More Americans are burning the midnight oil — and burning out on the job and on the road, with disastrous consequences.

Not too long ago, in the days of the blue laws, the only people who worked on Sunday or at night were those in public service. Now, one can shop for groceries at 2 am or take the family pet in for its annual shots at midnight. Even in small-town America there is usually one store open around the clock.

As we evolve into a 24-hour society, however, one must be cognizant that the human body clock (circadian rhythm) does not normally operate with such a high degree of flexibility. The body clock “sleeps” at night and “works” during the day. According to a recent National Sleep Foundation survey,1 nearly one in three Americans sleeps as few as 6 hours or less a night during the work week, with the majority averaging 7 hours of sleep a night. During the teens and twenties, our bodies require 8 to 10 hours of sleep a night. Thereafter, we need about 8 hours of sleep. Few people are really well rested with fewer than 7 hours of sleep a night.

Up All Night

Although a well-rested individual will spend only one third of his/her life asleep, our changing society seems to be demanding we spend even less time asleep. Twenty-four-hour industries are contributing to changes in what was once considered the norm, and for that, we are paying a steep price in fatigue-related accidents. Until recently, these incidents were largely unrecognized. The public is becoming aware of the problem, however, as fatigue-related deaths in the workplace and on the roads are beginning to make front-page news. Many accidents remain unreported because of a lack of training in the investigation of sleep/fatigue-related accidents. The medical community has been working on addressing this problem for years only to find its pleas unanswered. This situation is also affecting the very people poised to help resolve it-health professionals. Many health practitioners are required to work odd hours or double shifts, and medical interns are routinely assigned grueling 36-hour shifts.

The future looks more promising, however, as more attention is paid to fatigue and excessive sleepiness in the workplace. This change has occurred largely because of the report by the National Commission on Sleep Disorders Research2 and the subsequent establishment of the National Center for Sleep Disorders Research within the National Institutes of Health.

Costs to Industry

It is impossible to place a price tag on a human life; however, one can measure the cost of lost productivity and the potential of an individual, and the cost to families who have lost a beloved member. One can also factor in the cost of medical care before the individual’s death. The first two are considered indirect costs, the third, a direct or measurable cost. Ultimately, both direct and indirect costs of industrial accidents are passed on to consumers by increases in product costs, insurance premiums, and the like. We all pay for the evolution to a 24-hour society.

High-profile accidents such as the space shuttle Challenger and the Exxon Valdez3 have made excessive sleepiness newsworthy by revealing how sleep deprivation played an important role in these catastrophes. The direct cost for these accidents alone was in the billions of dollars. The cost of accidents related to fatigue in 1988 was estimated between $43.15 billion and $56.02 billion.4 Although these costs are estimated, they serve as a guide in addressing the impact of this prominent issue. The minimum cost of a single-vehicle accident involving a tractor trailer is $51,000.5 If a fatality occurs, the cost rises to $2.7 million. One of the single most costly traffic accidents occurred in the early nineties in New York City. A truck hauling liquid oxygen crashed in the Lincoln Tunnel. The tunnel was closed for some time as $40 million in repairs were made.4

Personal-injury costs from fatigue-related accidents are staggering. In 1988, an estimated 9.1 million people suffered debilitating injuries.4 The breakdown consists of 1.8 million in motor vehicle accidents (which represents 51 percent of all motor vehicle accidents in 1988); 3.4 million home-based accidents; 2.3 million public accidents; and 1.8 million work-related accidents. Trucking accidents make news since they often involve a fatality. The effect on traffic flow is immediate and often extensive, as is the cleanup. Automobile drivers are just at much at risk from fatigue and fatigue-related accidents as truck drivers, however, and these figures are also on the rise. In a 1995 National Sleep Foundation survey,6 individuals were asked whether they had driven while experiencing excessive sleepiness or had had an accident under such conditions; 31 percent stated they had dozed off while at the wheel. Of those, 12 percent reported they had had an accident, accounting for 4 percent of all interviewed participants.

The medical industry is not immune to the problem of fatigue-related performance deficits. Many studies have addressed the issue of the fragmented and diminished sleep of hospital interns and residents.7-10 It is no surprise to note a higher incidence of error occurring after little or no sleep, clearly indicating that the medical industry also needs to address the problem of work-related fatigue. Medical training programs are reviewing the value versus the risk of 36-hour on-call shifts.

