Perioperative prophylaxis of venous thromboembolism.

Venous thromboembolism is an important cause of morbidity and mortality in hospitalized patients, causing 100,000 to 200,000 deaths per year in the United States. Patients undergoing surgery are at the highest risk of venous thromboembolism. The magnitude of this risk in a patient depends on the surgical procedure performed and the presence of other risk factors that predispose to venous thromboembolism. The clinical diagnosis of both deep vein thrombosis and pulmonary embolism is notoriously inaccurate. Furthermore, two thirds of all fatal pulmonary emboli cause death within 30 minutes of the embolic episode, leaving little time for diagnostic work-up and effective treatment. Prophylactic treatment for prevention of venous thromboembolism is therefore important in these patients, and several effective mechanical and chemical methods for this purpose are available. The pathogenesis of deep vein thrombosis in the surgical patients, the predisposing risk factors, and the available prophylactic modalities are discussed in this article. Recommendations for the use of various approaches in different risk categories are provided.