12時間の二交代制勤務看護師の睡眠および眠気と疲労の特徴

Characteristics of Sleep States, Sleepiness and Fatigue among Nurses Working in 12-hour Double Shifts

要旨

　目的：12時間二交代制勤務の看護師の日勤，長日勤，夜勤における睡眠，眠気と疲労を明らかにする．

　方法：対象者は，22歳の女性看護師7人とした．交代制勤務時の睡眠状態，眠気，疲労感を「関西学院式眠気尺度」，「自覚症状しらべ」，PVT，アクティブトレーサー，アクチグラフを用いて測定した．

　結果：身体活動量は，長日勤が日勤や夜勤よりも多く，身体的負担も大きかった．日勤中と夜勤中には，疲労感と眠気は変化しなかった．長日勤では，勤務の終了にかけて直線的に疲労感と眠気は増加し，覚醒水準は低下した．一方，夜勤の開始時には眠気や疲労感は改善していたが，夜勤終了時には疲労のねむけ感やぼやけ感が増加した．さらに，睡眠時間は夜勤前が最も短く，交代制勤務では睡眠覚醒リズムの変化が一時的にみられたものの翌日には改善していた．

　結論：12時間交代制勤務では，長日勤が他の勤務より活動量も多く，疲労感や眠気は増加し，覚醒水準は低下した．睡眠時間は夜勤前が日勤後よりも短時間であった．

　Purpose: The present study aimed to elucidate sleep states, sleepiness, and fatigue among nurses working 12-hour double, day, full day, and night shifts using subjective and objective indicators.

　Methods: Sleep states, sleepiness, and fatigue during day, full day, and night shifts were measured in seven 22-year-old female nurses using the Kwansei Gakuin Sleepiness Scale (KSS), the Subjective Fatigue Questionnaire (Jikaku Sho Shirabe), the Psychomotor Vigilance Task (PVT), and an Active Tracer (GMS Inc., Tokyo, Japan). The nurses also wore an ActiGraph for four days at the end of their shifts for a total of seven days.

　Results: A full day shift required more physical activity than day or night shifts. Fatigue and sleepiness did not change during day or night shifts. Fatigue and sleepiness increased during the full day shift and arousal linearly decreased at the end of the shift. Meanwhile, nurses on night shift had less sleepiness and fatigue at the start of the shift, but drowsiness, eyestrain, and fatigue were increased at the end of the shift. The nurses slept for shorter periods before a night shift than after a day shift. Furthermore, sleep-wake rhythms temporarily changed after night shifts but recovered on the following day.

　Conclusions: The nurses were more active during 12-hour double and full day shifts than any other shifts, but fatigue was increased and arousal was decreased. The nurses slept for shorter periods before night shifts than after day shifts.