Deep Venous Thrombosis and Pulmonary Embolism

Abstract

Venous thromboembolic disease, including deep venous thrombosis (DVT) and pulmonary embolism (PE), is an under-diagnosed and under-appreciated medical problem that results in significant patient morbidity and mortality. Inadequate venous thromboprophylaxis in surgical as well as medically ill patients results in DVT and PE that negatively impact patient outcomes and increase health-care costs. A high index of clinical suspicion combined with an evidence-based use of diagnostic tests helps identify patients with acute thrombosis. Failure to accurately and promptly diagnose and treat DVT and PE can result in excess morbidity and mortality due to postthrombotic syndrome, pulmonary hypertension, and recurrent thrombosis. Conversely, unnecessary anticoagulation provides risk in the absence of any tangible benefit. The immediate commencement of parenteral anticoagulant therapy with intravenous unfractionated heparin or a subcutaneous low molecular weight heparin (LMWH) upon presentation with DVT or PE (often even before objective diagnosis confirmation) is necessary to minimize propagation, embolization, and recurrence rates. We favor weight-based LMWH therapy in most of our patients with DVT because of the ability to treat exclusively or primarily in the outpatient setting. We still admit patients with PE for a minimum duration of 2 days for close observation. Subsequent conversion to oral anticoagulation with warfarin (target INR of 2.0 to 3.0 in most patients) should include an overlap with parenteral therapy of at least 4 to 5 days and until a stable target INR has been achieved. A minimum of 3 to 6 months of anticoagulation is recommended following a first episode of idiopathic DVT and any PE. A shorter course of therapy may be sufficient following a situational (eg, after surgery and postpartum) or calf DVT. Long-term, and at times lifelong, therapy should be considered in patients with thrombosis in the setting of a persistent acquired or inherited hypercoagulable state. Thrombolytic therapy probably should be reserved for young patients with iliofemoral DVT, any patient with a threatened limb due to impending venous limb gangrene, and those with PE who have objective evidence of cardiopulmonary compromise. Unfavorable risk-to-benefit and cost-to-benefit ratios make more extensive use of thrombolytics undesirable. The prevention of the postthrombotic syndrome with fitted, graduated compression garments and age- and gender-appropriate cancer screening are indicated in all patients with DVT in an attempt to minimize morbidity and mortality. Hypercoagulable state testing is indicated when the results of individual tests will significantly impact the choice of anticoagulant, intensity of therapy, therapeutic monitoring, family screening, family planning, prognosis determination, and most of all, duration of therapy.