Mechanical methods for thrombosis prophylaxis.

Prevention of venous thromboembolism (VTE) remains the number one preventable cause of death in hospitalized patients. The pathogenesis of thrombosis involves the triad of venous stasis, dilatation of the leg veins, and changes in coagulability of the blood. These changes can be modified by the use of intermittent pneumatic compression devices (IPC) and, to a much lesser extent, by graduated compression hose (GCS). Studies have shown the effectiveness of GCS in preventing deep vein thrombosis (DVT) compared to placebo, but there is no evidence that they reduce the incidence of pulmonary emboli (PE). No venographic data are available regarding the efficacy of GCS; however, IPC have shown excellent efficacy in several venographic studies over the past 25 years. Mechanical methods are important to use in situations where the risk of bleeding exists, thereby making the use of anticoagulants hazardous. One of the key uses for mechanical methods is in combination with anticoagulants in patients at the highest risk of developing VTE. Chest consensus guidelines assigns a 2A recommendation for the use of combination prophylaxis in the highest risk patients. Unfortunately, studies to show which type of leg compression device is optimal for DVT prevention are not available, so individual preference, ease of use, and company support are the determining factors at the present time. Finally, compliance using these devices is a major problem, and until systems have been developed to easily monitor and ensure compliance, these methods will enjoy only limited use.