On September 18, 2014, ABC news presented a story on sleep deprived truck drivers. A 28 year old truck driver reported to his dispatchers that he was too fatigued to continue his run. He was told to drink coffee and walk around the truck to wake up. He continued to protest that he was too tired to continue driving safely, and was told by two other dispatchers to continue. Eventually, another driver came to pick up his load and complete the run, but he was warned that he might not get paid because of the call he made to dispatchers (Rhee, & Valient, 2014). By acting responsibly, striving to keep himself and others on the road safe, as well as protecting the trucking company's assets, and protecting them from liability, he was sanctioned. Would loss from not delivering his load on time have equaled damage or loss to the truck, or death or injury to the driver or the driver of another vehicle?
Current Social Norms and Sleep Deprivation
America is a very busy, high pressure society. We are hard driven to succeed, are expected to multi-task, and live a sometimes frantic pace of life. Sleep may be viewed as a waste of time by some people, or an interruption in their routine; a regrettable task they are compelled to carry out. Some people may think it is a sign of weakness to need to sleep, and that pulling all-nighters, working through the night, taking a shower, and getting a coffee before continuing to work a full day is a sign of dedication, drive, ambition, and toughness. I agree that it is all those things. You have to be tough to demonstrate the fortitude to fight the urge to sleep and stay up all night, and you have to be motivated and driven to do this. Sometimes, you have a job to do with a lot riding on it, and it has to be done, no matter what. My personal record is 64 hours with only two 15 minute, twitchy cat-naps. I was a senior in college, completing a research project for a required class that I needed to complete in order to graduate. I stayed awake by downing spoonfuls of instant coffee with a mouthful of cola. I sat in front of a computer and finished my project, and wandered around the campus half-asleep, then stupidly drove home to my off-campus apartment. Twice, I thought I saw someone ahead of me on the curb, waiting to cross the street. When I got closer, there was no one there. I was starting to hallucinate. When I got home, I checked the closets, under the bed, and behind the shower curtain, because I was seized by the feeling there was someone in my apartment. Paranoia is another symptom of sleep deprivation. I finally collapsed in bed and fell into a badly needed sleep. I got away with it safely.
However, sleep deprivation can come with a cost which can be considerable if you are working in a very high risk/low tolerance-for-error environment, such as:
Driving a Tractor Trailer at 65+ mph down a highway.
Driving a bus full of someone else's kids.
Flying a plane.
Removing someone's appendix.
Working at a nuclear power plant.
Working at a pesticide manufacturing plant.
Piloting a Tanker vessel.
Prepping a space craft for launch.
Many of the worst industrial accidents in history have been contributed to by sleep deprivation. The Pennsylvania Three Mile Island nuclear plant. And Bhopal India pesticide plant leak were at least partially the result of sleep deprived workers (WebMD, 2014). It is noted that the Chernobyl nuclear plant accident, the Exon Valdez running aground and dumping oil, and the Space Shuttle Challenger explosion were all traced back to sleep deprived key personnel as well (Tucker, Whitney, Belenky, Hinson, & Van Dongen, 2010). We do not all have such prestigious jobs as pilot and surgeon, but truck drivers and school bus drivers have a heavy responsibility, which they need to be awake and alert for.
Defining Sleep Deprivation
SD (Sleep Deprivation) can be defined as experiencing daytime fatigue due to insufficient sleep. Generally, adults need seven to eight hours of sleep about every 16 hours for optimal functioning. There are some people who can apparently function well on four or five hours of sleep, about half of what the average person needs. However, it is likely these people are very efficient sleepers. They fall asleep quickly, rapidly descend into Stage Three Sleep, or Deep Sleep, and stay there longer than the average sleeper. They don't need as much time in bed to get Deep Sleep, which is also called restorative sleep (American Academy of Sleep Medicine, 2010). If you will, Deep Sleep is the most valuable sleep that you need the most of. Other people are inefficient sleepers, who need to sleep nine or ten hours. They may take up to an hour to fall asleep, loiter in Stage One Sleep, or light sleep for an unusual amount of time, then gradually descend into Stage Two, and finally a brief stay in Stage Three before bouncing back up to Stage One and repeating the process. This means that sleep deprivation is a relative term, and varies from one individual to the next.
Myths about Sleep Deprivation
You need to sleep. That is the bottom line. Caffeine will only work for a limited amount of time, and will not resolve all of the effects of sleep deprivation. You cannot compensate for every hour of missed sleep with a cup of coffee or an energy drink. Some truck drivers use stronger stimulants than caffeine to stay awake- e.g.- methamphetamine. Any stimulant drug will crank up your central nervous system, delaying the effects of fatigue, making you more alert, and able to focus and concentrate more, but only for a limited time. When the stimulant wears off, you will crash. Your nervous system will rebound to compensate for overworking, and you will feel even more fatigued. At that point, you need to sleep even more. Some people are in a position where that is not possible, so they ingest more caffeine, or whatever they are using to stay awake. The alertness-enhancing effects will not be as pronounced this time. When that dose wears off, you will rebound harder, feeling even less alert and awake, and more exhausted. You will eventually sleep, whether you want to or not. You will experience periods of micro-sleep. Your eyes will be open, but your brain will be in Stage One Sleep. It will only last for two to five seconds. But a lot can happen in that time. If you are driving down a highway at 65 mph, in three seconds your vehicle will travel 95 yards, or about 285 feet. There are a lot of bad possibilities in that amount of distance and time.
