Obtaining sufficient quantity and quality of sleep: important safety concerns during EMS operations
By guest authors Billy Rutherford and Gerald P. Krueger
This is the second short article in the Vitals Program series covering EMS Operator Fatigue. It addresses the importance of obtaining daily a sufficient quantity of quality sleep; and it points out implications for safety and prevention of human error in EMS operations.
Quantity and quality of sleep
Most adults maintain an acceptable level of on the job alertness if they obtain 7-8 hours of sleep in every 24 hour day. Anything less tends to leave one feeling drowsy or fatigued, their on-the-job alertness gradually becomes compromised, and they are likely to perform poorly or to make mistakes. This is true for EMS providers who care for patients at a scene or en route in the ambulance, wherein medical errors can be made. Fatigue attributable to shortage of sleep can compromise our alertness to a level that degrades our reaction times as much as 10-20%. It can adversely affect our situational awareness and decision making, cloud our judgment, as well as make us moody and less compatible with the needs of our teammates or our patients.
Obtaining the desired 7-8 hours of sleep in a long contiguous bout of sleep is certainly preferred, however, in many around-the-clock EMS operations EMS providers often do not obtain lengthy bouts of uninterrupted quality sleep. This may be due to the frequency of response calls, noisy, uncomfortable sleeping environments at the station, or simply because it is difficult to sleep at various times in the body’s daily physiological cycles (i.e. circadian rhythms – covered in a subsequent article in this series).
On a daily basis, our tired brains seek out desired sleep in cycles of light sleep (phase 1 and 2 sleep), deep sleep (phases 3 and 4), and dreaming sleep (rapid eye movement or REM sleep). Research shows that obtaining at least 4-5 hour stretches of quiet, uninterrupted sleep helps us to obtain considerable amounts of deep sleep and sufficient episodes of dreaming sleep. These two forms of “quality sleep” are necessary to permit our brains to “recharge our batteries” and to restore acceptable levels of cognitive alertness before returning to work. Thus, if we obtain at least a 4-5 hour stretch of uninterrupted sleep, we can experience several cycles of both these important restorative stages of sleep. If we do not sleep the full 7-8 hrs in one sleep session, often we can augment or supplement that rest with another 2-3 hours of additional sleep, perhaps in the form of naps. The aggregate of over 7 hrs of sleep per 24 hour day (long bouts of sleep augmented by naps) helps us sustain work place alertness. It is also important to note that if one takes a nap for longer than about 50-60 minutes we are more likely to fall into the deeper phases of sleep, and then more likely to experience sleep inertia.
If we are somewhat sleep deprived, or we are pretty tired before lying down to sleep, we are more likely to fall into the deeper phases of sleep fairly quickly. It is important to note that if we are awakened from those deeper phases of sleep, say due to an incoming call, then immediately upon awakening we will likely have to overcome a bout of sleep inertia. This inertia manifests as feelings of severe drowsiness. We even may be a bit incoherent for a short while before we regain full return of our cognitive faculties. Sleep inertia needs to be overcome or dissipated before engaging in driving, or doing other important decision-making activities such as caring for or treating a patient. For some people, upon abrupt awakening, such sleep inertia may last as long as 15-20 minutes. Sleep inertia needs to be accounted for in job assignments of who accomplishes which tasks when awakening to participate in quick response EMS operations. EMS providers need to be attuned to whether or not their teammate(s) are experiencing sleep inertia when they perform the important work of operating the ambulance or caring for a patient.
Sleep debt and recovery sleep
Each day that we do not obtain the requisite 7-8 hours of sleep, we shortchange ourselves of needed sleep will contribute to developing a cumulative “sleep debt” wherein we “owe our brains” additional sleep to make up for those hours of missed sleep each day. Thus, if we only obtain 5 hours of sleep on a given day, then we “owe” our brains about 2.5 to 3 hours of sleep. If we miss 2+ hours of sleep on successive days, each day we build up an accumulating sleep debt. If that sleep debt accumulates to over about 10-12 hours near the end of a work week, we will perform on the job in the same manner as we would if we had stayed awake for a full 24 hours. With a sizeable sleep debt our reaction times, decision-making skills and judgment will be severely compromised. Thus, if we are fatigued with a sizeable sleep debt, we put ourselves, our teammates and our patients at risk of errors or mistakes.
Making up for a weekly sleep dept presents an interesting scenario. What often happens is our brain engages in recovery sleep. On our nominal weekend of 2 days off duty, we make up much of our sleep debt by sleeping for longer stretches, and by taking supplemental naps. But generally, during recovery sleep we do not regain sufficient additional hours of sleep to make up the missed difference on a one-for-one hourly basis. Rather, in a sense, our brain automatically determines that in most of the recovery sleep we are going to experience more deep sleep, and we are likely to experience significantly more dreaming sleep (sometimes quite vivid dreams), thus the brain maximizes the restorative value of our “weekend recovery sleep.” Sudden awakening during recovery sleep usually results in significant amounts of sleep inertia in the form of extreme drowsiness.
Summary: It is important for us to recognize our body and brain’s daily need for sufficient quantity of quality sleep, to understand when we have accumulated a weekly sleep debt, and how to recover from it to restore us to an acceptable level of alertness at work. You can only pay off your sleep debt with SLEEP.
Next issue: On the job alertness, fatigue and job performance
About the Authors:
Billy Rutherford, MS, President of American Integrated Training Systems, Inc. has managed the development of the USDOT Emergency Vehicle Operator Course (Ambulance). Billy also managed the development of over 500 hours of Pre-Hospital Computer/Internet Based training. He has been conducting EVOC Train-the-Trainer Courses Nationwide for over 20 years. Billy serves as an Expert Witness on cases where there was a serious injury or death when an emergency vehicle was involved.
Gerald P. Krueger, Ph.D., CPE, a research psychologist, is also a certified ergonomist who has spent much of the last 20 years examining issues of commercial driver alertness and driver fatigue (i.e., truck and bus drivers). Jerry has published numerous articles, and taught courses for DOT on driver fatigue and health and wellness. He also serves as an expert witness on cases of driver fatigue and driver performance.
In an attempt to stay abreast of NHTSA progress on their research initiative, Billy Rutherford and Jerry Krueger are participating in periodic EMS stakeholders’ meetings on these important topics to all EMS providers.