Takeyama Hidemaro, Itani Toru, Tachi Norihide, Sakamura Osamu, Murata Kensaburo, Inoue Tatsuki, Takanishi Toshimasa, Suzumura Hatsuko, Niwa Sayuri
Faculty of Human Wellness, Department of Registered Dietitians, Tokaigakuen University, 2-901 Nakahira, Nagoya, Japan.
J Occup Health. 2009;51(3):204-9. doi: 10.1539/joh.l7040. Epub 2009 Apr 1.
In the present study, we modified a night shift system for an ambulance service so that ambulance paramedics were assured of taking a nap, and examined the effects of this new system on the fatigue and physiological function of ambulance paramedics.
Ten ambulance paramedics at a fire station in the center of a large city in Japan voluntarily enrolled as subjects in this field study. They worked a 24-h shift system. There were two teams of 5 ambulance paramedics in the fire station. Three ambulance paramedics per shift usually provided the emergency services. In the traditional system, the ambulance paramedics had to deal with all emergency calls throughout a 24-h shift (T-shift). In the modified system, 2 ambulance paramedics were allotted time for naps in the 21:00-3:00 (C-shift) or 3:00-8:30 (B-shift) shift by the addition of another a firefighter (D-shift).
There were fewer emergency dispatches and nap time was longer in the B- and C-shifts than in the T-shift. Parasympathetic nerve activities during naps in B- and C-shifts were higher than in the T-shift. The results of critical flicker fusion frequency and 3-choice reaction time in the B-shift at 7:30 tended to be higher and shorter than that in T-shift.
The results of this study suggest that the modified night shift which ensured time for ambulance paramedics to take long, restful power naps alleviated subjective fatigue, and improved physiological functions which are often adversely affected by night workload.
在本研究中，我们对急救服务的夜班制度进行了改进，以确保急救医护人员能小睡一会儿，并研究了这一新制度对急救医护人员疲劳程度和生理功能的影响。
日本一个大城市中心消防站的10名急救医护人员自愿报名参加了这项现场研究。他们采用24小时轮班制。消防站有两个由5名急救医护人员组成的小组。每班通常有3名急救医护人员提供紧急服务。在传统制度下，急救医护人员在整个24小时轮班期间（T班）必须处理所有紧急呼叫。在改进后的制度中，通过增加另一名消防员（D班），安排2名急救医护人员在21:00至3:00（C班）或3:00至8:30（B班）轮班期间有时间小睡。
B班和C班的紧急调度次数较少，小睡时间比T班长。B班和C班小睡期间的副交感神经活动高于T班。B班7:30时的临界闪烁融合频率和三择反应时间结果往往比T班更高、更短。
本研究结果表明，改进后的夜班制度确保了急救医护人员有时间进行长时间、安稳的有效小睡，减轻了主观疲劳，并改善了经常受到夜间工作量不利影响的生理功能。
