Fatigue and SAR Research

Sleep Lecture Outline

I. Introduction

B.Problems of Continuous Sustained Operations (disasters, SAR, military, police work)

1Limited number of adequately trained and skilled individuals

2.Those individuals on-scene develop specific knowledge making them invaluable

3.Only four solutions exist

a.go without sleep

b.decrease the need for sleep

c.Shorten sleep and augment with naps

d.Adapt fragmented sleep schedule

D.Dedication and story of Lisa Hannon

E.SAR members trained in First-aid and Physiology (Food, Fluid, Temperature regulation etc.)

1No Food3-4 weeks survival

2.No water3-4 days survival

3.No shelter3-4 hours survival

4. No sleep3-4 seconds survival if driving.

1.issue complex

2.current policy

3.education is best method

4.About to receive your most important safety lecture.

G.Topics covered

1.Circadian Rhythms-your bodies natural alarm clock.

2.Sleep Cycle-what makes us fall asleep and when.

3.Required Sleep-how much is enough?

4.Naps-the power of the 20 minute nap.

5.Sleep and Accidents-understanding the lose of vigilance

6.Accident Prevention-how to STAY ALIVE!!!

II. Circadian Rhythms

Any rhythm that has a periodicity of about 24 hours. Average human cycle is 25.5 hours if stuck in a cave/room without any time cues. Explain why its easier to go to bed later each night. Monday morning blues are a result of attempting to shift time forward.

B.Introduction to Circadian Rhythms

1.Today's society thinks of time outside (sun, wristwatch, etc.)

2.Body has an internal clock (waking up before alarm clock)

3.Purpose of clock

a.conserve resources

b.wake up before something eats you.

c.wake up to eat something

d.predict events

e.synchronize all body rhythms (desynchronization results in jet lag)

4.Location of Clock

a.eukaryotic organisms- inside of cell (mitochondria?)

b.Snails and cockroaches- eyes

c.Mammals- Brain, hypothalamus

1.NOT the voodoo charts

2.Several types

3.Two of interest

a.mental alertness

b.Temperature

4.Important points from graph

a.Circadian controlled rhythms persist regardless of

(1)amount of previous sleep

(2)meals

(3)activity

(4)changing shifts

b.However, all of the above my strengthen or weaken the rhythm

c.the critical point is the time of day.

5.Several other important circadian rhythms

a.mental alertness

b.temperature

c.metabolism

d.vital signs

e.sleep

III.Sleep Cycle

A.Old Theory- Sleep passive

1.Gradual isolation of brain from body

2.Greeks- fumes in stomach rise and block the opening of the brain, stopping sensations from the body.

3.Newer- Blocking of the brain caused by blood excess, swollen thyroid gland, or actual disconnections between the nerve cells.

B.Active Theory

1.Gradual continuous process- accumulation of sleep factor

2.Current theory- sudden process under active control of part of the brain on other parts.

a.lower brain stem controls higher levels of the cortex.

b.Reticular Activating System

(1)Raphe nuclei sends signal to brain to sleep.

(2)Cut nerve tract in cats and they fail to fall asleep for 4-5 days.

(3)Story of person who never sleeps because of brain damage.

(4)Other signals sent to wake up.

c.Several different rhythms contribute to changes in level of alertness.

1.Mean Sleep Latency Test (MSLT)

a.Standard sleep setting

b.7/13 minute sleep wake cycle

c.Two test conditions

(1)Attempt sleep

(2)Resist sleep

2.Pooled data presents smooth curves because of averaging. Appearance gradually increased pressure (propensity) to sleep. Individual data show sudden change.

3.Sleep gates stable even after sleep deprivation.

4.Timing of sleep gates.

a.Morning persons very stable 2120-2320

b.Night person less clear after 00:00

c.Night person do not show prominence of mid-afternoon peak.

d.Forbidden zone for sleep 20:00 + 40 minutes.

5.Two characteristics appear in the resist sleep test.

a.In well rested person, difference between resist sleep and attempt sleep appears.

b.In sleep deprived person no significant difference between the two.

(1)Attempt sleep- 3.47 + 0.92

(2)Resist sleep- 3.08+ 1.00 (p=0.13)

c.Sleepy type of Person:

(1)Fall asleep easily both day and night

(2)efficient sleeper

(3)sleep activation voluntarily

(4)sleep involuntarily when sleep pressure high

d.Alert type of Person

(1)Difficulty sleeping during day, can sleep at night

(2)Able to resist sleep at night

e.Sleepy versus Alert independent of morning vs. night person.

