pertaining to or situated at or near the periphery.
peripheral vascular disease (PVD) any disorder affecting blood flow through the veins and arteries distal to the heart. Disruption of circulation in the peripheral veins can be caused by venous stasis, hypercoagulability, or injury to the vein wall secondary to immobility, orthopedic surgery, aging, and dehydration. Arterial insufficiency in the peripheral vessels is most often due to atherosclerosis, blood clots, trauma, spasms of smooth muscles in the arterial walls, and congenital structural defects in the arteries.
Diminished or interrupted flow of blood through peripheral arteries can eventually lead to ischemic necrosis and gangrene. Sluggish venous flow leads to increased pressure within the vessels, causing varicose veins and sometimes thrombophlebitis. When blood is not moved out of the veins of the lower limbs, it accumulates there and serves as an excellent medium for bacterial growth and contributes to the formation of leg ulcers. Treatment is aimed at improving blood flow by removing or mitigating the cause of impaired circulation.
Assessment of Arterial Circulation. Arterial insufficiency is characterized by two types of pain. The first is a cramping pain in the muscles brought on by exercise and relieved by rest (
intermittent claudication). The pain is most often felt in the calves of the legs, but it may also affect the thighs and buttocks. A second type of pain is characteristic of advanced chronic occlusive arterial disease. It occurs when the patient is at rest, usually at night while lying down. The sensation is described as burning and tingling, with numbness of the toes.
Assessment includes noting the color and temperature of the skin in the affected areas and any signs of trophic changes. Epidermoid tissues that are chronically malnourished because of poor blood supply appear shiny, smooth, and thin, with little or no hair on the surface. The nails are thick, with deposits of cornlike material under them. With time, a decreased blood supply produces ischemic changes that cause the skin to assume a purple-black color that is characteristic of cyanosis and gangrene. Additional assessment data include the rate, rhythm, and force of the peripheral pulses.
Assessment of Venous Circulation. Assessment of venous circulation focuses on changes in the hydration status (edema) and pigmentation of the skin. Chronic edema can lead to ulceration. Venous insufficiency also produces a darkened color, dryness, and scaling of the skin in the affected areas. Venography, a radiologic test in which the vein is injected with a radiopaque dye prior to filming, can also demonstrate engorged and tortuous veins.
Patient Teaching. In order to prevent or mitigate the effects of arterial insufficiency or venous stasis, patients must be taught techniques of self-care. Exercises such as the
buerger-allen exercises are often prescribed. Additionally, patients need to know how to take care of their feet and legs (see
foot care), the reasons for avoiding smoking and keeping warm, and the importance of taking prescribed medications.