Value of ultrasound imaging of the lower limbs for diagnosing deep vein thrombosis in the emergency department

Objectives: 1) To describe the characteristics of patients with these symptoms. 2) To assess agreement between compression ultrasonography performed in the ED and Doppler ultrasound imaging in radiology. 3) To assess the efficacy of a diagnostic algorithm that includes ultrasound imaging, clinical characteristics, and laboratory findings. Methods: Descriptive study of consecutive patients attending the ED complaining of symptoms suggestive of DVT. We applied a diagnostic algorithm requiring physical examination, D-dimer assessment, pretest probability (Wells score), and ED compression ultrasonography. Results: Thirty-seven patients were included; 48.65% were men. Pretest probability according to the Wells score was low for 9 patients (24.3%; 95% confidence interval [Cl], 9.1%-39.5%), moderate for 10 (27.0%; 95% Cl, 11.4%-42.7%), and high for 18 (48.6%; 95% Cl, 31.2%-66.1%). D-dimer level was not significantly associated with the findings of compression ultrasonography. The K index for agreement between compression ultrasonography and the gold standard (Doppler ultrasound in the radiology department) was 1. Sensitivity was 100% (95% Cl, 96.1%-100%), specificity 91.7% (95% Cl, 71.9%-100%), positive predictive value 92.9% (95% Cl, 75.8%-100%), and negative predictive value 100% (95% Cl, 95.4%-100%). Conclusions: The algorithm tested appears to be valid for evaluating patients who may have DVT. There is a high level of agreement between compression ultrasonography of the lower extremities in the ED and ultrasound findings reported by the radiology department. [Emergencias 2009;21:177-182]