Transcript Excessive Sleepiness in Shift Work Disorder

Fatigue Management in
Shift Work
NESS 2010
Newton, MA
Christopher P. Landrigan, MD, MPH
Director, Sleep and Patient Safety Program, Brigham and Women’s Hospital
Research Director, Children’s Hospital Boston Inpatient Pediatrics Service
Assistant Professor of Pediatrics and Medicine, Harvard Medical School
Disclosures and Acknowledgement
Dr. Landrigan has served as a paid consultant to:
1) Vital Issues in Medicine, developing an educational
course for physicians on Shift Work Disorder; this work
was supported by a grant from Cephalon, Inc. to Vital
Issues in Medicine.
2) In addition, Dr. Landrigan has received monetary
awards, honoraria, and travel reimbursement from
multiple academic and professional organizations for
delivering lectures on the quality of inpatient care, sleep
deprivation, resident performance, and safety.
• Some of the slides developed for this presentation were
developed with the support of Vital Issues in Medicine
• Thanks to the Harvard Work Hours, Health, and Safety
Group for providing additional slides
Case #1
(Lisbon Falls, ME, 13 Jun
01) – Trucker Jorge
Rosario of Orlando, FL,
after being awake for 32
hours, fell asleep at the
wheel of his tractor trailer,
crashed, and killed Mark
Leek, Pablo Jaramillo and
Geraldo Perez-Guerrero
while they were stopped at
a red light on US 27 (1998).
On 8 Jun 01, a Florida
court sentenced Rosario
to 15 years in a Florida
State prison. The trial
judge, in issuing the
sentence, stated,
“…you decided to get behind
the wheel. It’s like taking a
shotgun and shooting into the
crowd. There was a chance you
took, and you lost big.” (Ledger,
Lakeland, Fl.) … The three
families settled lawsuits totaling
$10 million against Rosario,
Whirlpool Corp., GPC Driving
Inc. and KENCO Logistic
Services.
(Source: Parents Against Tired Truckers
Photo courtesy of Florida Department of Corrections)
Case #2
• Heather Brewster’s car was
rear-ended by a medical
resident who had just completed
a 36-hour hospital shift
• Brewster…
– suffered massive brain
injuries
– was in a coma for weeks
– became permanently
disabled
– was declared incompetent by
the courts
Heather Brewster, pictured in 2002
Photo courtesy of the Brewster family; Story available at
http://www.npr.org/templates/story/story.php?storyId=4512366
Who Works
Shift Hours?
Shift
Workers
(1000s)
% of
Total
Force
Production
2021
24.4
Transportation & material moving
1900
28.5
Top Occupations
Evening
Night
Food preparation & serving
1568
40.4
Rotating
Split
Sales & related occupations
1464
15.2
Irregular
Other
Office & administrative support
1458
9.9
Health care practice & technical
1138
24.6
Protection services
1125
50.6
Management
612
9.8
Cleaning & maintenance
609
17.5
Personal care & service
542
28.1
Health care support
534
28.0
Installation, maintenance & repair
488
11.4
Construction & extraction
256
9.8
Community & social services
237
12.7
Arts, entertainment, media & sports
221
14.7
14,173
17.5
5%
33%
20%
22%
17%
3%
TOTAL
Data source: Bureau of Labor Statistics (2004) .Approximately 99.8 million workers >16
years. Available at: www.bls.gov/news.release/flex.t05/htm
Starting Times for Full-Time Workers
26% of the U.S. Labor Force at Risk for SWD
12:30 AM
10:30
PM
1.3%
8:30
PM
2:30
AM
0.2%
25.9%
Elevated risk
for SWD
72.6%
Day and evening
shift workers
0.8%
4:30
AM
0.7%
1.1%
6:30
PM
1.0%
4:30
PM
8.6%
Start
Time Varies
12.2%
6:30
AM
51.5%
3.1%
15.6%
2:30
PM
1.2%
8:30
AM
1.1%
12:30 PM
10:30
AM
Start time unknown: 1.5%
Unknown
risk
1.5%
Source: Bureau of Labor Statistics, May 2004 data; available at
http://www.bls.gov/news.release/flex.t07.htm
DETERMINANTS OF
ALERTNESS AND
PERFORMANCE
• Biological Time of
Day (circadian
rhythms)
• Consecutive
Waking Hours
• Night Sleep
Duration
• Sleep Inertia
Human Circadian Pacemaker in Suprachiasmatic
Nucleus (SCN) of Hypothalamus
SCN
Courtesy of D. Weaver, Univ Massachusetts Medical School, Worcester, MA
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Performance Efficiency Over 24 Hours
1.5
Efficiency (Mean Z)
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
-2.5
03:00 06:00 09:00 12:00 15:00 18:00 21:00 24:00
Efficiency assessed in 3 studies by: 1) delays in answering phone calls; 2) errors in
reading meters; and 3) time taken by spinners to tie broken threads.
