Shift - CAW

Error in Shiftwork
Pat Croskerry MD, PhD
CAW National Health Care Conference
Halifax, Nova Scotia May 7-9, 7
2010

What is Shift-Work
• Day shift
• Evening shift
• Night shift
• Rotating shifts
• Permanent shifts

In Australia
shift work
is defined as
‘aa workplace hazard’

In medicine, the patient is an
integral component of the
workplace

Memorable Night Shifts
• Titanic
• Exxon Valdez
• Three Mile Island
• Bhopal
• Chernobyl
• Space Shuttle Challenger
• Westray
• 15 - 20% of transportation accidents
(greater than drugs and alcohol combined)

Circadian Low Point
…the level of performance of someone who
has been up all night equates to a blood alcohol
level of 0.1%. In effect, by 0400 hrs, the
performance of nurses and physicians, up since
the previous day, is equivalent to being legally
intoxicated.
Dawson and Reid, Nature 1987

In healthcare, the patient is a
component of the workplace

Our major
adaptation has
been to the light
(and heat) of the
sun

Our
natural
circadian cycle
is about
25 hours

FromColeman 1986

Which explains why
it is sometimes
difficult to get out of
bed on
Monday mornings

Endogenous
Clock
Entrainment
of Physiological
Parameters
24 hrs
Physiological
Rhythms
Zeitgebers

Zeitgebers
• Light
• Melatonin
• Sound
• Smells
• Social
• Meals
• Activities

Use zeitgebers to minimize
impact of shift work

Prolonged
Wake-State
Shiftwork
Ill-Health
Circadian
Dys-synchronisation
Fatigue
Acute
Sleep
deprivation
Chronic partial
Sleep
deprivation
Neurocognitive deficits
+
Negative Mood States
Impaired clinical performance

‘…there is no evidence to suggest that any
amount of training, motivation or
professionalism is able to overcome the
performance deficits associated with fatigue,
sleep loss, and the sleepiness associated with
circadian variations in alertness’
Institute of Medicine, 2004

Main Issues
• Circadian rhythms
• Impact on worker
• Impact on patient

‘… circadian disruption is
the equivalent of all the
instruments in the
orchestra playing their
own separate tune’

Not only that, but we are different from
each other and we change as we age….

Diurnal Types
Morning Active (Larks)
Intermediate
Evening Active (Owls)

Chronotypes
(M-types or E-types) E
• People tend to be one or the other
• Women are more M-typeM
than men
• We get more M-typeM
as we get older

Ageing and Sleep
Alertness
Secretion/amplitude melatonin
Insomnia
Awakening from sleep
Duration of arousal
Moodiness
Advancing phase activity
Jet lag problems
Sensitization to noise during sleep
Stage 3 and 4 sleep
Sleep apnoea
Snoring

Ageing and Shift Work
De-synchronization tendency
Adjustment to circadian phase shift
Health problems
After 40-50 years

Clinical Symptoms of Sleep Deprivation
• Longer reaction time
• Lapses in attention or concentration
• Lost information
• Errors of omission
• Poor short term memory
• Poor mood (increased fatigue, confusion, stress,
irritability)
• Reduced motivation
• Distractibility
• Sleepiness
• Poor psychomotor performance

Poor Psychomotor Performance
• At circadian low points
• When sedentary
• On long, difficult, or externally paced tasks
• When feedback is poor
• In unchanging surround, particularly with
reduced light or sound and low motivation,
interest, or novelty

Human Performance Effects
• Increased tolerance for risk
• Passivity and avoidance of effort
• Decreased cognitive function
All lead to
• Serious accidents
• Account for 15 - 20% of transportation accidents
(greater than drugs and alcohol combined)

Fatigue Surveys in Health Care
• Rotating shift nurses more likely to report errors than day shift
• Anesthesia residents (Sleep on average 6.5 hours/day)
• 20% indicated sleepiness impacted their clinical work
• 12% attributed errors to fatigue
• Over 50% of anesthesia caregivers reported errors in
judgment from fatigue

Experimental Evidence of Fatigue Effects
in Health Care
Slower response time on monitoring tasks for
fatigued anesthesia residents
Reduced speed/quality in simulated intubation task
for ED physicians
Slower time and more errors in simulated
laparoscopic task for surgeons
Reduced alertness, falling asleep, and behavior
changes in tasks using a patient simulator

Outcomes Related to Fatigue in Health
Care
• Higher risk of unintended dural puncture in obstetric epidural
procedures at night compared with during the day
• 45% increase in post operative complications for resident
surgeons after a day on call
• Increased risks to health care providers
• Increased risk of car accidents after 9 th hour of work
• Needle sticks and exposure to blood borne pathogens
increases by 50% at night vs. day

Serious medical errors in the ICU
A B Increase
Medication 100 83 x1.2
Procedural 11 6 x1.3
Diagnostic 24 3 x5.6
Other 12 7 x1.2
NEJM, 2004; 351

Medical conditions associated with shift work
• Cancer
Increased incidence of GI disorders, particularly peptic ulcer disease
Increased incidence of cardiovascular disease
Mood disturbances
Impaired immunity
Infertility
Increased risk of preterm birth and fetal growth retardation
Increased anxiety and mood disorders
Stress, decreased motivation, and burnout
Increased likelihood of weight gain, obesity
Higher risk of motor vehicle accidents and work related accident
Increased likelihood of family problems, including divorce
Increased the risk of epilepsy predisposed people
Possible predisposition to diabetes, and exacerbation in diabetics
Exacerbation of epilepsy

