How to nap

Boston.com has posted a great informational graphic on how to take a nap. Regular visitors to the National Shiftwork Information Center website know that we believe napping is an important fatigue countermeasure for shiftworkers. We encourage 24/7 employers to develop napping policies. We've even had a napping room installed in our offices. Check out this very informative webpage at http://www.boston.com/bostonglobe/ideas/naps/.

Study of nurses highlights importance of sleep and effective schedules for shiftwork operations

ScienceDaily.com, a science-related press release website, has posted an item called "Nurses With Adverse Work Schedules Have Poor Sleep, Which Can Affect Their Work Performance." The post cites a study by researchers at the University of Maryland, first published at the American Academy of Sleep Medicine, which followed 2,273 nurses. As the headline suggests, poor sleep is affecting nurses work performance. Specifically, the item notes "According to the results, having inadequate sleep on three or more nights per week is associated with schedule-related poor sleep opportunity. Specifically, shift work, mandatory overtime, and on-call, quick returns, and long shifts increase the odds of having insufficient sleep. The worse the schedule, the worse the sleep for most nurses."

This study underscores several recurring themes of the National Shiftwork Information Center, namely:

* Sleep is particularly important for shiftworkers
* Smart managers make sure to implement sound shift schedules based on solid circadian physiology

There's also a good reminder in there about the importance of effectively managing overtime and on-call duty.

The National Shiftwork Information Center has a a list of shiftwork consulting firms to help 24/7 operations select and implement the most effective schedules.

Shiftwork adaptation technique: reset your circadian rhythm by fasting

Researchers in the Division of Sleep Medicine at Harvard Medical School and Beth Israel Deaconness Medical Center in Boston published a paper in this week's journal Science in which they cite the discovery of a second circadian clock in humans which appears to be triggered by fasting. The authors note that this discover could be used to reduce the effects of jet lag and could also help shiftworkers adapt to night work.

Human's primary internal clock is triggered by light. This is the clock we hear about most often -- getting exposure to bright light to increase alertness and avoiding light when trying to sleep. This second clock is triggered by food. The evolutionary underpinnings of the clock seem to be that for early humans not to have food available was a life-threatening situation. If they could not obtain food, their bodies kicked into an extra level of alertness to enable them to continue to search out food. Dr. Clifford Saper, one of the authors of the paper, noted it takes about 16 hours of fasting for this second clock to kick in and override the light-based clock.

This will be particularly important for shiftworkers on a rotating schedule as they prepare for the night shift, or a fixed schedule night shift worker returning to work after days off. A shiftworker might be able to reset his or her circadian rhythms faster by avoiding eating anything during the day prior to the night shift. This would raise alertness levels and the shiftworker would be able to then eat during the overnight shift. The same could also be used by air travelers to avoid jet lag. If the air traveler avoid eating ANYTHING on the flight on a flight from New York to Australia, he or she would better adapt upon arrival.

This will undoubtedly be studied further, so it's subject to modification, but the researchers are credible, and the work being published in the journal Science lends even more credibility. I think there's enough at this point that you might consider using this technique if you're having trouble adapting to night shifts.

Reference:
"Differential Rescue of Light- and Food-Entrainable Circadian Rhythms."
Patrick M. Fuller, Jun Lu, and Clifford B. Saper.
Science Vol. 320. no. 5879, pp. 1074 - 1077.
Published online on 23 May 2008.

Shiftworker Tips: getting the sleep you need

Take responsibility for getting enough sleep to feel rested and restored. For some people this happens without doing anything special. However, most shiftworkers need to become more aware of what to do to get satisfying sleep and when to do it.

When to Sleep after Night Shift
This depends on the individual. Try different times and see what works best for you. As you experiment with different sleep times, keep a written record of when you go to sleep, when you wake up, and how rested you feel. This will help you identify which sleep schedule works best for you.

Some shiftworkers like to sleep in one longer period, but many workers need two shorter sleep periods to get enough sleep after the night shift. It is a good idea to go to bed as early as possible after the night shift in order to maximize sleep. A second sleep also could be taken in the afternoon to get ready for night shift. Try taking advantage of the natural tendency to be sleepy in mid-afternoon. You might get your most satisfying sleep at that time.

Does Rest Equal Sleep?
Just resting without sleep is not enough. The brain has to have sleep, or you will be sleepy later in the day or during night shift. However, rest without sleep still is valuable for body and muscle recovery. Schedule at least seven hours in bed, even if you don't sleep the whole time.

What is the Minimum Amount of Sleep?