Folkard S, Tucker P. Occup Med. 2003;53:95-101.
DETERMINANTS OF
ALERTNESS AND
PERFORMANCE
• Biological Time of
Day (circadian
rhythms)
• Consecutive
Waking Hours
• Night Sleep
Duration
• Sleep Inertia
Acute Sleep Deprivation and Performance
Hours of Driving
Deviation from Mean (# attempted)
Cognitive Throughput
Hours of Wakefulness
0
10
20
30
40
50
0
10
20
30
40
50
10
0
-10
-20
-30
10
Deviation from Mean (mm)
Subjective Alertness
20
0
-10
-20
-30
Hours of Wakefulness
Jewett et al., 2000
National Transportation Safety Board
“...after [19] hours of sustained
wakefulness (at 3 am) cognitive
psychomotor performance decreased to a
level equivalent to the performance
impairment observed at a blood alcohol
concentration of 0.05 %. ... After 24 hours
of sustained wakefulness (at 8 am)
cognitive psychomotor performance
decreased to a level equivalent to the
performance deficit observed at a blood
alcohol concentration of roughly 0.10 %.”
- D. Dawson and K. Reid, Nature 388: 235, 1997.
DETERMINANTS OF
ALERTNESS AND
PERFORMANCE
• Biological Time of
Day (circadian
rhythms)
• Consecutive
Waking Hours
• Night Sleep
Duration
• Sleep Inertia
Chronic Sleep Deprivation and Performance
“Heavy Call” and Resident Performance
8
7
6
5
4
3
2
1
0
p=0.06
p=0.01
mean lane
variability (feet)
Van Dongen et al. Sleep 2003
Light call
Light call w / alcohol
Heavy call w / placebo
mean speed
variability (mph)
Arnedt et al. JAMA 2005
DETERMINANTS OF
ALERTNESS AND
PERFORMANCE
• Biological Time of
Day (circadian
rhythms)
• Consecutive
Waking Hours
• Night Sleep
Duration
• Sleep Inertia
Sleep
Inertia
Sleep Inertia
Aircraft Accident Data (Israeli
Airforce)
Time Course of Deficits from
Sleep Inertia
Fighters
All aircraft
1
2
3
4
5
6
7
Hours since 6 am wake time
Ribak et al., Aviat. Space
Environ. Med., 1983
Wertz et al.,
JAMA 2006
Chronic sleep restriction progressively degrades reaction time,
particularly during circadian night.
Cohen DA, et al. Science Translational Medicine 2010
Shift Work Coping Problems
Personal Factors
• Age ≥50 years
• “Morning-type” person
(“lark”)
• History of…
– Sleep disorders
– Medical illness
• Heavy domestic workload
• Second job (“moonlighting”)
Adapted from: Monk TH. Shift Work. In: Principles and Practice of Sleep Medicine.
3rd ed. 2000:600.
