Targeting the cognitive failures of fatigue: a randomized, double-blind, crossover pilot trial of a rapid...

The purpose is to investigate the effects of caffeinated chewing gum on the cognitive performance of emergency physicians (EPs) during a night shift. In this randomized, double-blind, placebo-controlled crossover exploratory pilot trial, 14 young male EPs (mean age: 29.9 ± 1.44) working an 8-h night shift received either caffeinated gum (200 mg) or a placebo mid-shift. A comprehensive cognitive battery assessing executive function, cognitive flexibility, and spatial memory was administered at three time points: pre-shift (baseline), mid-shift (10 min post-intervention), and end-of-shift. Performance changes between conditions were analyzed using the Wilcoxon signed-rank test, with effect sizes quantified via rank-biserial correlation. Caffeinated gum elicited immediate and large improvements in key executive functions. Compared to placebo, the caffeine condition was associated with significantly enhanced cognitive flexibility (reduced task-switching interference: r = -0.784, 95% CI [-1.000 to -0.354], p = 0.009; improved accuracy: r = 0.673, 95% CI [0.154-1.000], p = 0.026) and superior cognitive inhibition (improved Incongruent Stroop task performance: r = -0.745, 95% CI [-1.000 to -0.273], p = 0.015). These benefits were not sustained at the end-of-shift assessment, and no significant effects were observed for spatial memory or other cognitive domains at any time point. This exploratory trial found that 200 mg of caffeinated gum produced immediate, domain-specific gains in cognitive flexibility and response inhibition, functions closely linked to medical error risk. As the effects were transient, caffeinated gum may serve as a short-term "tactical safety tool" in high-risk scenarios, aligning with strategies in aviation and military operations, though larger studies are needed to confirm these findings and test for a direct impact on clinical performance.