A decade ago, pressure injury prevention and treatment was entirely based on the assumption that unrelenting pressure on tissues caused ischemia (a restriction of blood supply). Not enough blood moved through the blood vessels, surrounding tissues didn't receive enough oxygen, and they deteriorated and died... causing an ulcer.
If this process was in fact the cause, it would take several hours to significantly affect tissues. Based on this view, pressure injury prevention for the last decade has focused on support surfaces upon which a patient is likely to spend several hours of prolonged lack of movement. When a patient spends hours in a bed or wheelchair, we make sure the surface is made of materials that will distribute or reduce the pressure, and we reposition her to ensure she doesn't spend too much time with pressure on any one area.
Thankfully, as the years have gone by, we have seen less pressure injuries as a result of lying or sitting on these support surfaces.
But - and there's a big but - pressure injuries do still surface, in spite of repositioning and all the advanced technology.
Old Versus New Knowledge
Prof. Amit Gefen of Tel Aviv University explains that the research community now knows that pressure injuries form not from ischemia, but rather from tissue distortion. If a cell is squashed for too long, its structural skeleton and internal cell structures can’t hold up. They fail, and the cell dies. “Too long” for a cell is not measured in days or in hours. It’s measured in tens of minutes.
Any unprotected surface an at-risk patient is exposed to for even 20-30 minutes can create cell damage and death. Most of the damage is invisible, occurring at the point of most extreme pressure, where internal tissue is squashed against bony prominences. Tissues begin to die from the inside-out. The next time prolonged pressure (again – measured in tens of minutes!) occurs in that area, more cells die, and more… until finally the injury breaks the surface of the skin. By then it is much, much too late.
Overlooked Support Surfaces that Present Risk
What are the most common overlooked support surfaces that present real risks?
In assisted living facilities (where occurrences of pressure injuries are often high) a caretaker may bring one patient to the toilet and return 20 minutes later to retrieve him; the caretaker is likely spending those 20 minutes caring for the other patients he or she is responsible for.
Sitting on a non-cushioned toilet seat for 20 minutes, however, can easily spell the start of a pressure injury. The toilet seat presses the buttocks tissue against the bones within, the cells around the bones get squashed, and cells start to die. Even if a patient is in a top quality facility with specialized (and very expensive) pressure injury prevention equipment, the toilet seat is sometimes forgotten as a hidden support surface which can cause pressure injuries quickly.
Often, in these same facilities, the patient is seated on a non-cushioned plastic stool for showering. Showers, even assisted, can take 15-30 minutes. Even with advanced technology in the bedroom, the patient is at-risk in his or her bathroom.
That same well-intentioned and well-educated caretaker might bring the patient to a chair in the facility’s lobby for an activity or a change of view. While the wooden or plastic uncushioned chairs are fine for visitors, for a patient at risk, even a half-hour activity is liable to cause damage.
As a caregiver, you are the front line in ensuring patients’ health and preventing pressure injuries. While ischemia was seen and related to as the cause for years, we now know that tissue deformation is the real danger. With up-to-date knowledge about the causes of pressure injuries, your awareness will be heightened. You will be able to keep patients safe from avoidable, risky hidden surfaces.