Degrees of Excessive Sleepiness
Falling asleep or nodding off…
•
•
•
•
During conversation
Eating a meal
Driving
Walking
• Watching a movie
• Attending a concert
• In a meeting
During daily
activities requiring
moderate attention
• Riding in a car
• Watching TV
• Reading
During times of rest
or when little attention
is required
Severity
Marked
impairment
and severe
sleepiness
during
activities requiring
mild-to-moderate attention
Adapted from: International Classification of Sleep Disorders Diagnostic and Coding
Manual. 1st ed. Westchester, IL: American Academy of Sleep Medicine; 2000:23.
Relative Risk for Injuries and Accidents
By Successive Nights
1.4
1.4
1.3
1.3
Relative Risk
Relative Risk
By Shift
1.2
1.1
1.0
1.2
1.1
1.0
0.9
0.9
0.8
0.8
Morning
Night
Afternoon
Folkard S, Tucker P. Occup Med. 2003;53:95-101.
1
2
3
4
Effects of 24-hour Shifts on Safety
Motor Vehicle Crashes
1.2
OR: 2.3 (95% CI, 1.6-3.3)
Percutaneous Injuries
1.4
OR: 1.6 (95%CI, 1.5-1.8)
Extended
shifts
1.2
1
Nonextended
shifts
1
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0
0
Crashes per 1000 commutes home
Barger LK et al. NEJM 2005;
352:125-134
Injuries per 1000 opportunities
Ayas, et al. JAMA 2006;
296:1055-1062
100 Car Study
Virginia Tech and NHTSA
•Naturalistic study of 100 cars for
one year
•82 crashes, 761 near-crashes
•Fatigue contributing cause in:
20% of all MVCs & 16% of all nearcrashes
•Suggests could be as many as
8,000 fatigue-related fatal crashes
in U.S. each year
http://www.vtti.vt.edu/PDF/100-Car_Fact-Sheet.pdf
Gastrointestinal Disorders in Night-Shift Workers
16
*
14
15.4
*
12
12.5
10
8
6
4
6.0
†
38
30
25
20
20
15
10
2
5
0
0
Day
Shift
Functional Bowel Disorders
35
% of Nurses
% of Workers
18
Prevalence of Ulcers in Workers
Experiencing Insomnia or
40
Excessive Sleepiness
Rotating
Shift
Night
Shift
*P <0.05 vs no insomnia or ES
Drake CL, et al. Sleep. 2004;27:1453-62
Day
Shift
†P = 0.04 vs day shift.
Rotating
Shift
Zhen Lu W, et al. Eur J Gastroenterol
Hepatol. 2006;18:623-627.
Shift Work and the Risk for Coronary Heart
Disease in 79,109 Nurses
2.5
No Shift Work
Relative Risk (95% CI)
Any Shift Work
2.0
*
*
1.5
1.0
1.41
1.38
1.23
0.5
1.00
1.00
1.00
0.0
Fatal
CHD
Nonfatal
MI
*P <0.05 vs no shift work.
Kawachi I, et al. Circulation.1995;92:3178-3182.
Total
CHD
Studies Demonstrating a Significant Risk
for Cancer Among Shift Workers
Type of Cancer
Odds Ratio
95% CI
Reference
Night shift ≥0.5 year
1.5*
1.3 – 1.7
Night shift >6 years
1.7*
1.3 – 1.7
“Graveyard shift” (any)
1.6*
1.0 – 2.5
Shift work ≥5.7 hours/week
2.3*
1.0 – 5.3
Rotating nights; ≥30 years
1.36*
1.04 – 1.78
3
Rotating shift work: >20 years
1.79*
1.06 – 3.01
4
3.0*
1.2 – 7.7
5
Breast cancer
1
2
Prostate cancer
Rotating shift work
*P <0.05 vs comparator group.
