Blue River Community College
In the fields of emergency services, sleep patterns while on shift are often irregular. The lack of sleep, or regular sleep, can be a factor in other health problems, and can greatly decrease performance on the job. Interrupted sleep, or sleep fragmentation, is a common occurrence due to the nature of shift work, and the nature of emergency response requests. Shifts can vary in nature, and the two that will be focused on in this project is the “48/96” schedule (48 hours on shift, and 96 hours off shift), and the “Berkley” schedule (24 hours on, 24 hours off, 24 hours on, 24 hours off, 24 hours on, 4 days off). Some departments allow “safety naps” or prophylactic napping on shift during the day to help better rest personnel in preparation for calls throughout the night. This project will determine the effects of sleep fragmentation, and the effects of prophylactic sleeping periods, on personnel from the West Peculiar Fire Protection District (WPFPD) and Miami County Emergency Medical Services (MCEMS).
Table of Contents Abstract……………………………………………………………………………………………2 Table of Contents………………………………………………………………………………….3 Introduction………………………………………………………………………………………..5
Review of Literature………………………………………………………………………………8 Method……...……………………………………………………………………………………13 Results……………………………………………………………………………………………16 Conclusion……………………………………………………………………….………………20 References………………………………………………………………………………………..22 Appendices
Appendix A………………………………………………………………………………………24 Appendix B………………………………………………………………………………………25 Appendix C………………………………………………………………………………………28 Appendix D………………………………………………………………………………………30 Tables
Table 1………………………………………………………………………………………...…32 Table 2…………………………………………………………………………………………...34 Table 3………………………………………………………………………………………...…36 Table 4……………………………………………………………………………………….......38
One of the specific problems addressed in this paper is that the potential for sleep deprivation, and the health risks that go with sleep deprivation, are a very common problem for emergency workers on 24 hour or greater shifts. Interrupted sleep, also known as fragmented sleep, can affect performance on duty, and can have long lasting health effects (Hublin, 2001). These problems are generally not identified by departments using these schedules, and there is usually no education of the health and safety risks associated with them. West Peculiar Fire Protection District (WPFPD) and Miami County EMS (MCEMS) operate on 2 different but common types of schedules in the field of emergency services with shifts of 24 hours or longer. Both shifts allow for resting periods during the day, and sleeping periods at night. Naturally these can be interrupted by emergency calls, preventing or interrupting sleeping periods. Each type of shift allows for a different separation between on and off duty time and sleeping patterns can also be affected by this. Also, both departments have very different call characteristics, so the likelihood of fragmented sleep is also different. WPFPD is a combination fire/ems department with career, part-time, and volunteer personnel employed by the district. It operates advanced life support ambulances and engine companies out of two stations. Normal staffing consists of a minimum of 5 personnel with at least two paramedics and one Captain. The fleet consists of 3 engines, 2 ambulances, 2 staff vehicles, 1 technical rescue, 2 brush trucks, a rehab/support vehicle, and a tanker/tender. WPFPD provides fire and emergency medical services within a 42 square mile district and assists surrounding agencies when requested. WPFPD responds to approximately 900 emergencies calls annually. WPFPD operates on a Berkley Schedule, which is characterized by three 24 hour shifts, with 24 hour off days in between, followed by a 4 day off period (see Appendix A). This schedule will continue this rotation throughout the year. WPFPD has been considering a change to the 48/96 schedule for a period of time now. This schedule would have a continuous 48 hour period on shift, followed by 96 hours of off duty time (see Appendix B). The reason that the department has requested a change to this type of schedule is that it allows for more continuous time at home with family, and much shorter commutes in a weekly period. It also had perceived benefits of better time management, with daily duties only being performed once per 48 hour rotation, instead of being performed every day (UFFLAC, 2007). Currently, WPFPD operates on a “business day” of 0700 to 1700, with a lunch period from 1100 to 1300. During the business hours, employees are expected to be performing work related duties, training, or other assigned duties as deemed necessary by the Captain (shift supervisor) on shift. During the lunch period, employees are allowed to eat, engage in personal activities, or take a “safety nap”. Following 1700, employees are free to engage in any personal activities, as long as readiness is maintained for emergency responses. Employees are allowed in their bedrooms during the lunch period, or any period from 1700-0600. At 0600, employees are expected to be awake, and preparing for the oncoming shift. WPFPD also mandates an employee fitness program, requiring all employees to engage in physical