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A 44-year-old Caucasian woman presented to the emergency department with a 2-week-history of right-leg pain and edema involving the lower thigh to the ankle. One week prior to her emergency room visit, she developed increasing fatigue associated with pleuritic chest pain, exertional dyspnea, and palpitations. Her leg symptoms began within 2 weeks after she was discharged from the hospital after undergoing a 4-day stay for surgery for breast cancer. Her medical history is significant for vasculitis (granulomatosis with polyangiitis/Wegener granulomatosis) and mild iron deficiency anemia. She stopped taking a birth control pill a few weeks prior to surgery. Physical examination demonstrates blood pressure of 138/68 mm Hg, heart rate of 102 bpm, body mass index of 34, regular heart rate and rhythm, and lungs clear to auscultation. The right lower extremity has soft pitting edema with negative Homan sign. There is no cyanosis in the extremities, and distal lower extremity pulses are intact and symmetrical. Acute deep venous thrombosis (DVT) is suspected. The quantitative D-dimer level is 1200 mg/dL, and a venous duplex ultrasound reveals acute DVT involving the common femoral (Figure 53-1), femoral, and popliteal veins.
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Venous thromboembolic disease, including acute DVT and acute pulmonary embolism (PE), is the third most common cardiovascular disease in the United States.
Approximately two-thirds of all venous thromboembolic events (VTE) are related to hospitalization.
It is estimated that over a million cases of VTE are diagnosed each year in the United States alone.
The absolute risk of DVT or PE in the population (all ages) is estimated at 1% to 3% per year.
The incidence of DVT or PE increases with age. The estimated age-associated incidence of VTE increases approximately from 1 case per 100,000 person-years (1/100,000) in teenagers (estimated absolute risk of 0.001% per year) to 1/100 person-years over the age of 75 (estimated absolute risk of 1% per year).1
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ETIOLOGY AND RISK FACTORS
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Acute DVT or PE is a multifactorial disease. The greater the number of risk factors present, the more likely a patient is to develop acute DVT.
In addition to increasing risk with age, risk factors for DVT or PE can be classified as situational, acquired, or inherited (Table 53-1).1,2, and 3
Situational risk factors can be defined as transient clinical circumstances that increase the risk of VTE while they are present and for a short period (from a ...