The vast majority of workers need at least six hours of sleep but most need more than this. Most people do not feel refreshed and at their best with just six hours. Staying with your own preferred amount of sleep is best in the long run. You might find that you need less as you become more experienced with shiftwork.

Switching Back to Days: When switching back to days after the night shift, it is best to get most of your sleep the following night. Sleep just a couple of hours shortly after night shift to shake off sleepiness. Then stay awake all day and go to sleep at your regular bedtime at night.

Napping: Shiftworkers frequently nap, especially when working night shift. Added to your regular sleep, a short afternoon or evening nap will help fight sleepiness during the night. However, napping is not long enough to replace regular sleep. If you nap, allow enough time for drowsiness to wear off before starting work. If you have time to nap at work during your break, don't make the nap too short. A nap of 15 minutes or less might actually make you more sleepy. Twenty to 30 minutes should be the minimum for a nap during a work break. Again, allow enough time for drowsiness to wear off before doing hazardous work. And don't use work-break naps to replace your sleep at home. Naps work best when they are extra sleep time. They don't work as well when you are trying to make up for lost sleep.

Protect Sleep

• Block Out Noise: Switch off the phone and disconnect the doorbell. Use ear plugs. Ask the family to use headphones for the stereo or TV. Set strict times for noisy activity, such as vacuuming, clothes washing, or children playing. Don't allow these activities during your sleep times. Locate your bedroom in the quietest place. If possible, get away from outside noise and also away from the kitchen or bath-room. Soundproof the bedroom with insulation and heavy curtains. Put signs out to say you are sleeping. Tell friends and neighbors when not to call.
• Keep a Regular Sleep Routine: Make the bedroom as dark as possible. Always sleep in the bedroom. Follow your regular bedtime routine every time you go to sleep. For example, wash up and brush your teeth so you feel comfortable. This can serve as a signal to your body that it is time to sleep. Don't use the bed for anything except what it is intended for. For example, don't read, eat, watch TV, write bills, or argue with your spouse in bed. Make sure you have a comfortable bed that won't disturb your sleep.
• Avoid Heavy Foods and Alcohol Before Sleep: Heavy, greasy foods are anti-sleep because of stomach upsets. If you must eat, a light snack won't disturb your sleep. Alcohol might make you feel sleepy, but it will wake you up too quickly after falling asleep. Don't drink alcohol in the hour or two before sleep.

Source: Plain Language About Shiftwork (NIOSH)

Related Posts on National Shiftwork Information Center:

* Tips for getting better sleep

* Tips to help you avoid drowsy driving

* Handling long night shifts: 9 shiftworkers tips

* Foods that help you stay alert or help you sleep

* Shiftworker lifestyle training: fatigue countermeasures, sleep strategies, and more

Circadian rhythm "peaks and valleys" and drowsy driving

There are two circadian functions that we can observe on our own without complex measurements: changes in temperature and changes in drowsiness. These two are usually closely related and are most significant from 3:00 to 5:00 AM and PM (Figure). As core body temperature decreases, drowsiness increases.

Melatonin levels are substantially increased (a strong contributor to drowsiness). At the same time there is an increase firing of the brain’s sleep-inducing organs.

These inhibit the neural system/structures that keep our brain in the active waking state. This is the same system that acts on the brain of the baby rocked to sleep by its parent. Before sleep (bedtime), the brain begins a firing pattern that is characteristic to initial stages of sleep. With the depression in the activity of the neural system, we quickly lose interest in demanding intellectual activities. Soon the only thing we can think of is sleep. Once we rest in an undisturbed place, we drift into “dreamland”.

The risk of danger increases when sleepy people have a critical task to perform, like driving. In a National Sleep Foundation poll, half of Americans (51%) reported driving while drowsy during the past year and nearly one out of five (17%) say they have actually dozed off behind the wheel. According to the National Highway Traffic Safety Administration, 100,000 auto accidents occur each year because of “fall-asleep” crashes.

A AAA Foundation for Traffic Safety study identified lifestyle factors that contribute to sleepy driving. People who hold more than one job, who get six hours or less of sleep, or who drive between midnight and 6 a.m. are at significantly higher risk of a drowsy driving crash. Other studies show that sleep-deprived drivers have reactions like those of people who have been drinking alcohol. Your performance, particularly of critical tasks, is equally impaired by 17 hours of continuous wakefulness or a .05 BAC. Something to think about if you’re planning a trip.

