Preventing pressure ulcers Flashcards
Define a pressure ulcer
Pressure injury to the skin and or underlying tissue especially over a bony prominence especially as a result of pressure or pressure in combination with shear
What is the difference in the cause between pressure ulcers and moisture lesions?
PU: history of pressure, friction, shear
ML: skin moist (sweat, urine or faeces) or history of incontinence
BUT remember that a patient may have both a pressure ulcer and moisture lesion in a similar area, so can co-exist
What is the difference in the position between pressure ulcers and moisture lesions?
PU: area over bony prominence or compression eg oxygen mask, plaster cast, crutches
ML: natal cleft, or buttocks, copy lesions on both side of the body, not usually over bony prominences
What is the difference in the shape between pressure ulcers and moisture lesions?
PU: distinct shape with obvious edges, 1 or 2 wounds
ML: multiple wounds with diffuse edges
What is the difference in the depth between pressure ulcers and moisture lesions?
PU: may be down to bone
ML: Usually superficial – unless it becomes infected
What is the difference in the presence of necrosis between pressure ulcers and moisture lesions?
PU: Frequently necrotic tissue present as hypoxia
causes necrosis
ML: No necrosis
What is the difference in the edges between pressure ulcers and moisture lesions?
PU: Distinct edges, may be rolled or raised in
chronic stages
ML: Edges may be difficult to determine, jagged edges
are seen in moisture lesions that have been
subjected to friction
Which bony prominences are most suceptible to pressure ulcers?
- Sacrum
- Ischial tuberosity
- Heels
Other than bony prominences, where/how else can pressure ulcers form?
- Plaster casts
- Splints
- Arm slings
- Clutches
- Under glasses
- Around nose with nasal cannulae
- Other areas depending on the position of the pt eg their shoulder or knee if lying on their side
Explain the different theories of how pressure ulcers form
- top to bottom: Pressure ulcer develops on the skin and then progresses backwards towards the bone
- bottom to top: But also could be the bone applying pressure to the skin, so ischaemia could develop at the bone end and then progress outwards, explains the cone shape of ulcers
- reperfusion injury: an ulcer could form due to a series of small reperfusion injuries over time (due to repeated hypoxia and reperfusion) or could exacerbate an injury that has already formed
Explain the pathophysiology of pressure ulcers
where the pressure is greater than that in the tissue perfusion pressure (which is capillary pressure) over a long period of time. If the pressure is not removed, it will go down into the bone
What shape are pressure ulcers from superficial to deep?
Cone shaped - widest part near the bone and near surface it is small
Why is older skin more predisposed to breakdown?
- The epidermis (outer layer) gets thinner, so the skin is more susceptible to damage from mild injury
- Flattening out of the dermo-epidermo junction (part between the epidermis and dermis), which makes it more fragile and susceptible to shear forces
- Reduction in the thickness of the dermis by 20% - this reduces the number of blood vessels, nerve endings and therefore less ability to protect the body from damage
List 3 functions of skin
- sensation
- temperature control
- moisture retention
How can a pressure ulcer present?
- Non blanching erythema
- superficial skin loss
Remember that the amount of redness can be very small compared to the damage underneath
