managing fatigue kirsty mcculloch unisa, centre for sleep research

Managing Fatigue

Kirsty McCullochUniSA, Centre for Sleep

Research

When I die, I want to go peacefully,

Like my grandfather didIn his sleep…

Not screaming like thePassengers in his car!!

Background

Module One

In 1910 average sleep length was 9-9.5h

In 1913 tungsten-electric illumination introduced

In 1990 average sleep length was 7.5-8h

Caff

ein

e (

mg

/head

/day)

1910

1930 1950 1970 1990

Sle

ep

(h

rs)

10

9

8

7

500

400

300

200

100

Sleep length versus caffeine consumption 1910-90

Fatigue Definition

• Fatigue is the consequence of inadequate restorative sleep

• Fatigue is an experience that results physiological performance decrements and psychological functioning

Exercise

•Name some of the conditions

that make you feel

particularly tired or fatigued

at work

Causes of Fatigue

Work-related

Hours of work

Workload & environment

Non work-related

FATIGUEFATIGUE

Situation & lifestyle

Medical disorders

Joint Responsibility

Work-related

Hours of work

Workload & environment

Non work-related

FATIGUEFATIGUE

Situation & lifestyle

Medical disorders

Organisational Responsibilities Employee Responsibilities

Consequences of Fatigue

Module Two

Accident Risk

• 10-40% of road accidents involve driver fatigue (Shafer, 1993)– 5-15% of all fatal road accidents

(Hartley et al, 1997; Wang & Knipling, 1994)

• Fatigue is 4 times more likely to cause workplace impairment than drugs or alcohol (Akerstedt, 2000)

• Increase in fatalities beyond the 9th hour of work (Nachreiner etal, 2000)

Comparing Fatigue and Alcohol

• 40 subjects

• 2 experimental conditions•Sleep deprivation (28hours)•Alcohol (one standard drink every

30 minutes from 8:30am)

• Performance measured half hourly via computer based test

Comparing Fatigueand Alcohol

U N P R E D I C T A B L E T R A C K I N G

(CONTROLLED BYJOYSTICK)

CONSTANT MOVEMENT

Comparing Fatigueand Alcohol

-30

-20

-10

0

10

20

0.00 .025 .045 .065 .085 .10+

FIG. 5. Mean relative performance levels for the unpredictable tracking task in the alcoholintoxication (left) and sustained wakefulness condition. The equivalent performance decrement at aBAC of 0.05% and 0.10% are indicated on the right hand axis. Error bars indicate + one s.e.m.

Blood Alcohol Concentration (%)

3 7 11 15 19 23 27

0.05

0.10

Hours of Wakefulness

• Australian road statistics show that night shift workers driving home have a 4 to 7 times higher chance of having an accident

• What will help? Caffeine, a nap plus time to wake up, interesting conversation

• Above all else, pull over if you are fighting sleep because you cannot know the point at which you will fall asleep

Commuting

One of the greatest ‘costs’ of shiftwork and fatigue is paid by families

This is evidenced by: - increased divorce rates- learning difficulties for shift

workers’ children- increased domestic workload- difficulties with childcare; and - decreased involvement in daily

family life

Shiftwork and families

•Shiftworkers frequently cite social disruption as a major stress

•Many shiftworkers will choose to participate in social or community activities in preference to sleep

•If it is appropriate, inform your friends of your work times in advance of their event planning

Shiftwork and social life

“Shiftwork is probably bad for the heart, almost certainly bad for the head and definitely bad for the gut”

Monk &

Folkard, 1992

Shiftwork and health

Smoko Break

Managing the Risk

Module Three

A New Way of Thinking

• Fatigue-related accidents are no longer

viewed as ‘diminished responsibility’,

but as a result of ‘voluntary impairment’

