Fatigue Countermeasures

Objectives

Overview

The Science

Factors of Fatigue!

Facts about Fatigue!

Facts about Fatigue!

Operations and Fatigue

Operations and Fatigue

Sleep Physiology

Shift Work

Shift Work

Effects of Shift Work

Sleep Loss and Sleepiness:

Sleep Physiology

Sleep Physiology

Histogram of Normal Sleep

Over the course of a typical night, NREM and REM sleep occur in cycles, with about 60 minutes of NREM sleep followed by about 30 minutes of REM sleep.

Overall, about 25% of sleep time is spent in REM sleep and about 50% is spent in NREM stage 2,

Most deep sleep (i.e. NREM stages 3 and 4) occurs in the first third of the sleep period; and REM periods become longer and more regularly later in the sleep period.

Being disturbed in NREM Stage 3 or 4, or REM sleep can significantly disrupt the structure of sleep resulting in a degradation in the quality of sleep. The individual may not even be aware of such disturbances, such as a heater turning on or off or a plane passing overhead.

Overall, there is a tendency for individuals to subjectively overestimate how long it takes to fall asleep and underestimate total sleep time, relative to physiological measures.

Generally, people fall asleep faster and sleep longer than they think. So, when an individual experiences a bad night of sleep, it may not be as bad as it seems.

However, the tendency is for individuals to subjectively rate themselves as more alert than is indicated by physiological measures. That is, most individuals are more likely to be sleepier than they report or experience.

It is a myth that humans can continue to perform at normal levels until they reach a point of uncontrolled sleep.

In comparing physiological fatigue tests with subjective fatigue tests, science has found the individual is usually a poor judge of how fatigue is effecting their cognitive functions.

Common sense tells us that the older you are, the more susceptible to fatigue you are. The reality is that studies have shown that the sex and age group most susceptible to the affects of fatigue is 21-30 year old males. It appears that the youth and strength of these individuals can overcome the more noticeable physical symptom of fatigue, thereby masking the deeper physiological effects.

One widely held belief is that individuals can accurately and reliably estimate their alertness and performance. Many people believe that being motivated, well trained, and professional or having previous experience with sleep deprivation prepares them to combat the physiological consequences of sleep loss.

How many time have you said "I can just push through this." or "If I can just make it to there, I'll be O.K." or "I just need another cup of coffee."

This is a trap. You may do it once, but don't kid yourself, it's like Russian roulette. You may pull the trigger a hundred times and be alright, but sooner or later, you'll shoot yourself or somebody else.

Just as people have two low points in their circadian rhythms in every 24 hour period, they also have two high points. At these points of higher alertness, individuals may find it difficult, if not impossible, to fall asleep and stay asleep. Low points in circadian rhythms &e generally between 1 and 5 a.m. and 1 and 5 p.m. High points are normally between 9 and 11 a.m. and 5 and 7p.m. These time may vary between individuals and should be used only as a guide.

The number of variables needed to be taken into consideration to counter fatigue in the operational environment make it impossible to find. a "one size fits all solution.

Any interruption of the normal sleep architecture can have a detrimental affect on the quality of sleep. While a phone call in the middle of the night may have only a minimal effect on the overall quantity of sleep, it could disrupt the sleep structure such that it impairs the individual's ability to reach the deeper states of sleep (NREM stages 3 & 4) and may inhibit REM sleep. These effects are similar to those experienced by sufferers of some sleep disorders.

Sleep is a complex physiological process and fatigue is a complex issue. When implementing fatigue countermeasures into an operational environment, many people are tempted to look for the "quick fix" or "magic bullet." While there are some alertness strategies that can be implemented quick, they should not be considered as a complete package, nor do they resolve many of the "root causes" to fatigue in the work place. Many fatigue countermeasures require custom alertness strategies, tailored to the specific operational environment.

Education is a key element; everyone involved must understand the basic physiology of fatigue and the factors that affect meaningful sleep because it takes everyone's involvement to find the right solutions. Many of the "common sense solutions" don't stand up to scientific scrutiny. The puzzle of fatigue has many pieces. We all have some of the pieces, but if we don't work together, we'll never solve the puzzle.

We must build fatigue countermeasures programs based upon past research and what we know now. At the same time we must clearly delineate what we don't know about fatigue in the operational environment, so as to focus future fatigue research efforts.

