A pressure ulcer is localized injury to the skin and/or underlying tissue, usually over a bony prominence, as a result of pressure or pressure in combination with shear and friction.1 Because most pressure ulcers are preventable, they can be one of the most unnecessary, and often tragic, manifestations of wounds on the human body. Knowledge of the body sites at risk and prevention methods–such as the appropriate choice and use of support surfaces for both the bed and the chair, as well as correct positioning on both the bed and the chair–are of utmost importance for individuals with mobility deficits. In addition, fitted protective devices, including shoes or orthotics, frequent repositioning, positioning to off-load the risk sites, and proper nutrition and hygiene can dramatically reduce the occurrence and recurrence of these ulcers.
As with all dermal ulcers, treating the underlying cause of pressure ulcers is the most important principle. Treating the ulcer site with topical agents, dressings, and biophysical energies is not enough: Pressure must be removed from the ulcer site.2 Unfortunately, applying this principle is challenging because pressure ulcers are commonly found on all weight-bearing areas of the body, such as the sitting surface or the recumbent surface in the person's acquired or preferred positions. Prevention and treatment require knowledge of the physiological responses to the physical changes in tissues that lead to pressure ulcers, such as pressure, shear, heat, moisture, and friction. This knowledge provides a foundation for the clinician to address the causative physical factors and the person's overall risk level and to determine safe positions that remove pressure on those body areas at highest risk. This information is used to determine the proper body positions in sitting and recumbent postures and the equipment required to achieve those optimal positions.
This chapter presents information concerning factors the caregiver must consider when treating persons at risk for, or who have, pressure ulcers due to mobility deficits. The chapter focuses on prevention and treatment of pressure ulcers through appropriate body positioning and selection of bed surfaces and seat cushions. In addition, the detrimental effects of improper positioning on the integument and on other body systems are described.
The Pressure Ulcer Problem
The reported incidence and prevalence rates related to pressure ulcer formation show the devastating toll this diagnosis has on health, quality of life, and health-care costs. The Centers for Medicare and Medicaid Services (CMS) reported that in fiscal year 2006, 323,000 Medicare recipients had a diagnosis of pressure ulcers as a secondary condition and that these persons incurred, on average, $40,381 in hospital costs.3 Pressure ulcers have been cited as the cause of 115,000 deaths and cost $55 billion annually.4 Of course, the costs of pressure ulcers extend far beyond the medical costs incurred for treatment. Personal and societal costs from inactivity and missed educational, vocational, ...