Managing the Effects of Crew Endurance
Degradation on Operational Hazard
Exposure
April 2013
Carlos Comperatore, Ph.D.and Pik Kwan Ng
U.S. Coast Guard Office of Safety and Environmental Health
Washington, D.C.
Disclaimer: The following information solely
represents the views of the authors and it does
not represent the official position of the
Department of Homeland Security or the U.S.
Coast Guard
Search and rescue (SAR), medical evacuation, medical emergencies, and
fire rescue are few of the many on-demand operations where
dynamically changing contextual variables contribute to mission hazard
exposure level.
CREW ENDURANCE MANAGEMENT (CEM)
• A method of identifying and controlling hazards that
degrade crewmember alertness, rest, and recovery:
– Assess operations to identify crew endurance
hazards
– Implement shipboard and organizational practices
to protect crewmember endurance
CREW ENDURANCE RISK FACTORS
• Core Endurance Risk Factors – directly impact
the ability to produce and restore physical and
cognitive resources:
–
–
–
–
–
–
–
Insufficient Daily Sleep
Poor Sleep Quality
Fragmented Sleep
Main sleep during the day – night work
Changing work/rest schedules
Long work hours
No Opportunities to Make Up Lost Sleep
The Crew Endurance
Management
System (CEMS)
Environment
Organization
Personnel
The Crew Endurance
Management
System (CEMS)
Environment
Organization
Personnel
•Mission
Demands
•Operational
Safety
•24/ 7
Operations
•Area of
Operations
The Crew Endurance
Management
System (CEMS)
Environment
Organization
•Sleep
management
•Body clock
•Physical fitness
•Stress
management
Personnel
•Mission
Demands
•Operational
Safety
•24/ 7
Operations
•Area of
Operations
The Crew Endurance
Management
System (CEMS)
•Light/Noise
levels
•Vibration
•Temperature
•Work
environments
•Leisure facilities
•Sleeping
quarters
•Watch schedules
•Nighttime
adaptation
•Overtime policy
•Napping policy
•Berthing courtesy
policy
Environment
Organization
•Sleep
management
•Body clock
•Physical fitness
•Stress
management
Personnel
•Mission
Demands
•Operational
Safety
•24/ 7
Operations
•Area of
Operations
The Crew Endurance Management System
– Processes/Guidelines
• Organizational and
vessel implementation
• Crew Endurance Risk
Factors Assessment
– Knowledge
• Education program
– Practices/Controls
• Controls to mitigate the
incidence of endurance
risk factors in
operations
– Equipment/Tools
• CEMS tool
• Crew Endurance Risk
Factors Assessment
• Schedule Evaluation
Tool
• CEMS Guide
– Develop Expertise
– Provide Assistance
HUMAN ENERGY
REQUIREMENTS
• Studies of brain function have shown that seven to
eight hours of continuous sleep are necessary to
restore cell function to normal levels
DAILY SLEEP
REQUIREMENTS
• Varies with age
– Elementary students normally require 10-12 hours per
day;
– Pre-teens 9-11 hours;
– Teens 8½-10 hours;
– Most adults 7-8 hours per day
(For sleep to be restorative, it must be continuous and
uninterrupted)
Daily Minimum Sleep Requirement
7-8 Continuous Hours
Awake
REM
Stage 1
Stage 2
Stage 3
Stage 4
0
1
2
3
4
Elapsed Hours of Sleep
5
6
7
Belenky et.al. (2003). J. of Sleep Res.