1) Hansen J. Epidemiology. 2001;12:74-77; 2) Davis S, et al. J Natl Cancer Inst. 2001;93:15571562; 3) Schernhammer ES, et al. J Natl Cancer Inst. 2001;93:1563-1568. 4) Schernhammer ES,
Epidemiology 2006;17:108-111; 5) Kubo T, et al. Am J Epidemiol. 2006;164:549-555.
Fatigue Management
Systemic Changes: Schedule Design and
Other Workplace Interventions
• Eliminate shifts >12-16 hours
• Limit the number of consecutive night shifts
– The fewer, the better
– >4 12-hour night shifts associated with greatly increased risk of
performance lapses1
• Schedule rotating workers to rotate “clockwise”
• Screen workers for sleep disorders
• Educate workers about the risks of driving and working while
sleep deprived
Rotating shift work schedules that disrupt sleep
are improved by applying circadian principles
• Intervention changed workers’ rotation from “phase advance”
to “phase delay”, and increased time on rotation to 21 days
• Significant improvements in worker satisfaction and
productivity (22%, p<0.001) after change
Czeisler CA, Moore-Ede MC, Coleman RM. Science 1982; 217:460-463
Philadelphia Police Department
• Circadian-based scheduling intervention
(change from phase advance to phase delay)
• At Baseline:
−Over 50% of officers reported moderate to
severe problem with sleep quality
−Over 70% admitted falling asleep on the job
during the night shift
• Post-intervention:
−Four-fold reduction in poor quality sleep
−29% decline in sleep episodes at work
−40% decline in patrol car crashes
−38% increase in family satisfaction
Center for Design of Industrial Schedules. 1988. Boston, MA.
Effect of Implementing a Sleep and Circadian
Science–Based Intervention Schedule on
Interns’ Serious Medical Errors
160
140
Traditional "q3" 24-30
hour shifts
120
100
Intervention Schedule
- <16 hour scheduled
shifts
80
60
40
20
0
Serious
Medical Errors
- Total
Serious
Medication
Error
Serious
Diagnostic
Error
Lockley SW, et al. , Landrigan CP, et al. N Engl J Med. 2004;351:1829-1837; 1838-1848.
Bright Light and Sleep/ Darkness for Alleviating
Maladaptation to Shift Work
• 54 subjects
70
• Simulated 4-day, 3-night shift work
60
• 38-hour constant routine (CR)
• Light during 8-hr “shift work”
50
Subjective
Alertness
40
30
– Bright (~2500 lux)
20
– Room (~150 lux)
10
• Sleep
0
– Fixed 8 hr; darkened room
– Free schedule
Bright Fixed
• Nighttime alertness
Bright Free
– P <0.01: bright light vs room light
– P <0.01: fixed sleep vs free sleep
Room Fixed
Room Free
Horowitz TS, et al. Am J Physiol Endocrinol Metab. 2001;281:384-391.
Individual Level
• Nonpharmacologic interventions
– Work schedule changes
– Lifestyle changes
– Exercise
• Nonprescription interventions
–
–
–
–
Light
Melatonin
Caffeine (coffee, tea, colas, energy bars, caffeine tablets)
OTC sleep aids
• Prescription interventions
– Sleep promoting medications
– Wake promoting medications
Effect of Exogenous Melatonin on Sleep Efficiency in
the Presence or Absence of Endogenous Melatonin
Placebo
• Endogenous melatonin levels are…
– Low during the daytime
• Exogenous melatonin…
– Increases the duration of sleep
occurring out of phase with
endogenous melatonin secretion
– Attenuates the wake-promoting
drive from the circadian system
– Has little effect when taken at times
when endogenous melatonin is
present
Mean Sleep Efficiency (% ± SEM)
– High at night
90
Melatonin 0.3 mg
Melatonin 5.0 mg
*
85
*
80
75
Wyatt JK, et al. Sleep. 2006;29:609-618.
