Sleep And Fatigue

Question 1

Describe the stages of sleep

Answer 1

There are five stages - the first four are normal sleep, and the fifth stage is Rapid Eye Movement (REM) sleep.

Question 2

Stage 1 of sleep

Answer 2

Transitional phase between sleeping and waking, person begins to relax and slow rolling eye movements begin.
- Lasts 1 to 10 mins

Question 3

Stage 2 of sleep

Answer 3

Lasts 10 mins

Question 4

Stage 3 and 4 of sleep

Answer 4

Slow wave sleep

Question 5

Stage 5 of sleep

Answer 5

REM sleep - when dreams are recalled

Question 6

Describe the mechanism of sleep regulation

Answer 6

• Human body relies on circadian rhythms to regulate sleep
• Our natural cycle is 25 hrs, external factors such as light, social activities and meals adjust this to 24hrs
• Body temperature regulates sleep. Rising temp = waking up, falling temp = going to sleep

Question 7

Describe the problems associated with sleep at abnormal times of the day.

Answer 7

When circadian rhythms is disrupted or thrown off, may feel groggy, disorientated and sleepy at inconvenient times. Linked of a variety of sleeping problems

Question 8

What is sleep debt?

Answer 8

• Every hour you sleep, you are able to stay awake for two. If you keep awake more than you sleep enough for, you will eventually crash.

Question 9

What is meant by sleep inertia, when is it most likely to occur and how long does it take to wear off?

Answer 9

• When you are woken up in the middle of REM, feeling very groggy.
• Takes on average 15 minutes to recover.

Question 10

How do individuals differ in their requirement for sleep?

Answer 10

• Different ages require different amounts of sleep
• The individuals homeostatic mechanism that makes them feel sleepy and tells them when they have had enough sleep.

Question 11

What are the effects of napping?

Answer 11

• If they are less than 45 minutes, they do not result in sleep inertia - this coupled with caffeine is effective.

Question 12

What are the effects of caffeine?

Answer 12

• Short term solution and can be very effective when coupled with a nap.

Question 13

What are the effects of taking sedatives?

Answer 13

• Act on central nervous system and may suppress mental alertness.
• Melatonin should not be taken without advice from a specialist.
• Sleep inducing drugs can be prescribed to cure only SITUATIONAL insomnia.

Question 14

What are the effects of taking stimulants other than caffeine?

Answer 14

• If stimulants other than caffeine are required for a pilot to stay awake, then they are unfit to fly.
• “pep pills” impair judgement and cause a dangerous level of over confidence.

Question 15

What is clinical insomnia?

Answer 15

Difficulty sleeping in normal circumstances - an inability to sleep when the body requires it.

Question 16

What is situational insomnia?

Answer 16

Difficulty sleeping because the biological rhythms are disturbed due to travel and shift work.

Question 17

Describe narcolepsy

Answer 17

Sufferers fall asleep even when involved in a situation requiring their full attention = not pilot career

Question 18

Describe sleep apnoea

Answer 18

Temporary cessation of breathing during sleep, may cause the sufferer to wake often causing sleep deprivation.

Question 19

Define fatigue.

Answer 19

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.

Question 20

Causes of fatigue

Answer 20

• Disturbed or insufficient rest
• Low humidity
• Glare
• Vibration
• Noise
• Anxiety
• Distubrance of biological rhythms
• Excessive physical or mental activity

Question 21

Physical symptoms of fatigue

Answer 21

• Feeling tired
• Reduction in vigilance
• Growing and irresistible need to sleep
• Inadvertent napping
• Lethargy
• Slowed reaction time

Question 22

Mental symptoms of fatigue

Answer 22

• Difficulties memorising information
• Lack of concentration
• Periods of inattention
• Slow understanding
• Tendency to forget information and actions
• Bad mood
• Poor decision making
• Apathetic

Question 23

Explain the difference between acute and chronic fatigue.

Answer 23

Acute: Short term - easily recognised and fixed by not flying

Chronic: Long term - difficult to recognise, more severe, a pilot must stop flying

Question 24

Methods of managing fatigue

Answer 24

• Well rested
• Good sleep habits
• High level of physical fitness
• Eating regular, balanced and nutritional meals
• Avoid excessive use of alcohol
• Good mental health

Question 25

Define biological clock

Answer 25

Innate mechanics that controls the physiological activities of an organism which change on a daily, seasonal, yearly or other regular cycle.

Question 26

Define circadian rhythm

Answer 26

Physical, mental and behavioural changes that follow a roughly 24hr cycle, responding primarily to light and darkness in an organism’s environment.

Question 27

Define circadian dysrhythmia

Answer 27

Any disturbance in the circadian rhythm.

Question 28

Define desynchronisation

Answer 28

- Transmeridian desynchronisation - change in time zones = jet lag

Question 29

Define zeitgeber

Answer 29

- “time givers” - daylight and mealtimes - Environmental cues that entrain our biological rhythms

Question 30

Describe the central human physiological processes underlying circadian rhythm processes.

Answer 30

- Wake with increasing body temp, fall asleep with decreasing body temp - Performance increases with an increases in body temp and decreases as temperature decreases - Verbal and mental reasoning peak around midday - Some physiological functions are suppressed at night

Question 31

How do circadian rhythms affect pilot performance?

Answer 31

- When pilots are operating outside the regulated rhythm, performance decreases and the effect of circadian dysrhythmia will be more likely.

Question 32

Explain the effects of circadian dysrhythmia and methods of managing these

Answer 32

- Increased reaction time - Decreased attention - Impaired memory - Emotional irritability To overcome: - Spend time in daylight - Plan sleep periods - Ensure sleep area is comfortable - Avoid mental and physical excercise before bed - void alcohol and drugs - suppresses REM sleep - Avoid adjusting to the new time one if there for less that 48hrs

Question 33

What is the rate of adjustment to crossing time zones in both east and west directions?

Answer 33

- Faster travelling to the west than the east (easier to stay awake than force sleep) - In general, the body will adjust to the new time zone at the rate of one or two time zones per day.

Question 34

What is the impact of shift work on pilots performance?

Answer 34

- Circadian rhythms are only partially adapted to current work/rest schedule - Sleep deprivation is a fact of life for commercial aircrew - Fatigue can occur due to sleep deprivation

Question 35

Describe how the biological effects of shift work can be minimised.

Answer 35

If rotating shift are unavoidable: - Phase delay/advance - gradually change the time you sleep and wake - Bright lights as mimic daylight - Sensible napped - Regular balanced meals and limited alcohol

Question 36

Identify the principles of good rostering practice

Answer 36

Long haul: - Consideration to the length and number of sectors to be flown - Length of total duty - Avoid rostering night flights following transmeridian flight - Transmeridian flights should be altered with ones in the same Timezone to allow the circadian rhythm to reset Short haul: - 2 early starts 3 late finishes max