Fundamentals - Practice & Skills, part 12: Pressure Injuries - Risk Factors, Prevention, and Staging

by Meris Shuwarger August 02, 2021 Updated: December 29, 2021 9 min read

This article focuses on pressure injuries, their causes and how to stage them. You can follow along with our Fundamentals of Nursing flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX.

If you want more in-depth information on pressure injuries, check out our Wound Care Flashcards for Nurses.

What is a pressure injury?

A pressure injury is damage to the skin and underlying tissue due to prolonged or intense pressure to that area. Pressure injuries can lead to inadequate perfusion (the exchange of oxygen and carbon dioxide between red blood cells and the body's tissues) and/or oxygenation and cell death.

Risk factors for pressure injuries

Among the biggest risk factors for pressure injuries is immobility. Patients who must remain immobile for a period of time or who must wear a medical device that puts constant pressure somewhere on their body are at risk for a pressure injury. For example, a patient using a nasal cannula might have a pressure injury under their nose or behind their ears.

Other risk factors for pressure injuries include older age, incontinence, poor nutrition, perfusion issues, diabetes, smoking, and the use of corticosteroids.

Braden scale score

A patient whose Braden scale score is less than or equal to 18 is also at risk for developing a pressure injury. The Braden scale assesses six risk factors related to the development of pressure injuries: sensory perception (the ability to respond meaningfully to pressure-related discomfort), moisture, activity, mobility, nutrition, and friction and shear. It is important to assess a patient's Braden scale score at least once per shift.

Pressure injury prevention

There are a number of preventative measures that may be taken to reduce the risk of pressure injuries.

Pressure-redistribution bed and mattress

Place at-risk patients on a bed that provides pressure redistribution, which works through the use of a special type of mattress that uses a combination of foam and air. Another tactic is to set the angle of the head of the bed at less than or equal to 30 degrees. This is because the more upright a patient sits, the more shearing force is placed on their sacrum and other parts of their body.


Reposition the patient every two hours to help redistribute pressure.

Waffle seat cushion

Utilize a waffle seat cushion for a patient who is chair-sitting or in a wheelchair. These cushions help to redistribute pressure. Advise the patient to shift their weight every 15 minutes as they sit.

Heel elevation

For a patient in bed, elevate their feet up off the bed so their heels dangle freely. This can be done with pillows or heel-elevation boots.

Padded dressings over bony prominences

Depending on how the patient is most frequently positioned, pad their bony prominences. This could mean padding the sacrum, the greater trochanter (the big bump on the femur right below the hip), or their scapula or shoulder.

Adequate nutrition

Ensure the patient receives adequate nutrition, especially protein. This will help to maintain the strength of their skin integrity as well as to help to repair any existing tissue damage.

Staging Pressure injuries

Pressure injuries progress in seriousness from stage 1 to stage 4. There are two additional, related wound categories, “unstageable” and “deep tissue injury.” Understanding these stages is an important aspect of nurse training, as prospective nurses will often be asked during their examinations to stage a pressure injury, either by using pictures or by describing the features of a particular stage.

Stage I: Damage limited to epidermis

A stage one pressure injury is damage that is limited to the epidermis (skin). This damage will appear non-blanchable. Blanchability, or blanching is when, if pressed upon with a finger, the skin will briefly turn white and then return to its normal color. In stage one pressure injuries, the skin will not blanch when pressed upon. Additionally, the skin will appear intact (there is no actual, visible wound) and will display erythema (redness).

Stage II: Damage into dermis

In stage two, there is damage to the epidermis and dermis. Again, the skin will display non-blanchable erythema, but now with the addition of a shallow erosion. For example, the skin will have a scrape or an open blister. This is not a deep wound, but the surface of the skin has been eroded through the epidermis into the dermis, usually indicated by a red, moist wound base.

Stage III: Damage into subcutaneous tissue

Stage three is where more serious damage has occurred. This is an open wound, where the adipose (fatty) tissue is visible. Adipose tissue has a yellow, chicken fat appearance. In a stage three wound, the underlying structures are not visible, that is, muscle, tendon, and bone cannot be seen.

Stage IV: Damage extends beyond subcutaneous tissue

Stage four indicates damage that extends beyond the subcutaneous tissue. It is a deep wound, in which another structure may be visible, including muscle, tendon, or bone, or any combination of those — likely in addition to visible adipose tissue. When the underlying structure can be seen, that indicates a stage four wound.

Unstageable: Unknown depth

When the wound bed cannot be seen — if the wound is obscured due the presence of eschar or slough — then it is considered unstageable. Eschar is a type of necrotic tissue, usually brown or black. A slough is more likely to appear tan or yellowish and slimy. No matter what is obscuring the wound base, if it is not possible to determine how deep the wound is, that indicates an unstageable wound.

Deep tissue injury

This is when there is damage at the bone-muscle interface, usually in the form of a bruise. The skin may be intact or non-intact, and it is non-blanchable, with a purple or maroon discoloration.

The differences between a deep tissue injury and a pressure injury are that a bruise is usually caused by an impact of some sort and appears purple or maroon, while a pressure injury is caused by prolonged pressure on an area of the skin and has a red appearance (erythema).

