Pulmonary embolism in rehabilitation patients: relation to time before return to physical therapy after diagnosis of deep vein thrombosis.

OBJECTIVE: There is increased risk of a pulmonary embolism (PE) after a deep vein thrombosis (DVT). The effect of mobilizing the affected lower extremity has not been well studied. The purpose of this study was to detect any change in the rate of PE occurrence dependent on time to mobilization in patients diagnosed with a DVT in a rehabilitation hospital.

DESIGN: Retrospective case-control study.

SETTING: Urban rehabilitation hospital.

PATIENTS: Data were collected from charts of 190 patients with a discharge diagnosis of PE or DVT at an urban rehabilitation hospital from January 1991 to June 1995; 127 patients met inclusion criteria in the study.

INTERVENTIONS: Measurement of time to return to physical therapy after diagnosis of DVT.

MAIN OUTCOME MEASURES: A DVT was diagnosed with either Doppler ultrasound or venogram testing, a PE by ventilation/perfusion (V/Q) scan, and time to mobilization in hours until return to physical therapy.

RESULTS: One hundred twenty-one patients had a DVT without a subsequent PE and a mean time of 123.2 hours until mobilization. Six patients had a subsequent PE and a mean time of 48.3 hours until mobilization (p = .021). A Fischer exact test comparing patients with and without PE who were returned to therapy before 48 hours and after 48 hours (p = .018), and before and after 72 hours (p = .059), supports the hypothesis that patients who return to physical therapy earlier are more likely to develop a PE than patients who return later.

CONCLUSIONS: It is imperative to prophylactically treat all patients at risk of a DVT with anticoagulation if possible. Once a DVT is diagnosed it is prudent to keep the affected limb immobilized for at least 48 to 72 hours while the patient is being anticoagulated. A large prospective cohort study is needed to answer the question of when to mobilize a patient after diagnosis of a DVT.