Venous thromboembolism (including deep venous thrombosis [DVT] and pulmonary embolism) is the third most common vascular condition, exceeded only by coronary artery disease and stroke. For approximately the past 10 years, the initial treatment for DVT has consisted of heparin plus oral anticoagulation for at least five days. Heparin is discontinued when the anticoagulant has maintained an International Normalized Ratio of 2.0 to 3.0 for two consecutive days. Because low-molecular-weight heparin therapy can be provided at home, hospitalization is no longer required. However, outpatient therapy raises safety concerns. Douketis reviewed the literature to identify any subgroups of patients with DVT who should be hospitalized for treatment.
The author’s search of electronic databases identified 17 clinical studies of outpatient therapy for DVT. Seven of the studies were randomized controlled trials and 10 trials were not randomized.
Among the patients who received adequate anticoagulation, 3 to 5 percent developed recurrent thromboembolism. The rates of major bleeding during the first three months of treatment were 3 to 5 percent. The case-fatality rate in patients with recurrent venous thromboembolism is 5 percent.
The author identified four sets of criteria for determining if patients should be considered for hospital admission (see accompanying table): (1) does the patient have massive DVT?; (2) does the patient have objectively confirmed symptomatic pulmonary embolism?; (3) is the patient at high risk of anticoagulant-related bleeding complications?; and (4) does the patient have major comorbidity or other factors that might require hospitalization?
Massive DVT is characterized by severe pain, swelling of the entire limb, acrocyanosis, and ultrasonic findings of involvement of the iliofemoral vein segment and/or inferior vena cava. These patients require aggressive pain control and may require prolonged use of heparin or unconventional anticoagulation. Patients with iliofemoral DVT who are not treated aggressively are more than twice as likely to develop thrombosis than patients with less severe DVT (11.2 compared with 5.3 percent).
Approximately 10 percent of patients with DVT also have symptomatic pulmonary embolism. Some studies suggest that hemodynamically stable patients who did not require parenteral analgesia and had oxygen saturations greater than 95 percent on room air can be treated at home despite evidence of pulmonary embolism. Until further evidence is provided, patients with DVT and symptomatic pulmonary embolism should receive in-hospital anticoagulant therapy for at least the initial two to three days of treatment.
Between 5 and 10 percent of patients with recently diagnosed DVT have an increased risk of bleeding during anticoagulation. This group includes patients with metastatic cancer, gastrointestinal bleeding conditions, coagulation disorders or thrombocytopenia, and patients who have had recent surgery or trauma. Patients in this group require intensive monitoring and prompt intervention for those in whom bleeding occurs. Hospitalization is required for patients with serious comorbidities and/or limited capacity for home care.
|Does the patient have massive DVT?
|Swelling of entire lower limb
|Venous limb ischemia
|Extension of DVT into iliofemoral veins or inferior vena cava
|Does the patient have symptomatic pulmonary embolism?
|Requirement for supplemental oxygen or other supportive care
|At risk for cardiorespiratory deterioration
|Is the patient at high risk for anticoagulant-related bleeding?
|Active bleeding (e.g., active gastrointestinal bleeding source)
|Recent (within four weeks) bleeding episode (e.g., peptic ulcer disease)
|Recent (within one week) surgery or trauma
|Thrombocytopenia (platelet count < 100 × 106 per L)
|Coagulopathy (INR > 1.4 or activated PTT > 40 seconds)
|Advanced cancer with intracerebral or intrahepatic metastases
|Does the patient have major comorbidity or other factors that warrant in-hospital care?
|Severe pain or discomfort related to DVT that warrants parenteral analgesia
|Major comorbidity (e.g., advanced cancer) that requires in-hospital care
|Cognitive impairment or language barrier that precludes outpatient care
|Impaired mobility that precludes outpatient visits or laboratory monitoringof anticoagulant activity
The author concludes that four criteria can be used to determine if patients with DVT should be considered for in-hospital treatment.