Proactive error analysis of ultrasound-guided axillary brachial plexus block performance

BACKGROUND: Detailed description of the tasks anesthetists undertake during the performance of a complex procedure, such as ultrasound-guided peripheral nerve blockade, allows elements that are vulnerable to human error to be identified. We have applied 3 task analysis tools to one such procedure, namely, ultrasound-guided axillary brachial plexus blockade, with the intention that the results may form a basis to enhance training and performance of the procedure. METHODS: A hierarchical task analysis of the procedure was performed with subsequent analysis using systematic human error reduction and prediction approach (SHERPA). Failure modes, effects, and criticality analysis was applied to the output of our SHERPA analysis to provide a definitive hierarchy to the error analysis. RESULTS: Hierarchical task analysis identified 256 tasks associated with the performance of ultrasound-guided axillary brachial plexus blockade. Two hundred twelve proposed errors were analyzed using SHERPA. Failure modes, effects, and criticality analysis methodology was applied to the output of SHERPA analysis to prioritize 20 errors. CONCLUSIONS: This study presents a formal analysis of (i) the specific tasks that might be associated with the safe and effective performance of the procedure and (ii) the most critical errors likely to occur as trainees learn to perform the procedure. Potential applications of these data include curricular development and the design of tools to teach and assess block performance.