Sleep Series 3: Acute effects of Sleep Deprivation

Acute effects of Sleep Deprivation

This article addresses the very real effects of poor sleep in the fire service. When firefighters receive inadequate amounts of sleep, they are likely to experience acute signs and symptoms of sleep deprivation, which may include low levels of alertness, poor performance, decreased reaction sleep, and decreased memory recall.1

Have you ever arrived at a scene at night and wondered how you got there?

Two studies compare the severity of sustained wakefulness to the equivalent effects of intoxicated individuals.2,3 In the first study (Dawson and Reid 1997), researchers obtained a sample of 40 participants and divided them into two groups. The control group was required to remain awake for 28 hours while the treatment group consumed alcohol (10-15 grams every half hour) until their Blood Alcohol Concentration (BAC) reached 0.10 percent. The following day, the participants switched groups and either consumed alcohol or remained awake. The researchers measured cognitive performance by using a computer hand-eye coordination test every half hour. The results of the study illustrated that at 17 hours of sustained wakefulness, participants had equivalent performance levels as recorded from individuals with a 0.05 percent BAC. At 24 hours of wakefulness, participants reordered performance levels equivalent to individuals with a 0.10 percent BAC. For compassion, these individuals would be over the legal limit (0.8 percent BAC) to operate a vehicle.

The second study (Williamson and Feyer 2000) indicated similar results. Interestingly, the researchers decided to incorporate more performance measurements, including reaction time, time to complete dual tasks, hand-eye coordination, accuracy of selection, grammatical reasoning, memory recall, coding test, and spatial memory search. The researchers found that at 16.91 to 18.55 hours, participants recorded performance measures equivalent to those with a 0.05 percent BAC. It only took 17.74 to 19.65 hours of wakefulness to have equivalent performance measurements of those with a 0.10 percent BAC (which took fewer hours than noted in Dawson and Reid 1997).

Both studies highlight the challenges associated with sleep deprivation. Additional studies have found that attention, coordination, cognitive performance, and motor speed decrease as sustained wakefulness increase, which may likely lead to errors, accidents, and injuries.4,5 Similar findings are reported for medical residents6 and the transportation industry.7 Sleep related errors, in part, helped lead the National Highway Safety Administration and the Federal Aviation Administration to develop regulations that limit the number of consecutive hours driving/flying between breaks. Furthermore, lack of sleep has contributed to human error leading to several disasters including Three Mile Island,1,4,8,9 Davis–Besse reactor,8 Chernobyl,1,4,8,9 and Bhopal.1,4,9

It is easy to understand how performance decreases as one prolongs wakefulness. Yet, when responding to emergencies, firefighters are already at a greater risk for injuries and accidents. The effects of prolonged wakefulness, sleep deprivation, or poor sleep quality can have synergistic consequences, which may multiply their risk factor.

  1. Joffe, Mark D. 2006. "Emergency Department Provider Fatigue and Shift Concerns," Clinical Pediatric Emergency Medicine 7(4):248-254. doi:
  2. Dawson, Drew and Kathryn Reid. 1997. "Fatigue, Alcohol and Performance Impairment," Nature 388(6639):235-235. 
  3. Williamson, A. M. and Anne-Marie Feyer. 2000. "Moderate Sleep Deprivation Produces Impairments in Cognitive and Motor Performance Equivalent to Legally Prescribed Levels of Alcohol Intoxication," Occupational and Environmental Medicine 57(10):649. 
  4. Costa, Giovanni. 1996. "The Impact of Shift and Night Work on Health," Applied Ergonomics 27(1):9-16. doi:
  5. Raslear, Thomas G., et al. 2011. "Predicting Cognitive Impairment and Accident Risk," Progress in Brain Research 190(155-167. doi:
  6. Samkoff, Judith S and CH Jacques. 1991. "A Review of Studies Concerning Effects of Sleep Deprivation and Fatigue on Residents' Performance," Academic Medicine 66(11):687-693. 
  7. Durmer, Jeffrey S and David F Dinges. 2005. "Neurocognitive Consequences of Sleep Deprivation," Seminars in Neurology 25(01):117-129. 
  8. Mitler, Merrill M., et al. 1988. "Catastrophes, Sleep, and Public Policy: Consensus Report," Sleep 11(1):100-109. doi:10.1093/sleep/11.1.100
  9. Folkard, Simon and Torbjörn Åkerstedt. 2004. "Trends in the Risk of Accidents and Injuries and Their Implications for Models of Fatigue and Performance," Aviation, Space, and Environmental Medicine 75(3):A161-A167.

Next Series - Chronic effects of Sleep Deprivation