Pressure/Shear Injury: Clinical Progression and Medical Device Related Pressure Injuries (MDRPIs)
Skin and Wound Care. Produced by the Emory Nursing Wound Ostomy Continence Nursing Education Center.
Transcript
Okay, so in this next section we are going to talk about the clinical progression and we're going to focus on medical device related pressure injuries.
Speaker A:So let's walk through what happens at the tissue level when you expose tissue to prolonged or intense pressure.
Speaker A:We're going to talk about the normal response and then we're going to talk about pathologic response.
Speaker A:So let's talk about normal.
Speaker A:So this is a patient who maybe has average weight.
Speaker A:You've turned them three hours ago, you come back to turn them again.
Speaker A:Okay, so during that three hour period where I've been, let's say on my back then, I had some reduction in blood flow, variable.
Speaker A:So I might have had almost complete obliteration of blood flow to that area, or it might have been partial.
Speaker A:Now, when that happens, when you essentially compress the tissues, compress the vessels, and significantly reduce blood flow to the area if you could crawl underneath, and that's exactly what you see on the top.
Speaker A:Somebody is sitting on plexiglass so that you can see what happens with intense pressure.
Speaker A:And what you see is pallor right over the bony prominences, because you have almost complete compression of the blood vessels to those bony prominences when you're sitting on a rigid surface.
Speaker A:So you've pushed the blood out of that area, you have acute pallor.
Speaker A:And then if you look around the area, you see intense erythema surrounding those areas of pallor.
Speaker A:Why do you have that intense erythema?
Speaker A:Because the cells within the ischemic area are becoming progressively more hypoxic.
Speaker A:They're sending signals.
Speaker A:We need oxygen.
Speaker A:Please send oxygen.
Speaker A:Is anybody picking up our distress calls?
Speaker A:The blood vessels in the area are responding by dilating, trying to get blood flow into that ischemic area.
Speaker A:Now, as soon as you relieve the pressure, what's going to happen?
Speaker A:Blood flow is going to rush into those dilated vessels and you're going to go from areas of pallor to areas of redness, erythema.
Speaker A:And this is known as reactive hyperemia.
Speaker A:So you had an area where blood flow was reduced for a period of time due to tissue and vessel compression.
Speaker A:You relieve the compression, blood flow rushes in.
Speaker A:Is that abnormal?
Speaker A:No, that is a totally normal response.
Speaker A:I consider this to be tissue CPR in progress.
Speaker A:So we've relieved the pressure, we've eliminated the obstruction to blood flow.
Speaker A:Blood flow is now filling those vessels, initiating exchange with the tissues.
Speaker A:That redness will be blanchable.
Speaker A:And that's how you differentiate between abnormal and normal.
Speaker A:As long as I can compress that area with my Index finger, and it goes back to normal color or blanches, turns white, and then I move my finger and becomes red again.
Speaker A:That's a normal response.
Speaker A:Now, typically, that reactive hyperemia will resolve in less than an hour once the tissue is oxygen needs are met.
Speaker A:Once metabolic pathways go back to normal, then there's no longer the need for increased blood flow.
Speaker A:Vessels go back to normal size and the redness goes away.
Speaker A:So reactive hyperemia, blancible erythema is a normal response to a period of tissue ischemia.
Speaker A:It is not a stage one.
Speaker A:Now, let's talk about what happens if you got prolonged or intense pressure and you actually sustain damage to the tissues.
Speaker A:So when you sustain ischemic damage to the tissues, remember you get vessel compression.
Speaker A:You may have shear effects and possibly reperfusion injury.
Speaker A:Then typically, these wounds begin at the muscle bone interface, just like we said.
Speaker A:That's where the tissue pressures are the highest, right at the interface between the muscle and the bone.
Speaker A:That's where you have the tissue layer that is most sensitive to the negative impact of ischemia.
Speaker A:Okay, so you've got tissue that is compressed for a prolonged period of time or where you have very high intensity pressure.
Speaker A:You're going to get acute ischemic damage to the tissues.
Speaker A:What happens at a cellular level, whenever the tissues become acutely ischemic, they shift from aerobic metabolism to anaerobic.
Speaker A:You no longer have enough oxygen to maintain normal metabolic pathways, normal metabolic activities.
