School of Medicine, Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
School of Health and Rehabilitation Sciences, Department of Rehabilitation Sciences and Technology, Emergency Medicine Program, University of Pittsburgh, Pittsburgh, Pennsylvania.
Prehosp Emerg Care. 2023;27(6):807-814. doi: 10.1080/10903127.2023.2227696. Epub 2023 Jul 17.
We sought to test the effects of different duration naps on post-nap cognitive performance during simulated night shifts.
We used a randomized laboratory-based crossover trial design with simulated 12-hr night shifts and each participant completing three conditions of 72 hrs each (Clinicaltrials.gov; registration # NCT04469803). The three conditions tested included no-nap, a 30-min nap opportunity, and a 2-hr nap opportunity. Naps occurred at 02:00 hrs. Cognitive performance was assessed with the Brief 3-min Psychomotor Vigilance Test (PVT-B). Four PVT-B measures include: reaction time (RT in milliseconds (ms)), lapses (RT > 355 ms), false starts (reactions before stimulus or RT <100 ms), and speed (1,000/RT). The PVT-B was performed at the start of the simulated night shift (19:00), end of shift (07:00), pre-nap (02:00), and at 0 mins, 10 mins, 20 mins, and 30 mins following the 30-min and 2-hr nap conditions. Simultaneously, participants reported subjective ratings of fatigue and other constructs.
Twenty-eight (15 female), mostly certified emergency medical technicians or paramedics, consented to participate. For all three conditions, looking within condition, PVT-B lapse performance at the end of the 12-hr simulated night shift (at 07:00) was poorer compared to shift start ( < 0.05). Performance on PVT-B speed, RT, and false starts were poorer at shift end than shift start for the no-nap and 30-min nap conditions ( < 0.05), but not for the 2-hr nap condition ( > 0.05). Compared to pre-nap measures, performance on the PVT-B assessed at 0 mins post-nap showed significant performance declines for lapses and speed for both the 30-min and 2-hr nap conditions ( < 0.05), but not at 10, 20, or 30 mins post-nap. After waking from the 2-hr on-shift nap opportunity (at 0 mins), participants rated sleepiness, difficulty with concentration, and alertness poorer than pre-nap ( < 0.05). Participants in the 30-min nap condition rated alertness poorer immediately after the nap (at 0 mins) compared to pre-nap ( < 0.05).
While sleep inertia was detectable immediately following short 30-min and long 2-hr nap opportunities during simulated night shift work, deficits in cognitive performance and subjective ratings quickly dissipated and were not detectable at 10-30 mins post-nap.
我们旨在检验不同时长小睡对模拟夜间轮班后小睡后认知表现的影响。
我们采用随机、基于实验室的交叉试验设计，模拟 12 小时夜间轮班，每个参与者完成三种 72 小时的条件（Clinicaltrials.gov；注册号 NCT04469803）。三种条件测试包括无小睡、30 分钟小睡机会和 2 小时小睡机会。小睡时间为凌晨 2:00。使用简短的 3 分钟精神运动警觉测试（PVT-B）评估认知表现。PVT-B 的四项测量包括：反应时间（以毫秒（ms）为单位）、失误（RT > 355 ms）、假启动（在刺激之前或 RT <100 ms 时反应）和速度（1,000/RT）。PVT-B 在模拟夜间轮班开始时（19:00）、轮班结束时（07:00）、小睡前（02:00）以及小睡后 30 分钟和 2 小时的 0 分钟、10 分钟、20 分钟和 30 分钟进行。同时，参与者报告了主观疲劳和其他结构的评分。
共有 28 名（15 名女性），主要是经过认证的急诊医疗技术员或护理人员，同意参加。对于所有三种情况，在同一条件下，12 小时模拟夜间轮班结束时（07:00）的 PVT-B 失误表现比轮班开始时（ < 0.05）更差。与无小睡和 30 分钟小睡条件相比，小睡结束时 PVT-B 速度、RT 和假启动的表现比小睡开始时更差（ < 0.05），但在 2 小时小睡条件下则不然（ > 0.05）。与小睡前的测量相比，小睡后 0 分钟评估的 PVT-B 表现显示，30 分钟和 2 小时小睡条件下的失误和速度均出现显著下降（ < 0.05），但在小睡后 10、20 或 30 分钟时则不然。参与者从 2 小时轮班小睡机会中醒来（在 0 分钟）后，与小睡前相比，他们的困倦感、注意力集中的难度和警觉性更差（ < 0.05）。在 30 分钟小睡条件下，参与者在小睡后立即（0 分钟）的警觉性评分低于小睡前（ < 0.05）。
虽然在模拟夜间轮班工作中，短 30 分钟和长 2 小时的小睡机会后立即出现睡眠惯性，但认知表现和主观评分的缺陷迅速消散，在小睡后 10-30 分钟时无法检测到。
