Acute deep vein thrombosis: Early mobilization does not increase the frequency of pulmonary embolism

Outpatient treatment for acute symptomatic deep vein thrombosis (DVT) was shown to be safe for most patients. However, little is known whether patients treated on an outpatient basis were ambulating or predominantly resting, a factor which may be decisive for the outcome. In the present study 129 DVT patients were randomized to either strict immobilization for 4 days or to ambulate for greater than or equal to4 hours per day under supervision in order to show, whether the old concept of temporary immobilization is superior to early mobilization or not. The DVT diagnosis was based on duplex sonography; all patients were screened for PE at baseline and at day 4 by pulmonary ventilation-perfusion scanning and were followed up for a total of 3 months. Clinically, changes in leg circumferences and leg pain were evaluated. The frequency of PE at baseline was 53.0% and 44.9% in the immobile and the mobile groups, respectively. During the 4 days observation period new PEs were found in 10.0% and in 14.4% of the immobilized and the ambulating patients (Delta 4.4%; 95% CI -0.5 to 13.8; chi (2) = 0.596, p = 0.44). The occurrence of new PE was related to the presence of PE at baseline but not to other potential predictors. The magnitude of a decrease in leg circumferences and leg pain was comparable in both groups. No patient died during the 4 day observation period. The total 3 month mortality rate was 3.9% (5 patients; 2 from the immobile, 3 from the ambulating group). All 5 patient suffered from malignancies. The results of this study show in accordance with the trial hypothesis that, regarding the frequency of PE, immobilization is not superior to early mobilization, suggesting that early mobilization is safe.