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KEY POINTS
Venous thromboembolism (VTE) continues to elude diagnosis due to its diverse presentations and etiologies.
Proximal deep vein thromboses (DVT) have a 90% likelihood of progressing to pulmonary embolism (PE).
Although DVT and PE have similar risk factors and many overlapping features, the risk of death within 1 month is far higher in patients with PE than with DVT; thus, aggressive management for PE is recommended compared to isolated DVT.
Risk stratification based on pretest probability results in a cost-effective and practical diagnostic evaluation of VTE.
The major complications of anticoagulant therapy for VTE are hemorrhage and heparin-induced thrombocytopenia.
Focus must lie in the diagnosis, treatment, and prevention in order to improve survival of the critically ill patient with VTE.
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Venous thromboembolism (VTE), manifested as either deep venous thrombosis (DVT) or pulmonary embolism (PE), is a leading cause of morbidity and mortality in the critically ill patient. Standardizing for age and race, the incidence of VTE in the United States is approximately 70 to 120 cases per 100,000 individuals. The incidence of VTE increases exponentially as the population ages although no difference is apparent between genders. The high incidence of VTE is mainly dominated by PE diagnosed at autopsy and as a contributory factor in 4% to 11% of deaths. Despite appropriate therapy, 1% to 8% of patients with PE will not survive and others will experience long-term complications including postphlebitic syndrome (40%) and chronic thromboembolic pulmonary hypertension (4%). In the International Cooperative Pulmonary Embolism Registry, the death rate was 58% in patients who were hemodynamically unstable at the time of presentation and 15% among those who were hemodynamically stable.
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VTE often eludes diagnosis due to its wide variety of presentations and diverse pathophysiological mechanisms. The diagnosis of PE is confirmed by objective testing in only about 20% of patients. Accurate diagnosis of VTE can minimize the risk of thromboembolic events and complications related to unnecessary anticoagulation and treatment. Consequently, the Agency for Healthcare Research and Quality ranks prevention of VTE as the first priority out of 79 preventive initiatives that can improve patient safety in healthcare settings.
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Because DVT and PE have a spectrum of presentations, they have been approached by many clinicians in an algorithmic manner to address diagnosis, treatment, and prevention. The clinical presentation of VTE ranges from asymptomatic tachycardia to respiratory failure and hemodynamic instability. Additionally, VTE can occur spontaneously or from predisposing risk factors, catheter related, and may arise from genetic predisposition. In more than half of the cases, VTE is provoked by surgery, immobilization, advanced age, pregnancy, the use of oral contraceptives, or hormone-replacement therapy. The difficulty for clinicians lies in the early recognition and prompt treatment of VTE because of these widely diverse presentations. Prevention of DVT/PE in the ICU patient also poses many difficulties in choosing the appropriate regimen for prevention based on the risk-benefit ratios. ...