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Compression therapy is a frequently used physical therapy in conditions involving venous and lymphatic insufficiency in the lower limbs, including varicosities, lymphedema, venous eczema and ulceration, deep vein thrombosis and postthrombotic syndrome. The many forms of compression therapy include elastic and nonelastic bandages, boots, hosiery or stockings (Box 1), and pneumatic devices.1 Graduated compression stockings (Figure 1) are often prescribed and have the advantage of being more acceptable, relatively easier to put on and less cumbersome than bandaging and pneumatic devices. However, not all pa - tients tolerate graduated compression stockings, and problems with compliance are not uncommon.
We review the current evidence of the therapeutic roles of graduated compression stockings and the problems associated with their use. The evidence used in this review is described in Box 2.
What are the mechanisms of action of compression stockings?
Figure 2 summarizes the mechanisms of action of graduated compression stockings. The stockings work by exerting the greatest degree of compression at the ankle, with the level of compression gradually decreasing up the garment. The pressure gradient ensures that blood flows upward toward the heart instead of refluxing downward to the foot or laterally into the superficial veins. The application of adequate graduated compression reduces the diameter of major veins, which increases the velocity and volume of blood flow.2 Graduation compression can reverse venous hypertension, augment skeletal-muscle pump, facilitate venous return and improve lymphatic drainage.3 It also initiates complex physiologic and biochemical effects involving the venous, arterial and lymphatic systems, although the exact mechanisms remain unclear.2,4,5 One study that used near-infrared spectroscopy to monitor changes in tissue oxy hemo - globin and deoxyhemoglobin re ported that limb oxygenation increased with the use of graduated compression stockings, especially with highcompression stockings.4 Another study showed that levels of proinflammatory cytokines (e.g., interleukin-1α, interleukin-6 and interferon-γ) in ulcer tissue in patients with active ulcers were significantly reduced following compression therapy.5
How is the strength of compression graded?
Graduated compression stockings are classified according to the sub-bandage compression pressure applied by the garment at the ankle level. The pressures are determined by the manufacturer based on laboratory measurements. The degree of pressure is classified into several standards. Unfortunately, there is no single standard used worldwide, which may cause confusion. In general,...