Source: http://www.lakehurst.navy.mil/nlweb/safety/documents/traffic-safety/Shiftwork-Pamphlet.pdf.

Related Posts:

* Worker who falls asleep at wheel after 27 hours on the job denied workers comp

* Drowsy driving quiz -- for shiftworkers, and everyone else

* Tips to help you avoid drowsy driving

Napping, especially on the job, may have benefits but remains controversial

The issue of napping on the job is almost always controversial. Some sleep experts extoll the benefits of a nap, while others say it interferes with getting quality primary sleep. Of course the (understandable) management aversion to paying people who are sleeping is a significant hurdle to overcome. And the cultural taboos around napping -- nappers are lazy, etc. -- are often an issue too.

I am not a sleep expert but I'll tell you I use naps as a fatigue countermeasure and I think it helps. I'm VERY conscious of not napping too long out of concern for not being able to sleep in bed later. But, all things considered, I use napping, and recommend them to others, on or off the job. And, when I was Managing Director at Circadian Information, I can tell you that we had a napping room in our offices which I made use of from time to time.

One of the many shiftwork consultants out there, Shiftwork Solutions, posted a note to their blog today also citing the benefits of napping, and particularly napping on the job. They calculate that a 15 minute nap only needs to improve productivity by 4.5% to be worthwhile. Ultimately, I think most managers are going to permit napping on the job based on a gut instinct, but I think having some numerical back up may help some. Check out the blog post, "I need a nap!" -- It's time to sleep on shift.

Time to set your clocks ahead (and lose an hour of sleep)

It's time once again, albeit earlier than usual, to set your clocks forward an hour. Yes, this Sunday night, March 9 in the wee hours of the morning, we'll be losing an hour -- even the folks in Indiana. While this seems like a minor inconvenience, there are actually real safety issues as our already sleep-deprived society loses another hour of sleep (because, let's face it, most people don't modify their schedule to lose a waking hour).

Studies have found accidents rates increase in the week immediately after the shift to standard time as we reset our circadian clocks. And, not coincidentally, accident rates decrease in the fall immediately after we when we gain an extra hour.

[As an aside, studies have found that the energy savings often touted as the
reason for shifting to daylight savings time, are nonexistent. In fact,
energy usage appears to have increased by roughly 4% this year in Indiana which
shifted to daylight savings for the first time. Maybe we can finally get
rid of this annoying and unsafe practice, although as I understand it, retailers
feel the extra daylight hours at the end of the day increase people's spending.]

Yesterday, USA Today ran an article on this very issue, Bodies don't 'spring ahead', that is worth taking a look at. Today's Wall Street Journal also ran a helpful article Learning to Live Like an Early Bird by Melinda Beck.

So remember to reset your clocks, and please be careful next week. Even if you plan appropriately for the lost sleep, the other folks on the road may not.

Glossary of shiftwork terms: shiftwork, sleep, circadian rhythms, and more

Chronobiology: A subdiscipline of biology concerned with the timing of biological events, especially repetitive or cyclical phenomena, in individual organisms.

Circadian: A term derived from the Latin phrase “circa diem,” meaning “about a day”; refers to biological variations or rhythms with a cycle of approximately 24 hours. Circadian rhythms are self-sustaining (i.e., free running), meaning that they will persist when the organism is placed in an environment devoid of time cues, such as constant light or constant darkness. For comparison, see diurnal, infradian, and ultradian.

Day shift: In an 8-hour shift operation, the day shift may also be called the first shift and typically begins between 6 am and 8 am. In a 12-hour shift operation, this shift typically also begins between 6 am and 8 am.

Diurnal: Varying with time of day. Diurnal rhythms may persist when the organism is placed in an environment devoid of time cues, such as constant light or constant darkness. Therefore, diurnal variations can be either light driven or clock driven. For comparison, see circadian.

Entrainment: The process of synchronization of a timekeeping mechanism to the environment, such as to a light-dark cycle. For comparison, see free running.

Evening shift: This most commonly refers to the second shift in an 8-hour operation and typically begins between 2 pm and 4 pm. Also often referred to as the swing shift.

Fatigue countermeasures: Any of an array of steps taken to help people maintain alertness, specifically to help shiftworkers maintain health and safety. These may include such things as napping and sleep strategies, managing the use of caffeine and other substances to promote alertness or sleep, lighting and temperature of the work environment, and many other areas.

Fixed schedule: A shift schedule in which workers are permanently assigned to a specific shift -- day, evening, or night. This contrasts with a rotating schedule.

