Integrated management of venous thromboembolism

Diagnostic methods for pulmonary embolism and deep vein thrombosis of the lower extremity are intertwined, since the latter nearly always precedes the former. Recent prospective studies show that an independent clinical estimate of disease probability helps to refine probability estimates of ventilation-perfusion lung scans and of ultrasonography with compression, reducing the need for pulmonary angiography and contrast venography. Repeated ultrasonography with compression can also be used to stratify patients into groups that are at high or low risk for subsequent pulmonary embolic events. I give algorithms and guidelines for the clinical use of these findings. Effective treatment of acute venous thromboembolism depends on achieving an antithrombotic state with heparin and warfarin. I give recommendations for dosing and monitoring heparin and warfarin that are based on knowledge of heparin blood levels and on use of the international normalized ratio with warfarin therapy. Use of low-molecular-weight heparin to prevent deep vein thrombosis is briefly described.