The aviation industry is already making impressive strides in addressing fatigue. The Federal Aviation Administration now requires a mandatory sleep period for pilots on transoceanic flights exceeding 10 hours and sleep/rest periods for attendants. In the past, falling asleep, even during a 12- to 18-hour flight, was grounds for immediate dismissal. One of the nation’s largest railroads, Union Pacific, is also taking steps to eliminate fatigue-related accidents after it experienced a record number of derailments and accidents last year. These accidents were a direct result of fatigue among engineers and yard personnel, who routinely worked 80 to 120 hours a week.11 As a result, the Federal Rail Administration launched one of the most thorough investigations into the operations of the railroad.12 By adding more engineers, reducing work shifts, and generally addressing fatigue in the workplace, Union Pacific has seen a 40 percent decrease in reportable injuries and a 23 percent decrease in derailments compared to last year.12 The savings have not yet been calculated.

Dangers on the Job

There are several reasons so many people are injured on the job because of fatigue. Oftentimes, without even realizing it, an employer may be using operational disincentives that can result in excessive sleepiness among employees. For example, a truck driver who has just delivered his load heads to a nearby motel for his sleep period. A dispatcher at the main hub calls him 4 hours into this sleep period and asks if he can pick up another load at point A and take it to point B, not knowing the driver has had only 4 hours of sleep. Afraid to refuse, the driver proceeds to point A, adding to his sleep debt. This is also true in the hospital setting, where many workers have “pulled a double shift” without prior notice.

One of the major causes of fatigue in shift workers is what is known as the weekend transition. Again, the transportation industry provides a good example: A driver comes home on Friday to spend the weekend with his family and friends. He has been driving all night in order to see his son’s baseball game. He gets in around 9 am and takes a short nap. Then the driver tries to maintain a normal sleep schedule for the weekend by sleeping at night and being a dad during the day. He is due back at the terminal 11 pm Sunday to head out for the week. Oftentimes, he will arrive with an accumulative sleep debt as he has napped for only a few hours Sunday afternoon. After reporting to work, he finds out his load has been delayed, and he does not pull out until 3:30 am. This driver may have accumulated an 8-hour sleep debt before he even begins his work week. This shifting of his circadian rhythms may eventually result in a flattening of his natural rhythm so that he no longer experiences the peaks and dips in alertness that result in good-quality sleep. As the week continues, the driver continues to accumulate his sleep debt because of his irregular sleep/wake schedule and the poor quality of sleep he obtains on the road.

Night shift workers often suffer from circadian dyssynchrony. Their common complaints include insomnia and excessive sleepiness during their shifts. There have been recent studies involving the use of melatonin and other medications and “natural” remedies, with results indicating they can aid night shift workers in modifying their circadian clock. The risk of use, however, has not been completely identified13; neither have clear usage patterns.

Diet and Lifestyle

Lifestyle choices play a significant role in self-inducted fatigue. Healthy lifestyles include a good diet, exercise, and adequate sleep. As a society, we have done quite well at describing and accepting good diets and exercise, but what is good sleep? Do healthy diets, exercise, and good sleep interact? Foods high in fat, such as biscuits and gravy, may lead to irresistible sleepiness a few hours after ingestion. By simply changing drivers’ diets and giving them fresh fruit, Hudson Foods was able to reduce accident costs by $6.4 million the first year. In addition, the company has realized a decrease in health insurance claims since making this change. The company has also introduced an exercise program drivers can do on the road.14,15

Schlumberger Oilfield Services has one of the most comprehensive and synergistic fatigue and alertness programs to date. As part of orientation, all new hires are taught about circadian rhythm and its effect on performance, and learn the definition of good sleep. This program also addresses work habits and employees’ lifestyles. The employees and their families are taught techniques for improving diet, exercise, and sleep hygiene. Drivers for Schlumberger have the right to refuse to drive, without reprisal, if they believe they are too fatigued. By providing such training, Schlumberger has not only reduced accidents and health insurance claims, but has also inspired new levels of loyalty from its employees.16

Another culprit leading to accidents in the workplace is time of day and day of the week. The peak times for accidents are 2 pm to 4 pm and 2 am to 5 am. In 1995, Horne and Reyner17 reported three major peaks for sleep-related accidents in England: 2 am, 6 am, and 4 pm. These times have such a profound effect on accidents because of dips in core body temperature that correlate with dips in alertness. During our 24-hour day, we experience peaks and troughs in our core body temperature. As it begins to fall, we may experience significant levels of sleepiness; as it rises, we experience more alertness. As one’s sleep debt increases, the ability to maintain alertness during these dips can completely disappear.

