OBJECTIVE: To monitor surgeons' performance and cognition during night shifts.

DESIGN: Surgeons were monitored before call and on call (17-hour shift). Psychomotor performance was assessed by laparoscopic simulation and cognition by the d2 test of attention. The surgeons performed the laparoscopic simulation and the d2 test of attention at 8 a.m. before call and at 4 a.m. on call. Sleep was measured by wrist actigraphy and sleepiness by the Karolinska sleepiness scale.

SETTING: Department of Surgery at Herlev Hospital, Denmark.

PARTICIPANTS: Overall, 30 interns, residents, and attending surgeons were included and completed the study. One participant was subsequently excluded owing to myxedema.

RESULTS: The surgeons slept significantly less on call than before call. There was increasing sleepiness on call; however, no significant differences were found in the precall laparoscopic simulation values compared with on-call values. The d2 test of attention showed significantly improved values on call compared with before call.

CONCLUSION: Sleep deprivation during a 17-hour night shift did not impair surgeons' psychomotor or cognitive performance.