Ultrasound imaging obtained by emergency department physicians to diagnose deep vein thrombosis: accuracy, safety, and efficiency.

Objectives: To assess the accuracy, safety, and efficiency of ultrasound images obtained by emergency physician to diagnose deep vein thrombosis (DVT). patients with acute heart failure (AHF) attended in a hospital emergency department (ED).

Material And Methods: Prospective multicenter cohort study. We assigned patients suspected of having DVT to an intervention or control group. Emergency physicians took ultrasound images that were later evaluated by a radiologist in the intervention group. In the control group, images were evaluated only by the radiologist. We analyzed patient, physician, and episode variables. Test results, times until imaging, and 30-day adverse events were also analyzed. Sensitivity, specificity, positive and negative likelihood ratios, and agreement between physicians and radiologists (κ statistic) were calculated.

Results: A total of 304 patients (209 in the intervention group and 95 controls) were included. The groups were comparable. The overall prevalence of DVT was 35.5% (95% CI, 30.3-41.0). The sensitivity of ultrasound images obtained by emergency physicians was superior in relation to experience: 71.4 (95% CI, 50.0-86.0) for those in a training course, 75.0 (95% CI, 80.0-95.4) for those with at least 2 months' practical experience, and 94.7 (95% CI, 82.7-98.5) for routine users. Specificity statistics for the 3 levels of physician experience were 83.3 (95% CI 55.2- 95.2), 100 (95% CI 83.0-100), and 96.6 (95% CI 88.4-99.0), respectively. The positive and negative likelihood ratios for ultrasound imaging by physicians were 27.94 and 0.054, respectively. The κ statistic was 0.80. Mean (SD) time until a physician took ultrasound images was 1.81 (1.46) hours versus 4.39 (1.81) hours until a radiologist obtained images (P = .007). Three deaths occurred within 30 days. They were not attributable to recurrence or bleeding.

Conclusion: Ultrasound images taken by emergency physicians to diagnose DVT are accurate and safe and may be efficient. However, routine experience with ultrasound is necessary.