Photic resetting in night-shift work: Impact on nurses' sleep

摘要

The objective of this study was to quantify daytime sleep in night-shift workers with and without an intervention designed to recover the normal relationship between the endogenous circadian pacemaker and the sleepwake cycle. Workers of the treatment group received intermittent exposure to full-spectrum bright light during night shifts and wore dark goggles during the morning commute home. All workers maintained stable 8-h daytime sleepdarkness schedules. The authors found that workers of the treatment group had daytime sleep episodes that lasted 7.1±.1h (mean±SEM) versus 6.6±.2h for workers in the control group (p.04). The increase in total sleep time co-occurred with a larger proportion of the melatonin secretory episode during daytime sleep in workers of the treatment group. The results of this study showed reestablishment of a phase angle that is comparable to that observed on a day-oriented schedule favors longer daytime sleep episodes in night-shift workers. (Author correspondence: diane.boivin@douglas.mcgill.ca)