Recent findings on decubitus ulcer pathology: implications for care.

Vasodilators are ineffective therapy for decubitus ulcers because blood vessels are absent in the necrotic areas. Systemic application of vasodilating drugs actually decreases the nutritional blood flow through the damaged zone. Protracted healing of decubitus ulcers may be explained by an altered nutrient transport rate to the cells caused by fibrin thrombi in the capillaries and fibrin deposits in the intercellular space, resulting from decreased fibrinolytic activity.