１集中治療部における当直医師仕事量の調査

A night shift as a part of regular work hours should not be conducted as sole night watch or extra light work. There is some confusion in the management of ICUs in Japan, as to whether the mission of duty intensivists should be considered as a night shift or as a sole day/night watch during hospital closing. We assessed the workload of duty intensivists in our institution by questionnaire survey. The questionnaire survey was facilitated over 69 days, from Jan. 30, 2003. Each duty intensivist evaluated his/her hours of work by a six grade scale, immediately after his/her duty. Workload grade 0, 1, 2, 3, 4, 5 corresponded to sleep, sole watch, light work: including change of respirator settings, IV injection, ordinary tasks: including change of respirator settings followed by arterial blood gas analysis, changes of continuous catecholamine/vasodilator infusion settings, extraordinary order of electrolyte balance adjustments, changes of continuous hemodialysis filtration device settings, discussion about a change of management policy to a consultant of responsible department of a patient, more than ordinary tasks: including ICU admission on emergency, the heaviest tasks: including CPR. Overall fatigue was expressed to a 100mm VAS. More than or equal ordinary tasks for the day-time during hospital closing (9:00-17:00), evening (17:00-1:00), midnight (1:00-9:00) was 58.8%, 41.7% and 28.5%, respectively. Likewise, sleep or sole watch for the same work period was 8.1%, 11.8% and 34.9%, respectively. Sleep duration was 2.5±1.3 hours (mean±SD). Overall fatigue VAS was 54.9±18.1mm. A correlation was found between workload grades per hour and overall fatigue VAS in the whole population (r=0.737). The Japanese Labor Standards Act defines a day/night watch as light work, including inspection tour and telephone correspondence to other departments and outsiders. Sleep time of at least six hours is simultaneously ensured. Therefore the day/night watch is authorized separately from regular work. Since intensivists frequently managed more than or equal ordinary tasks on their duty, and since their sleep duration was insufficient, the duty workload at our institution was not applicable to the sole day/night watch. The mission of duty intensivists in institutions similar to our own in Japan should be considered as a part of the regular 40 hour work week.