fitness activities on duty for one hour for every 24 hour period on shift as allowed by emergency calls and other duties. Fitness equipment is provided at each fire station. MCEMS is an EMS only department comprised of 21 full time and 10 part time employees. It staffs 3 advanced life support ambulances out of two stations staffed with one paramedic and one emergency medical technician. MCEMS also has one Battalion Chief (shift supervisor) on duty to respond to calls as needed to assist crews. The fleet consists of 4 ambulances, 3 staff vehicles, a disaster response trailer, and a specially equipped ATV capable of carrying a loaded stretcher and EMS equipment. MCEMS responds to all EMS requests within Miami County, KS, which is approximately 590 square miles, as well as surrounding areas when their own EMS resources are depleted. MCEMS responds to approximately 3,000 calls annually. MCEMS currently operates on a 48/96 schedule, after changing from the Berkley in 2008. They wished to change for many of the same reasons as WPFPD. Many of the employees lived in excess of 50 miles away, and wanted shorter commutes, and more time at home. MCEMS has no form of scheduled “business hours” and only requires that daily station duties and equipment checks are performed before personal activities. Occasionally, the Battalion Chief may require scheduled training activities that will occur during the day. Employees are allowed to sleep or rest at any time during the shift, as long as these items are complete, and readiness for emergency calls is maintained. MCEMS also has an employee wellness program, mandating one hour per 24 hour period on duty for fitness activities as allowed by emergency calls. Fitness equipment is provided at Station 2, and Station 1 employees have unregulated access to the YMCA five minutes away.
Review of Literature
Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than being in hibernation or a coma. Sleep is a heightened anabolic state, accentuating the growth and rejuvenation of the immune, nervous, skeletal and muscular systems (Macmillian 1994). Research shows that sleep has five typical phases. These phases are called stages 1, 2, 3, 4, and REM (rapid eye movement) sleep. REM sleep is often referred to as stage 5 sleep. These stages progress in a cycle from stage 1 to REM sleep, then the cycle starts over again with stage 1. We spend almost 50 percent of our total sleep time in stage 2 sleep, about 20 percent in REM sleep, and the remaining 30 percent in the other stages (Benedictis, 2007). During stage 1, which is light sleep, we drift in and out of sleep and can be awakened easily. Our eyes move very slowly and muscle activity slows. People awakened from stage 1 sleep often remember fragmented visual images, such as, a television show that is playing in the background. Many also experience sudden muscle contractions called hypnic myoclonia, often preceded by a sensation of starting to fall (Benedictis, 2007). These sudden movements are similar to the "jump" we make when startled. Stage 1 sleep is also characterized by slow rolling eye movements. Stage 1 is considered the transitional phase from wakefulness to sleep, and usually occurs during the first 5-10 minutes of the sleeping period. When we enter stage 2 sleep, our eye movement stop and our brain waves (fluctuations of electrical activity that can be measured by electrodes) become slower, with occasional bursts of rapid waves called sleep spindles. Stage 2 sleep will typically occur throughout the sleeping period, and accounts for 50% of sleep (Magee, 1986). In stage 3, extremely slow brain waves called delta waves begin to appear, interspersed with smaller, faster waves. By stage 4, the brain produces delta waves almost exclusively. Delta wave sleep accounts for 20-25% of a normal sleep period in adults, and normally occurs during the first 2-3 hours of sleep (Magee, 1986). It is very difficult to wake someone during stages 3 and 4, which together are called deep sleep. There is no eye movement or muscle activity. People awakened during deep sleep do not adjust immediately and often feel groggy and disoriented for several minutes after they wake up. When we switch into REM sleep, our breathing becomes more rapid, irregular, and shallow, our eyes jerk rapidly in various directions, and our limb muscles become temporarily paralyzed. Our heart rate increases, our blood pressure rises, and males develop penile erections. When people awaken during REM sleep, they are often able to describe bizarre and illogical tales – dreams. The first REM sleep period usually occurs about 70 to 90 minutes after we fall asleep. A complete sleep cycle takes 90 to 110 minutes on average. The first sleep cycles each night contain relatively short REM periods and long periods of deep sleep. As the night progresses, REM sleep periods increase in length while deep sleep decreases. By morning, people spend nearly all their sleep time in stages 1, 2, and REM (ASA, 2007). While literature on sleep needs vary to a degree, research shows that the average adult requires seven to eight hours of sleep in a night. Unfortunately, research has found that firefighters on shifts average only 4.8 hours of sleep at night. While