Boudreau Philippe, Lafrance Sylvain, Boivin Diane B
a Centre for Study and Treatment of Circadian Rhythms, Douglas Hospital Research Centre, Department of Psychiatry , McGill University , Montreal , Canada.
b Innovation Maritime , Rimouski , Canada.
Chronobiol Int. 2018 Jun;35(6):773-784. doi: 10.1080/07420528.2018.1466796. Epub 2018 May 22.
Fatigue is recognized as an important safety concern in the transportation industry. In this study, our goal was to investigate how circadian and sleep-wake dependent factors influence St-Lawrence River pilots' sleep-wake cycle, alertness and psychomotor performance levels at work. A total of 18 male St-Lawrence River ship pilots were recruited to a 16-21-day field study. Pilots' chronotype, sleepiness and insomnia levels were documented using standardized questionnaires. Their sleep-wake cycle was documented by a sleep-wake log and wrist-worn activity monitoring. Subjective alertness and objective psychomotor performances were assessed ~5×/day for each work and rest day. Ship transits were distributed throughout the 24-h day and lasted on average (± SEM) 5.93 ± 0.67 h. Main sleep periods occurred mainly at night, and objectively lasted 6.04 ± 1.02 h before work days. When going to bed at the end of work days, pilots subjectively reported sleeping 7.64 ± 1.64 h in the prior 24 h. Significant diurnal and wake-dependent effects were observed for subjective alertness and objective psychomotor performance, with minimum levels occurring between 09:00 and 10:00. Thus, despite their irregular work schedule, ship pilots presented, as a group, a diurnal variation of alertness and psychomotor performance indicative of a day-oriented circadian system. Important inter-individual differences were observed on psychomotor performance mesor and phase. In individuals, earlier phases in psychomotor performance were correlated with earlier chronotype. This study indicates that both circadian and homeostatic processes modulate alertness and psychomotor performance levels with worst levels reached when long shifts ended in the morning. This work has potential applications as it indicates fatigue countermeasures considering both processes are scientifically based.
疲劳被认为是运输行业中一个重要的安全问题。在本研究中，我们的目标是调查昼夜节律和睡眠-觉醒相关因素如何影响圣劳伦斯河引航员的睡眠-觉醒周期、警觉性以及工作时的精神运动表现水平。总共招募了18名男性圣劳伦斯河船舶引航员参与一项为期16至21天的实地研究。使用标准化问卷记录引航员的昼夜节律类型、嗜睡和失眠水平。通过睡眠-觉醒日志和佩戴在手腕上的活动监测器记录他们的睡眠-觉醒周期。在每个工作日和休息日，每天约5次评估主观警觉性和客观精神运动表现。船舶航行分布在全天24小时内，平均持续时间（±标准误）为5.93±0.67小时。主要睡眠时间主要发生在夜间，在工作日之前客观上持续6.04±1.02小时。在工作日结束上床睡觉时，引航员主观报告在前24小时内睡了7.64±1.64小时。在主观警觉性和客观精神运动表现方面观察到显著的昼夜和觉醒相关效应,最低水平出现在09:00至10:00之间。因此，尽管他们的工作时间表不规律，但作为一个群体，船舶引航员表现出警觉性和精神运动表现的昼夜变化，这表明存在一个以白天为导向的昼夜节律系统。在精神运动表现的中值和相位上观察到了重要的个体间差异。在个体中，精神运动表现的较早阶段与较早的昼夜节律类型相关。这项研究表明，昼夜节律和稳态过程都调节警觉性和精神运动表现水平，当长时间轮班在早晨结束时达到最差水平。这项工作具有潜在的应用价值，因为它表明考虑到这两个过程的疲劳对策是有科学依据的。
