The Hidden Dangers of Fatigue - IOSH

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© The Keil Centre, 2015

The Hidden Dangers of Fatigue

Janette Edmonds BSc(Hons) MSc CErgHF FIEHF CMIOSH

Director / Principal Consultant Ergonomist

www.keilcentre.co.uk

[email protected]

07967 164145

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v1.0 0215

© The Keil Centre, 2015

About The Keil Centre…

• Based in the Edinburgh & Australia

• 23 staff & associates

• International client base / cross-industry

• 3 business areas:

• human factors, assessment & development, clinical psychology

• Our human factors capability includes:

v1.0 0215 2 Therapy & Counselling –Human Factors Analysis Tools® - Organisational development - StressTools® - 360 degree feedback - Safety Culture Maturity® - Coaching

Managing human failure

Procedure Design

Training and competence

Staffing

Organisational change

Safety-critical communication

Human factors in design

Fatigue & shift work

Organisational (safety) culture

Maintenance, inspection and testing

http://www.keilcentre.co.uk/

mailto:[email protected]

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© The Keil Centre, 2015 3

Presentation Overview

Definitions & Consequences of Fatigue

The Science of Sleep & Fatigue

Fatigue risk management


What do we mean by “Fatigue”?

‘Mental, physical or emotional impairment, caused by

inadequate sleep or excessive wakefulness’.

Insufficient quality, quantity & excessive time awake

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Fatigue Related Disasters 5


Consequences of Fatigue Effects on Task Performance

• Reduced alertness

– Affects tasks requiring vigilance & concentration

– Momentarily may fall asleep – micro-sleep

– Such as: driving, control room operations

• “Drowsy Driving” causes between 15-20% of UK

road accidents

• These account for only “fall asleep” accidents

– Absence of skid marks or other signs of hard

braking

– Other causes have been eliminated (e.g. bad

road, mechanical defect)

• Statistic is likely much higher if we account for

lower level impairment

Source: Horne & Reyner (1998) ‘Vehicle accidents related to sleep: a review’,

Occupational & Environmental Medicine, Vol. 56, 289 - 294

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Consequences of Fatigue Effects on Task Performance

• Interpersonal skills

– Become more reserved & less communicative

– Affects activities such as:

– shift handover, interacting with colleagues & customers

• Lose situational awareness (‘big’ picture)

– Affects team / operational management

• Attention to detail – adversely affected

– Analysing data, working on the right equipment

• Complex decisions

– Attention tunnelling, difficulty handling uncertainty


Wakefulness

Comparing Fatigue & Alcohol

• 40 subjects

• 2 experimental conditions

o Sleep deprivation (28hrs)

o Alcohol (1 standard drink every 30mins from 0830)

• Performance measured half hourly via computer

based tests

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Wakefulness

Comparing Fatigue & Alcohol


We don’t get used to being

sleepy

1 3 5 7 9 11 13

Alertness

Performance

# Nights on Shift

Good

Poor

feeling

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Health Effects

• Short term

– Immune system / gastrointestinal performance

• Longer term

– Physically - cardiovascular disease, colon cancer

– Mentally / socially

– early onset dementia and alzheimers.

– increased rates of divorce

– Increased rates of social anxiety disorders, stress, depression,

• Many dealing with issues through drugs and medication

– Better managed by having enough sleep

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The Science of Sleep

• With a show of hands……..!

How much sleep do you get on average

per night?

How much time do you think you need to perform safely?

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Sleep Quality – a Picture of

‘Normal’ Sleep


Folkard, S. and T. Akerstedt, (1991) A three-process model of the regulation of sleepiness and alertness. In Ogilvie, R. and Broughton, R. (eds.) Sleep, arousal and performance: problems and promises, Boston, Birkhäuser, 1991:11-26 .