12, 1-12
•
•
•
•
•
•
•
•
Sleep and Health
Obesity
Cardiovascular Disease
Hypertension
High Blood Pressure
Diabetes
Depression
Stroke
Immune Deficiencies
CREW ENDURANCE
RISK FACTORS
• Modulating Endurance Risk Factors – contribute to “sap”
energy levels and worsen the effects of the “core” risk
factors
–
–
–
–
–
–
–
–
High Workload
Lack of Control Over Work Environment or Decisions
Poor Diet
No Opportunity for Exercise
High Work Stress
Family Stress
Isolation From Family
Excessive exposure to extreme environments
DECLINING ENDURANCE RESULTS IN
HUMAN ERROR
Contributing Factors
• Sleep deprivation
• Sleep cycle disruption
Symptoms
Physical Symptoms
•Difficulty focusing eyes
•Clumsy
• Working at
inappropriate times
of day
•Sore muscles
• Job role and life stress
• Forgetful
• Physical stress
• Hard to do mental
arithmetic, recognize
codes/symbols
• Environmental stress
Mental Symptoms
• Less motivated
• Slow to respond
• Tasks out of sequence
Human Errors
•Unable to recognize
input (e.g. nav aids,
radio calls, gauges)
•Forget to check
critical info (e.g.,
fathometer, fuel
levels)
•Fail to secure
equipment (e.g., cargo
transfer)
•Alter something that
did not need to be
changed (e.g., course,
fuel transfer)
Wind
WindSpeed
Speed
Number
Numberof
of
Victims
Victims
Ceilings
Ceilings
B -
Coordinating
Coordinating
Multiple
MultipleResponse
Response
Assets
Assets
R +
R +
Environmental
Environmental
Conditions
Conditionsat
atArea
Area
of
ofOperations
Operations
R +
Visibility
Visibility
R +
R +
Operational
Operational
Complexity
Complexity
B -
Threat
Threatto
to
Victim
Victim(s)
(s)
R +
Air
AirTraffic
TrafficDensity
Density
R +
OPNL
OPNL
Experience
Experience
B -
R +
Decay
Decayof
of
Perishable
Perishable
Skill
Skill
AOR
AOR
Familiriarization
Familiriarization
R +
R +
Platform
Platform
Experience
Experience
TTP
TTP
Mission
Mission
Relevance
Relevance
R +
R +
OPNL
OPNL
Proficiency
Proficiency
R +
B -
Mission
Mission
Hazard
Hazard
Level
Level
B -
OPNL
OPNL
System
System
Capacity
Capacity
R +
R +
B B -
OPNL
OPNL
Tempo
Tempo
R +
Sleep
Sleep
Duration
Duration
Adequacy
Adequacy
R +
Sleep
Sleep
Quality
Quality
B B -
R +
R +
Sleep
Sleep
Environment
Environment
Adequacy
Adequacy
B -
B -
OPNL
OPNL
Tempo
Tempo
Personnel
Personnel
Proficiency
Proficiency
Capacity
Capacity
Congruence
Congruenceof
of
Sleep
SleepTiming
Timingand
and
Endogenous
Endogenous
Circadian
CircadianPhase
Phase
FATIGUE
FATIGUE
Level
Level
R +
Sustained
Sustained
Wakefulness
Wakefulness
R +
OPNL
OPNL
Tempo
Tempo
Mission
Mission
Equipment
Equipment
and
andPlatform
Platform
Capacity
Capacity
Sleep and Performance
Logical Reasoning
Mental Arithmetic
Aircraft Piloting
24-hour Rhythms
Alertness Level &
Core Temperature
Sleep
12
15
18
21
24
3
Time of Day
6
9
12
80
Melatonin
ACROPHASE
60
40
20
ONSET
0
2000
2200
0000
0200
0400
Hours
0600
0800
1000
80
Serum
specimens
ACROPHASE
60
40
20
ONSET
0
2000
2200
0000
0200
0400
Hours
0600
0800
1000
Use of “Monochromatic” Green Light
24-hour Rhythms
Sleep
Alertness Level &
Core Temperature
20
15
10
5
0
12
15
18
21
24
3
Time of Day
6
9
12
Light Induced Delays
Alertness Level &
Core Temperature