We must keep in mind that the affects of fatigue, and the dangers of fatigue are not limited to operating crews or hours-of-service employees. Fatigue is a human phenomena and affects all of us. Operating crews, supervisors, planners, decision-makers, vehicle drivers, etc. are all affected by fatigue. Solutions must be scientifically based, comprehensive in application, and measured and refined until successful.

• focus on the underlying physiology
• attempt to manage and maximize sleep promoting circadian adaptations
• are used before work and when required to be away from home

• measures at work that help to maintain alertness and performance

Operational strategies do not necessarily affect the underlying physiological mechanisms but focus more on managing fatigue during operations. Primarily, these short4erm strategies help to conceal or reduce underlying physiological sleepiness. Within the transportation industry it is critical that we develop both preventive and operational strategies. All parties, both companies and employees have a major responsibility for developing and implementing these strategies. This is not a "who's to blame" situation. As individuals, as corporations, and as regulators, we all share the responsibility. At a minimum, individuals should be afforded an emergency "safety valve" to be used as a last resort.

Remember there is no "quick fix" or "silver bullet." Any of these suggestions may or may not help you manage fatigue. However, a combination which is right for you, can significantly improve your alertness during waking hours.

The following recommendations are generally considered important for maintaining good sleep habits. They are applicable to everyone:

Practice a regular pre-sleep routine to teach your mind and body that it is time to relax and fall asleep. Establish a set of cues to condition pre-sleep relaxation anywhere and anytime before going to sleep.

One significant factor in the severity of fatigue can be prior sleep loss. That is, individuals who are sleep deprived before work can experience more difficulty than those who are well rested.

Consider the previous information regarding sleep debt and the expected sleep loss associated with an individual's work period. If an individual is not fully rested before work and then begins work with a sleep debt, then generally it should be expected that the sleep debt will only worsen during the work period.

The recommendation is to begin work as sleep saturated as possible. Many operations are characterized by sleep loss. Individuals should attempt to obtain at least as much sleep when away from home as they typically would during a normal 24 hour period at home. Knowing that circadian and other factors will diminish the physiologically available windows for sleep, attempts should be made to maximize these opportunities.

Learn to trust your own physiology. When struggling to stay awake, the sleepiness should be taken as a clear signal to get some sleep. Instead of fighting the sleepiness, take a brief nap or a longer sleep time -- if at work, do so only if authorized.

If after awakening spontaneously you are unable to return to sleep within 15-30 minute, get out of bed.

Disruptive environmental factors should be minimized. Sleep in a dark, quiet, temperature controlled room, and use a comfortable sleep surface.

Laboratory studies suggest that regular exercisers may have increased amounts of NREM stage 3 and 4. However, exercising too close to bedtime can disrupt subsequent sleep.

Although physically tiring, exercise elevates heart, breathing rates, and core body temperature, and is generally physiologically activating. Usually, it is not possible to immediately wind down and fall asleep after exercise.

• If hungry or thirsty at bedtime, eat a light snack or have a small quantity of something to drink. Going to bed hungry or thirsty can delay falling asleep. Eating a heavy meal can also disrupt sleep because the stomach is busy digesting food.
• Avoid alcohol before going to bed because of its disruptive effects on sleep.
• Limit caffeine consumption. Caffeine in coffee, tea, and colas can prevent sleep onset and disrupt subsequent sleep. Some individuals are sensitive to caffeine in chocolate and even a chocolate dessert after dinner is enough to interfere with their sleep. Many mild pain relievers also contain caffeine; read the label for ingredient information. Be sure to stop caffeine intake several hours before planned bedtime.
• Try mental and physical relaxation techniques to promote sleep onset and good sleep. Like any skills, these techniques can be practiced; and can then be used in a wide range of applications, essentially anywhere.
• If unable to fall asleep in 30 minutes, don't lie in bed trying to fall asleep. Instead, get out of bed and engage in some activity that you know to be conducive to relaxation and sleep.

There is extensive scientific literature that clearly demonstrates the effectiveness of naps in improving subsequent alertness and performance.

One important consideration when napping close to a work period is to minimize the chance of going into deep NREM (stage 3 & 4) sleep. If awakened out of deep sleep, an individual may continue to feel groggy, sleepy, or disoriented for 10 - 15 minutes. This is called sleep inertia.

Therefore, if taking a nap before a work period and there is not sufficient time to recover from sleep inertia, limiting its duration to 45 minutes or less will decrease the chances of having significant amounts of deep sleep.

A brief nap can be an important way to decrease the length of continuous wakefulness. It is much better to get some sleep than none at all.