Regulation of Sleepiness and

Alertness

• Sleep need (homeostatic mechanism)

– Increases with time awake

– Decreases with sleep

• Sleep urge (circadian mechanism – the body clock)

– Sleepiness & alertness vary over 24 hour rhythm

• Sleep inertia

– Temporary grogginess on waking from deep sleep

Sleepiness is a function of time since the last

sleep & quality of that sleep

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Ind

ivid

ua

l

resp

on

sib

ility

Org

an

isation

al

resp

on

sib

ility

Causes of Fatigue

Fatigue

Work-Related

Hours of Work

Work Tasks & Environment

Non-Work Related

Situation & Lifestyle

Physiological / Medical Reasons


How Can I Improve My Alertness?

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Setting Up the Sleep

Environment

Minimise Light

Temperature 18-24oC

Minimise Noise

Minimise Distractions/ Disturbances


Getting Good Quality Sleep

It doesn’t matter what time you go to bed

Watching TV helps you fall asleep

Alcohol / sleeping tablets help you get a good night

sleep

Dispelling the Myths…

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Identifying Poor Sleep Quality

Snoring is normal

Falling asleep quickly means you’re a good sleeper

If you’re tired, you need more sleep

Sleep disorders are difficult to treat

Dispelling the Myths…


Key Symptoms of Fatigue

Physical

Yawning Heavy Limbs Appearance

Headache/Nausea Sore Eyes

Poor Coordination Slow Reaction Speed

Extreme Drowsiness Heavy Eyelids Micro-sleeps Falling Asleep

Mental

Poor Concentration Disorganisation Easily Distracted

Poor Communication Situational Awareness Poor Info Processing

Poor Memory

Poor Decision Making Risk Taking Behaviour

Errors

Emotional

Quiet and Withdrawn Lack of Motivation

Increased Stress Levels

Mood Change Decreased Tolerance

Irritability

Uncontrolled Temper Aggression

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Symptoms of Sleep Disorders

• Excessive daytime sleepiness despite a 'good' night's sleep

• Loud snoring

• Irritability or mood changes

• Restless sleep

• Morning headaches

• Poor concentration or memory

Do I have a problem?

• Insomnia

• Sleep Apnea

• Sleep Walking

• Narcolepsy


Fatigue Risk Management Models

• Restricted Hours

• Industrially Negotiated

• Largely Ineffective at FRM

Traditional FRM

• Multiple Controls

• “Red Flag” System

• Identify Risk Manage Risk

Best-Practice FRMS

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Fatigue Risk Management System

Sleep Opportunity (Work Hours)

Actual Sleep

Symptoms and Behaviours

Errors & Near-

misses

INCIDENTS Dawson & McCulloch (2005), Sleep

Medicine Reviews, 9 (5), 365-380


Risk Identification Risk Mitigation

• Have rostered hours been exceeded? ID

• Has the individual obtained at least 6hrs sleep in the last 24hrs?

ID

• Is the individual experiencing fatigue-related symptoms or behaviours?

ID

• What safety critical tasks is this individual performing?

• What could potentially go wrong if they’re tired? Mitigation

• Should this individual continue with planned work?

• What can be done to reduce the likelihood of error? Mitigation

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Sleep Opportunity

• Predict sleep based on work hours

• Provide ‘risk’ levels across shift patterns

Biomathematical Fatigue Models

• Rostering guidelines

• Actual work hours guidelines

Work Hours Parameters


Biomathematical Fatigue Models

Fatigue Audit InterDyne (FAID)

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Summary

Definitions & Consequences of Fatigue

The Science of Sleep & Fatigue

Fatigue risk management


Resources

• A Manager’s Guide to Fatigue Risk Management

(2014). Energy Institute, London.

• UK Heath and Safety Executive (HSE) - Key topic

‘Shiftwork and fatigue’

• IPIECA/OGP – Performance Indicators for Fatigue

Risk Management Systems: Guidance for the Oil and

Gas Industry

• IPIECA/OGP – Managing Fatigue in the Workplace

• API 755 – Fatigue Risk Management Systems for

personnel in Refining and Petrochemical Industries

The Hidden Dangers of Fatigue - IOSH

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