Free running: The state of an organism (or rhythm) in the absence of any entraining stimuli. Typically, subjects are kept in constant dim light or constant darkness to assess their free-running rhythms. For comparison, see entrainment.

Graveyard shift: See night shift.

Infradian: A term derived from the Latin phrase “infra diem,” meaning “less than a day”; refers to biological cycles that last more than 1 day and, therefore, have a frequency of less than one per day. For comparison, see circadian and ultradian.

Masking: The obscuring of the “true” state of a rhythm by conditions that prevent its usual expression. Usually, the phase of an entrained rhythm or the absence of entrainment (e.g., in an animal that is unable to entrain because of some defect) is said to be masked by a light cycle. For example, the aversion of a nocturnal rodent to bright light results in its activity onset appearing to coincide with the absence of light, or “lights off,” when the animal actually has been awake for hours. For comparison, see entrainment.

Night shift: In an 8-hour shift operation, the night shift may also be called the third shift and typically begins between 10 pm and midnight. In a 12-hour shift operation, this shift typically begins between 6 pm and 8 pm. Also sometimes referred to as the graveyard shift.

Nonrapid eye movement (NREM) sleep: Sleep stages that include the “deeper” stages of sleep in which dreaming typically does not occur. Also referred to as slow-wave sleep. There are four non-rapid eye movement (NREM) sleeps stages. Stage 1 is a transitional phase, with brain activity slowing. This is the drowsy state when sudden movements and hallucinations may occur. In stage 2 sleep, muscular activity decreases and humans lose awareness of their environment. We stay in stage 2 sleep for approximately half of a typical session of sleep.
Stage 3 is a deep phase of sleep, characterized by slow-wave wave activity. This is the stage in which people experience sleep walking, sleep talking, and bed wetting. Stage 4 sleep is a deeper stage of sleep but similar to stage 3. For comparison, see rapid eye movement sleep.

Phase shift: A change in the phase of a rhythm. This change can be measured by observing a change in the timing of a phase reference point (e.g., activity onset or the nocturnal rise in the release of the hormone melatonin) from the timing expected based on previous, free-running cycles. Phase shifts may be either advances (i.e., the phase reference point occurs earlier than normal) or delays (i.e., the phase reference point occurs later than normal).

Phase-response curve (PRC): A graphical summary of the phase shifts produced by a particular manipulation, such as a light pulse or a pharmacological treatment, as a function of the phase (i.e., circadian time) at which the manipulation occurs. Defining the PRC to light has enabled researchers to understand and predict how entrainment to light cycles is accomplished.

Rapid eye movement (REM) sleep: A stage of light sleep characterized by rapid eye movements and associated with dreaming. REM sleep is the stage when humans dream most and muscle activity falls. Also called paradoxical sleep. For comparison, see nonrapid eye movement sleep.

Rota: See shift schedule.

Rotating schedule: A shiftwork schedule in which workers rotate between day and night shifts on a 12-hour shift schedule, or between day, evening, and night shifts on an 8-hour shift schedule. There are many factors to consider when setting the speed and direction of the rotation. This contrasts with a fixed schedule.

Shift schedule: The schedule of shifts to be worked. Also referred to as a rota, particularly in European countries. See also rotating schedule and fixed schedule.

Sleep stages: Human sleep consists of 5 stages, each with its own unique characteristics, through which humans cycle while they sleep. See rapid eye movement sleep and non-rapid eye movement sleep.

Suprachiasmatic nucleus or nuclei (SCN): A cluster of nerve cells located in the brain region called the hypothalamus that is responsible for generating and coordinating circadian rhythmicity in mammals.

Swing shift: See evening shift.

Ultradian: A term derived from the Latin phrase “ultra diem,” meaning “more than a day”; refers to biological cycles that last less than 1 day and, therefore, have a frequency of more than one per day. For comparison, see circadian and infradian.

Zeitgeber: A German word literally meaning “time-giver.” A time cue capable of entraining circadian rhythms. Light represents the most important Zeitgeber.

Sources: National Shiftwork Information Center research staff, http://www.niaaa.nih.gov/publications/arh25-2/85-93.htm

Have terms you'd like to see defined?
Post a comment. We'll add them to the list. This glossary is an ongoing project.

Hours of service issues on the railroads: part II, sleep deprivation and alertness

[Our series on Dr. Martin Moore-Ede's testimony before Congress continues]


1. Does sleep deprivation and fatigue significantly impair railroad employee alertness and vigilance in our railroads?
Much has been written in the scientific and industry literature, and already reported to this Subcommittee, on the prevalence of fatigue, or more precisely loss of attention and vigilance due to sleep deprivation in railroad employees. Like other transportation modes which operate 24/7 (twenty-four hours a day - 7 days a week), the railroads by their nature have to work continuously around the clock to perform their vital mission in our economy.

