Deep vein thrombosis and pulmonary embolism: prevention, diagnosis, and treatment.

Pulmonary embolism (PE) is a significant cause of mortality in the elderly. More than 90% of pulmonary emboli originate from a thrombus in the deep veins of the legs. Proper diagnosis and treatment of deep vein thrombosis (DVT) are thus essential to prevent PE. Diagnosis of new or recurrent DVT is based on the results of one or more tests, including impedance plethysmography (IPG) or duplex venous scan; venography can often be avoided, based on results of initial testing. For suspected PE, perfusion lung scanning is the initial test of choice, followed by IPG/duplex or venography. Pulmonary angiography is indicated for patients with decreased cardiorespiratory reserve. Decisions governing prophylaxis of DVT are based on individual relative risk; prophylactic therapies include intermittent compression, low-dose heparin, and oral anticoagulants. Management of thromboembolism requires IV and oral anticoagulant therapy.