Although the adverse effects of total absence of sleep extending beyond 24 hours are well recognized, impairment related to less severe degrees of sleep loss or irregularity of sleep are equally important. The most likely sleep problems encountered by aircrews in sustained operations are fragmented sleep associated with partial sleep loss, disruption of sleep-wakefulness cycles and circadian rhythm disruption. For some individuals, the loss of only two and a half hours of sleep each night for two nights has been shown to impair vigilance the next morning, and so it must be suspected that repeated partial sleep loss will lead to impaired performance after several days of irregular work and rest. In addition, irregularity of sleep and the disruption of the normal sleep-wakefulness cycles, rather than a reduction of total hours of sleep, is also likely to disturb performance. The factors which influence performance with total sleep loss are probably equally relevant to those which occur with partial sleep loss or disturbed sleep due to irregularity of work and rest.
Sleep is essential to sustain high levels of vigilance and maintain effectiveness.
Careful attention to sleep is all important because impaired performance follows sleep disturbance even though impairment may not be easy to demonstrate. The University of Iowa. All rights reserved.