IV. Required Sleep

A.Sleep physiology

1.Purpose of sleep

2.2 parts of sleep

a.Core sleep (obligatory)

b.Voluntary

3.Effects of lack of sleep

a.Will not kill you directly (40 years of no sleep)

b.Sleep deprivation record 18 days 17 hours

c.effects of no sleep after 100 hours.

(1)hallucinations, paranoia, increased appetite, increased sexual drive, sleepiness, decreased performance, and microsleep.

C.Training to Sleep less

1.Takes about two weeks to reach level

2.Minimum represents core sleep, 4.5-5.5 hours

3.Performance stays the same

4.Mood often drops.

1.Advantage of field studies over lab

a.closer to SAR

b.Tasks more demanding and interesting

c.Motivation higher

d.Physical component added.

2.Paratrooper Study (field)

a.Setting: 9 day field tactical defensive exercise, with a steady downpour during the first 4 days.

b.Tasks: Marching, patrolling, attacking, digging, shooting.

c.Test of performance: Map plotting, encoding grid references, short term memory tasks, and vigilance shooting.

d.Results:

(1)0 sleep platoon.

(a)Everyone quit after 4 days.

(b)Military effectiveness loss after 3 days.

(2)1.5 hours of sleep per night platoon.

(a)52% completed 9 day study

(b)Military effectiveness loss after 6 days.

(c)Cheerful Sergent motivated those that continued

(3)3.0 hours of sleep per night platoon.

(a)90% completed study

(b)Military effectiveness all 9 days.

(4)Overall observations

(a)Vigilance skill that dropped the most

(b)Everyone became more docile

(c)Personal hygiene became worse.

3.Command and Control Headquarters (Staff)

a.Setting: Brigade headquarters, play operations officer

b.Tasks: Monitor communications network, update tactical maps, read messages, Answer questions, identify locations of various units using map grid references, describe units activities, select appropriate unit for specific task, decode equipment resource orders, estimate travel distances and ETA's. Performed Moderate exercise.

c.Results:

(1)Circadian nature

(2)Mid-afternoon drop

(3)Power of napping

(4)Sleep inertia

(5)Exercise did not affect loss of alertness

(6)Greater decrements in performance after sleep loss and intensive mental work.

d.Types of errors seen after sleep loss.

(1)Errors of Omission versus Commission

(2)No errors seen if subject allowed unlimited time to complete task.

(3)Errors appear if limited time.

(4)Motivation to perform drops

(5)In desert war games. "Soldiers forget to top off water supply"

(6)In cold weather games "Officers forget to force soldiers to change socks"

(7)Medical care- correct drugs and dose given, forget to check patient.

1.Naps greatly increase performance

2.Minimum nap time

a.1 minute at a time, total sleep 5 hours . Does not restore alertness.

b.10 minutes at a time, minimum sleep to restore alertness.

c.20 minutes optimal nap time for a fragmented sleep schedule.

3.Ocean racing Nap Study

a.Setting: Solo sailing race across the Atlantic.

b.Tasks: Adjust sails, adjust course, navigate, look for other ships.

c.Tests: Winning the race

d.Results: Those you took 20 minute naps performed the best. Total sleep time came to 6.33 hours + 1.7. Two groups. 5 hour and 8 hour sleepers.

4.Nap timing- Anytime is ok. Naps during the drop in alertness that naturally occurs mid afternoon is good. Prophylactic napping (naps before sleep deprivation expected) are also useful. Usually on the order of two hours worth of napping or extra sleep.

5.Nap side effects: Sleep Inertia "sleep drunkenness"

a.What it is.

b.Duration ranges from a couple of minutes to a couple of hours.

c.Naps at 04:00-05:00 result in the longest sleep inertia

d.Waking from SWS- worsens sleep inertia

6.Methods to reduce Sleep Inertia

7.Recommendations for Base camp

a.Establish "napping area" close to staging area with cots.

b.Encourage Field personal to nap for 20-30 minutes during lunch break or any other time.

c.Encourage staff to take 20-30 minute nap whenever feasible.

F.Sleep Timing

1.Going to bed around 01:00 results in the longest sleep time

2.Going to bed around 03:00 results in the best sleep efficiency

3.After 04:00 body temperature increases make sleep more difficult.

4.The temperature dip and alertness dip between 12:00-14:00 make naps easier.