From the dispatchers to the yard workers, from the track repair crews and signalmen to the train crews, work and rest is driven by the incessant 24/7 demands of the business. This means work intrudes into the natural nocturnal hours of sleep, when staying alert is more challenging, and off-duty rest must be obtained during the daytime hours, when good quality sleep is more difficult to obtain.

Scientific research and industry experience both confirm that, because of our inherent human biology, sleep deprivation and fatigue is a significant issue for many railroad employees.

Train crews face special challenges. Even when trains are scheduled, as in the passenger railroads, the work patterns can lead to sleep disruption and fatigue. Train crews in most freight railroads work on-call, non-scheduled shifts.

The flow of trains across the system is impacted by weather, mechanical failure, track conditions and the schedules of shippers and receivers of freight, so that most train crews do not know precisely when they will be called to work. Thus not only do they work on irregular 24/7 schedules but many of them also have unpredictable hours of work and rest, making it difficult for employees to plan their sleep. You can, for example, be up all day at home and then get called with 2 hours notice at 11PM, just as you are climbing into bed, to operate a freight train for up to 12 hours throughout the night and into the next afternoon.

Source: http://www.house.gov/transportation/rail/06-06-02/mooreede.html

Related Posts:

* Hours of service issues on the railroads: part I

* Hours of service issues on the railroads: part III, safety threat?

* Hours of service issues on the railroads: part IV, increasing risk?

* Hours of service issues on the railroads: part V, hours of service rules

* Hours of service issues on the railroads: part VI, train control technology

* Hours of service issues on the railroads: part VII, alertness monitoring technology

* Hours of service issues on the railroads: part VIII, risk-informed fatigue management

* Hours of service issues on the railroads: part IX, parallel models

* Hours of service issues on the railroads: part X, how to proceed

Drowsy driving information and tips -- for truckers and others

The trucking industry website Layover.com has posted an article on the dangers of drowsy driving. We have covered much of the information in previous posts but this is a nice article and worth taking a look if you're concerned about drowsy driving. It discusses the importance of sleep and offers some other fatigue countermeasures.

Related posts:
* Tips to help you avoid drowsy driving
* Drowsy driving quiz -- for shiftworkers, and everyone else
* Boost your alertness with coffee or a nap? Or both?
* Drowsy drivers, sleeping drivers in the UK

Shiftworker health and safety: short-term effects, part I

There are many positive aspects of shiftwork and our 24/7 society. Operating 24/7, shiftworkers make this world safer, more productive, and more convenient for everyone else. Employers often offer differential pay for shiftwork, and shiftworkers often have time off when the majority of workers are working.

Shiftwork schedules are also demanding and likely to produce stress and fatigue. Shiftwork can affect safety, health, or ability to do the job. Some of these things happen very soon after starting shiftwork. We talk about these under Immediate Effects. Health changes take a longer time to appear. We talk about health under Long-Term Health Effects.

Immediate Effects
Sleep
Soon after starting shiftwork, people notice changes in their sleep. Night workers usually get the least amount of sleep. Evening shift-workers get the most sleep, and day shiftworkers get a medium amount of sleep. Night workers are forced to sleep during the day, when their circadian rhythm makes them feel more awake. Day sleep is usually shorter than night sleep—sometimes two or three hours shorter. Day sleep also is lighter than night sleep.

Day sleepers often say they don't sleep as deeply as they do at night. Because their sleep is lighter, they are easily awakened by sounds. This makes sleeping difficult. Since there is more activity during the day, there are more sounds to wake up the sleeping shiftworker. Both permanent night workers and rotating shiftworkers sleep worse when working nights. However, rotating shiftworkers sleep the least of all.

Sleep loss makes it much easier to fall asleep at inappropriate times. This affects a worker's ability to perform safely and efficiently. Sleepiness can affect performance both on and off the job. Driving to and from work is a major concern. Sleepiness affects our ability to concentrate or pay attention, and driving requires us to pay attention at all times.

So, if a person is sleepy, it is easier to have an accident. Several jobs, such as operating dangerous machinery, also require us to pay attention at all times. So sleepiness can be risky in many different occupations. This risk is not simply a matter of falling completely asleep. After sleep loss, it is possible to have very brief periods of sleep that last only a few seconds.

