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Working the night shift

If something goes wrong on a night shift, fatigue is no defence. Sara Dawson explores how managing your sleep will safeguard your practice and the lives of your patients

What do industrial incidents at Bhopal, Chernobyl and Three Mile Island have in common? They all happened at night.

Many studies of human efficiency and mental agility have shown significant dips between 10pm and 6am, and the risk of injury is 30% higher on a night shift compared to a morning one. Twenty to twenty five hours without sleep – as might be experienced by a doctor who has worked just one night and was without rest during the day leading into the shift – reduces psychomotor performance to the level of someone with a blood alcohol concentration of 0.10%.1 Night work requires doctors to remain awake and alert, when physiologically programmed to be asleep.

Sleep deprived interns and community service doctors work up to 200 hours of overtime per month owing to chronic medical staff shortages.2 Junior doctors often work extremely long hours – a normal day, through the night, and possibly a short next day. Working the night shift involves covering several hospital wards and managing acute admissions.

In the medicolegal world, a mistake by an overworked and tired doctor is still a mistake
On the one hand, working nights is a great learning opportunity for new doctors to cover unfamiliar specialties, have increased clinical responsibility and deal with acutely ill patients for the first time. But on the other, a lack of sleep can strongly impair human functioning and lead to memory loss, attention deficit, negative mood changes, over-optimistic risk-taking, prolonged post-call recovery, road accidents and mistakes on duty and in surgery.3
In the medicolegal world, a mistake by an overworked and tired doctor is still a mistake. Exhaustion is no defence for poor decision-making. Doctors who adequately prepare for a night shift minimise the risks for themselves and their patients, and reduce the likelihood of making errors.

Before a night shift

  • Be organised – Sort out personal issues, such as paying bills, etc, before starting a week of nights.
  • Be healthy – Generally living a healthy and active lifestyle may reduce the negative effects of working nights
  • Be prepared – Several common clinical problems occur on night shifts, including shortness of breath, chest pain, hypertension and hypotension, confusion and agitation, fever, hyperglycaemia and hypoglycaemia, pain and common postoperative conditions.
  • Get plenty of sleep – A doctor who has no sleep during the day leading into a shift will have gone 20-25 hours without sleep. This could reduce their psychomotor performance to the level of someone with an alcohol concentration of 0.10% – the legal limit to drive is 0.08%.
  • Avoid your bedroom – Associate your bedroom with sleeping, by playing video games, etc, in another room.
  • Socialising – See your friends or undertake a sporting activity.
Your response is not as safe as it is during the day, so repeat calculations and double-check drugs

During a night shift

  • Eat and drink properly – Follow a similar eating pattern to the one you follow in the day. Eat a main meal before you start, have “lunch” halfway through the shift and an easily digestible meal when you get home.
  • Double-check – Your response is not as safe as it is during the day, so repeat calculations, double-check drugs, etc.
  • Staff support – There are fewer nursing staff on the wards, so patients are not as closely observed as they would be during the day.
  • Ask for help – Grappling with a difficult consultant is better than having to deal with an adverse incident that leads to a patient’s death. The one thing you don’t have is experience.
  • Caffeine – The circadian nadir is between 3am and 6am, so it may be tempting to drink more coffee to keep awake, but remember if it is consumed four hours before the end of your shift it will make it harder to sleep.
  • Take naps – Short naps have shown to provide positive benefits for shift workers, but they should not last more than 45 minutes. Set an alarm beforehand to prevent you falling into a deep sleep. By taking a small dose of caffeine before your nap, you should start to feel the effects when you wake up, which may help overcome the sleep inertia you will feel after a nap.
  • Maximise exposure to light – Exposure to bright light has an alerting effect on the brain and improves performance.

After a night shift

  • Limit the effects – Our bodies are controlled by our body clock, situated in the suprachiasmatic nucleus (SCN) in the hypothalamus. It generates circadian rhythms that regulate the physiological processes in the body. Working nights causes a mismatch between the circadian timing system and environmental synchronisers. Circadian rhythms are strongly influenced by natural light and dark, so wearing dark glasses on your way home, using earplugs, blacking out curtains and turning off your phone, will limit the effects and make it is easier to sleep during the day.
  • Be extra vigilant – If you’re planning to drive home, consider the risks of doing so. If in doubt, take a taxi.
  • Sleeping pills are not recommended – They can cause hangover-like symptoms and addictive effects. Consult your GP if you think they are necessary; never self-prescribe.


  1. Williamson AM, Feyer AM, Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication, Occup Environ Med 2000, 57:649–55
  2. Erasmus N, Slaves of the state – medical internship and community service in South Africa, SAMJ 2012, 102:8
  3. Ibid