Essential Sleep (Part 7). Sleep fatigue and accidents

Fatigue

Sleep deprivation also contributes to the physiological state known as fatigue.  A fatigued person is accident prone and judgment impaired.  After approximately 20 hours of no sleep, reaction times are comparable to having a blood alcohol reading of .08.  Staying awake for 24 hours leads to a reduced hand‑to‑eye coordination that is similar to having a blood alcohol content of 0.1. An example of a sleep deprivation accident occurred when a space shuttle mission was aborted 30 seconds before lift‑off because a technician who had worked several consecutive l2hr shifts accidentally released 18,000 pounds of liquid fuel just minutes before the scheduled flight. An investigation of the Challenger space shuttle disaster attributed ground crew fatigue as one of the factors contributing to the disaster. An incident such as this shows the seriousness of the situation and the potential loss of life through human related errors in technical fields. Even operating simple machinery such as forklifts can become extremely dangerous if the operators are not filly alert. Other examples of work related sleep deprivation include a flight which flew 100 miles out over the Pacific before controllers on the ground were able to wake the pilots up using chimes, piped into the cockpit audio. It is common practice for flight attendants to check in on pilots to ensure they do not fall asleep. The Exxon Valdez oil spill occurred on a ship with a crew that had had very little sleep, with the accident happening in the middle of the night.

Pain

45 to 80% of all nursing home residents suffer from chronic pain and this pain is strongly linked to insomnia (Dodla and Lyons, 2006). In Japan a survey conducted by Tanaka and Shirakawa (2004) found that one in five Japanese people suffer from insomnia, and within the elderly population one in three suffer, because of this the Japanese government increased the needs of insomnia patients at community health sites and names insomnia a refactory disease of the 21st centuary. A similar Honk Kong based study found 11.9% of Chinese people living in Honk Kong suffer from insomnia approximately three times a week and the females were 1.6 times more likely to show symptoms of insomnia than males (Li et a!. 2002). 

Accidents, errors and Risk taking

Studies using card games have found that with little sleep, players get stuck in a strategic rut. Sleepy people keep taking risks, even though it’s obviously not working for them.

A study of musicians who practised a new song had improved in speed and accuracy compared with before a night’s sleep. a good night’s sleep can also improve motor performance.

In a study of 1891 male employees compared with those working 6-8 h day(-1) with good sleep characteristics, positive interactive effects for workplace injury were found between long work hours (>8-10 h day(-1) or >10 h day(-1) ) and short sleep duration (<6 h). This study suggests that long work hours coupled with poor sleep characteristics are synergistically associated with increased risk of workplace injury. Greater attention should be paid to manage/treat poor sleep and reduce excessive work hours to improve safety at the workplace (Nakata 2011).

A study looking at the effect of working “standard shifts” (that is, the traditionally accepted long, sleepless shifts) for hospital interns showed that the interns made 36 percent more serious medical errors during a standard work schedule compared to during an intervention schedule that eliminated extended work shifts.  The errors included significantly more serious medication errors and 5.6 times as many serious diagnostic errors.  As a consequence, the overall rates of serious medical errors were significantly higher during the standard schedule than during the intervention schedule (Landrigan, 2004).  Fortunately, most serious medical errors were either intercepted by people who were awake and concentrating or did not result in clinically detectable harm to the patient.  How does this affect you?  It might be all right if you could always go into hospital at the beginning of the shift or be operated on only by doctors who had just started a shift. 

One study found that interns who worked 24-hour shifts made 36 percent more medical errors than those working 16-hour shifts and five times the number of diagnostic errors, and were 61 percent more likely to accidentally cut themselves during procedures.

The study found that the rates of serious medical errors in two intensive care units “were lowered by eliminating extended work shifts and reducing the number of hours interns worked each week.” By asking interns to work less, the hospitals improved their performance.

A number of studies have highlighted the increased number of motor vehicle accidents associated with young adults driving fatigued. It’s conservatively estimated that at least 112 lives could be saved in Australia if fatigue and falling asleep at the wheel were eliminated.

Several studies have highlighted the increased number of motor vehicle accidents associated with young adults driving while fatigued.  Fatigue is estimated to be responsible for 35 percent of road accidents.  It’s conservatively estimated that at least 112 lives could be saved in Australia every year if fatigue and falling asleep at the wheel were eliminated.  In the United States, the National Highway Traffic Safety Administration (NHTSA) reports that fatigue and sleep deprivation contribute to about 100,000 highway crashes each year, causing more than 1,500 deaths annually (Sullivan, 2003).  At a grander level the 1989 Exxon Valdez oil spill off Alaska, the Challenger space shuttle disaster and the Chernobyl nuclear accident have each been attributed to human errors in which sleep deprivation played a role (Grunstein, 2000).