Most people may not even realize these short sleeps are happening. During those few seconds of sleep, they are not paying attention at all. If something dangerous happens at those times, the worker or somebody else could get seriously hurt.

Circadian Rhythm, Performance, and Safety
The circadian rhythm is a major body rhythm with regular ups and downs in the 24-hour day. Many systems in the body are very active at certain times of day, and not active at all at other times of day. Usually the most activity happens in late afternoon or early evening. For example, the body's ability to produce energy from food (metabolism) is highest in the afternoon to evening. The least activity usually happens in the middle of the night when most people are asleep. This is one reason people feel most active and alert around 4 to 6 o'clock in the afternoon, and sleepiest at 4 to 6 o'clock in the morning.

There also are personal differences in circadian rhythms. Some people are morning types or “larks.” Morning people feel most active and alert early in the day. They usually go to bed early in the evening. Other people are evening types or “owls.”

Evening people feel most active in late afternoon or evening, and like to stay up late into the night. Fishermen who are out on the water before dawn usually are morning types. Musicians who perform in the evening usually are evening types. Most people, however, are somewhere in-between the strict morning and evening types.

The internal circadian rhythm affects how alert people feel. This affects their ability to perform. People perform best when alertness and internal body activity is high, and worst when alertness and activity are low. In the normal day-work, night-sleep situation, people work when the circadian rhythm is high and sleep when it is low.

On average, this schedule is best for performance, which means it also is best for safety. When workers perform poorly, they are more likely to make errors that could lead to accidents or injuries.

When working the night shift, a person is at work when his or her circadian rhythm is low and asleep when it is high. Such a schedule means that a person is trying to stay alert when the circadian rhythm is low.

On average, this is not the best time of day for performance. This low-point affects physical activity and the ability to concentrate. If a worker also has lost sleep, fatigue could combine with the circadian low-point to double the effect on one's ability to perform. Poor performance could affect both productivity and safety. Studies of errors and accidents at different times of day show an increased risk at night when the circadian rhythm is low and sleep has been lost.

Source: Plain Language About Shiftwork (NIOSH)

Continued in:
* Shiftworker health and safety: short-term effects, part II

Prepare for daylight savings time

Sleep. Most people need every minute they can get. So, every year articles remind us that daylight savings time is coming and provide tips to minimize the disruption. This year with the extended daylight savings time schedule, we'll need those reminders earlier.

Many may think, "what's the big deal, it's only an hour?" but research has shown accident rates go up in the week following the start of daylight savings. It appears losing an hour of sleep does really matter and resetting your circadian clock by even just an hour is worth your attention. Of course, as we always say, if it has to do with sleep and is important to the general public, it's even more important for shiftworkers.

The main points is to prepare early over a few days to try to shift your bedtime earlier by an hour or at least part of it. To accomplish that, use all of the Tips for getting better sleep we've posted previously. These include making the sleeping room dark, quiet, comfortable temperature, etc.

Here's another brief article that provides some additional tips from a hospital press release -- Don't Lose Sleep Over Daylight Saving Time.

Notes about what happens when you sleep

An article on ScienceLine.com discusses What Happens to Your Body When You Fall Asleep.

The post notes "There is no universally agreed-upon definition because falling asleep is not a split-second occurrence, not an abrupt switch from awake to asleep. Rather, it is a gradual progression of stages in which body and brain activity changes."

If you're wanting a brief overview of sleep, this is a useful and quick read that discusses the various stages of sleep.

The drivers of human alertness and sleep

Your alertness is the result of nine elements, what Dr. Martin Moore-Ede in his book The Twenty-Four-Hour Society termed the nine switches of alertness. Knowing these elements can help you better manage your environemtn and behavior to improve your alertness or help you sleep. The nine elements are:

1. Interest, opportunity, or sense of danger -- when you are mentally engaged or threatened in some way, your body rises to the challenge by increasing alertness.
2. Physical activity -- when you are physically active, you increase your alertness. This effect can last for a while, making sleep difficult after intense exercise.
3. Time of day on your circadian clock -- if your body is telling you it's night time, your alertness will drop. You can reset your circadian clock (as evidenced when you travel across time zones) but it takes time and careful attention if you're a shiftworker.
4. Your sleep "bank balance" -- if you have gotten inadequate sleep over the past few days, your alertness will suffer.
5. Ingested nutrients and chemicals -- caffeine and other substances have a stimulating effect while tryptophan and sleeping pills will encourage sleep.
6. Environmental light -- bright lighting wakes you up and dim lighting tends to make you sleepy.
7. Temperature -- warm and stuffy rooms make you sleepy while cold, bracing increases alertness.
8. Sound -- loud, erratic noises increase alertness while soft sounds and white noise reduce it.
9. Aroma -- This last one, aroma, has somewhat less research to support it, but there is at least some evidence that certain aromas have a stimulating effect while others have just the opposite. Scents like lemon and peppermint have been found to increase alertness.