The Effects of Sleep Deprivation
The short version is you make mistakes. You are not going to be operating at your optimal level.
Short-term (< 48 hrs) effects of SD has a significant effect on most areas of mental ability. SD is hardest on the ability to sustain attention in simple repetitive tasks. Research has found that monotonous tasks- e.g.,- looking at a stretch of highway which all looks alike- are more seriously affected by SD (Lim & Dinges, 2010). That SD causes problems with sustained attention is also noted by Lo, Groeger, Santhi, Arbon, Lazar, Hasan, Schantz, et al (2012). The Prefrontal cortex is the part of the brain behind the right side off your forehead. It has many important functions, such as self regulation, inhibition, and judgment, and consideration of consequences. Research involving use of f MRI (functional Magnetic Resonance Imaging) have shown that SD diminishes activity in this part of the brain (Lim & Dinges, 2010). The ability to maintain attention and be vigilant to changes in your environment are also especially impaired by SD (Lim & Dinges, 2010).
The Impact of Sleep Deprivation
What is important is how the effects of sleep deprivation are translated to real-world situations.
A brief loss of vigilance can be disastrous It has been found that brief loss of vigilance is the main cause of SD related MVA's the eyes closing for only four seconds is enough time for a driver to steer their vehicle off the road (Lim & Dinges, 2010). Mental performance declines with SD, and grows worse after being awake for 24 hours. Research has shown that 24 hours without sleep produces impairment similar to be under the influence of alcohol (Lo, et al, 2012).
Another study found that 24 hours of SD increases stress stress hormones, and results in reduced ability to attend and to hold items in short term memory. Overall, SD makes it easier to make mistakes Joo, Yoon, Koo, Kim, & Hong, 2012). Ironically, the perception that going without sleep makes you tough is challenged in that SD actually makes you more susceptible to the effects of stress, and more emotionally reactive (Minkel, Banks, Htaik, Moreta, Jones, McGlinchey, & Simpson et al, 2012).
There are long term impacts on people whose profession produces chronic SD. SD is a factor in obesity. It was found that SD reduces normal calorie burn in a study sample of healthy men (Benedict, Hallschmid, Lassen, Mahnke, Schultes, Schiöth, Born, et al, 2011). In persons who already have a sedentary lifestyle, this will further reduce calories in/calories expended and can result in weight gain, and all the many diseases which accompany obesity.
The effects of sleep deprivation can be costly in terms of human life and dollars. Over focus on short term profit, instead of long term loss and expense through accidents, injury and liability has to be weighed. Recognition that sleep makes for more efficient and productive workers is also part of the equation.
American Academy of Sleep Medicine. (2010). The Science of Sleep. American Academy of Sleep Medicine. Retrieved August 16, 2014, from: http://yoursleep.aasmnet.org/Topic.aspx?id=6
Benedict, C., Hallschmid, M., Lassen, A., Mahnke, C., Schultes,B., Schiöth, H.B., Born, J., and Lange, T. (2011). Acute sleep deprivation reduces energy expenditure in healthy men.The American Journal of Clinical Nutrition. 93.(6).1229-1236 doi: 10.3945/ajcn.110.006460
Joo, E.Y., Yoon,C.W., Koo, D.L., Kim, D., and Hong, S.B. (2012). Adverse Effects of 24 Hours of Sleep Deprivation on Cognition and Stress Hormones. Journal of Clinical Neurology. 8(2):146-150. http://dx.doi.org/10.3988/jcn.2012.8.2.146
Lim, J., and Dinges, D.F. (2010). A Meta-Analysis of the Impact of Short-Term Sleep Deprivation on Cognitive Variables. Psychological Bulletin.136. (3):375–389. doi: 10.1037/a0018883 PMCID: PMC3290659 NIHMSID: NIHMS354534
Lo, J.C., Groeger, J.A., Santhi, N., Arbon, E.L., Lazar, A.S., Hasan, S., Schantz, M.V., Archer, S.N., and Dijk, D.J. (2012). Effects of Partial and Acute Total Sleep Deprivation on Performance across Cognitive Domains, Individuals and Circadian Phase. Plos One. DOI: 10.1371/journal.pone.0045987
Minkel, J.D., Banks, S., Htaik, O., Moreta, M.C., Jones,C.W., McGlinchey, E.L., Simpson,N.S., and Dinges, D.F. (2012).Sleep Deprivation and Stressors: Evidence for Elevated Negative Affect in Response to Mild Stressors When Sleep Deprived. Emotion. 12(5): 1015–1020. doi: 10.1037/a0026871 PMCID: PMC3964364 NIHMSID: NIHMS443115
Rhee, J. and Valient, A. (2014). The Danger of Forcing Truck Drivers to Drive Sleep-Deprived Exposed. ABC News. Retrieved September 19, 2014, from http://abcnews.go.com/US/danger-forcing-truck-drivers-drive-sleep-deprived-exposed/story?id=25544862
Tucker, A.M., Whitney, P., Belenky, G., Hinson, J.M., and Van Dongen, H.P.A. (2010). Effects of Sleep Deprivation on Dissociated Components of Executive Functioning. Sleep. 33(1): 47–57. PMCID: PMC2802247
WebMD. (2014). 10 Things to hate about sleep loss. WebMD. Retrieved August 14, 2014, from: http://www.webmd.com/sleep-disorders/excessive-sleepiness-10/10-results-sleep-loss