some departments have reported an average as high as 5.9 and 6.4 hours of sleep during a 24 hour shift and 48 hour shift respectively, emergency service employees are still not receiving adequate amounts of sleep (Wilmoth, 2009). At least 24 hours of time off with appropriate rest is needed at the end of the night to recover, with some studies suggesting that at least 48 hours may be needed. Continued nights of sleep deprivation will eventually accrue what researchers have called “sleep debt”. In general, the body will typically not recover from cumulative nights of sleep deprivation with one full night of rest (Dinges, 1997). The concept of sleep debt and crew fatigue is a large concern with the 48/96 schedule, where crew members may have consecutive nights of sleep debt during on duty periods. Also, if employees are not receiving optimal sleep at home, they may arrive at work with sleep debt already accrued. Our own experiences tell us that predictable fluctuations exist in daytime sleepiness primarily as a function of the amount of nocturnal sleep in the preceding 24 hour period. In general, the more we sleep at night, the less sleepy we are in the daytime. Historically, sleep investigators have developed different scales to measure sleepiness. These include introspective reports of sleepiness on subjective rating scales and readiness to fall asleep (Carskadon, 1977). The most widely used subjective scale used to assess sleepiness is the Stanford Sleepiness Scale (SSS) (see Appendix C). This is also the scale that will be used for the purposes of this project. Typical experimentation has indicated that subjects had significantly higher SSS ratings on the days following one night of sleep deprivation. There are objective methods of determining sleepiness such as the Multiple Sleep Latency Test (MSLT). It is used to measure the time elapsed from the start of a daytime nap period to the first signs of sleep, called sleep latency (Carskadon, 1986). The test is based on the idea that the sleepier people are, the faster they will fall asleep. However, with the difficulties of assessing this in a crew’s quarters, the current study did not use this test. With a greater understanding of sleep and sleepiness, the next concern is the effects of this on an emergency services employee. Chronic sleep deprivation can cause a very long list of physiological problems. It includes increased blood pressure, increased risk of diabetes, obesity, hallucinations, increased stress hormone, and irritability to name just a few. Unfortunately, emergency service workers are prone to many health problems already from other factors on the job, so the likelihood of sleep deprivation is a very serious problem to consider (Reid, 2009). There are methods that emergency service workers will try to utilize to negate some of the effects of sleepiness other than prophylactic napping. These include caffeine, energy drinks, exercise, and combinations thereof. With prophylactic napping, the assumption is that resting during the day will help counter sleepiness at night in the event of emergency calls (Caldwell, 2007). It is well established that practically everyone experiences post-nap sleepiness, termed "sleep inertia," immediately upon awakening from a nap (Magee, 1986). Performance and mood generally are lowest during the first five minutes after awakening, but usually recover after 15 to 30 minutes. Unfortunately, during the worst period of wakefulness, emergency workers could be driving to the scene of an emergency, and during the recovery period, performing typical duties (Paley, 1994). While napping will almost always provide a higher state of wakefulness prior to a period of sleep deprivation, it also causes an additional period during the day where wakefulness may not be as high. This study will outline if prophylactic napping will increase wakefulness when sleep is interrupted at night. There is one more problem to consider. There have been studies done on several types of jobs with an “on-call” type environment during a period of sleep. Two particular studies, on ship engineers and medical students, measured the effectiveness of sleep during an on-call period. All subjects were told that they were “on-call” but only half of the subjects actually received a call for duty. The subjects that received a call obviously had an increased level of sleepiness while performing duties, and an increase in sleepiness the next morning. However, the subjects who did not receive a call had a marked increase in sleepiness (in comparison with a typical night’s sleep off duty) as well (Torsvall, 1988). In relation to emergency workers, there will be nights when no emergency calls are dispatched, yet the workers will still have a higher level of sleepiness the following day. During sleep, the brain maintains a certain level of awareness and readiness that does not allow for complete sleep. The sleep study performed on the above noted subjects revealed that most subjects did not reach the REM phase of sleep, and the subjects who did attain REM sleep experienced it for much shorter periods. These results did not differ from the group with interrupted sleep, to the group without interrupted sleep (Torsvall, 1988).