Keep these factors in mind and use them to your advantage.

Hospitals looking for ways to get patients better sleep

An article in today's USA Today discusses the growing concern, and body of research, that finds patients in hospitals, particularly in intensive care units where glaring lights and beeping monitors can make sleep extremely difficult, are not recovering as well as they could. The article cites studies in a 2005 review article in Critical Care Nursing Clinics of North America and a January, 2008 issue of Nursing Critical Care.

Adapting to night shifts -- helping shiftworkers adapt and avoid shiftworker maladaptation

Adapting to nighttime or daytime work requires synchronization of your biological clock (which controls your circadian rhythms) to the work schedule. Maladaptation results if your biological clock is not adjusted to the work schedule. To adapt the biological clock, shiftworkers must be exposed to daylight (or bright artificial light of 1,000 lux or more) both upon awakening and
throughout their active periods (for example, during work hours).

Also, shiftworkers must avoid bright light from approximately three hours prior to the end of their long sleep period.

The only way to fully adapt to nightshift schedules is to reset the biological clock so that energy peaks during nighttime. Work must take place under artificial light (of at least 1000 lux) that mimics daylight. Although this is a far lower level than actual daylight, it will seem far brighter than normal indoor lighting which is typically in the 300-400 lux range. Sleep must take place in a dark and noise-free environment for approximately seven to eight hours. Failure to control daylight and/or light exposure is a significant contributor to fatigue and shiftwork maladaptation.

Maladaptation to shiftwork schedules and lack of energy-restoration sleep can result in persistent sleepiness, low energy, lack of motivation, and depression; in performance degradation during duty hours; and in increased safety risk.

Other health effects such as increased incidence of cardiovascular disease, gastrointestinal disorders, and sleep disorders have been historically documented in populations subjected to shiftwork maladaptation. The combined effects of disrupted sleep and biological clock disorganization can lead to endurance degradation, jet-lag-like symptoms, irritability, depression, and, in extreme cases, psychosis.

Optimizing Adaptation to Shiftwork
Optimizing shiftworker rest, while preventing shift lag (inadequate adjustment to shiftwork schedules), can contribute significantly to shiftworker adaptation to work and life aboard a maritime vessel.

Listed below are some recommendations that can prevent shift schedules from inducing short and disrupted sleep periods and shift lag.

Avoid allowing staff to work more than 12 hours in a 24-hour period. Count
these 24 hours from the time shiftworkers wake up from their longest daily sleep
period (not naps).

Total Adaptation to Night Work

• Provide bright-light exposure (e.g., fluorescent bulbs of at least 1000 lux) during the work period. Note: This artificial-light exposure can only be implemented in environments where night vision is not required for performing normal duties (so, for instance, ambulance drivers who will need to be able to drive in the dark at night should not be exposed to bright artificial lighting between calls).
• Provide nightshift staff with small-size meals that promote energy and alertness (high protein, low fat, low sugar, low starch, no dairy products or turkey).
• Adjust meal times so nightshift personnel can eat a brunch on waking (at approximately 1:00 pm), including brewed coffee and breakfast foods, if desired.
• Adapt the cafeteria services to accommodate crewmember needs. This accommodation supports both safety and crew morale.

Partial Adaptation to Night Watch or Work Schedules
When bright lights cannot be used in the work environment, stick to the following recommendations:

• Reduce the duration of the shift in order to minimize the impact of endurance degradation on safety. Promote exercise in the evening hours.
• Allow shiftworkers from any shift ending in the morning hours to retire prior to sunrise, and to sleep at least seven to eight hours free of noise and with absolutely no interruptions.
• Overtime should be scheduled to occur after wake-up time (e.g., from 2:00 pm to 6:00 pm), whereas leisure activities should be scheduled for the evening hours.

Source: http://www.uscg.mil/hq/g-m/cems/PDF/light_management.pdf.

Shiftwork Research: safety, sleepiness and sleep.

We receive requests for references to shiftwork-related research so we'll start posting abstracts and excerpts (in the public domain) for shiftwork research that you might want to check out:

Shiftwork: safety, sleepiness and sleep.
By Folkard S, Lombardi DA, Tucker PT.