Shiftwork Solutions

Solutions
• General
• Individual
• Family
• Workplace

General Strategies
• Awareness of impact of shift work
• Shift scheduling
• Travel home window
• Naps
• Diet
• Exercise
• Drugs
• Alcohol
• Worry periods/thought insertion
• Protected sleep setting

Individual
• Acknowledge significance/impact
• Awareness of general adaptation issues
• Protect self
• Recruit family

Family Adaptation
• Recognize/acknowledge shift work
• Do not disturb
• No scheduled tasks before sleep
• Adjust family life to shift worker
• Adjust social life to shift worker
• Make allowances

Workplace Adaptation
• Only when necessary
• Increase remuneration for night shifts
• Rational scheduling
• Material support (rest area, facilities)
• Bright light
• Do tedious tasks early in shift
• Consider problematic workers

Problematic Workers
• Over 50 years
• Additional commitments outside work
• Heavy domestic commitments
• Morning active (Larks)
• Sleep disorders
• Neuroticism/introversion
• Psychiatric illness
• Alcohol/drug dependence
• Gastrointestinal complaints
• Epilepsy
• Diabetes
• Heart disease
• Asthma

Shift Scheduling
• Preserve anchor sleep
• Reduce frequency of changes
• Permanent days, evenings or nights best
• No backwards rotation
• Minimize shift length (6-8 8 hours)
• Travel home window
• Diurnal preferences/self-scheduling
scheduling
• Age considerations
• 1-22 night shifts maximum
• Minimum 24 hr recovery period
• No ‘extra’ shifts or callbacks

The
Anchor
Period

The
Anchor
Period
• Approximately 0200-0600 0600 hrs
• Moveable within circadian cycle
• Tied to day-night cycle
• Preserves circadian rhythm
• Get as much sleep in it as possible

Preserving
the
Anchor Period

Halifax Infirmary
Emergency Department
Physicians
(Survey Study, 2002)

The Casino Shift

Casino shift scheduling
• Casino A: work the first part of the night
shift – say from 9pm to 3am
They sleep from 4am until noon
• Casino B: work the second part of the
night – say from 3am until 10am
They sleep from 9pm until 2am

Casino Shift Scheduling
Casino A
T
Sleep
4pm
8pm
Midnight
4am
8am
Noon
Sleep
T
Casino B

Interview Survey
• Level 1 Emergency Department
• Annual census 75,000
• 17 Emergency Physicians
• 15 males 2 females
• Variable FTE 50-100%
• 16 married : 1 single
• Average age 41.9 years + 7 (S.D)

Shift preference
Physician: Casino 14/17
(82%)
14/17 (82%)
Family: Casino 9/15 (60%)

Casino Shift Study
Total Time to Get to Sleep
(Minutes)
Number of
Minutes
20
15
10
5
11.3
14.8
Casino
Regular
0
Shift

Estimated Time to get to Sleep
(mins.)
__________________________
Mean SD p
________________________________
Casino 11.3 8.3
Regular 14.8 14.1
0.4
________________________________

Casino Shift Study
Total Time Sleep Time
(Minutes)
400
368.2
Number of
Minutes
300
200
100
267.2
Casino
Regular
0
Shift

Total Sleep Time (mins.)
____________________________
Mean SD p
__________________________________
Casino 369 72
Regular 267 80
0.0006
__________________________________

Casino Shift Study
Cognitive Impairment (%)
35
30
30.1
%
25
20
15
18.1
Casino
Regular
10
5
0
Shift

Estimated
Cognitive Impairment (%)
____________________________
Mean SD p
__________________________________
Casino 18 11
Regular 30 12
0.02
__________________________________

Casino Shift Study
Time To Recovery
(Days)
Number of Days
2.5
2
1.5
1
0.5
0
1.3
2
Casino
Regular
Shift

Estimated Time to Recovery
(days)
____________________________
Mean SD p
__________________________________
Casino 1.3 0.6
Regular 2.0 0.8
0.004
__________________________________

Survey of emergency physicians
comparing two types of shift scheduling
____________________________________________
Variable Casino Traditional p value
Time to get to sleep (mins) 11.3 + 8.3 14.8 + 14.1 ns
Total sleep time (mins) 369 + 72 267 + 80

Self Scheduling
Casino A
•
- Young
- Owls
- Male
Casino B
- Old
- Larks
- Female

Casino Shift Benefits
• Preferred by the majority of the group
• Preservation of circadian rhythm
• More total sleep
• Reduced sleep debt
• No light pulse in travel home window
• Minimal exposure to other zeitgebers before sleep
• Shorter recovery time
• Reduced cognitive impairment
• Improved work performance
• Improved career longevity

Summary
• Shift work is a workplace hazard
• Many workers suffer chronic sleep debt
• It is dangerous and deleterious to physical and mental health
• Sleep deprivation and debt result in neurocognitive defecits
• Oncoming day teams should be vigilant about off-going shift
• The impact increase with age
• Personal and professional responsibility to strategize adaptation
• Casino scheduling is presently main strategy
• Night shiftwork should be avoided whenever possible
• Schedules must be optimized for individual preferences