Complications such as sepsis, chronic infection, cellulitis, and osteomyelitis prolong hospitalization and rehabilitation. Moreover, pressure sores increase the mortality rate in elderly patients. Etiology and Classification Risk factors that may lead to the development of pressure sores can be categorized as extrinsic or intrinsic. Poorly nourished or chronically ill elderly persons are at high risk as well. Persons who are delirious, demented, partially or completely paralyzed, or bedridden are most likely to develop pressure sores.
Pressure is the primary external cause of ischemic damage and tissue necrosis.
Normal capillary blood pressure at the arteriolar end of the vascular bed averages 32 mm Hg. When tissues are externally compressed, however, blood pressure may exceed 300 mm Hg, which reduces blood supply to and lymphatic drainage from the affected area. Common pressure points are shown in Figure 124-1. Most of them are over bony prominences. Shearing occurs when two layers of skin slide on each other, moving in opposite directions and damaging the underlying tissue.