Bed sores, also known as decubitus ulcers, are localized injuries to the skin and underlying tissue that usually occur over a bony prominence as a result of pressure, or pressure in combination with shear and/or friction in the areas with partial or complete blood flow obstruction.
Sacrum, coccyx, heels or the hips, are most common sites affected by bed sores but other sites such as the elbows, knees, ankles or the back of the occiput can be affected.
Staging of Pressure Ulcers
Stage I
Intact skin with non-blanchable redness of a localized area usually over a bony prominence. The darkly pigmented skin may not have visible blanching; its color may differ from the surrounding area.
The area may be painful, firm, soft, warmer or cooler as compared to adjacent tissue. Stage I may be difficult to detect in individuals with dark skin tones. It may indicate a person who is at risk.
Stage II
The damage has extended dermis and presents as a shallow open ulcer with a red pink wound bed, without slough. It may also present as an intact or open/ruptured serum-filled blister.
The ulcer presents as a shiny or dry shallow ulcer without slough or bruising.
Stage III
This stage involves full thickness tissue loss. Subcutaneous fat may be visible but bone, tendon or muscle are not exposed. Slough may be present but does not obscure the depth of tissue loss. It may include undermining and tunneling.
The depth of a stage III pressure ulcer varies by anatomical location. The bridge of the nose, ear, occiput and malleolus do not have subcutaneous tissue and stage III ulcers can be shallow. In contrast, areas of significant adiposity can develop extremely deep stage III pressure ulcers. Bone/tendon is not visible or directly palpable.
Stage IV
It represents full thickness tissue loss with exposed bone, tendon or muscle. Slough or eschar may be present in some parts of the wound bed. this often includes undermining and tunneling. The depth of a stage IV pressure ulcer varies by anatomical location as in stage III.
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Unstageable
These are ulcers with full thickness tissue loss in which the base of the ulcer is covered by slough or eschar. Until enough slough and/or eschar is removed to expose the base of the wound, the true depth, and therefore stage, cannot be determined.
Healing time is prolonged for higher stage ulcers.
Causes of Bed Sores
Pressure
This could be due to the force of bone against a surface especially when the patient remains immobile in a posture for long period. Decreased tissue perfusion, ischemia leads to tissue necrosis. External devices, such as medical devices, braces, wheelchairs can also cause pressure.
Shearing
The patient stays in one place as the deep fascia and skeletal muscle slide down with gravity can also cause the pinching off of blood vessels which may lead to ischemia and tissue necrosis.
Moisture
Moisture on the skin causes the skin to lose the dry outer layer and reduces the tolerance of the skin for pressure and shear.
People who are immobile are at highest risk of developing bed sores.
Treatment of Bed Sores
For stage I bed sores, removal of pressure is enough. For stage II bed sores hydrocolloid or foam dressings and skin care are sufficient for treatment.
For those with Stage III or IV ulcers, once the necrotic tissue has been removed, a moisture retentive dressing or gel is used to facilitate healing.
Negative pressure may be used to improve granulation tissue formation, where indicated.
Necrotic tissue should be removed in most bed sores by moist dressings to promote autolytic debridement by body’s own enzymes, biological debridement [maggot debridement therapy], chemical debridement, or enzymatic debridement, mechanical debridement[ debriding dressings, whirlpool or ultrasound for slough], surgical debridement.
Tissue flap, free flap or other closure methods may be required in extensive tissue loss.
Air fluidized therapy beds have been found to prevent further damage.
Patients at risk for bed sores and those with bedsores turning and repositioning to reduce pressure should be done Controlling the heat and moisture levels of the skin surface, known as skin microclimate management, also plays a significant role in the prevention and control of bed sores.
Complications of Bed Sores
Following complications can occur from bed sores
- Autonomic dysreflexia
- Infection – Osteomyelitis, septic arthritis, sepsis
- Amyloidosis
- Anemia
- Fistulae
- Gangrene
- Malignant transformation
- Recurrence