20
Sleep
15
10
5
delay
0
12
15
18
21
24
3
Time of Day
6
9
12
Light Induced Delays
Alertness Level &
Core Temperature
20
Sleep
15
Rate of shift:
app. 1 hr/ day
10
5
delay
0
12
15
18
21
24
3
Time of Day
6
9
12
Light Induced Delays
Alertness Level &
Core Temperature
20
Sleep
15
10
5
delay
0
12
15
18
21
24
3
Time of Day
6
9
12
Light Management
24-hour Rhythms
Sleep
Alertness Level &
Core Temperature
20
15
10
5
0
12
15
18
21
24
3
Time of Day
6
9
12
Light Induced Advances
Sleep
Alertness Level &
Core Temperature
20
15
10
5
advance
0
12
15
18
21
24
3
Time of Day
6
9
12
Light Induced Advances
Sleep
Alertness Level &
Core Temperature
20
15
10
5
advance
0
12
15
18
21
24
3
Time of Day
6
9
12
30
28
26
24
22
Melatonin pg/ml
20
18
16
14
12
10
8
6
4
2
0
2130
Red Light Laboratory
2230
2330
Green Light Laboratory
0030
0130
2-3Nov
0230
4-5Nov
Time
6-7Nov
8-9Nov
10-11Nov
12-13Nov
14-15Nov
20-21Nov
23-24Nov
25-26Nov
0330
0430
15 Minute Exposure by 2 hours Calibration
14
12
10
8
6
4
2
0
1700
1800
1850
Baseline
1900
Day 3
1950
Day 4
2050
2150
Control 1
2250
Control 2
2350
0050
0150
0250
0350
This Page Left
Intentionally Blank
Hazard Exposure as a
Function of Operational
Complexity
• Each operational environment involves specific
– Operational objectives,
– Crew operational proficiency,
– Crew State
– Response platform capacities,
– Platform tolerance thresholds for varying
environmental conditions,
– Variation in coordination of multiple (e.g.,
shipboard, afloat, aviation, command and control,
etc.) assets, and in some cases inter-agency
coordination.
Wind
WindSpeed
Speed
Number
Numberof
of
Victims
Victims
Ceilings
Ceilings
B -
Coordinating
Coordinating
Multiple
MultipleResponse
Response
Assets
Assets
R +
R +
Environmental
Environmental
Conditions
Conditionsat
atArea
Area
of
ofOperations
Operations
R +
Visibility
Visibility
R +
R +
Operational
Operational
Complexity
Complexity
B -
Threat
Threatto
to
Victim
Victim(s)
(s)
R +
Air
AirTraffic
TrafficDensity
Density
R +
OPNL
OPNL
Experience
Experience
B -
R +
Decay
Decayof
of
Perishable
Perishable
Skill
Skill
AOR
AOR
Familiriarization
Familiriarization
R +
R +
Platform
Platform
Experience
Experience
TTP
TTP
Mission
Mission
Relevance
Relevance
R +
R +
OPNL
OPNL
Proficiency
Proficiency
R +
B -
Mission
Mission
Hazard
Hazard
Level
Level
B -
OPNL
OPNL
System
System
Capacity
Capacity
R +
R +
B B -
OPNL
OPNL
Tempo
Tempo
R +
Sleep
Sleep
Duration
Duration
Adequacy
Adequacy
R +
Sleep
Sleep
Quality
Quality
B B -
R +
R +
Sleep
Sleep
Environment
Environment
Adequacy
Adequacy
B -
B -
OPNL
OPNL
Tempo
Tempo
Personnel
Personnel
Proficiency
Proficiency
Capacity
Capacity
Congruence
Congruenceof
of
Sleep
SleepTiming
Timingand
and
Endogenous
Endogenous
Circadian
CircadianPhase
Phase
FATIGUE
FATIGUE
Level
Level
R +
Sustained
Sustained
Wakefulness
Wakefulness
R +
OPNL
OPNL
Tempo
Tempo
Mission
Mission
Equipment
Equipment
and
andPlatform
Platform
Capacity
Capacity
Operational Proficiency
(OPNL Experience (w) + Skill Decay(w)+ AOR Fam(w) + Platform Qual(w)+ Last
Flight(w))
Contact
Information
• Dr. Carlos Comperatore
• carlos.a.comperatore@uscg.mil
• 202-475-5182