Pressure-induced skin and soft tissue injury: Clinical sciences

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Introduction0:00–1:03

Pressure-induced skin and soft tissue injury, sometimes called pressure ulcer, or bed sores, refers to damage to the skin and underlying soft tissues caused by prolonged pressure.
Pressure injuries most commonly develop over bony prominences, such as the sacrum, greater trochanter, lateral and medial malleoli, calcaneus, scapula, and occiput.
Pressure decreases blood flow to the affected skin and soft tissues, leading to hypoxia, ischemia, and necrosis. Based on the depth of the tissue involved, pressure injuries can be subdivided into four main stages.
In stage one, there’s intact skin with non-blanchable erythema; in stage two, there’s partial thickness loss of dermis; while in stage three, there’s a full thickness skin loss.
Finally, stage four is associated with full thickness skin loss and exposure of underlying muscles, tendons, or even bones.The first step in evaluating a patient with signs and symptoms of pressure injury is to obtain a focused history and physical examination.

History and Physical1:03–3:25

Patients often have a history of risk factors such as immobility, like using a wheelchair or being bed bound, in fact they can start developing pressure injuries after just 2 hours of immobility!
Other risk factors include malnutrition; neurological diseases like stroke and neuropathy; diabetes; or perfusion disorders, like heart failure and peripheral vascular disease.
Additionally, they typically have pain in the affected area, but keep in mind that individuals with sensory neuropathy, diabetes, or altered mental status may not report pain.
Now, during the physical examination, you’ll need to assess the wound bed and depth, which are the most important factors as they determine the grade of the injury.
The wound bed is the base of the wound, while the depth is how deep the wound bed is from the skin surface. While examining the wound, don’t forget to note the type and quality of tissue seen at the wound bed.
You may find exudate, or a wet, fibrinous biofilm caused by cell necrosis, covering the wound bed. Next, check the skin color and look for edema surrounding the wound, which can help you identify the presence of infection.
For example, erythema and mild edema can indicate cellulitis; while “bogginess” or gray discoloration with moderate to severe edema might suggest infectious tissue necrosis.
Gas producing pathogens can cause crepitus, or a crackling sound on skin palpation. Finally, there might be signs of wound healing, such as granulation tissue and epithelialization.
The presence of “beefy red” granulation tissue indicates adequate blood flow fundamental to the healing process; while epithelialization occurs later, as the wound bed creates a healthy protective layer that functions like the epithelium of the skin.
Some high yield facts to keep in mind! Because pressure injuries are open to the atmosphere, the wound is never sterile and the risk of infection is high.
If you see any signs of infection or necrosis, make sure to treat the infection and remove any necrotic tissue before starting treatment.
The presence of infection and necrosis will prevent proper wound healing, rendering other additional methods of treatment ineffective.Alright, during the initial evaluation, you should look out for any signs of critical infections including sepsis, limb-threatening ischemia, and rapidly progressing skin and wound changes.

Critical infection & management3:25–3:56

If you suspect any of these, immediately establish IV access, draw blood cultures, start empiric IV antibiotics, and call for an emergent surgery evaluation.
The surgical team will usually perform wound debridement, but amputation might be required in severe cases. Now, if you find no signs of critical infection, the next step is to determine the stage of the pressure injury.

Stage 1 and Stage 2 pressure injuries3:56–4:57

Stage 1 injuries present as intact skin with non-blanchable erythema and no signs of necrosis; while stage 2 wounds usually have a shallow, open ulcer with partial thickness loss of dermis.
Both stage 1 and stage 2 pressure injuries require local wound care, which involves keeping the wound moist with medicated gauze and decreasing pressure and friction with cushioned dressings.
Now, if the patient is bed or wheelchair bound, you should try to reduce pressure on the affected area. This can be done by repositioning every 2 hours on specialized support surfaces, such as foam wedges, cushioned seating, or even water beds.
Finally, don’t forget to address modifiable risk factors, which can help promote adequate wound healing. If there’s malnutrition, initiate supplementation with so-called “wound vitamins”, which include Vitamin A, Vitamin C, and zinc.
Let’s switch gears and talk about more invasive pressure injuries, which include stages 3 and 4. Stage 3 pressure injuries include full-thickness loss of the skin, and exposure of subcutaneous fat.

Stage 3 and Stage 4 pressure injuries4:57–6:48

Now, if you see any muscle, tendon or bone, exposed, it’s classified as a stage 4 pressure injury. Both stage 3 and stage 4 injuries require local wound care similar to stages 1 and 2, as well as more invasive therapies.
Because deeper wounds tend to have a greater amount of fibrinous exudate and necrotic tissue, they require debridement. This can be done surgically or through chemical enzymatic debridement, which uses cell or tissue-based products to clean the wound bed.
Often, serial debridement is necessary to maintain a healthy, clean wound bed. In addition to treatment, if the bone is exposed, you should order a bone biopsy to assess for osteomyelitis.
Once the wound bed is clean, and the underlying tissue is healthy, you can apply a negative pressure wound dressing to reduce bacterial growth and promote granulation tissue formation.
Negative pressure dressings have 2 important components: an antimicrobial sponge, which is placed directly onto the wound; and a mechanical device that provides continuous suction on the sponge via plastic tubing.
Stage 4 ulcers do not heal well on their own, so you might need to consult a surgeon for autologous tissue grafts, which can provide adequate coverage of the wound.
Autologous tissue grafts, also known as flaps, are performed by transferring healthy tissue from one part of the body to another.
For example, full- or partial-thickness skin grafts can be surgically transferred from the thighs to cover the sacral decubitus pressure injury.
However, autologous tissue grafts cannot be performed when there’s an infection or necrosis because the risk of flap failure is extremely high.
Finally, the last group of pressure injuries includes the ones that cannot be properly examined due to necrotic debris or an eschar, which is when necrotic debris forms a hard, black patch, covering the entire wound bed.

Unstageable pressure injuries6:48–7:17

This is considered an unstageable pressure injury. The eschar and necrotic debris must be removed by sharp surgical debridement to expose the depth of the wound and determine its stage.
After this, the treatment depends on the staging. Alright, as a quick recap… Pressure-induced skin and soft tissue injuries are caused by prolonged pressure and their treatment is based on the depth of the tissue involved.

Review7:17–7:52

Stage 1 and 2 injuries are treated with local wound care, repositioning, and the use of specialized support surfaces. Similarly to stage 1 and 2, stage 3 and 4 require local wound care, but may additionally require more invasive treatment such as wound debridement, negative pressure devices, and sometimes autologous tissue grafts.
Finally, if the injury is unstageable, consult a surgeon for mechanical or sharp debridement of eschar to expose the wound bed and determine the exact stage.