Seeking sleep solutions for shift workers
Researchers assess various remedies
As emergency physicians, we are all too familiar with the challenges of shift work: The bleary-eyed drive home at 8 a.m., the struggle to sleep while the sun is shining brightly outside, and the heartburn from coffee guzzled on the way to the next night shift.
Out of phase with the world’s natural circadian rhythms, shift workers can develop sleeping disorders, which not only affect their health, but which put them at risk of making serious mistakes while at work. Many shift workers have occupations with a high degree of mental or physical strain, making the risk of human error both greater and more serious.
Shift workers, who account for about a quarter of the workforce, are about 30 per cent more likely to fall asleep while at work, and they sleep less and more poorly in general than daytime workers. This type of work extracts a physical toll, as shift work has been implicated as a risk factor for cardiovascular disease, cancer, miscarriage, and premature labour. Cognizant of this, shift workers employ a variety of strategies to rest properly between shifts and to ensure excellent performance while at work.
The typical tricks are to sleep in a quiet, completely black room, to avoid excessive caffeine, and to try to sneak in a nap in the early evening before returning to the night shift. But any shift worker will tell you that these tricks are not universally effective, and the cumulative effects of sleep deprivation prompt many to ask their GP for a prescription for sleeping pills.
Sleeping pills come in a few different forms. There are over-the-counter agents, most of which are also used for nausea or allergies, and which are prone to causing a daytime “hangover” effect. Also available without a prescription is melatonin, which is a hormone naturally produced by the brain to cue sleep. Prescription agents include medications like lorazepam, zolpidem, and zopiclone; with these medications there are serious risks of daytime sleepiness and driver error, as well as a risk of dependency with long-term use. Also available are stimulant medications meant to increase alertness while at work.
Given the risks, are prescription sleeping aids or stimulants a good idea for shift workers?
A group of Finnish researchers conducted a comprehensive review of the best available evidence on this subject. Working as part of the Cochrane collaboration, an international health project aimed at bringing together the best of research evidence to inform patients and providers, the Finnish researchers identified 15 medical trials that met the standard for good study design.
The most extensive evidence looked at the impact of taking varying doses of melatonin before heading off to bed after a night shift. With doses ranging from one mg to 10 mg, the duration of daytime sleep increased by an average of 24 minutes. Nighttime sleep improved by a slimmer margin — just 17 minutes. There was no effect on the time it took to fall asleep as compared to study subjects who received a placebo.
A commonly used sleeping pill called zopiclone was examined in one small trial and failed to report an improvement in daytime sleep after a night shift. In another small study, taking a nap before a night shift and stocking up on caffeine in one form or another increased levels of alertness during the shift.
Much of the attention of the Cochrane review was directed to a relatively new class of stimulant medications, chiefly modafinil and armodafinil. Both agents resulted in improved alertness and reduced reaction times in shift workers — but not without a price. These agents were associ- ated with an increased risk of skin reactions, headaches, nausea and increased blood pressure.
The authors conclude that none of the medications looked at were useful remedies for shift-workrelated sleep disorders (although some might be worth a try) and that more studies are needed.
The Cochrane collaboration is developing a similar project on non-pharmacological aids to help shift workers make it through the night and hopefully we’ll see more promising approaches. In the mean- time, we’ll stick to a nap and an extra-large coffee to go.