Level 2: Mid-level evidence

Early mobilization was associated with a lower incidence of deep venous thrombosis (DVT) progression in a randomized trial of 103 patients hospitalized for proximal DVT, but the results did not reach statistical significance (Curr Med Res Opin. 2006;22:593-602). Patients were randomized to five days of strict bed rest vs. early mobilization; those with symptomatic pulmonary embolism (PE) were excluded. All patients were treated with dalteparin (Fragmin) and compression bandages; follow-up at 10-12 days included color duplex sonography or phlebography to detect DVT progression and perfusion/ventilation scanning or spiral CT to detect PE.

Participant enrollment was terminated early due to reluctance of study centers to continue randomizing patients to immobilization.

Comparing bed rest vs. early mobilization, 50% vs. 48% had scintigraphic PE at baseline, 20% vs. 7.7% had progression of DVT based on follow-up imaging (P =.088), 10% vs. 1.9% had “clinically relevant [not clearly defined] or symptomatic pulmonary embolism” (P =.109), and 6% vs. 1.9% had nosocomial infection and/or serious adverse event (not significant). There were no deaths in either group.

Based on a previous randomized trial (N = 129), walking is not clearly harmful during initial treatment of DVT (Thromb Haemost. 2001;85:42-46). Patients in this study were randomized to strict immobilization for four days vs. ambulation for at least four hours per day. Screening for PE with ventilation-perfusion scanning was done at baseline and at four days; patients were followed clinically (leg circumferences and leg pain) for three months.

Comparing immobilization vs. ambulation, 53% vs. 45% had PE at baseline and 10% vs. 14.4% had a new PE at four days (not significant but 95% CI approaches NNH 7 for ambulation). However, the baseline differences in rates of PE may affect rates of new PE.