. As such, when one sits, the sharp tip of the IT bone is compressing on a very small area of soft tissue with the full force of the individuals weight. The soft tissue is pinched between the IT and the surface on which the individual is sitting. Such a situation creates the environment for the development of pressure ulcers.
Once a client has a pressure wound, it is very probable that they will have a recurrence. While the term “healed” is used at the end of treatment, it is now understood that pressure sores never totally heal. The healed area is a scar which is never going to have the elasticity and load-bearing abilities of the original healthy skin and tissue. As such the resulting scar is now significantly more susceptible to again becoming another pressure ulcer.
Even with scar tissue present, it is possible to manage pressure ulcers and deep tissue injury risk safely depending on characteristics of the wheelchair seat cushion chosen. To help reduce the resulting pressure of a client sitting, the best cushion technology should distribute the client’s weight equally across the top of the cushion while providing additional relief for the IT and scar tissue that may be internal and/or on the skin surface.
Wheelchair cushions of foam, liquid gel or air all react the same when the client’s weight is introduced in a seated position. These cushions allow the weight to sink directly downward until they hit bottom or to the point that the cushion will not give any further. Hence, these cushions continue to press upward against the client which can be detrimental to the IT or any scar tissue, whether it be surface or internal.
The only cushions found to actually evenly distribute a client’s weight evenly across the top of the cushion while allowing for relief of the IT and scar tissue is the EquaGel cushions using the buckling column technology. The buckling column technology was developed in the mid 1990’s and has been very successfully employed in critical care hospital beds around the world. Now, under the name EquaGel, wheelchair cushions provide the same extended comfort and superior protection provided by the buckling column technology. EquaGel wheelchair cushions are exclusively offered through GelTechCo, LLC of Denver, CO.