Emergency Medicine: All Areas
Emergency Medicine 9
Jiwoong J. Shin, MD (he/him/his)
Peds ER Fellow
University of Texas Southwestern Medical School
Dallas, Texas, United States
Skin and soft tissue infections are a common presenting chief complaint in pediatric emergency departments. Point of care ultrasonography (POCUS) is often used to distinguish between cellulitis and abscess. There is limited data regarding the number of ultrasound scans needed to demonstrate competency in ultrasound.
The objective of this study was to determine using the cumulative summation test for learning curve (LC-CUSUM) and cumulative sum analysis (CUSUM), if competency in skin and soft tissue ultrasound can be achieved and maintained in the American College of Emergency Physicians (ACEP) recommended 25 scans for physicians using a practice-based pathway to learn pediatric skin and soft tissue POCUS.
This was a retrospective observational study of pediatric emergency medicine faculty and fellows’ progress through a practice-based ultrasound training program based upon ACEP guidelines. A successful ultrasound required adequate image acquisition (score > 3) along with accurate interpretation based on ACEP suggested quality assurance grading scale. Learning curve cumulative sum (LC-CUSUM) analysis was used to analyze the learning curve and to monitor technical quality by using a predetermined acceptable failure rate of 10% (P0=.1) and an unacceptable failure rate of 25% (P1=.25). Once competency was achieved, continued progress was tracked using cumulative sum (CUSUM) analysis with similar parameters to ensure competency was maintained.
10 attendings and 6 fellows performed a total of 231 soft tissue ultrasound scans during the two-year study period. A median of 16 ultrasound scans were performed (interquartile range [IQR], 8-33) by each learner. In total, 207 (90%) of the scans were successful based on previously selected criteria. Among the failures, 31 (92%) were due to poor image acquisition, while 2 (8%) were due to poor image interpretation. An overall Kappa value of .93 was obtained for quality review of the scans between the two POCUS trained house staff members.
14 out of the 15 ultrasound learners demonstrated competency in obtaining and interpreting soft tissue scans during the two-year study period. Of these, 5 learners demonstrated competency as early as 8 ultrasound scans, while one demonstrated competency after 19 scans. One learner completed a total of nine scans but was not considered to be competent during the study period. Based on our results, the ACEP recommended 25 scans is an appropriate number to ensure competency for skin and soft tissue POCUS in a practice-based pathway.