Full Transcript

Hi, I'm Meris. And in this video, we're going to be talking about pressure injuries. I'm going to be following along with our Fundamentals of Nursing flashcards. If you want a set for yourself, you can grab them at our website, And if you already have a set and you are following along, I'm starting on card number 79. Let's get started.

Okay. So starting off, what is a pressure injury? Well, it's what happens to the tissue after prolonged or intense pressure to that area. So for instance, we commonly see this in patients who are immobile for a period of time or who have medical devices that are putting pressure somewhere on their body. For instance, someone using a nasal cannula might have one right here under their nose and behind their ears, right? So definitely important to think of those things. What are the risk factors? Immobility, that's going to be a big one, right? Older age, incontinence, poor nutrition, perfusion issues, maybe because of something like diabetes mellitus, smoking, corticosteroids, and a Braden Scale less than or equal to 18. A Braden Scale should be done on your patient at least every shift. And this is going to give us an idea of how at risk they are for pressure injuries based on different risk factors such as moisture, nutrition, friction and shear, activity, those sorts of things. So very important that you're doing Braden Scale assessments on your patients at least once per shift.

All right. How do we prevent pressure injuries? Well, we talked about it a little bit in the video about the effects of immobility. Big things are going to be repositioning your patient at least every two hours. We're going to want to put them on a pressure-redistribution mattress if possible. So if I know my patient is at risk, I want them on this special type of mattress, and I want the head of the bed less than or equal to 30 degrees. The higher up the bed is-- the higher up your patient is sitting, the more shearing force is placed on the sacrum and other parts of their body. So we want a lower head of the bed. If my patient is sitting, use a waffle seat cushion to redistribute the pressure. And then I want my patient to be educated that they should adjust their position, redistribute their weight, every 15 minutes while they're sitting. If my patient is in bed, I want to elevate their feet up off the bed so that their heels are dangling freely. This can be done with pillows or heel-elevation boots. And then I want to pad bony prominences. So if my patient is at risk, I'm going to pad these bony prominences like the sacrum, perhaps the greater trochanter, maybe their scapula or shoulder, depending on how my patient is most frequently positioned. And then I want to make sure my patient is getting adequate nutrition, most especially protein, because this is going to help to keep that skin integrity strong and help to repair any existing tissue damage.

Okay. So now let's talk about staging pressure injuries. This is very important for nursing school. You could be asked to stage these using pictures or words. So we have a nice table here for you that breaks it down by stage in words, tells you what's the most important feature of each stage, okay? So this is really good for your test-taking skills and for NCLEX.

So stage 1, this is damage that's limited to the epidermis. And what it's going to look like, it's going to be nonblanchable, intact skin with erythema. Nonblanchable, think about a sunburn or even just your normal skin. If I take my finger and I push down, it briefly turns white and then goes back to normal color. Same thing with a sunburn, right? If I push on a sunburn, it's going to turn white and then be red again. That is called blanching. So blanchability is absent here. If I have nonblanching erythema, I've got to be thinking pressure injury, okay? Stage 1, the skin is intact. I don't see an actual wound. I just see the redness that does not turn white when I touch it.

Stage 2, the damage now is epidermis and dermis. So what you're going to see is, same thing, nonblanchable erythema, but I have shallow erosion. So it's going to look maybe like a scrape or an open blister. It's not a really deep wound, but I have now eroded through the epidermis and part of the dermis. And that's what you're seeing, that red, moist wound base. That is going to be stage 2.

Moving on to stage 3. Stage 3, I want you to think damage. We are now to the hypodermis, the subcutaneous tissue, which means that I'm going to see, visibly see adipose tissue, fatty tissue. This is that yellow, chicken fat appearance, right? This is going to be called adipose. When I see that, I need to be thinking stage 3. But I'm not seeing anything else. I see no other structures. I just see adipose, stage 3.

Stage 4, though, this is going to be damage extending beyond the subcutaneous tissue, and now I have to see another structure. It could be muscle. It could be tendon. It could be bone. It could be all three, two of them, just one of them, but for it to be stage 4, I need to see one of those structures. So I may also see adipose tissue, right? That's possible. I could see adipose tissue and bone and muscle. It's still stage 4.

Now we call a wound unstageable when we can't see the wound bed. So if the wound is obscured, meaning I can't see past it because of slough or eschar, then it is unstageable. Now eschar is going to be this kind of necrotic tissue, that brown or black tissue, where a slough is going to be kind of tan, yellowish in appearance and it's going to look kind of slimy. But it doesn't matter which one it is. If I can't see the wound base, I can't tell how deep it is, right? So very important to understand that.

And then deep tissue injuries, I always think of someone getting hit in the thigh with a baseball, right? Someone hits a baseball really hard, really fast, and it hits me right in the thigh. I'm probably going to have a deep tissue injury. So I could have intact or nonintact skin, but it's going to be nonblanchable but purple or maroon, a really, really deep color like a really bad bruise. So that's going to be the difference between that and a pressure injury which is going to be from prolonged pressure. It's going to have that red appearance, erythema, okay?

So that is a review of pressure injuries, how to prevent them, what causes them and how we stage them. If that was helpful to you, I would love it if you could like this video. Please leave me a comment below. I know that someone out there has a really great way to remember the different stages of the wounds. So if you have one, I want to hear it in the comments below. Be sure that you subscribe to our next videos. We have so much coming out for you, and you want to be the first to know. Thanks so much for watching, and happy studying.

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