Control charts to establish and monitor proficiency in the detection of pulmonary B-lines with Point of Care Ultrasound

Objective: Point of care ultrasound (POCUS) is a widely used clinical tool. This operator-dependent technique requires methods to establish individual benchmarks and to monitor the learning process. We present the use of the learning curve standard cumulative summation (LC-CUSUM) and CUSUM control charts to establish and monitor, respectively, the proficiency of a physician to detect pulmonary B-lines with POCUS. Materials and Methods: A training course for general practitioners was conducted to detect plasma leakage using POCUS. The trainees and an expert radiologist identified the number of pulmonary B-lines in the POCUS images of 53 hospitalized patients. The interpretation of one trainee was compared to that of the expert radiologist using LC-CUSUM and CUSUM considering image quality and anatomical site. Results and Discussion: We found that image quality was better in the apices than the bases of the lungs. The trainee learning curve differed by anatomical site and the results of LC-CUSUM and CUSUM differed when only high-quality (first scenario) or all images (second scenario) were included in the analysis. Conclusion: The LC-CUSUM and CUSUM control charts were useful to evaluate the learning curve in this case and to identify image quality as an important factor in the evaluation process. They warrant further study as graphical tools for real-time monitoring of POCUS training.