Physiological Parameters Associated With Non-technical Skills During Surgical Crises Simulation

To investigate linear and non-linear associations between physiological measures of cognitive load and expert-rated non-technical skills during simulated surgical crises DESIGN: This was a multicenter, prospective observational study. Crisis simulations comprised 3 categories: bleeding, perforated viscus, unexpected finding. Multivariable linear and quadratic (non-linear) regression investigated relationships between cognitive load measures and NTS. Cognitive load was assessed subjectively (SURG-TLX) and objectively (heart-rate variability [HRV]; electrodermal activity [EDA]). Non-technical skills were assessed by expert raters (Non-technical Skills for Surgeon's Taxonomy [NOTSS]). Sensor data were segmented and a delta value calculated (Delta = Simulation-Debrief).

Three dedicated surgical simulation suites in Glasgow, Edinburgh and Dundee, UK.

All second-year core surgical trainees in a national training program attending the Managing Surgical Crises course were eligible; 32 were approached for enrollment, and all participated.

Thirty-two participants conducted 72 simulations. Multivariable regression (p = 0.006, Adjusted R² = 0.26) identified 2 associations with NOTSS score: each 1-unit (µS) increase in Tonic EDA delta was associated with a 0.89-point reduction in NOTSS score, whereas an additional 1 beat/minute increase in mean HR delta corresponded to a 0.09-point increase in NOTSS score. Quadratic regression identified a significant non-linear ("Inverted-U") relationship between (standard deviation of normal-to-normal intervals (SDNN) and NOTSS score (p = 0.034, R² = 0.11), with peak predicted NOTSS score (13.4/16) corresponding to a model derived SDNN delta of -6 ms. Among simulation categories, highest subjective cognitive load was observed in bleeding (p < 0.0001), and highest NOTSS scores were observed in perforated viscus (p = 0.002).

This study has identified meaningful changes in cognitive load measures associated with NOTSS scores during surgical crisis simulation, advancing knowledge in the pursuit of automated and objective assessment of surgical NTS.