1: Ind Health. 2005 Jan;43(1):20-3. Related Articles, Links
Liberty Mutual Research Institute for Safety, 71 Frankland Road, Hopkinton, MA 01748, USA.

This brief paper reviews the available published literature on shiftwork and safety that allows the relative risk of "accidents" or injuries associated with specific features of shift systems to be estimated. Three main trends in risk are discussed, namely that (i) risk is higher on the night shift, and to a lesser extent the afternoon shift, than on the morning shift, (ii) risk increases over a span of shifts, especially so if they are night shifts, and (iii) risk increases with increasing shift length over eight hours.

We discuss that some of these trends are not entirely consistent with predictions derived from considerations of the circadian variations in sleep propensity or rated sleepiness, and consider factors relating to sleep that may underlie the observed trends in risk. Finally, the practical implications of the trends in risk for the design of safer shift systems are discussed.

MeSH Terms:
Accidents, Occupational/psychology
Accidents, Occupational/statistics & numerical data*
Disorders of Excessive Somnolence/epidemiology
Disorders of Excessive Somnolence/psychology
Humans
Personnel Staffing and Scheduling/classification
Risk
Safety
Sleep Disorders, Circadian Rhythm/epidemiology
Sleep Disorders, Circadian Rhythm/psychology
Time
Work Schedule Tolerance*

PMID: 15732299 [PubMed - indexed for MEDLINE]

Source: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15732299&dopt=Citation

Harvard study finds sleep, napping important for learning and memory

In case there's a shiftworker who needs another reason to get some more sleep ...

an article in the February 1, 2008 issue of the journal Sleep says "Sleep appears to have an impact on what is learned well, but not so much when one is not motivated to learn," according to lead researcher Matthew Tucker, a postdoctoral fellow at the Center for Sleep and Cognition at Harvard Medical School (Boston, Massachusetts, USA). Mr. Tucker believes sleep, even a nap can help improve memory and learning.

So, sleep well.

Ed

Shiftworkers share what it's really like to work shiftwork

The experts have a lot to say that can be helpful to shiftworkers and 24/7 managers -- advice on sleep and napping, shift scheduling, fatigue countermeasures, caffeine, shiftworker lifestyle training, etc. But, a central goal of the National Shiftwork Information Center is to provide a place where shiftworkers of all types can exchange ideas -- shiftworker to shiftworker.

So, here are some additional quotes, from conversations with the shiftworkers in the U.S. National Weather Service. The question posed was, "tell us what shifwork is really like for you?" Here's what three shiftworkers had to say:

"Shiftwork is definitely not for everyone...it is hard on your body and you never seem to get enough rest. However, meteorologists are but a few of the career fields that rotate shifts, and the rewards of a job which is always different and presents new challenges cannot be overestimated. "

Another person said ...

"I would rather work an evening shift or a mid than days. It is so hard to get up early and I love having weekdays off sometimes. Also, we get enough weekends off to satisfy "weekend trips" that I need to take sometimes. Also, working 9 to 5 all of the time can get monotonous. "

Finally, we heard this ...

"Due to the fact that weather does not work a 9 to 5 schedule, having to staff National Weather Service (NWS) field offices around the clock is necessary. I don't know if there is a better solution at this time than rotating shifts. The few studies that I've read and agree with suggest that if you must work rotating shifts, then work a week or longer of the same shift and then rotate to the next shift. Our office rotates this way, as do many others in the NWS. After 3 years of shift work, I don't think I would WANT to go back to working straight day shifts from 8 to 5. I enjoy having weekdays off to get things done such as going to the post office, banking and the like. Sure, I may miss out on some social gatherings, but I would even if I worked straight day shifts. Shiftwork in the summer is great, in that you can often enjoy most of the daylight hours with the kids or other family before going in to work. "

As you can see, there are drawbacks and challenges but also many reasons people like shiftwork.

What is shifwork really like for you? Post your comment below.

Ed

Source: http://www.srh.noaa.gov/women/faqshift.html#shifts_and_kids

Sleep disorders warrant attention from shiftworkers

The British newspaper, The Independent, published an article, "Sleep disorders: Don't take it lying down Millions suffer from sleep disorders – and many never seek help. But the cures are out there," that can be a good first read to help shiftworkers (or anyone else for that matter) identify sleep disorders -- whether insomnia, sleep apnea, or something else -- and tips for minimizing their effects. It's worth taking a look.