Impact of moderate alcohol consumption on visuo-motor skills in neurosurgical residents

Alcohol adversely affects cognitive and motor functions that are critical for surgical performance. Although its general physiological and neurocognitive effects are well documented, evidence regarding its impact on complex, high-precision tasks-such as surgical procedures-remains limited. In this study, nine neurosurgeons performed a series of standardized surgical tasks assessing fine motor skills, gross motor control, and hand-eye coordination under three conditions: sober, acutely influenced (blood alcohol concentration [BAC] ~ 1.0 g/kg), and during the elimination phase several hours after alcohol consumption (BAC ~ 0.6 g/kg), with blood samples collected in each condition for BAC determination in accordance with German forensic standards. Across all nine participants, a total of 189 tests were conducted and evaluated, taking into account both the time required to complete each task and the quality of task performance. Task quality declined in both the acutely influenced and elimination phases. Significant impairments in quality were observed in almost all tasks. During acute influence, tasks such as suturing took longer to complete, whereas others like drilling were performed more quickly. In the elimination phase, all tasks were completed faster than at baseline. These findings suggest that even moderate alcohol intake can have lasting effects on surgical precision and may have implications for patient safety in operative settings.