The subjects were 5 employees from WPFPD, and 5 employees from MCEMS. There were 2 female participants and 8 male participants overall. They ranged in age from 24 to 55 years (see Table 1). No subject reported any prior sleeping disorder, or medication that would affect sleeping. Each subject was tested for 2 consecutive shifts (48 hours total for WPFPD, and 96 hours total for MCEMS), with evaluations of daytime sleepiness every morning, and evaluations of cognitive and psychomotor functions every night. The participants received free meals as compensation for their participation. The subjects were tested individually. They reported to work at their typical shift start time, and a baseline test of sleepiness was performed using the SSS (see Table 1). Tests were performed on a Monday and Tuesday for the smallest statistical chance of receiving a call a night. All participants were encouraged to have a full night’s sleep prior to reporting to work. At WPFPD no one was allowed to take a daytime nap on the first shift, but was allowed to nap at their discretion during the allotted personal time on the second shift. All naptime was recorded as data for further testing. At MCEMS, naps were allowed during the first shift and second shift, but all naptime was recorded and noted as a variable for further testing. Following every napping period, participants were evaluated for sleepiness using the SSS. The author maintained observation over the crews as closely as possible to insure that all nap time was recorded. All participants were encouraged to go to bed at a time that would allow for a minimum of 8 hours of sleep (not including prior napping periods), while maintaining readiness for emergency calls. During the sleeping period, 2 of the subjects from each group of 5 would be awakened at 3 intervals throughout the night to evaluate psychomotor and cognitive function: 20 minutes after falling asleep, 1 hour after falling asleep again (following the first evaluation), and 4 hours after falling asleep again (following the second evaluation. The remaining 3 subjects from each group of 5 would remain asleep while maintaining readiness for emergency calls. The following morning, all participants would be evaluated again for sleepiness using the SSS. For MCEMS, the same tests were performed on the second 24 hour period of their shift, with no changes in procedure. On the second shift of each department, the same procedures were performed other than the change in napping periods at WPFPD as noted above. The subjects had no form of observation or testing in their off-duty time. The subjects from both departments slept on twin-size beds in a crew sleeping area in their respective stations. The ambient noise was approximately that of a whisper, and there was no noticeable illumination when the door was closed. When crews were awakened to be evaluated, special care was taken to not awaken the other crewmembers. Subjects being evaluated for psychomotor and cognitive function would be escorted to the training room in their stations. The psychomotor function was measured by a subject performing an endotracheal intubation on an adult manikin, followed by intubation on a pediatric manikin. The subjects were evaluated by utilizing evaluation sheets for endotracheal intubation used by the National Registry of Emergency Medical Technicians (NREMT) (see Appendix D). This is the standard that is used to evaluate those attempting to receive their paramedic license. All subjects are licensed paramedics, and were familiarized with the equipment earlier in the testing day. All subjects also had an opportunity to perform the evaluation (without instruction) during the day while awake, to evaluate baseline capability. Subjects were not informed of their results following evaluation during the day, or following sleeping periods. Subjects were timed from the command of “go”, until the objectives from the evaluation sheets were completed. Cognitive function was measured by having the subject perform “serial sevens”. Serial sevens are counting down from 100 to 0 by sevens, and is a widely accepted test for assessing mental function. While the inability to perform serial sevens does not diagnose any particular disorder or impairment, it is a quick and easy test of concentration and memory (Young, 1997). The subjects were timed while performing the serial sevens test to determine difficulty in completion, and the number of errors were recorded. Baseline statistics for serial sevens were performed during the day. All subjects were also evaluated according to the SSS every time they were evaluated for psychomotor and cognitive function.
