Sleep And Fatigue Flashcards
34.40.2/46.40.2 Describe the 5 stages of sleep
Stage 1: Transitional phase between sleeping and waking. Person begins to relax, and slow rolling eye movements begin. The sleep lasts 1 – 10 minutes
•Stage 2: Lasts 10 minutes
•Stage 3 and 4: Slow wave sleep
•Stage 5: REM sleep, eye movement is rapid and muscles are relaxed. REM sleep is when dreams are recalled.
34.4.4/46.40.4 Describe the mechanism of sleep regulation
The human body relies on the circadian rhythms to regulate sleep. It has been proven though that if humans were put in a room (temporal isolation) the free running cycle for humans is 25 hours.
However external factors such as light, social activities and meals adjust this to 24 hours.
•Another regulator is body temperature, you wake with a rising temperature but fall asleep with a falling temperatures.
34.40.6/46.40.6 Describe problems associated with sleep at abnormal times of the day
When your circadian rhythms are disrupted or thrown off, you may feel groggy, disoriented, and sleepy at inconvenient times.
• Circadian rhythms have been linked to a variety or sleeping problems and sleep disorders, including insomnia, jet lag, and shift work sleep difficulties.
34.40.8/46.40.8 Explain what is meant by sleep debt
Sleep is similar to a credit card. Every hour you sleep earns +2 points, every awake hour spends -1 point.
Therefore 8 hours of sleep give you 16 points to use throughout the day. The body can only store a certain amount of sleep. If you are spending more than earning you go into sleep debt.
46.40.10 Describe what is meant be sleep inertia, when is it most likely to occur and how long it takes to wear off
Sleep Inertia is a physiological state characterised by a decline in motor dexterity and a subjective feeling of grogginess immediately following an abrupt awakening.
The severity and time to recover depends on three factors:
- The depth of sleep when woken–REM sleep is the worst
- The timing of sleep–Related to the circadian rhythm
- Chemical Influence–Caffeine
•On average 15 minutes to recover form sleep inertia.
34.40.10 Explain how individuals differ in their requirement for sleep (2)
- At different ages we require different amounts of sleep.
- It is the individual’s homeostatic mechanism that makes them feel sleepy and tells them when they have had enough sleep.
34.40.12/46.40.12 Explain the effects of the following alertness management techniques, napping, caffiene, sedatives, stimulants other than coffee
a) napping
•Naps of less than 45 minutes do not result in sleep inertia. Use napping sensibly before a shift
- b) caffeine
- Caffeine may be used as a short-term solution and can be very effective when coupled with a nap.
c) taking sedatives
•Sedatives act on the central nervous system and may suppress mental alertness. Melatonin has been promoted to help sleep and cure jet lag, but it should not be taken without advice from a specialist.
•Sleep inducing drugs are sometimes prescribed, when these are prescribed, they need to be used to cure situational NOT clinical insomnia.
d) taking stimulants other than caffeine
•If stimulant such as Dexadrine and Benazadrine are required to stay awake a pilot is unfit to fly
•Any such “pep pills” impair judgement and cause a dangerous level of over confidence.
34.40.14 Describe the main sleep disorders and their effects on pilot performance
Clinical Insomnia – Difficulty sleeping in normal circumstances; an inability to sleep when the body requires sleep.
•Situational Insomnia – Difficulty sleeping because the biological rhythms are disturbed due to travel and shift work.
Describe the other sleep disorders and their effects
Sleep Walking/Sleep Talking – Neither usually pose a problem to pilots.
- Narcolepsy – Sufferers fall asleep even when involved in a situation requiring their full attention. This would preclude a flying career.
- Sleep Apnoea – Temporary cessation of breathing during sleep, may cause the sufferer to wake often causing sleep deprivation.
Define fatigue
a condition characterised by increased discomfort with lessened capacity for work, reduced efficiency of accomplishment, loss of power or capacity to respond to stimulation, and usually accompanied by a feeling of weariness and tiredness
34.40.16 Explain the causes of fatigue (7) and its effect on pilot performance for short haul and long haul pilots
- Disturbed or insufficient rest •Low humidity (dehydration) •Glare •Vibration •Noise •Anxiety •Disturbance of biological rhythms
Short haul pilots are often unable to compensate for early wake ups by falling asleep earlier. Therefore multi-leg duties and repetitive early starts are main causes of fatigue.
- Long haul pilots also encounter fatigue from long flights and crossing multiple time zones
- Fatigue ultimately leads to pilot error.
34.40.18 physical symptoms of fatigue (5)
- General feeling of tiredness •Reduction in vigilance •Growing and irresistible need to sleep and inadvertent napping •Lethargy •Slowed reaction time
Mental symptoms of fatigue (6)
- Difficulties memorising information and forget things •Lack of concentration •Slow understanding •Bad mood •Poor decision making •Apathetic
34.40.20 Explain the difference between acute and chronic fatigue
Acute: Short term – related to current activities and the pilot will recover when the situation resolves itself. Acute fatigue is easily recognised and fixed by not flying.
•Chronic: Long term – more serious and there is a cumulative effect, this makes the body susceptible to illness and increased stress. It can be difficult to recognise, a pilot must stop flying.
34.40.22/46.40.14 Describe methods of managing fatigue (6)
Fatigue Risk management Systems (FRMS)
●Be well rested before reporting for duty
●Maintain good sleep habits
●Maintain a high level of physical fitness
●Eat regular, balanced and nutritional meals
●Avoid excessive use of alcohol
●Good mental health.
