Professor Sanae Oriyama and his colleagues at Hiroshima University compared the effects of taking a 120-minute nap all at once and dividing it into 90-minute and 30-minute naps while working a night shift, and found changes in sleepiness and fatigue. .
The longest night shift for nurses is said to be 16 hours, and there are concerns that increased fatigue and drowsiness among nurses could increase risks to medical safety.For this reason, many nurses who work 16-hour night shifts take naps in shifts, but the times and duration of naps are not uniform, and it is important to take naps effectively to reduce drowsiness and fatigue and maintain work ability. It is not clear how to do so.
そこで今回、折山教授は夜勤時の仮眠の効果を検証するために収集したこれまでの実験データを再分析し、16:00-09:00の16時間夜勤を想定して仮眠を120分間（22:00-00:00）まとめてとる条件（単相性仮眠）、 90分間（22:30-00:00）と30分間（02:30-03:00）に分けてとる条件（分割仮眠）、仮眠をとらない条件の3つを比較検討した。
As a result, although no statistical differences were observed in sleep efficiency or sleep latency (time until falling asleep), split naps were more effective in suppressing early morning sleepiness and reducing fatigue than monophasic naps. I also found it to be excellent.On the other hand, in the no-nap condition, sleepiness and fatigue increased in the early morning.
Furthermore, an analysis of the correlation between sleep status, body temperature, sleepiness, and fatigue revealed that when the total sleep time was long, a 120-minute nap led to an increase in fatigue, and a 30-minute nap led to an increase in drowsiness.It was also shown that when sleep latency is short, a 90-minute nap increases body temperature and increases drowsiness and fatigue.
From the above, it was shown that dividing the nap into two times is more effective in reducing sleepiness and fatigue than taking a single nap, and that the effects on body temperature, sleepiness, and fatigue differ depending on how the nap is taken. It became clear.
The results are expected to be useful as basic materials for developing effective napping methods for night shift workers, including not only nurses but also night bus drivers and shift-work factory workers, thereby reducing the mental and physical burden on workers. It is believed that this will also contribute to the creation of a safe and secure working environment.
Paper information:[Scientific Reports] Effects of 90- and 30-min naps or a 120-min nap on alertness and performance: reanalysis of an existing pilot study
