How Many Ultrasound Examinations Are Necessary to Gain Proficiency in Accurately Identifying the Nerves of the Brachial Plexus at the Level of the Interscalene Space?

INTRODUCTION: There has been a trend toward the use of alternative treatments to opioids for adequate pain management. This has paralleled a growing interest in the utilization of bedside point-of-care ultrasonography to guide placement of regional anesthesia in the emergency department. The purpose of this study was to establish the number of supervised examinations required for an emergency medicine resident to gain proficiency in accurately locating and identifying the nerves of the brachial plexus at the level of the interscalene space. METHODS: Proficiency was defined as the number of attempts a resident required to accurately locate and identify the nerves of the brachial plexus on 10 separate, consecutive examinations. Didactic education was provided prior to the study and residents also participated in two instructional hands-on ultrasound examinations prior to the commencement of initial data collection. Count data are summarized using medians, means, and ranges. Random effects negative binomial regression was used for modeling panel count data where negative coefficients indicate increase in proficiency. RESULTS: A total of 24 emergency medicine residents were enrolled in the study. Fourteen males and ten females participated. There were nine PGY-1 residents (37.5%), nine PGY-2 residents (37.5%), and six PGY-3 residents (25%). The median number of required supervised attempts and range for correctly performing both steps in the identification of the nerves of the brachial plexus was 2 (range 2–12). The median starting confidence level was 2 (range 1–4), and the median ending confidence level was 4 (range 1–5). Increases in confidence from start to finish were found to be statistically significant (P < 0.001). CONCLUSION: Emergency medicine residents are easily adept in the identification of the nerves of the brachial plexus at the level of the interscalene space following two supervised examinations. Residents made steady gains in confidence and proficiency throughout the study; statistical analysis found a significant association between the two.