V. Sleep and Accidents

A.Sleep Accident in Transportation and Industry

1.Constant vigilance required while sleep gates opened

2.Traffic accidents

a.200,000 auto collisions/year sleep related

b.10,000 fatalities/year sleep related

c.50% of all drivers admit near mishap.

d.20% of all drivers have fallen asleep at wheel.

e.SAR statistics ????????

3.Train drivers

a.11% doze off on most night runs

b.70% dozed off at least once during a night run.

c.0% reported dozing off on most day runs

d.23% dozed off at least once during a day run.

4.Industrial Accidents

a.Three mile island: 04:00

b.Chernophyl:01:35

c.Challenger: 08:00 Mission Control up all night

1.Frequency of Accidents closely follows the natural circadian rhythm

2.Alertness nadir (minimum) 08:00

3.Alertness Peak (16:00-18:00)

1.Train drivers

a.Semi-automatically drive train for some minutes

b.Fall asleep with eyes open

c.Not aware of the fact they fell asleep

d.No premonition of imminent dozing off.

e.All drivers knew they were sleepy.

2.Extended Driving

a.drove on unused airfield with researcher

b.most subjects fell asleep in early morning

c.dozed off for 1-2 seconds after fighting sleep

d.fell asleep again after 20-30 minutes rest breaks did not help

3..Sleepiness and Drunkenness Attitude towards a searcher who would drive home drunk.

4.Loss of reaction time

a.after 16 hours awake

b.after 40 hours awake

5.Flight simulator @ 16 hours = 0.05% BAC

6.Driving sleep deprived is driving drunk.

D.Gethomeitis

1.Attitude towards pilots who fly into bad weather.

2.Pushing limits usually due to desire to get home.

3.Searchers fall victim to the same pressures.

4.Factor in needed sleep as part of on-scene time.

E.Signs and Symptoms of Sleepiness

1.Tunnel or fixed vision, eyes strain, eyes want to close, inability to focus

2.Head nods or bobs

3.Persistent yawning

4.Wandering dream like thoughts

5.Microsleeps

VI. Accident Prevention

1.Driving while sleepy similar to drunk driving

2."I just spilled a little bit of gasoline on the rope its ok for vertical work"

3."Its just me in the car"

a.Pain of other SAR members

b.Pain if another innocent driver involved.

1.Only method to avoid sleepiness is sleep

2.Obtain at least 4.5-5.5 hours in the last 24 hours.

3.Total sleep time may be obtained in 20 minute of more naps.

4.Calculate nap time into search availability.

1.Primary gate: 00:00-07:00

2.Secondary gate 12:00-14:00

1.Pre-plan possibility of taking a nap on road

2.Pull over

a.Sleeping on interstate illegal and dangerous (other sleepy driver rear end)

b.Sleeping on off ramps also illegal and dangerous.

c.Sleeping on other roads allowed.

d.Sleep in well lit patrolled area (rest stops allow about 2 hours of sleep)

e.Turn on blinkers, lock doors.

3.Nap for 20-30 minutes

4.Walk around, stretch before starting to overcome sleep inertia.

F.Don't drink alcohol. Drinking large amounts of fluids story.

G.Exercise during rest breaks.

H.Carpool if possible

1.share driving

2.most rested person comes from back seat.

3.Do not depend upon passenger to keep you awake.

1.potent stimulation

2.changes clock time

3.Monitor effects (rebound) as it wears off. Tolerance to Caffeine develops.

4.Studies show caffeine increases mood not performance.

1.sunglasses while in bright sunshine

2.clean windshield at night

1.Talking

2.Chewing

3.Radio

4.Cold

5.Short term solutions.

M.Role of Safety officer

1.Ultimately safety is your responsibility as the pilot of the car.

2.NO good short term test for sleepiness

3.Sleep test only measures current status, not 30 minutes from now.

4.MSLT as a possible test for all SAR members before leaving.

1.How many hours since you last slept?

2.How long did you last sleep for?

3.How long is your drive home?

4.Is anyone going to be in the car with you?

5.How are you feeling now?

6.Do you promise to pull over and take a nap if you become sleepy?

VII. Specific Recommendations for Action

1.Teach all SAR members about sleep needs

2.Teach all SAR members about Accident prevention.

C.Teach members to calculate sleep time into time on search Calculations.

D.Obtain funding to provide for hotel/motel room when returning from a search.

E.Establish napping area close to staging area.

F.Consider MSLT for safety check

G.Encourage staff members to take naps. Change attitudes to encourage naps.

Copyright © 1995 dbS Productions

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Sleep Disorders Center kumpf last updated Jan 22, 2003