Speaker A:So they go to plan B, our emergency system, which is anaerobic metabolism.
Speaker A:Now we have low ATP levels that's going to impair the sodium potassium pump.
Speaker A:As a result, potassium, your intracellular cation, moves out of the cell.
Speaker A:Sodium and calcium move into the cell.
Speaker A:What happens clinically now, you get a very edematous leaky cell.
Speaker A:So you have a very damaged cell.
Speaker A:You start to produce oxygen free radicals, because now you're in anaerobic metabolism.
Speaker A:The oxygen free radicals damage the vessels, damage the cells, and you end up with a sick cell, an altered cell function.
Speaker A:Now, if you have many cells that are involved, you're going to end up with clinically significant tissue damage and breakdown.
Speaker A:You can have limited tissue damage that presents as an inflammatory response, and that resolves spontaneously if it's managed correctly.
Speaker A:So let's say that you.
Speaker A:That's what happens.
Speaker A:You do get some cellular damage, but it's not extensive.
Speaker A:It's enough to cause an acute inflammatory response, but it doesn't involve a significant portion of the tissue.
Speaker A:And before major tissue damage has occurred, you come in and you turn that patient, but when you turn them, you notice, wow, that area is really erythematous and it does not blanch.
Speaker A:So look at this slide right here.
Speaker A:If you see this, what's going on, you've got that sit central area of intense non blancheable erythema.
Speaker A:That tells you you've got an acute inflammatory response and that is triggered by cell damage.
Speaker A:You've got a surrounding zone of erythema that is blanchable.
Speaker A:So that's an area of ischemia that will recover.
Speaker A:Now, what can you do about that central area that's non blanchable?
Speaker A:All you can do is eliminate pressure, protect from shear, from friction, make sure that there are no repeated episodes of ischemia and hopefully the tissues will recover.
Speaker A:Most of the time they do.
Speaker A:You see that on the slide.
Speaker A:Tissues usually recover without an open wound if you provide appropriate preventive care.
Speaker A:So protect against shear, protect against friction, make sure the patient's turned at appropriate intervals so they're not exposed to another episode of ischemia.
Speaker A:Deep tissue injury very, very different than a stage one.
Speaker A:You can see it looks very different.
Speaker A:So deep tissue injury is described as bruising under the intact skin.
Speaker A:That's what it looks like.
Speaker A:So you've got this deep purple, maroon, or sometimes purple, black, purple, gray discoloration under the intact skin.
Speaker A:So the skin itself is intact.
Speaker A:But you've got lots of indications that things are not well, that there are major problems going on with the tissue.
Speaker A:That deep purple discoloration is thought to be reflective of either vessel damage, so that you're leaking red blood cells out into the tissue or possibly to necrosis of the underlying tissue.
Speaker A:It may be one thing in some situations and the other in other situations.
Speaker A:So you know that sometimes deep tissue injuries resolve on their own and sometimes they rapidly progress to deep cratered wounds.
Speaker A:So again, a lot that we don't know about deep tissue injury, but we do know this.
Speaker A:When you see an area of deep discoloration, you have to provide aggressive preventive care and monitor.
Speaker A:You cannot undo the damage that's already occurred.
Speaker A:So there's nothing I can put on it that is going to fix it that we know about at this point.
Speaker A:Ischemic damage that has occurred, has occurred.
Speaker A:All I can do is monitor, wait to see what happens and manage any wound that results.
Speaker A:So how does it look?
Speaker A:It looks like bruising under intact skin.
Speaker A:It may progress to a deep ulcer despite everything you do, and it may take up to four days post injury before it's visible.
Speaker A:Now, that has implications for us, when we're doing patient admissions, if you admit a patient, they come from home, they come from another facility, and the history is that the patient was found down.
Speaker A:You want to inspect the area very carefully.
Speaker A:So if the patient was found on their right side, you want to inspect that area very carefully.
Speaker A:Let's say you don't really see anything at the time of admission.
Speaker A:It would be important to document that the patient was found down lying on the right side for an unknown period of time, that at this point we do not see any evidence of tissue damage.
Speaker A:Two days later, the patient develops purple discoloration.
Speaker A:Very important to link it back to the fact that the patient was found down and that this damage in fact was related to that injury that occurred prior to admission.
