Venous Thromboembolism and Pulmonary Embolism

Venous thromboembolism (VTE) is a blood clot, or thrombosis, that forms in a vein which may or may not break off into emboli. The classification of pulmonary embolism into low risk, sub-massive, and massive pulmonary embolism is based on hemodynamic manifestations and not degree of radiographic clot burden. This chapter provides information on the prevention, prognosis, diagnosis, management, and treatment of VTE and pulmonary embolism. Risk factors for VTE events include venous stasis, hypercoagulable states, and endothelial injury. Duration of anticoagulation therapy differs depending on the mechanism of VTE formation. Provoked VTE events may only require therapy for a limited time whereas unprovoked VTE events may require lifelong anticoagulation. The mainstay of treatment for VTE is systemic anticoagulation.