Coping with irregular working hours: preventing sleep problems in doctors, nurses, and other health professionals
• Sleep is essential to health and well-being
• Scheduling adequate time for sleep is very important
• Aim for 7–8 h of bed rest per 24 h
• Establish and maintain a sleep–wake routine on days with normal hours and on rest days in between shifts
Long and irregular working hours and difficult, responsible work with limited resources are just some of the stresses experienced by doctors and other health professionals (Ahmed-Little 2007). On top of all this are often extra stressors such as sleep deprivation and fatigue. Maintaining good sleep is therefore extremely important in order to be able to do the job properly and also to be able to enjoy life outside work. Much of the information in this chapter has been mentioned elsewhere with regard to patients with sleep problems, but is just as relevant to healthy people.
10.1 Sleep is a priority
Scheduling enough time for sleep is very important, and should not be relegated to the bottom of the list when everything else has been fitted in. Good sleep is essential for health and well-being, and if we allow it to deteriorate, there is a risk that it will not normalize once the stressful or irregular work pattern has ended. We have seen many doctors and nurses as patients in the sleep clinic, whose sleep pattern never recovered properly after they stopped working shifts or on call.
We all have different sleep requirements, but in general the standard 7–8 h in bed is probably a good rule of thumb to aim for. Many people who work in the daytime for 5 days a week, with weekends off, tend to have shorter sleep in the week and catch up the sleep debt at weekends. This is fine so long as sleep is satisfactory and tiredness in the day does not become obvious before Friday evening. However, when there are irregular working hours, a certain amount of planning is needed, in order that the sleep debt is made up adequately and in time so that we function optimally every day. There are many anecdotal reports which suggest that poor sleep and consequent daytime mental fatigue are associated with errors and omissions at work, and a study in the USA found increased attention errors in junior doctors working in intensive care settings dependent on the number of hours worked per week (Lockley et al 2004). Recently, an international committee of experts in circadian rhythm and sleep produced some recommendations for coping with irregular work patterns in doctors (Horrocks and Pounder 2006). These apply to all of us who need to work shifts out of hours, and some of them are included in the section that follows.
Medical practice has improved in recent years so that the worst excesses of nightly on-call with the expectation of a full day’s work afterwards have been abolished under European working time directives. However, even these new working practices still mean that doctors and nurses are called upon to work night shifts at least weekly, sometimes for several nights, and to work in the daytime for the rest of the week. Understanding the basic regulation of sleep can help when forming a strategy to manage the disruption of routine that these shifts cause.
10.2 Control of sleep
Sleep pattern is controlled by two main processes, which were described in Chapter 1. The first is circadian rhythm, a 24-h pattern of sleeping and waking that is usually synchronized with the outside world by bright light, physical activity, and routine. Innate circadian rhythm is governed by the suprachiasmatic nucleus in the hypothalamus, which sets the timing not only for sleeping and waking, but also for liver function, hormone release, digestion, and most other bodily functions. If this pattern of light and routine is changed—for example, when travelling across time zones—it takes a few days for the internal clock to synchronize with the new environment, and if we are staying in this new environment for longer than a week, it is important to take steps to synchronize as fast as possible. Similarly, people on permanent night shifts often plan their activities outside work so that their internal clock stays on the ‘day-for-night’ rhythm. However, for people who only work 1–3 nights a week, it is sensible not to try to change the circadian drive, but to maintain a regular routine while on days.
The second process is the homeostatic process (S) or recovery sleep drive, which gets stronger the longer we are awake, as it builds up a sleep debt. When these two drives are strong at the same time, usually at around 11 p.m., then we are more likely to fall asleep readily, so long as we are fairly relaxed. It is when these two drives become separated in time that we have problems getting to sleep or waking up, and this happens when working at night. The internal clock’s sleep phase is at its maximum at about 04.00 a.m., but we need to be awake then, and in the daytime the internal clock is programmed for waking when the S process is making us sleepy.
The best we can do in the short periods of out-of-hours working is to minimize the sleep debt and attenuate the external cues, which strengthen the circadian process. This will not stop us feeling tired altogether, but it will help.
10.3 Establishing a sleep–wake routine during the non-night-shift period
Box 10.1 lists some useful points. Note that these points are just as relevant for improving sleep in people who do not work nights.