Speaker A:You know that there are stage two, stage three, stage four and unstageable pressure injuries.
Speaker A:So typically the initial presentation is going to be either stage one, which is non blanchable erythema, or it's going to be deep tissue injury.
Speaker A:That purple black discoloration that tells you that there may be a lot of damage underneath.
Speaker A:How do pressure injuries progress?
Speaker A:If it starts out as a stage one non blancheable erythema, it may progress to a stage two where you lose the superficial skin layers.
Speaker A:It may progress to a stage three where it goes to the subcutaneous tissue.
Speaker A:It may progress to a stage four.
Speaker A:If it's a deep tissue injury, it's much more likely to progress to a 3 or a 4 than it is to progress to a 2.
Speaker A:Because again, we're looking at deep tissue injury.
Speaker A:Unstageable, of course, is where you cannot tell the depth of damage because the surface of the wound is obscured by necrotic tissue.
Speaker A:I really don't want you to worry about stages right now.
Speaker A:We're going to go into that in detail when we talk about wound assessment a little bit later in the course.
Speaker A:So what I really want you to focus on right now is that the initial indications of pressure injury development are almost always either a stage one non blanchable erythema, which is almost always reversible with appropriate management, or you may see deep tissue injury, that purple maroon discoloration, which may or may not be reversible.
Speaker A:Now, I want to spend our last little bit of time in this class talking about medical device related pressure injuries.
Speaker A:These wounds are a little bit different.
Speaker A:So they are pressure injuries that are associated with the use of devices that are applied either for diagnostic or therapeutic purposes.
Speaker A:It's easy to tell when a pressure injury is device related because it Almost always has exactly the same configuration as the device.
Speaker A:Medical device related pressure injuries frequently develop rapidly.
Speaker A:Many times they occur in areas where there's no subcutaneous tissue and areas that are very vulnerable.
Speaker A:So they can become deep very quickly.
Speaker A:So you've seen these, you've seen pressure injuries that match tubing, that match devices.
Speaker A:You've seen circumferential breakdown associated with compression hose, you've seen breakdown under cervical collars, under trachs.
Speaker A:All of those are medical device related pressure injuries.
Speaker A:Interestingly, wounds caused by what is commonly known as bed trash, things that get left in the bed, those are classified as medical device related pressure injuries as well.
Speaker A:These injuries can involve the skin.
Speaker A:So if you look at the slide on the right, so that's over the bridge of the nose, it involves the skin, there is no soft tissue there, so it rapidly developed into an unstageable wound.
Speaker A:It can also involve the mucous membranes.
Speaker A:So sometimes you'll end up with pressure injuries involving the lip or involving the tongue, especially with endotracheal tubes.
Speaker A:Who's at risk for medical device related pressure injuries?
Speaker A:Well, obviously anyone with a medical device.
Speaker A:Your neonatal and ICU patients are the highest risk because they have the most devices and they're very vulnerable at baseline because of their cardiovascular status and multiple comorbidities conditions.
Speaker A:The specific risk factors, if you have sensory impairment, you're not going to recognize that that device is causing trauma.
Speaker A:Or if you have intact sensation but you're unable to communicate appropriately, what the staff might see is just restlessness.
Speaker A:Actually, what's going on is you're having pain from the device and from ischemic injuries.
Speaker A:So when we have a patient who's restless and who cannot communicate, one of the things we should be doing is checking for anything that could be causing discomfort, morbid obesity, because devices tend to get caught in the tissue.
Speaker A:A lot of times when you have a patient who's morbidly obese, we might have a device that doesn't really fit correctly.
Speaker A:And so it can cause very high level pressure, that adipose tissue.
Speaker A:So one of the preventive measures you'll hear about in just a minute makes your devices are sized appropriately.
Speaker A:If it's stockings, make sure they're sized, appropriate cervical collars, all of those things.
Speaker A:Edema obviously compromises perfusion.
Speaker A:Incorrectly sized devices we've talked about a little bit.
Speaker A:And probably the number one thing is that was a good while before we started recognizing that these are almost always preventable injuries.
Speaker A:And that when we're using medical devices, there's associated care we should be providing to prevent pressure injuries.
Speaker A:What's the pathology?
Speaker A:Is it the same?
Speaker A:Might it be a little bit different?