There were several variables in this study that were beyond the means of control for research. While evaluating subjects during a time period in which they can be removed from the study for an emergency call poses several challenges in the accuracy of the evaluations. However, the emergency calls acted as another means of sleep fragmentation, and is the actual event in which the subjects are being tested against. Also there is the possibility of skill improvements with familiarity with the test methods used. A subject could begin to have partial memorization of serial sevens, or have increased familiarity with the intubation manikin. However, while a test of psychomotor function, intubation is a procedure that the subjects are much more familiar with than serial sevens. The study also brought about additional questions with the inability to monitor the sleeping habits of subjects while off duty. One factor that was also not tested is fatigue. The subjects from MCEMS responded to more emergency calls overall on each evaluation shift, yet these numbers were not recorded. Fatigue could have had a significant impact on the level of sleepiness. However, with baseline stats recorded, and differences from one shift to another, these variables were countered as efficiently as possible. The analysis of performance in psychomotor and cognitive function for the first and second shift appears in Figure 3 and 4 respectively. A total of 83 intubation evaluations were performed over the course of both shifts, along with 83 serial seven evaluations. Napping periods for each subject widely varied. However, the shorter the napping period, the lower the SSS rating would be. For example, subject 6 took a 62 minute nap on day 1 of shift 1. The subject reported a SSS of 4 after awakening. In contrast, subject 7 took a 97 minute nap, and reported a SSS of 6 after awakening. Also there was a noticeable difference in the desired napping length between day 1 and day 2 of subjects on the 48/96 schedule. On day 2, subjects that didn’t feel the need to take a nap, took naps on the second day, and subjects that napped both days had a much longer nap on the second day. However, the difference in SSS rating between day 1 and day 2 on the 48/96 following naps did not appear to have a remarkable difference. Subjects on the Berkley schedule only napped on day 2, but the relationship between nap length and SSS rating appeared to be the same. The cognitive and psychomotor functions were evaluated on 2 nights (2 shifts) for the Berkley schedule and 4 nights (2 shifts) for the 48/96 schedule. Subjects from WPFPD did not receive emergency calls throughout the night on either shift, so evaluation wasn’t compromised, and completed without incident. However, subjects from MCEMS experienced a few emergency calls throughout the evening that prevented evaluation of certain subjects during certain periods. Over the first shift, WPFPD subjects had noticeable but acceptable increase of sleepiness according to the SSS evaluation at period 1 (20 minutes after falling asleep). There was an 80% pass rate on intubation, and 5 total errors on serial sevens. The average time to complete the intubation evaluation increased by 43 seconds, and the average time to complete serial sevens increased by 6.5 seconds. Subject 4 was the only subject to fail intubation in period 1. In periods 2 and 3, the trend continued to increase for the worse. Serial seven and intubation times continued to increase, and additional intubations were failed. Subjects also noted a much larger increase in sleepiness from period 1 to period 2, than from period 2 to period 3. The overall success rate on intubations on night 1 of interrupted sleep was 73%, and there were a total of 25 errors on serial sevens for subjects from WPFPD. MCEMS had increases in sleepiness that appeared to be unaffected by periods of sleep taken during the day. The SSS evaluation at period 1 showed an average SSS rating that was higher than that of WPFPD, yet every subject from MCEMS other than subject 8 took a nap. Psychomotor evaluation with intubation appeared to be improved in period 1 in comparison to that of WPFPD. All subjects passed, and with a significantly lower average time. However, cognitive function appeared to be similar to that of WPFPD in the serial sevens evaluation. The amount of decreased performance between period 2 and 3 appeared to be similar to the results from WPFPD. There were additionally more noticeable differences in sleepiness between period 1 and period 2, than that of period 2 and period 3. Intubation and serial seven performances also continued to decline. On night 1 of shift one, the successful intubation rate was 91% with a total of 17 errors on serial sevens. On night 2 of the first 48/96 shift, more and longer naps were taken as mentioned above. The average level of sleepiness over all periods was increased, and performance in intubation and serial sevens were decreased. Only 2 subjects showed an improvement in time with any test within the 3 periods. Overall intubation success rate on night 2 of shift 1 was 66% with a total of 31 errors in serial sevens. The second shift displayed an interesting change in performance between the Berkley and 48/96 schedule. Shift 2 allowed WPFPD personnel to take naps during the day. The naps were, on average, shorter than those taken at MCEMS, and had a lower average SSS rating upon awakening. The WPFPD level of performance in serial sevens and intubation showed an overall decrease of completion time, SSS rating, serial seven errors and intubation failures. While the subjects from MCEMS reported that they had full nights of sleep prior to the second shift, nap periods were averaging longer on shift 2. Performance of MCEMS subjects during night evaluations were very similar to the first shift; with day 2 of the 48/96 schedule having drastically decreased performance and increased sleepiness. Night 2 of shift 2 recorded an all-time low of 53% success in intubation evaluations and 32 serial seven errors. However, WPFPD had minor improvements on shift 2 with a 16 serial seven errors and an intubation success rate of 80%.