Make sure that your bedroom is suitable and not used for other activities such as watching TV or using the computer. It is important to associate being in bed with being asleep.
10.3.1 Regular bedtimes
During periods of ‘normal’ working, it is important to schedule say 8 h in bed each night, and the critical aspect of this is deciding on a regular getting-up time and sticking to it, and going to bed 8 h before that time. Most people find that sleeping on in the morning for long periods on rest days makes it less likely that they will go to sleep quickly at their normal bedtime, so on the last rest day before a day shift it is best to get up at the workday time.
10.3.2 Morning daylight
If there is any, go out and get it! During normal working, getting morning daylight is important—for example, by being outside for half an hour soon after getting up, cycling or walking to work perhaps. This provides the light cue, which strengthens the circadian clock.
It is best to take exercise in the morning or late afternoon but not in the evening, because exercising after about 7 p.m. means that the rise in body temperature and increase in circulating adrenaline levels will not have recovered by bedtime and will be arousing.
10.3.4 Winding down in the evening
Excessive arousal near bedtime will delay and fragment your sleep, so late-evening activities should be relaxing and not strenuous, upsetting, or very intellectually demanding like studying.
10.3.5 Caffeine and alcohol
Caffeine keeps you awake, and as little as one cup of coffee near bedtime will make it less likely that you will go to sleep quickly, so it is probably best to stop caffeine 4 h before going to bed. Alcohol tends to make you sleepier at bedtime, but as the effects wear off during the last part of the night, you are more likely to have fragmented sleep.
10.4 The day before a night shift
On this day, get up at your usual time or a bit later and have your meals as usual. In the afternoon or early evening, have a nap for 2–3 h to reduce the sleep debt for later. The effects of caffeine in tea, coffee, and cola begin to occur after about 20–30 min and last for about 4 h, so these beverages can be taken in the evening.
10.5 During the shift
During the night it is very important to try to have at least one nap, for about 30–45 min. Nurses usually plan this, but it is becoming more difficult for junior doctors, because on-call rooms have disappeared in many hospitals. There is great pressure to have these facilities restored. It is a good idea to take a caffeinated drink just before the nap, so that by the time you wake up, the effects will be apparent, but remember that caffeine will work for 4 h, so do not take it after about 5 a.m. Your memory and concentration are likely to be impaired for a few minutes immediately after this sleep (see Chapter 1).
10.6 The day after a night shift, if you do not have to work the next night
When you go off duty in the morning, remember that your risk of having a car accident on the way home may be increased by about three times, so if you can use another form of transport, do! If possible, try not to see much daylight—for example, wear sunglasses if it is bright. Have a light meal if you wish, and then go to bed with the curtains drawn (avoid lying on the sofa if possible, bed is best because you are used to being asleep there) and sleep for about 3 h.
For the rest of the day be active, and take your meals as usual. You will probably feel the urge to go to bed early, but if so, try to keep awake until about an hour before your usual bedtime. You will then be ready to assume your usual routine the next morning.
10.7 If you have to work another night shift
The same advice about driving home applies. It is important that your bedroom remains dark, quiet, cool, and undisturbed, because now you need to sleep for 6–7 h, or sleep deprivation will impair your functioning at night. Your family or housemates should be primed about this. If you cannot sleep for very long, try to have a nap later in the day as well (see Box 10.2). Get some exercise during the late afternoon or evening as you usually do.
Sleep deprivation and alcohol have similar effects on vigilance, and together they are additive. Alcohol will therefore have more impairing effects, especially on driving and the skills you use at work.
10.8 Learning and memory
It is fairly well established that learning is consolidated and improved by sleep (see Chapter 1), and this makes it even more important to sleep after you have learned some procedural skills during the night. Also, material that is studied for exams on days between night shifts may be less successfully remembered than that studied on ‘normal’ days.
Take sleep seriously—for your own sake and that of your patients.
Ahmed-Little Y. (2007). Implications of shift work for junior doctors. BMJ 334:777–8.Find this resource:
Horrocks N, Pounder R (2006). Working the night shift: preparation, survival and recovery—a guide for junior doctors. Clin Med 6: 61–7.Find this resource:
Lockley SW, Cronin JW, Evans EE et al (2004). Effect of reducing interns’ weekly work hours on sleep and attentional failures. N Engl J Med 351: 1829–37.Find this resource: