Background
According to the Labor Law, shift work refers to employees working staggered and alternately at the same workplace: “Shift work occurs when two or more groups of employees are assigned to work staggered and alternately at the same workplace according to a specific schedule.” This definition also refers to work during the day. From a medical perspective, shift work is usually understood to mean night work and the associated health risks. Night work poses a potential risk not only to the employee, but also to the employer and the business. For example, many of the major technological disasters of recent decades, such as Chernobyl, Bhopal, and Exxon Valdez, occurred during the night. Night work, its duration and work schedules are very heterogeneous and include operations during on-call, rotating systems to permanent night work.
Symptoms
A number of health complaints are attributed to night work, which may occur during work (e.g., fatigue) or leisure (e.g., sleep disturbances). These include fatigue, lack of concentration, reduced performance, sleep disorders such as insomnia or increased need for sleep, reduced sleep duration, digestive disorders, cardiovascular disorders, increased risk of accidents, emotional problems, and stress and its negative consequences. Whether night shift work also poses a longer-term health risk, for example, for the development of certain cancers, is a matter of debate.
Causes
Humans are biologically diurnal and rest at night, during the dark phase. The “internal clock” in the hypothalamus dictates this circadian rhythm, keeping us awake during the day and letting us sleep at night. Especially early in the morning, between about 2 and 5 a.m., we are less productive and the need for sleep reaches a maximum. A second mechanism ensures that we get enough sleep overall and also makes us tired during the day if we get too little rest. The potential problems of night work arise as a result of the desynchronization of the circadian rhythm. The sleep-wake rhythm does not coincide with that of the internal clock. At night, when the worker wants to sleep, he may not, and in the morning, when he could sleep, he does not succeed or not in the sufficient quality, because the internal clock keeps him awake. The usual consequence is a shortened sleep duration. The inner clock can be changed, but this takes several days. In addition, the disturbed social rhythm must be taken into account, which can strongly affect the relationship and family life.
Non-drug measures
From the point of view of health, it is always advantageous in principle to refrain from night work. There are a number of recommendations for increasing the tolerance of night shift work:
- In the morning when going home, bright light should be avoided by wearing sunglasses, because light is the natural antagonist of melatonin. When sleeping after work, the rules of good sleep hygiene should be followed. This includes a sufficiently darkened, quiet, cool room. Do not eat large, fatty meals before bedtime. Also, sufferers should always go to sleep at the same time (even during days off).
- Expose themselves to bright light during the night work.
- Sleeping briefly several times during the shift (napping, short naps).
- Continuing education and medical care
- Conversion of the sleep phase through light therapy
- Adjusted work schedules
Further tips can be found, for example, in Kuhn (2001, Pubmed).
Medication measures
Stimulants:
- Such as caffeine, for example in the form of coffee or energy drinks, are taken during the night shift to prevent falling asleep. A possible problem is a lingering stimulation during free time, which can lead to insomnia.
- In the US and EU, but not in many countries, modafinil is approved for the treatment of severe symptoms for shift work sleep disorder. It is taken before night work and keeps one awake. Armodafinil, the enantiomer of modafinil, has also been studied, but is not commercially available in many countries.In July 2010, the European Medicines Agency recommended against the use of modafinil in this indication because modafinil can rarely cause serious side effects.
- We do not consider amphetamines such as methylphenidate to be appropriate because of the possible adverse effects and potential for dependence. They are also not approved for this indication in many countries.
Sleeping pills:
- Herbal medicines such as valerian, lemon balm, hops and passionflower are well-tolerated but weakly effective sleep aids.
- Antihistamines such as doxylamine and diphenhydramine, as well as benzodiazepines and mechanistically related agents such as zolpidem or zopiclone, while well effective, are addictive and may cause a number of adverse effects. In our view, they do not represent an optimal solution.
Melatonin:
- Is a hormone of the pineal gland (pineal gland) of the brain, which plays an important role in the regulation of the sleep-wake cycle. It has a sleep-inducing effect and reduces body temperature. Physiologically, melatonin levels in the blood rise after nightfall and peak around the middle of the night. From a theoretical point of view, there is a good case for taking it during the day before bedtime, but melatonin is not approved for this indication and has not been adequately studied scientifically.
- Melatonin receptor agonists could also be used, but they are not approved by the authorities for this indication.