The goals of the current project were to determine the effectiveness of “safety naps” taken during the day to allow for a heightened state of readiness for night time emergency calls, and to assess the effects of sleep fragmentation on cognitive and psychomotor function. With the current results, the effects of prophylactic napping appeared to help overall performance of personnel on a Berkley schedule. It also decreased the overall level of sleepiness throughout the night. Additionally, if the prophylactic napping period is under 60 minutes, the level of sleepiness afterward would be greatly less than a napping period over 60 minutes. From our literature review, this would probably be due to the prevention of allowing the body to reach deeper phases of sleep. In regards to the 48/96 schedule, prophylactic napping had no obvious effect on reducing sleepiness from sleep fragmentation. However, this could be due to more crew fatigue due to a higher call volume, or other non-recorded factors. Further research will be necessary with repeated experimentation to truly determine the effectiveness. Sleep fragmentation had a profound effect on psychomotor and cognitive performance, as expected. The Berkley shift had a noticeable decrease in overall performance as the night progressed however, when sleep was interrupted at the 20 minute interval; the deficit was much lower than at the 1 and 4 hour interval. While prophylactic napping appeared to help the deficit, it was still present and increased throughout the night. The 48/96 schedule had expected decreases in overall performance over the first night, but even greater decreases in performance over the second night. This increase in sleepiness and decrease in performance could carry over the second day, as napping periods appeared to increase on both shifts during day 2. Due to call interruptions throughout the night evaluation period, further research could provide additional and more accurate results. “Safety naps” could truly help with improving safety and performance if limited to an appropriate length. The differences in the 48/96 shift and the Berkley shift are definitely a measurable effect. The 48/96 shift appears to carry sleep debt from day 1 into day 2 regardless of if sleep is fragmented by emergency duties at night. This will ultimately cause a decrease in work performance. The prophylactic napping period on day 2 of the 48/96 may not be a “prophylactic nap” after all. It could merely be a time for the body to make up for sleep debt accumulated during the first night of the shift. This could be the reason for a lack of improvement on the second night. Despite the socioeconomic benefits of the 48/96 schedule, the results of the current project make the health and safety risks of sleep deprivation and fragmented sleep worth evaluating. Even though there were occasionally only 24 hours of off duty time before returning to duty in the Berkley schedule, one night of sleep at home is a drastic improvement over one night of sleep at work. This is also true even if emergency calls did not occur at night while on duty. The results of this project raise several possibilities for further inquiry. Additional variables such as age, call volume, caloric intake, and overall health could be factors involved in the increase or decrease of performance. Psychomotor and cognitive function can be attributed to many job tasks performed by emergency services personnel. Driving emergency vehicles, performing patient interventions, performing tasks on the fire ground, and other typical functions could be effected by sleep deprivation and sleepiness. Along with inherent risks with job tasks, additional health problems from sleep deprivation and sleepiness could cause even further deficits in general wellness and job longevity. References
