SFD Sleep Study
“It is well recognized that loss of 1 night of sleep has impairing effects on performance and consistently reduces multiple sleep latency test latencies below 5 min, well within the pathological range” (Bishop, Roehrs, Rosenthal, and Roth, 1997)
Part 1
Background
“Sleep restriction to less than 4 hrs per night for even 1 night can produce impairment” (Rosenthal et al., 1993)
There are countless studies based on the cognitive and physical impairments of sleep deprivation and the long term negative health effects. Most of the studies use less than 4 hours per night as the equivalent of zero hours of sleep, or in other words once a person has slept less than four consecutive hours in a twenty four hour period their deficits will be the same as someone who has not sleep at all.
As call volume has quantitatively increased, the anecdotal narrative of sleep deprivation has increased as well. The SFD sleep study is a pilot study to quantify sleep deprivation and subsequently intervene in cases of less than four hours of sleep within 24 hours of continuous work with the intent of reducing liability and increasing employee health and safety.
Baseline
In concert with the major sleep deprivation studies, SFD used a minimum of four hours of sleep as a goal in order to reduce cognitive and physical detriments. Since, for obvious reasons, SFD cannot guarantee a person sleep, the best that SFD can do is ensure employees get an opportunity for sleep in a four hour block without a disturbance; including drills, meals, dispatches, or special assignments. Hence, a four hour block between 11:00 pm and 8:00 am the next day becomes the baseline for the study.
Methodology
Using SFD’s record management system (RMS), the on duty EMS captain can monitor the gap between calls for each medic from 11:00 pm and 8:00 am by calculating the time an ambulance clears a call until the next dispatch. If any ambulance crew did not receive a four hour block between clear times and dispatch times, it is assured that the crew received less than the minimal baseline of sleep.
Intervention
Ambulance crews that received less than the baseline of sleep were put out of service for a four hour block to sleep the following day. No more than two ambulances were put out of service at once.
Initial findings
The sleep study has formally been conducted over three rotations at the time of this writing. Each study has shown six ambulance crews received less than the baseline of sleep every night. Those ambulance crews were subsequently put out of service on a rotational pattern the follow day.
4/26/16 — M1, M2, M6, M10, M20, M56
5/2/16 — M2, M6, M12, M17, M20, M57
5/8/16 — M1, M2, M7, M17, M56, M57
After the rest period each ambulance crew was asked the qualitative and subjective question of “Did the rest period help?” The responses were overwhelming positive to the general conclusion that the small amount of sleep made an incredible difference over their shift.
Conclusions
In concert with the anecdotal complaints of sleep deprivation, the sleep study demonstrates a major problem of sleep deprivation on SFD ambulances. Lacking intervention, the SFD ambulance crews would have likely completed a forty-eight hour shift without any sleep. The routine act of driving a city ambulance, assessing/treating patients, and performing complex drug calculations while suffering from severe sleep deprivation may put the employee and city at greater risk for litigation if a negative event occurs. In addition, the scientifically validated negative health effects of sleep deprivation on employees may open the city up to increased costs, not to mention the simple fact that we may be knowingly harming our employees.
Part 2
Background
The initial sleep study performed by SFD on the ambulance crews showed a consistent occurrence of extreme sleep deprivation, defined as less than 4hrs of sleep, on about six ambulances a night. Once the sleep deprivation was identified, the affected ambulance crews were put out of service for a 4hr block so they could continue the remainder of shift safely. Unfortunately, there was no way of measuring the effectiveness of the intervention at the time of the first study other than subjective anecdotes. This report is the measurement and quantification of the effect of 4hrs of sleep over a typical shift on the ambulance using the Epworth Sleepiness Scale.
Epworth’s Sleepiness Scale (ESS)
“If your score is greater than 6 points then you are sleepy. If your score is more than 10 points you are very sleepy. If your score is more than 16 points you are dangerously sleepy.”[1]
Introduced in 1991 by Dr. Johns, the ESS is a measurement of sleepiness through an eight question survey.[2] Each question in the survey is scored from 0 to 3 and then totaled to reach a final score. The final score of the survey is then used to quantify the subject’s daytime sleepiness before and after intervention. The following is the scored metric
· 0 to 6 — Normal
· 6 to 10 — Sleepy
· 10 to 16 — Very sleepy
· 16 to 24 — Dangerously sleepy
The ESS was used to quantify the effectiveness of a 4hr rest period after personnel on an ambulance received less than 4hrs of sleep between the hours of 11:00pm and 8:00am the proceeding night.
The ESS was administered by EMS 22 over the phone before and after the personnel were allowed to rest and recorded in a spreadsheet. Over the initial study period the ESS was recorded twelve times.
Findings
Of the twelve times the survey was conducted, the average score before rest was 17.9, or “Dangerously sleepy,” with a high score of 23 and a low score of 12. The average score after a 4hr rest period was 1.75, or “Normal,” with a high score of 5 and a low score of 0. The survey showed a dramatic shift from “Dangerously Sleepy” to “Normal” with an intervention of four hours of rest.
Conclusions and Recommendations
The evidence supports that SFD has on average six ambulances a night that receive less than four hours of sleep during a 48 hours shift. The ESS showed a dramatic shift with a small intervention on the second day of a person’s shift if they received no rest the night before. Therefore, I recommend a formal policy to monitor workload between the hours of 23:00 and 08:00, and intervene with a 4hr rest period when crews did not get a minimum of 4hrs of rest the night before.
[1] https://www.slhn.org/docs/pdf/neuro-epworthsleepscale.pdf
