Pediatric Resident The Barbara Bush Children's Hospital at Maine Medical Center Portland, Maine, United States
Background: Point of care US (US) is becoming ubiquitous in its utilization due to its ability to provide immediate information that can guide clinical decision-making. The utility of bedside US requires training and skill, and objective metrics of expertise are needed to limit the potential for misdiagnosis. Cognitive load (CL) is a correlate for understanding expertise, as it is reflective of attentional resource allocation that decreases with expertise, but its assessment requires task interruption or post-task assessment. Eye blinking has been shown in the surgical realm to decrease in frequency and duration in response to increase in task difficulty. Objective: We sought to determine whether individual blink dynamics would show differences between experts’ and novices’ during point of care lung US interpretation. Design/Methods: We conducted a prospective, observational, multi-institution study comparing expert pediatric critical care and emergency medicine US faculty with advanced US training against novice resident physicians with no advanced US training. Participants were shown and asked to interpret a set of 10 lung US clips while eye tracking data was collected. After the US clips, participants completed the NASA Task Load Index (NASA-TLX) to assess CL. Eye tracking data was then analyzed for the frequency and duration of eye blinks. Results: 29 participants completed the study (13 experts, 16 novices). Experts had significantly higher rates of correct interpretation (p < 0.001), lower CL by NASA-TLX (p < 0.001), as well as increased frequency of blinking during US interpretation (all p< 0.001). There was no statistically significant difference in blink duration between groups.
Conclusion(s): In our cohort, blink frequency could be used to discriminate between levels of expertise. Future work should focus on its ability to discriminate intermediate levels of expertise to understand whether it would be a viable metric to measure skill acquisition during US training.