Speaker A:We're thinking it might be a little bit different.
Speaker A:We definitely know that localized pressure can play a role because remember, it matches the size of the device.
Speaker A:And remember that perfusion to the epidermis comes from horizontally oriented vessels.
Speaker A:So if you put point pressure against horizontally oriented vessels, it's very easy to cause blood to shunt away from the site of the device.
Speaker A:So it could be the impact of localized pressure.
Speaker A:It could be that negative impact could be enhanced by edema.
Speaker A:If you have very edematous tissues.
Speaker A:We know that sometimes maceration plays a role.
Speaker A:We think that sometimes friction plays a role.
Speaker A:So you can tell a lot by the specific injury.
Speaker A:But you can see that this is a little bit different than when we talk about pressure injuries over bony prominences, where we're talking about high intensity or prolonged pressure, we're talking about shear, we're talking about tissue tolerance.
Speaker A:Now we're talking about localized pressure, maceration and friction.
Speaker A:What are the things that we can do to prevent medical device related pressure injuries?
Speaker A:Now, we're going to come back to this in our further discussion on pressure injury prevention.
Speaker A:But these are general prevention guidelines.
Speaker A:First of all, you want to fit the device correctly.
Speaker A:And one of the things that I always think about is compression stockings.
Speaker A:So probably all of you have seen patients who were wearing stockings that were too small and they were literally cutting into the tissue and acting like a tourniquet.
Speaker A:And then sometimes you take the stockings off and there's a circumferential wound.
Speaker A:So fitting the devices correctly, we should be securing devices without tension.
Speaker A:One of the things that we see a lot in our setting is indwelling catheters.
Speaker A:So we have these stabilization devices.
Speaker A:But many times we find, especially with our very heavy patients, that if we don't put the stabilization device up very high on the inner thigh, if we don't put it almost to the groin, we're creating too much tension, the urethra.
Speaker A:And we have seen urethral injuries from catheters.
Speaker A:So you want to make sure that your indwelling catheters are secured without tension, and that might mean relocating your stabilization device.
Speaker A:One thing that's been shown in studies to make a huge difference is if you use protective dressings to pad, redistribute pressure and absorb moisture.
Speaker A:So under tracheostomy tubes, foam dressings make a big difference and significantly reduce the incidence of medical device related pressure injuries.
Speaker A:Same thing under G tubes.
Speaker A:So you've all seen wounds that occurred where the disc kind of bored into the skin.
Speaker A:We can prevent that by putting a protective dressing.
Speaker A:So when it's something pressing against the skin, you want to think, can I put padding between the device and the skin?
Speaker A:So I've already said yes, that's shown to be effective.
Speaker A:They have shown that if you use a product that has both padding and absorption properties, it's more effective than if you use something that just adds a layer to the skin.
Speaker A:For example, foam products are more effective than just transparent film products.
Speaker A:And that makes sense because foam products provide padding and provide moisture control.
Speaker A:One thing we have to be careful about.
Speaker A:So you know how sometimes patients come back and their trach tubes are sutured tightly to the skin.
Speaker A:And most of the time, you can't even get a dressing under there.
Speaker A:And even if you could, you would be adding pressure.
Speaker A:So if the device is secured in the way in a way that adding a dressing adds pressure, you don't want to do that.
Speaker A:Sometimes you have to go to a very thin dressing.
Speaker A:So if you have a trach that is very tight against the skin, maybe sutures have been removed, but you have a beer, a patient with a large neck, and so just the securing the device to maintain airway, you've got your little securement straps.
Speaker A:If you can't get a normal thickness foam, use a thin foam.
Speaker A:So look at what you're doing.
Speaker A:You never want to add pressure.
Speaker A:You want to distribute pressure and minimize the adverse effects.
Speaker A:A big thing for us, especially when we have ICU patients with many, many lines, especially when we have very heavy patients, and it's very hard to get them turned, and it's very easy for a line to be caught underneath them.
Speaker A:It's every time we turn them, checking the bed for bed trash and making sure that all lines are positioned out from under the patient.
Speaker A:Now, one of the hardest things to get done is your endotracheal tube.
Speaker A:So the current guidelines are it's helpful if you can reposition the device at routine intervals.
Speaker A:So you don't want to disrupt the airway.
