How fast is the focused assessment with sonography for trauma examination learning curve?

Objective: Although accuracy for focused assessment with sonography for trauma (FAST) examination interpretation has been widely reported, the learning curve for FAST interpretation by emergency medicine (EM) residents who are novice to ultrasound has not been well described. The present study's objective was to analyse EM resident FAST interpretation accuracy over 18 months. Methods: Prospective comparison of EM resident FAST interpretation accuracy for a class of nine EM residents at baseline after initial training, and then every 6 months over 18 months. Accuracy was scored after viewing the same 20 video clip images of the four anatomic views for five FAST examination cases. Three video clips had large anechoic stripe (AS) (>6 mm), four had moderate AS (6 mm ≥ AS ≥ 3 mm), two had small AS (<3 mm), and eleven had no AS (AS = 0 mm). A surgeon with 20 years of ultrasound experience confirmed the video clip interpretations. Data analysis used descriptive statistics with 95% confidence intervals. Results: For no AS views, EM resident accuracy was 79.8% (70.3-86.9%) baseline, 91.9% (84.2-96.2%) at 12 months, and 92.9% (85.5-96.9%) at 18 months. For small AS views, resident accuracy was 27.8% (10.7-53.6%) baseline, 66.7% (41.2-85.7%) at 12 months, and 72.2% (46.4-89.3%) at 18 months. For large AS views, resident accuracy was 77.8% (57.3-90.6%) baseline, 86.1% (69.7-94.8%) at 12 months, and 100.0% (84.5-100%) at 18 months. Conclusion: Over 18 months, EM resident FAST interpretation accuracy steadily increased. By 12 months (or 35 examinations), the accuracy of EM residents novice to ultrasound approximated previously reported accuracy rates.