Fatigue Management

mental recovery from sleep loss, REM sleep appears critical to mental
stability and important to memory and learning. Lack of REM sleep is known
to cause irritability, disorientation and attention deficits. When REM debt is
extreme, perceptual and mental distortions, such as hallucinations, are
common. Following sleep deprivation, Slow Wave Sleep (Stages 3 and 4) is
usually recovered completely on the first night at the expense of Stage 2 sleep,
while REM sleep recovery is more apparent on the second night.
Case Study. Private J. M., a sniper on Resistance to Interrogation
training, had gone 56 hours without sleep and was beginning to lose touch
with reality. He was told that the exercise was over and to get some sleep,
but convinced that his captors were lying, he ‘escaped.' He was found 200
metres from the exercise compound, naked and gingerly tiptoeing in
circles on a road trying to avoid smashed milk bottles that he imagined
were strewn on the ground. He was given a hot drink and placed on a
stretcher where he slept 11 hours.
The Effects of Medication and Alcohol on Sleep Patterns. Both the
occasional use of sleeping pills and the consumption of alcohol effect sleep
patterns by suppressing REM sleep. Overuse of sleeping pills significantly
reduces both REM and Stage 4 sleep, the two most critical stages of sleep.
Alcohol results in more awakenings during sleep and more frequent shifts in
sleep stages. The message is clear: the use of drugs and alcohol should be
avoided during sustained and continuous operations. An exception may be
caffeine. While caffeine can be useful for improving and maintaining alertness
when sleep deprived, its impact is diminished if used constantly. In addition,
caffeine increases the time to fall asleep and decreases time spent asleep. The
benefits caffeine can provide in enhancing alertness must be carefully
weighed against the potential for adverse impact on quality of sleep (and
hence recovery). Too much caffeine can have seriously detrimental health and
performance consequences.
Caffeine. Many military organisations are studying the value of various
drugs and nutritional substances (‘ergogenic aids') for sustaining physical
and mental performance. A common finding is that caffeine is one of the
most useful substances available. For example, caffeine can help to delay
hypothermia, and some studies report it can increase time to exercise
exhaustion by up to 25 per cent. However, dosage must be carefully
controlled. Caffeine in coffee provides inconsistent dose levels, hence
slow-release caffeine is most beneficial. Of course, adverse side-effects can
result if the drug is misused.
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