Fatigue and Stress Flashcards
What is the definition of fatigue?
a physiological state of reduced mental or physical performance capability resulting from sleep loss or extended wakefulness, circadian phase or workload (mental/physical) that can impair a crew member’s alertness and ability to safely operate an aircraft or perform safety related duties
What is the difference between acute and chronic fatigue?
- Acute is short lived and can be treated with 2 nights uninterrupted sleep
- Chronic is built up over time and may require extensive recovery. May be sleep disorders, continued circadian disruption, shift work, poor quality sleep, high mental workload
What are some things that will optimise circadian resynchronisation?
- Travelling westbound will make it happen 50% faster
- Easier to extend a day to recalibrate, than to shorten a day.
What is the approximate rate of circadian resynchronisation per day?
1-2 hours of time zone difference per day
What are some ways to ‘treat’ fatigue around the workplace?
- Modify the workplace
- Rotate duties
- Pace yourself
- Brief exercise before tasks
- Remove yourself from duty when fatigues
What is a micro sleep? Describe it?
- Uncontrolled episodes of sleep
- Last seconds or minutes
- People have no control over when they happen
- Disengages form reality and becomes unresponsive
With regarded to micro sleeps, how far along a glide slope at 180kts will an aircraft travel?
93 meters
What happens during REM sleep?
Strengthening and organising memory
Active dreaming
Brain activity is similar to wakefulness
What happens during NREM sleep?
Body restoration
Brain activity is slowed
What is sleep inertia? When is it good and bad?
- The time taken after sleep to return to full capability
- Sleep inertia is worse after longer, deeper sleep
- Will be worse after naps taken during natural circadian lows
- Effects may be immediately overcome due to the release of adrenaline in an emergency
- Can be a small price to pay after controlled rest for increased alertness later in the flight
What are some symptoms of fatigue?
edginess short term memory loss agitated increased reaction times poor decision making acceptance of lower standards reduced attention span fixation mistakes
What are the effects of fatigue on performance?
Reaction time changes Reduced attention Diminished memory Mood a social interaction changes Impaired communication
How can fatigue be prevented?
- Control sleep environment (sleep/sex)
- Adjust to shift work even on days off\
- Maintain good mental and physical health
- Practice good eating habits
- Moderate and controlled use of alcohol and caffeine
- Have good time management
- Practice realising planning
- Maintain optimal work conditions
- Take naps
What effect does alcohol have on sleep?
- Relieves anxiety
- Promotes early deep sleep
- Suppresses early REM sleep
- REM will rebound and happen more often for longer later in the night
- Has a diuretic effect
- BAC or 0.025% (1-2 standards) can reduce overall sleep quality
What is a Zeitgiber? What are some examples of them?
a rhythmically occurring natural phenomena which acts a cue in the regulation of the body’s circadian rhythms
- Light
- Hormones
- Temperature (cool temps induce sleep)
- Social interactions
- Exercise
- Eating and drinking patterns
- Sound
