Lower extremity venous thrombosis triggers pulmonary embolism

Condition analysis:
Venous thromboembolism (VTE) is a disease that includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). It is a common, lethal disorder that affects hospitalized and nonhospitalized patients, recurs frequently, is often overlooked, and results in long-term complications including chronic thromboembolic pulmonary hypertension (CTPH) and the post-thrombotic syndrome (PTS).

Venous thromboembolism results from a combination of hereditary and acquired risk factors, also known as throm-bophilia or hypercoagulable states. In addition, vessel wall damage, venous stasis, and increased activation of clotting factors first described by Rudolf Virchow more than a century ago remain the fundamental basis for our understanding of thrombosis.

Instructions:
Initiate treatment immediately. Patients without contraindications to anticoagulation should begin treatment at time of diagnosis [IA]. If pulmonary embolism (PE) is clinically likely, initiation of anticoagulation should not await testing; if only deep vein thrombosis (DVT) is suspected and testing will be prompt, initiation may await testing. Therapeutic levels of anticoagulation should be achieved as quickly as possible. If warfarin is used for anticoagulation, initiate it on treatment day 1 simultaneous to initiation of low molecular weight heparin. Other oral agents may not require bridging treatment with heparin.