Hand motion analysis using the imperial college surgical assessment device: validation of a novel and objective performance measure in ultrasound-guided peripheral nerve blockade.

Background and Objectives: The Imperial College Surgical Assessment Device (ICSAD) has been validated in various settings as an objective tool to measure technical performance. We sought to establish (1) the construct validity of the ICSAD as an assessment tool in ultrasound-guided supraclavicular block by determining its ability to discriminate between operators of different experience level and (2) the concurrent validity of the ICSAD by correlating it with a task-specific checklist and a global rating scale. Methods: We compared 30 performances of ultrasound-guided supraclavicular block by junior residents with 30 performances by highly experienced consultant anesthesiologists. We also studied 10 anesthesiologists undertaking a 1-year regional anesthesia fellowship and compared a performance in their first month to one in their last 3 months. We used the ICSAD to measure 3 dexterity parameters during the scanning and needling phases of each block: time taken, number of movements, and path length traveled by each hand. Two blinded expert observers evaluated video recordings of each block using a 30-item task-specific checklist and a 7-item global rating scale. Results: Consultants (experts) performed significantly better than residents (novices) on all ICSAD parameters in both scanning and needling phases. Fellows demonstrated improvement in all ICSAD parameters between their early and late performance, reflecting their transition from novice to expert. The task-specific checklist and global rating scale were also highly discriminating between novice and expert performances. There was excellent correlation between all 3 measurement tools, thereby establishing their concurrent validity. Conclusions: The ICSAD is both valid and useful in assessing performance of ultrasound-guided supraclavicular block.