American Sleep Association. (2007) “What is Sleep?” Retrieved July 07, 2012, from http://www.sleepassociation.org/index.php?p=whatissleep. Benedictis, Tina, PhD, Heather Larson, Gina Kemp, MA, Suzanne Barston, Robert Segal, MA (2007). "Understanding Sleep: Sleep Needs, Cycles, and Stages". Retrieved June 30th, 2012, from http://Helpguide.org. Caldwell, J (October 2002). “Napping: Power or Poison”. Flying Safety Carskadon, M.A., Dement, W.C., Mitler, M.M., Roth, T., Westbrook, P.R.; Keenan, S. (1986). “Guidelines for the Multiple Sleep Latency Test (MSLT): a standard measure of sleepiness”. Sleep 9:519–524 Carskadon, M.A.; Dement, W.C. (1977). “Sleep tendency: an objective measure of sleep loss”. Sleep Research 6: 200. Chee, M. W. L., Tan, J. C., Parimal, S. & Zagoradnov, V. (2009). “Sleep deprivation and its effects on object-selective attention”. Neuroimage, 1-8 Dinges DF, Pack F, Williams K. (April 1997). "Cumulative sleepiness, mood disturbance, and psychomotor vigilance performance decrements during a week of sleep restricted to 4–5 hours per night". Sleep 20 (4): 267–77. Hublin C, Kaprio J, Partinen M, Koskenvuo M. (2001). “Insufficient sleep: a population-based study in adults”. Sleep, 24: 392–400 Macmillan Dictionary for Students Macmillan, (1994). “sleep” Pan Ltd., p. 936. Magee, Jon, PhD (1986) “Effects of Experimentally Induced Sleep Fragmentation on Sleep, Auditory Evoked Potentials, and Measures of Sleepiness”. Psychophysiology 24 (5): 528-534 Paley MJ, Tepas DI. (1994). “Fatigue and the shiftworker: firefighters working on a rotating shift schedule.” Hum Factors. 36(2):269-84. Reid, D. E. (2009). Identifying the Potential for Intrinsic Sleep Disorders in the Stanwood Camano Fire Department. Emmitsburg, MD: National Fire Academy, EFO Program. Silber, MH, Ancoli-Israel, S, Bonnet, MH; Chokroverty, S, Grigg-Damberger, MM, Hirshkowitz, M, Kapen, S, Keenan, SA (March 2007). "The visual scoring of sleep in adults". Journal of Clinical Sleep Medicine 3 (2): 121–31. Torsvall L, Akerstedt T. (1988). “Disturbed sleep while being on-call: an EEG study of ships' engineers.” Sleep 11 (1):35-8 United Fire Fighters of Los Angeles City Local 112. (2007). “The 48/96 Work Schedule” Retrieved July 14, 2012, from http://www.uflac.org/files/UFLAC%2048-96%20Color%20Primo%20v1.3.pdf. Wilmoth, Janet. (2009). “Sleep on It” Fire Chief. Retrieved July 18, 2012, from http://www.firechief.com Young, C, Jacobs, B, Clavette, K, Mark, D; Guse, C (Jul 1997). "Serial sevens: not the most effective test of mental status in high school athletes". Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine 7 (3): 196–8.
Stanford Sleepiness Scale
Stanford Sleepiness Scale
1. Feeling active and vital; alert; wide awake.
2. Functioning at a high level, but not at peak; able to concentrate. 3. Relaxed; awake; not at full alertness; responsive.
4. A little foggy; not at peak; let down.
5. Fogginess; beginning to lose interest in remaining awake; slowed down. 6. Sleepiness; prefer to be lying down; fighting sleep; woozy. 7. Almost in reverie; sleep onset soon; lost struggle to remain awake.
National Registry of EMT’s grading sheet for Ventilatory Management and Endotracheal Intubation
Basic Subject Demographics
Basic Subject Demographics
Data involving napping periods, and SSS evaluation following napping periods
Data involving napping periods, and SSS evaluation following napping periods*
*Since MCEMS works 48 hour shifts, napping periods on each day are divided by /, as well as coordinating SSS evaluation.
Evaluation summary of psychomotor and cognitive function with SSS evaluation for shift 1
Evaluation summary of psychomotor and cognitive function with SSS evaluation for shift 1*
*Since MCEMS works 48 hour shifts, results on each day are divided by / . **Subjects 7,8, and 9 received an emergency call at the approximate time of period 3 evaluations on the first night of the first shift.
Evaluation summary of psychomotor and cognitive function with SSS evaluation for shift 2
Evaluation summary of psychomotor and cognitive function with SSS evaluation for shift 2*
*Since MCEMS works 48 hour shifts, results on each day are divided by / . **Subjects 6 and 10 were on an emergency call during Period 2's evaluation time on day 1 shift 2. ***Subjects 7 and 9 were on an emergency call during Period 3's evaluation time on day 1 shift 2.