• Liability for accidents is now extended

beyond the individual, to the

company and other

stakeholders

The Magic Cure

Sleep Obtained During Breaks

02468

1012141618202224

Time of Break Onset

7 hrs sleep

6 hrs sleep5 hrs sleep4 hrs sleep3 hrs sleep2 hrs sleep

1 hr sleep

120

0

140

0

160

0

180

0

200

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220

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000

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020

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Len

gth

of

Bre

ak

Napping

• Cannot be achieved by everyone

• Can be a powerful supplement to sleep but cannot replace it

• Naps 10 minutes or longer may provide benefits such as improved alertness, communication & mood

• Allow for 15 to 20 minutes wake-up time for sleep inertia to pass

Alcohol & Sleep

• A couple of drinks before bed has no negative consequences on sleep but it is not a recommended strategy

• At higher levels, that is four or more drinks, alcohol acts as a sedative to promote being unconscious

• In addition, at these levels the structure and function of sleep can be negatively effected

Caffeine

• Has stimulant effects that can improve alertness and performance

• Is most effective when used strategically; that is, not all day every day but when you really need help staying awake

• Can be effective for up to 4 hours

Caffeine Levels in Common Drinks

• Instant coffee: 1 teaspoon contains approx. 80 milligrams

• Brewed, plunger or espresso coffee: 1 cup contains between 80 and 120mg

• Herbal tea: 1 cup contains from 0 to 30mg

• Normal tea: 1 cup contains approx. 60mg

• Others: 200ml Red Bull 80mg, 500ml Jolt cola 100mg, 375ml cola 50mg

Foods that Alert Us

• Some studies have shown that eating low-fat high-protein foods can increase alertness

• These foods must be low in fat because high-fat foods will slow you down

• The effect is subtle and may be noticed after approximately 30 minutes

• It is recommended that at least 100 to 120 grams of an appropriate food is eaten

Foods that Alert us• Fish: cooked or tinned

• Low-fat dairy: cottage cheese, yoghurt

• Lean meat: steak, chicken breast, lamb

• Others: hard boiled eggs, protein powder

• NOT deep fried food, nuts, fatty meats or pies, full cream dairy products

Foods that Slow us Down

• Research shows that processed carbohydrates can give a ‘sugar hit’ but ultimately slow us down

• Processed carbohydrates convert to simple sugars (the ‘sugar hit’) but insulin quickly reduces blood sugar levels

• Examples: cakes, lollies, sweet biscuits, soft drinks, white bread, chocolate etc

‘Good’ Carbohydrates

• Any fresh fruit or vegetable

• Wholegrain breads, pasta, cereals and brown rice

• Rice cakes, popcorn

• These ‘good’ carbohydrates have not been found to have any negative effect on alertness

Hydration

• Dehydration slows you down and increases feelings of lethargy

• Working in heat, air conditioning or at night is likely to be dehydrating

• Drinking coffee, tea, soft drinks, cordial and eating salty foods can also make it worse

• Adults should drink at least 2 litres/day

Exercise

• Is obviously good for health and fitness

• May have significant benefits on the quality and quantity of your sleep

• Doesn’t need to be extreme; any activity that keeps your heart rate constantly elevated for at least 20 minutes is good

• Suggested activities include a brisk walk with the dog, swimming, jogging, riding

Relaxation

• If you can’t get to sleep after 30 minutes in bed, get up and do something relaxing

• This can be anything from reading the paper or a book to listening to music; try not to do anything too physical

• Many people have also reported considerable benefits of learning relaxation techniques like meditation or yoga

Finally…

• Managing fatigue will always have its challenges

• There are no golden rules but practical information helps good decision making

• Appropriate solutions will depend on your age, household structure, sleeping environment and any medical condition

• Individual differences will determine your ability to recover from various work regimes and fatigue

Questions??

Contact Details:Centre for Sleep Research, UniSAL7 Playford Building, City East

p: (08) 8302 6624f: (08) 8302 6623

kirsty.mcculloch@unisa.edu.au