Low to Absent
Endogenous
Melatonin
Elevated
Endogenous
Melatonin
Phase Shift in Circadian Rhythms With
Melatonin in a Simulated Night-Shift Study
Endogenous Dim-Light Melatonin Onset
5
Mean Phase Shift (hours)
P <0.001
4
P <0.05
3.9
3
3.0
2
1
1.7
0
Placebo
Melatonin
0.5 mg
Melatonin
3.0 mg
Sharkey KM, et al. Am J Physiol Regulatory Integrative Comp Physiol. 2002;282:454-63
Caffeine
Baseline
Cognition
DSST (# correct)
15
10
5
0
-5
0
S
L
E
E
P
S
L
E
E
P
Vigilance & Reaction
PVT (slowest 1000
10% [msec])
Extended Wake Duration
P <0.05
S
L
E
E
P
P <0.05
S
L
E
E
P
P <0.05
S
L
E
E
P
Placebo
Caffeine
2000
Sleepiness
KSS (units)
-1
0
1
2
3
S
L
E
E
P
0
8
16 24 4.8
Wyatt JK, et al. Sleep. 2004;27:374-381.
28.6
Hours
42.9
Treating Daytime Insomnia
• Sleep hygiene
–
–
–
–
–
Dark, cool, quiet bedroom
Avoidance of caffeine, tobacco, and alcohol
Consistent sleep & wake times
Regular exercise
Cognitive therapy
• Nonprescription interventions
– Antihistamines
• Prescription interventions
– Benzodiazepines
– Nonbenzodiazepines
– Sedating antidepressants
Shift Work Disorder (SWD):
Diagnostic Criteria
(1) Insomnia or excessive sleepiness temporally
associated with a recurring work schedule that
overlaps the usual time for sleep;
(2) symptoms must be associated with the shift work
schedule over the course of at least one month;
(3) circadian and sleep-time misalignment as
demonstrated by sleep log or actigraphic monitoring
for ≥ 7 days; and
(4) sleep disturbance not explained by another sleep
disorder, medical or neurological disorder, mental
disorder, medication use, or substance use disorder.
Adapted from: International Classification of Sleep Disorders Diagnostic and Coding
Manual. 2nd ed. Westchester, IL: American Academy of Sleep Medicine; 2005.
Modafinil for Excessive Sleepiness in Patients With SWD
Placebo
Modafinil 200 mg
60
Sleep Latency
MSLT
*
5
74
4
†
3
3.8
Minutes
% of Patients Improved
Clinician’s Global Impression
of Change (Improvement)
80
40
2
2.4
36
20
1
0
Final Visit
0
*P <0.001 vs placebo.
†P = 0.002 for change from baseline vs change from baseline with placebo.
Czeisler CA, et al. N Engl J Med. 2005;353:476-486.
Baseline
Final Visit
Reducing the Effects of Sleepiness
When Commuting
• Shift workers have a greatly increased risk of suffering a motor
vehicle crash on the drive home from work1,2
•
Measures for the employer
– Facilitate establishment of taxi services and/or company car pools
– Provide a place for workers to nap before driving home
• Measures for the employee
– Minimize commuting; move closer to the work place or use public
transportation
– Avoid traveling at high speeds on highways
– If you feel sleepy when driving, pull over and nap; rolling down
the window and turning up the radio will not work
1) Barger LK, et al. N Engl J Med. 2005;352:125-134;
2) Gold DR, et al. Am J Public Health. 1992;82:1011-4.
Summary
• A large segment of the U.S. population works shifts
• Shift workers are prone to circadian misalignment, acute
sleep deprivation, chronic sleep deprivation, and sleep
inertia
• These forces increase the risk of accidents, injuries,
mistakes on the job, and motor vehicle crashes (either
on the job or driving home)
• Systemic interventions to optimize work schedules have
been shown to be effective across occupations
• At an individual level, optimizing sleep hygiene,
melatonin, caffeine, and pharmaceuticals can be helpful