Medical Researches

Pressure ulcers result from prolonged compression of soft tissues
overlying bony prominences ( Figure 21-9 ). However,
whether excessive pressure is suffi cient to create an ulcer
depends on the intensity and duration of the pressure as well
as on tissue tolerance. Factors that contribute to pressure
ulcer development are immobility, sensory and motor defi -
cits, reduced circulation, anemia, edema, infection, moisture,
shearing force, friction, and nutritional debilitation ( Cuzzell
and Workman, 2010 ). The most common sites of pressure
ulcers are the sacrum, the ischium, the trochanter, the malleolus,
and the heel; these are called decubitus ulcers. These ulcers
are different from chronic ulcers such as vascular, diabetic, and
neurogenic ulcers. Surgical interventions for pressure ulcers are usually based on ulcer staging (also referred to as grading ).

In stage I the ulcer involves the epidermis and has soft tissue
swelling that is irregular and ill-defi ned; heat and erythema
at the ulcer site are characteristic. A stage II ulcer involves
the epidermis and dermis but not the subcutaneous fat. Stage
III ulcers show full-thickness skin loss with injury to underlying
tissue layers and may contain necrotic material. Thorough
excisional debridement is performed, and IV antibiotic
therapy is instituted. Although debrided stage III ulcers often
heal on their own, surgical excision and closure may be done
to prevent a lengthy spontaneous closure, which may result
in a weak, unstable scar with resultant recurrence. Stage IV
ulcers are the deepest, requiring more radical excisional
debridement. Adequate soft tissue cover may be obtained by
either split-thickness or full-thickness skin grafting or tissue
fl aps