Other causes of Poor Sleep

A factor that is most often overlooked when treating sleep apnea patients who drive for a living is altitude. At or near sea level, a patient may have a basal oxygen saturation of 92 percent. If a driver stops for the night outside of Denver, at an altitude of three-quarters of a mile above sea level, basal oxygen saturation may drop as low as 85 percent. Decreased barometric pressure adversely affects oxygen transport to tissues, causing a more profound physiological effect. Basal oxygen saturation is not the only problem associated with altitude. A person could develop short-term insomnia as well as short episodes of periodic breathing. These changes usually moderate over time as the body compensates for changes in barometric pressure associated with increased altitude. Professional drivers as well as leisure drivers must be aware of the transient changes since simple snoring, otherwise treated obstructive sleep apnea (OSA), or untreated, mild OSA may increase in severity, increase sleep disruption, and have more severe cardiopulmonary consequences, increasing the possibility of fatigue-related accidents.

Another common cause of excessive sleepiness is caffeine abuse. Caffeine is known to have a paradoxical effect as its alerting effects diminish. Many over-the-counter alerting medications contain significant levels of caffeine. Using one of these medications may provide a quick peak in alertness only to be followed by a paradoxical and steep dip in alertness that may be unexpected. Many an unsuspecting person has used such a medication to remain awake only to have a paradoxical alertness dip that unmasks their sleepiness and allows them to nod off.

Lifesaving Education

Many manufacturers have consulted with sleep specialists to adjust light levels for maximum alertness during third-shift work. As a result, they have experienced a decrease in workplace injuries. Sleep researchers are already utilizing light therapy by applying bright light to the back of employees’ knees-more convenient than having employees face a large bank of lights. Prior to this research, the eyes were considered the primary site for light to enter the body. This type of light therapy is showing promise during transcontinental flight to reduce jet lag. Light therapy has been used for a number of years, primarily to treat Seasonal Affective Disorder (SAD). Preplanned naps for transmeridian flight crews while in the air, as noted earlier, were the result of multidisciplinary research efforts in which sleep medicine researchers played a prominent role.18

Despite the advantages education in sleep medicine confer, a number of concerns may delay implementation of antifatigue strategies. In the transportation industry, overnight polysomnography testing is not being widely used to evaluate those at risk. Many of the major carriers feel that this is a Pandora’s box and their level of culpability could dramatically increase if a high rate of untreated OSA and/or sleep deprivation is discovered. Preemployment screening for sleep disorders could be used as an exclusionary tool to discriminate against new hires. In some states, a person cannot hold a commercial driver’s license if he/she has sleep apnea. There are a number of trucking companies that will allow drivers being treated with nasal continuous positive applied pressure (CPAP) to continue driving regardless of the law. The distinction between treated and untreated sleep apnea in not universally understood, resulting in treated drivers who are required by law to reveal they have sleep apnea being prohibited from driving.


Fatigue is a public health issue. Legislation and cooperative research projects between industry and sleep medicine researchers may help industry realize sleep medicine is a tool to increase safety and promote a healthier environment for employees and their families. To be successful, industry must first see curtailing fatigue and sleepiness as a cost savings tool. As the ability to identify fatigue-related performance deficits and accidents increases, we will have the data to demonstrate the true cost of ignoring our need for sufficient sleep.

Stephen Eller is a clinical coordinator at Oak Park Hospital, in Oak Park, Ill. Pamela Minkley, RRT, CPFT, RPSGT, is a member and past president of the Association of Polysomnographic Technologists and is team leader of the Sleep/Wake Center at Ingham Regional Medical Center, in Lansing, Mich.


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