Standardised colour-coded compartmentalised syringe trays improve anaesthetic medication visual search and mitigate cognitive load

Anaesthetic procedures are complex and subject to human error. Interventions to alleviate medication errors include organised syringe storage trays, but no standardised methods for drug storage have yet been widely implemented. We used experimental psychology methods to explore the potential benefits of colour-coded compartmentalised trays compared with conventional trays in a visual search task. We hypothesised that colour-coded compartmentalised trays would reduce search time and improve error detection for both behavioural and eye-movement responses. We recruited 40 volunteers to identify syringe errors presented in pre-loaded trays for 16 trials in total: 12 error present and four error absent, with eight trials presented for each tray type. Errors were detected faster when presented in the colour-coded compartmentalised trays than in conventional trays (11.1 s vs 13.0 s, respectively; P=0.026). This finding was replicated for correct responses for error-absent trays (13.3 s vs 17.4 s, respectively; P=0.001) and in the verification time of error-absent trays (13.1 s vs 17.2 s, respectively; P=0.001). On error trials, eye-tracking measures revealed more fixations on the drug error for colour-coded compartmentalised trays (5.3 vs 4.3, respectively; P<0.001), whilst more fixations on the drug lists for conventional trays (8.3 vs 7.1, respectively; P=0.010). On error-absent trials, participants spent longer fixating on the conventional trials (7.2 s vs 5.6 s, respectively; P=0.002).
Colour-coded compartmentalisation enhanced visual search efficacy of pre-loaded trays. Reduced fixations and fixation times for the loaded tray were shown for colour-coded compartmentalised trays, indicating a reduction in cognitive load. Overall, colour-coded compartmentalised trays were associated with significant performance improvements when compared with conventional trays.