When you nap at times other than immediately before a work period, then the nap can be longer. In this case, a nap longer than 2 hours is likely to get an individual through at least one NREM/REM cycle.

Strategic napping can be an extremely effective countermeasure in improving subsequent alertness and performance.

Napping can also be considered as an operational strategy. There is some concern that if an individual takes a nap during working hours, they may suffer from sleep inertia. Keep in mind four significant items:

Don't kid yourself People in transportation are out there sleeping right now. We need to get out of our state of denial. Don't ignore napping, manage it! Remember, some sleep is better than none at all.

The earliest sleep deprivation experiments demonstrated that the most successful operational technique for combating sleepiness involves physical activity:

• Engage in an activity that involves physical action even if it is only stretching. Take regular stretch breaks and while seated remain as active as possible --even writing helps.
• Engage in conversations with others and be sure to participate; don't just nod and listen.
• Operational Strategies

Caffeine (a Stimulant) can be consumed strategically at times to acutely increase alertness. It is best not to continually consume caffeine before, during, and after work. Instead, determine the potential periods when caffeine could be used to combat a specific period of sleepiness (e.g., 1-5 A.M. or 1-5 P.M.).

Avoid using caffeine when already alert; for example, when just beginning a daytime or immediately after a nap.

Though affected by several variables (e.g., body size, previous food intake), caffeine will usually take 15-30 minutes to take effect and then lasts up to 34 hours. Therefore, continually consuming caffeine throughout work could interfere with subsequent sleep. Stop caffeine consumption far enough in advance of a planned bedtime so that it will no longer be active.

Be sensible about nutrition. Whenever possible, maintain a balanced diet. Obviously, work operations can interfere with regularly scheduled balanced meals. Try to carry appropriate snacks as needed.

Drink plenty of fluids and stay hydrated. Between varying temperatures, low humidity and caffeine (a diuretic), it is easy to become dehydrated.

Education Emergency Responders

Work/Rest Cycles Lodging Considerations

Work Schedules Napping Strategies

Shift Work Alertness Strategies

On-call Employees ??????

An effective fatigue countermeasures program must be scientifically based and comprehensive. It must address a multitude of human, operational, and environmental conditions that can affect fatigue. At a minimum an effective program must address:

Education - Without education there can be no understanding; without understanding there can be no resolution.

Work/Rest Cycles - To counter chronic fatigue

Work Schedules - To counter cumulative fatigue

Shift Work - To counter disruption of circadian rhythms

On-call Employees - To counter both chronic and cumulative fatigue

Emergency Responders - To counter both chronic and cumulative fatigue

Lodging Considerations - To counter sleep disruption

Napping Strategies - To enhance alertness and as a "safety valve."

Alertness Strategies - To ensure maximum possible alertness while on-duty

Other Initiatives - Be flexible enough to be able to incorporate new knowledge and technology as it becomes available

There is a societal lack of understanding in regards to fatigue and its costs, in terms of safety, quality of life, and job performance. It will take the combined efforts of employees, management, and government to change the mind set of society. This societal problem is not new, as illustrated by Lausius, an ancient poet, when he wrote "{Nature} decrees five hours sleep for the young man and the graybeard, six for the merchant, seven for aristocrats, and for the lazy and wholly idle man eight hours".

The North American Rail Alertness Partnership was formed to provide overall leadership for fatigue countermeasures initiatives.

The problem of fatigue permeates our modern society. It isn't limited to railroads; it affects our entire way of life.

All organizations committed to solving this problem must be willing to learn and change. These attributes can make each participating organization truly high performance.

Fatigue is a physiological condition which, in an operational environment can not be eliminated, but can be managed if the proper set of tools are put in place.

Sleepiness is not an indicator of laziness; sleep is a physical requirement just like eating, drinking, and breathing. Failure to recognize this requirement and effectively manage it results in a degradation of human performance and an increased risk of incidents (i.e. rules violations, collisions, personal injuries, fatalities, etc.).

Individuals can improve their alertness on the job by learning more about the science of sleep and by developing good sleep habits. Organizations can improve the alertness of their membership and work force by working in partnership to develop science based fatigue countermeasure policies and programs.

Organizations and individuals need to analyze the various fatigue countermeasures currently available; determine which ones are effective in their operational environment; and implement those countermeasures now. There is no quick fix or magic bullet; build a package of countermeasures into a comprehensive program; implement them now, and cooperate in partnership in the exploration of new techniques and technologies.