Managing Sleep and Fatigue in Today s Healthcare Environment Tricks of the Trade

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Trevor Reeves
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1 Managing Sleep and Fatigue in Today s Healthcare Environment Tricks of the Trade 92 nd Annual Meeting of the American Association of Thoracic Surgery Scott Shappell, Ph.D. Clemson University

2 How tired are you, really??? The worst person to is the person that you are worried about!

Effects of Fatigue on Performance Increased reaction time

Reduced attention Preoccupation with single tasks or

peripheral tasks Revert to old habit patterns Withdrawn

3 Effects of Fatigue on Performance Increased reaction time Timing errors in response sequences Less smooth control Reduced attention Preoccupation with single tasks or elements Reduced audiovisual scan Diminished memory Forget peripheral tasks Revert to old habit patterns Withdrawn mood Less likely to converse Less likely to perform low-demand tasks

Circadian Rhythms We have an intrinsic biological clock with a cycle of roughly 24-25 hours.

4 Circadian Rhythms We have an intrinsic biological clock with a cycle of roughly hours. Many bodily functions cycle about these daily circadian rhythms a) Blood Pressure b) Heart Rate c) Core Body Temperature d) Others... Perhaps most important is that performance also cycles about normal circadian rhythms. Given the typical circadian cycle, performance peaks between 1200 and 2100 hours and falls to a minimum circadian trough between 0300 and 0600 hours.

5 PERFORMANCE Circadian Rhythms OPTIMAL PEAK ALERT Circadian Trough SLEEPINESS WORST NADIR SLEEPY Time of Day (24 hour)

Circadian Rhythms While the body clock is inherently capable of monitoring the passage of time, it differs from most clocks in that it is flexible and must be set, or

6 Circadian Rhythms While the body clock is inherently capable of monitoring the passage of time, it differs from most clocks in that it is flexible and must be set, or synchronized, before it can accurately predict the timing of events. Entrained by external synchronizers, Zeitgebers a) Sunrise-Sunset b) Ambient Temperature c) Meals d) Social Cues

irritability, depression Slow reaction times, defective memory for recent

7 Circadian Desynchronization Jet Lag Deficits in performance, mood, motivation, and behavior Sleep disturbances Lassitude, anxiety, irritability, depression Slow reaction times, defective memory for recent events, errors in computations, and a tendency to accept lower standards of performance.

Circadian Desynchronization Jet Lag Rapidly traveling from one time zone to another, the body clock and rhythms it controls must resynchronize to the local

8 Circadian Desynchronization Jet Lag Rapidly traveling from one time zone to another, the body clock and rhythms it controls must resynchronize to the local geophysical and social zeitgebers. Eastward travel shortens the day. Westward travel lengthens the day. Resynchronization occurs much more rapidly when traveling west

9 Sleep Our sleep/wake cycle is closely tied to our circadian body temperature a) Cave studies

10 PERFORMANCE Circadian Rhythms OPTIMAL PEAK ALERT Circadian Trough SLEEPINESS WORST NADIR SLEEPY Time of Day (24 hour)

11 Stages of Sleep

12 Stages of Sleep

13 PERFORMANCE Circadian Rhythms OPTIMAL PEAK ALERT Circadian Trough SLEEPINESS WORST NADIR SLEEPY Time of Day (24 hour)

14 Sleep Our sleep/wake cycle is closely tied to our circadian body temperature Cave studies The duration and quality of sleep is dependent upon body temperature People sleep longer and report a better night s sleep when they retire near the temperature trough. It is the timing of sleep, not necessarily the amount of sleep, that is most significant.

There are essentially two times when your

15 When is the Best Time to Sleep? The circadian rhythm of sleepiness (MSLT) is remarkably similar to the circadian rhythm of body temperature. There are essentially two times when your body is prepared to sleep. 1) The most obvious is between ) Post-prandial dip

16 Performance Percent of Baseline How Much Sleep Do You Really Need? Hours of Total Sleep Deprivation: Effect on Complex Mental Operations Better Worse Sleep Deprivation (Hours)

17 Response Speed How Much Sleep Do You Really Need? Better Baseline (8 hrs) Worse Days on Experimental Schedule

18 How Much Sleep Do You Really Need?

19 How Much Sleep Do You Really Need? Sleep requirements vary among individuals. A minimum of 5 hours of uninterrupted core sleep during the circadian trough is necessary to maintain performance in the lab. Sleeping in excess of 10 hours may produce sleep drunkenness. When physical and mental workload exceed normal limits, the minimum amount of sleep needed to sustain performance is more.

Even naps as short as 10 min are restorative in nature Long naps (typically greater than

20 When sleep is not available or shortened by operational concerns, strategic naps are a viable alternative. Even naps as short as 10 min are restorative in nature Long naps (typically greater than 1 h) may leave the individual feeling more tired than before napping (Sleep Inertia) a) Sleep inertia may last 5-20 min upon awakening Practice Napping Napping

21 Napping

22 Countermeasures to Fatigue Pharmacological a) Caffeine b) Meth-amphetamine c) Amphetamine d) Methylphenidate Non-Pharmacological a) Tyrosine

23 Countermeasures to Insomnia Pharmacological a) Barbiturates b) Benzodiazepines c) Alcohol d) Antihistamines Non-Pharmacological a) Keep a routine b) Vigorous exercise b) Warm baths c) Tryptophan

24 Sweet Dreams! Scott A. Shappell, Ph.D. Clemson University (405)

P08 Reversible loss of consciousness. E365 Aviation Human Factors

P08 Reversible loss of consciousness E365 Aviation Human Factors Need to sleep Sleep is a natural state of rest for the body and mind that involves the reversible loss of consciousness. You sleep to not