Effects of Sleep Deprivation on Fire Fighters and EMS ... - NAEMT

<strong>Effects</strong> <strong>of</strong> <strong>Sleep</strong> <strong>Deprivation</strong> on Fire Fighters and EMS Responders
recommendations is not possible. However, principles from studies in other settings can be
used when assessing existing fire fighter and EMS responders’ work structures.
In general, fixed shifts cause the least disruption to circadian rhythms, provided that workers
maintain the same sleep and wake cycle on their rest and work days. For example, fixed shift
patterns are popular with police <strong>of</strong>ficers, where <strong>of</strong>ficers bid for a shift. In those and other
settings with fixed shifts, the most senior workers <strong>of</strong>ten obtain their preferences. As a result,
those working nights are newly hired or those who prefer nights due to second jobs or other
daytime activities, such as care giving duties. For the latter group, their daytime commitments
and nighttime work make adequate restorative sleep almost impossible.
Rotating shifts are a means to deter workers from combining fixed daytime commitments with
their nighttime shift work. Studies on shift workers have shown it takes about 21 consecutive
days for circadian rhythms to fully adjust to night shift. Most rotating shift schedules make
changes too rapidly to allow circadian adjustment to the new work pattern. The direction for a
rotating shift is most physiological when it is forward, (early/later/nights), because the internal
bodily clock naturally tends to run slow (i.e., every 25 hours). That is why it is easier to delay
sleep than it is to advance it and why people experience less jet lag going from east to west than
from west to east. Despite that rationale, some workers prefer a backward rotation (nights/later/
early), because it affords more time to recover lost sleep and prepare for the next night shift.
When to begin daytime shifts also has been examined, and as a rule, early starts to morning
shift should be avoided. While there is no optimum starting time, 0700 is better than 0600
which is better than 0500. Early starts reduce sleep, as by choice or by family circumstances,
most workers go to bed around their normal time the prior evening, despite the early shift.
Reduced sleep because <strong>of</strong> early shift starts leads to fatigue, which can increase the risk <strong>of</strong> errors
and accidents on morning shifts.
Extended shifts is the term used for shifts lasting longer than the typical eight hours. Available
information indicates that jobs not requiring a high degree <strong>of</strong> physical exertion or that have
natural resting periods may be most suitable for the extended workday schedule (Canadian
Centre for Occupational Health and Safety, 1999). For example, a machinist who has cycle
time between setups that allows reduced attention while the machine is running can probably
work a longer day. On the other hand, a data entry operator who must continually enter data
while sitting in one position and concentrating for long periods would find the extended workday
more difficult.
The potential advantage and disadvantages <strong>of</strong> properly designed extended workdays are that
longer periods <strong>of</strong>f can compensate for longer workdays. On the other hand, with longer shifts,
workers have little time for anything other than their jobs, eating and sleeping, during their working
days. Workers with other responsibilities, such as child care and other family responsibilities, may
find the extended workdays especially tiring. Time spent travelling to and from work is <strong>of</strong>ten viewed
by workers as lost time. The extended workday means fewer commuting trips and, therefore, less
wasted time. When supported by the workers, extended shifts may enhance worker morale and
job satisfaction, which must be balanced with a need for more breaks and a slower work pace with
extended shifts (Canadian Centre for Occupational Health and Safety, 1999).
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