Sleep Series 2: Sleep Recovery

Sleep Recovery

This article focuses on sleep recovery for firefighters. In a typical eight-hour sleep at night, humans generally progress through five cycles of uninterrupted REM and NREM sleep. Yet, fire and emergency services personnel typically experience at least one interruption during night sleep and sleep fewer hours while at work compared to when at home.1 Studies found that frequent calls and sudden alarms tend to increase stress and fatigue among paramedics and firefighters in Japan.2,3 cited in 4 A recent study suggest that alarm have an effect on heart rates.5

Sleep recovery consists of two important needs: quality and quantity.6 Recovery is not simply lying in bed for eight hours. Each sleep bout should include several consecutive and uninterrupted cycles of REM and NREM sleep. The quality of sleep is important because deeper stages of NREM sleep are responsible for restoring functions, psychological well-being, and cognitive rebuilding.6 If a firefighter experiences several calls during the night, they may never progress into deep sleep nor receive sleep of sufficient quantity, and therefore will not recover completely.

Effective recovery is also a function of quantity (length).6 The National Sleep Foundation recommends adults receive seven to eight consecutive hours of sleep each night. Although individuals may differ in the exact number of hours needed, any decreases from their normal amount will contribute to a sleep debt. This sleep debt, if continued, leads to poor sleep quality and sleep deprivation.

A firefighter’s alertness and cognitive performance may not recover fully if they respond to several incidents in one night. Considering that fire and emergency personnel typically do not have discretion whether to respond to an incident at night, the question remains: how to achieve sleep recovery?

Unfortunately, this question is difficult to answer and evidence suggest that perhaps firefighters working 24-hour shifts may not be able to fully recover even after the end of the tour.1 Nevertheless, improvements to facilitate the recovery process can be categorized into three treatment areas. 1) Occupational actions - include redesigning the scheduling system to allow for circadian rhythm re-normalization between shifts. 2) Environmental actions - include ensuring personnel sleep on quality bedding material, limiting noise and light, and adjusting temperature to a comfortable level. 3) Individual actions - include taking naps during the day, limiting caffeine, adapting a healthy diet and lifestyle.


References
  1. Billings, Joel and Will Focht. 2016. "Firefighter Shift Schedules Affect Sleep Quality," Journal of Occupational Environmental Medicine 58(3):294-298. doi:10.1097/jom.0000000000000624
  2. Takeyama, Hidemaro, et al. 2005. "Effects of Shift Schedules on Fatigue and Physiological Functions among Firefighters During Night Duty," Ergonomics 48(1):1-11. doi:10.1080/00140130412331303920
  3. Takeyama, Hidemaro, et al. 2001. "Job Stress and Fatigue of Ambulance Paramedics and Fire Fighters," Job Stress Research 8(1):223-231. 
  4. Takeyama, Hidemaro, et al. 2009. "Effects of a Modified Ambulance Night Shift System on Fatigue and Physiological Function among Ambulance Paramedics," Journal of Occupational Health 51(3):204-209. doi:10.1539/joh.L7040
  5. MacNeal, James J., et al. 2016. "Effect of Station-Specific Alerting and Ramp-up Tones on Firefighters' Alarm Time Heart Rates," Journal of Occupational and Environmental Hygiene 13(11):866-870. doi:10.1080/15459624.2016.1183018
  6. Joffe, Mark D. 2006. "Emergency Department Provider Fatigue and Shift Concerns," Clinical Pediatric Emergency Medicine 7(4):248-254. doi:http://dx.doi.org/10.1016/j.cpem.2006.08.008

Next Series - Acute effects of Sleep Deprivation