Speaker A:But can you move it from the right side of the mouth to the middle, to the left to the middle, to the right?
Speaker A:In many agencies, respiratory therapy is working with nursing, and respiratory therapy takes the lead on repositioning the endotracheal tube.
Speaker A:You just want to make sure a plan is in place.
Speaker A:Ideally, you want to see the device repositioned every two to four hours, because if you do it every shift.
Speaker A:That's like eight to 12 hours.
Speaker A:That's too long.
Speaker A:What about nasogastric tubes?
Speaker A:If that nasogastric tube is positioned in a way that it's putting pressure against the nare or against the septum, then you need to reposition it, you need to re tape it, you need to re look at your securement device because now there are devices out there that allow the NG tube to hang free with no pressure against the nare or against the septum.
Speaker A:And finally, we should be monitoring and inspecting.
Speaker A:So that means we take off stockings, we take off splints, we take off heel offloading devices, we check around the trach, we check around the G tube.
Speaker A:We want to make sure that our prevention plan is working.
Speaker A:Now, we'll come back to this when we talk about pressure injury staging, but I'm just going to mention it now, medical device related pressure injuries fall into two categories.
Speaker A:There's mdr, MM injuries, those are the ones involving mucous membranes, and then there's MDRs, those are the ones involving skin.
Speaker A:If you have a mucous membrane medical device related pressure injury, you do not stage it.
Speaker A:We'll come back to that.
Speaker A:If you have a skin medical device related injury, you do stage it because you've got the standard layers of the skin.
Speaker A:But if it occurs in a site where there's no sub Q tissue, like over the bridge of the nose, obviously you modify your staging somewhat.
Speaker A:Again, we'll come back to that, don't worry about that.
Speaker A:So in summary, we've talked about pressure injury development, what happens on a cellular basis and what do we see?
Speaker A:So at a cellular level, if the tissue becomes acutely ischemic, you shift from aerobic to anaerobic metabolism.
Speaker A:That causes major changes in cell activity and cell metabolism, which results in cell damage and cell death.
Speaker A:What do we see at the skin level?
Speaker A:We can't see through to see what's happening to the cell, but we see indicators.
Speaker A:So if we get there in time and we restore blood flow before any significant ischemic damage has occurred, we'll get reactive hyperemia.
Speaker A:So we'll get a warm dark area that is blanchable and that tells us tissue CPR is in progress.
Speaker A:That's a normal response.
Speaker A:It will resolve in less than an hour.
Speaker A:If there has been enough tissue damage to trigger an inflammatory response, we will see a stage one non blanchable erythema.
Speaker A:When we see non blanchable erythema, we are seeing an inflammatory response to limited cell damage.
Speaker A:That is a Message to us as the clinician, this area is very high risk.
Speaker A:Now we have to provide very high level prevention.
Speaker A:If we eliminate shear, prevent recurrent pressure damage, prevent friction damage, then most of the time us stage one pressure injury will resolve without tissue loss because it's limited cell damage and it will self repair.
Speaker A:If you see deep purple, deep maroon discoloration, that's deep tissue injury.
Speaker A:It typically indicates significant cell damage that may extend to the deeper tissue levels.
Speaker A:It may occasionally resolve without any skin or tissue loss that's uncommon.
Speaker A:The most common scenario is that it progresses to a stage 3 or 4 pressure injuries.
Speaker A:In a minority TF cases it may be limited to a stage 2 partial thickness.
Speaker A:What can you do about deep tissue injury?
Speaker A:All you can do is what you do for stage one, prevent further damage and monitor.
Speaker A:Then you can have stage two, three, four or unstageable.
Speaker A:We're going to talk about those more when we talk about wound assessment and staging.
Speaker A:Medical device related pressure injuries are caused by tissue compression by a medical device or by bed trash.
Speaker A:We can do a lot to prevent.
Speaker A:We can correctly size, we can pad appropriately.
Speaker A:We can change the position of devices.
Speaker A:We can be sure that devices are not under tension.
Speaker A:So in our next class we'll talk about pressure injury prevention.
Speaker A:You'll hear a lot of these things again, but in more detail about how we put everything together and create a agency wide pressure injury prevention program.
Speaker A:But that's it for this class.
Speaker A:Thanks.
