Take steps to protect nurses and ensure patient safety.

Takeaways

• Shift work is common among nurses and can lead to significant health, social, and family disturbances.
• Individual nurses and healthcare organizations must work in tandem to promote healthy sleep and minimize the negative effects of shift work.

The standard Monday through Friday, 9:00 am to 5:00 pm work schedule has become a thing of the past for many workers. The global economy, expanded technology use, and competitive labor markets have dramatically changed when, where, and how work is done. The prevalence of nonstandard work hours, flexible schedules, contract work, and shift work vary by occupation, education, gender, race, and ethnicity, but the U.S. workforce is made up of approximately 157 million individuals, and estimates suggest that 20% work shifts.

Because of the ubiquity of nurses across care settings and the high-touch nature of bedside care, the health and safety ramifications of shift work on nurses and their patients is significant. When individual nurses and organization leaders understand the basic principles of human sleep, the effects of shift work, and the implications for nursing practice, they can take steps to mitigate health and safety risks.

Sleep essentials

Sleep is as necessary for human survival as air, food, and water. Sleep is separated into two states—non-rapid eye movement (NREM) and rapid eye movement (REM)—which are measured using an electroencephalogram. In healthy adults, sleep onset occurs through NREM sleep and is followed by REM sleep. Then, NREM and REM sleep alternate throughout the night in 90- to 120-minute cycles. Most sleep is NREM, which has four distinct stages. The National Sleep Foundation recommends that healthy adults (26 to 64 years) get 7 to 9 hours of sleep each night and that older adults (≥65 years) get 7 to 8 hours of sleep.

How is sleep regulated?

The classic sleep model has two distinct processes that overlay one another: sleep homeostasis (Process S) and circadian rhythm (Process C). Process S is based on prior sleep and wakefulness. As wakefulness is maintained, sleep pressure builds—the propensity to sleep increases. After sleep occurs, that pressure diminishes until the next bout of wakefulness begins and sleep pressure builds again.

Process C is governed by our central clock, the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. This central clock oscillates in an approximate 24-hour period, thus the term “circadian rhythm,” which is derived from the Latin words “circa” (about) and “dies” (day). The SCN is affected by external stimuli, such as eating and drinking, exercise, and temperature, but light is the strongest synchronizer. When the SCN is properly synchronized with the daily light/dark cycle, other behavioral (eating/fasting, sleeping/waking) and physiologic (body temperature, melatonin) rhythms will align. In addition to the SCN, other peripheral clocks function in the body’s organs and tissues (such as the liver and adipose tissue), as well as in metabolic pathways. Coordinated central and peripheral circadian rhythms are essential for virtually all biologic processes.

What are the genetic components of sleep?

Individual differences in human sleep need are well documented. However, sleep need follows a Bell curve, indicating that most people require the recommended 7 to 9 hours of sleep each night and few people require a lot more or a lot less sleep.

Several heritable sleep phenotypes (chrono­types) have been identified. They’re commonly described in terms of morningness and eveningness (diurnal preferences, sleep–wake activity pattern, and morning and evening alertness). Someone on the extreme morningness end of the spectrum (early lark) is an early riser, performs best in the morning, and goes to bed early in the evening. Those who fall on the extreme eveningness end (night owls), go to bed late, get up later in the morning, and perform best in the late afternoon and evening. Most people, however, display an intermediate chronotype; they’re not an early lark or night owl, but fall somewhere in between.

Unlike animal models, identifying human genes that regulate sleep and circadian rhythms have been primarily limited to candidate gene analysis. This approach focuses on associations between genetic variation within specific genes of interest rather than looking at the entire genome. More research is needed to identify genes specific to sleep disorders to aid treatment decisions and develop best clinical practices.

What’s the connection between circadian misalignment, shift work, and disease?

Shifts in sleep and wake patterns are affected by changes in photic (light) and nonphotic (eating, exercising) input. Bright light exposure at night or a change in mealtimes can lead to circadian desynchronization. A main source of circadian desynchronization is shift work, which requires workers to be awake when they normally would be asleep and asleep when they normally would be awake. Most shift workers have different wake/sleep schedules on work and non-workdays because of family and social responsibilities, putting them in a chronic state of circadian misalignment, which can lead to serious health consequences. Across peripheral organ systems, circadian disruption has been linked to cancer (breast, prostate, colorectal), mood disorders (depression), cardiovascular disease (coronary heart disease), metabolic dysfunction (impaired glucose tolerance), and decreased fertility. Nursing is primarily a female profession, making the links between nightshift work (even for only a few years) and breast cancer and reproductive issues particularly concerning.

Shift work sleep disorder (SWSD) is characterized by circadian rhythm disruption as a result of social and work schedules that lead to excessive sleepiness and/or insomnia. Sleep/

wake disturbances also may cause significant distress or impairment in mental, physical, and social functioning. Approximately 20% to 30% of shift workers experience symptoms consistent with SWSD; however, more population-based studies are needed to determine the exact prevalence. If switching to a standard dayshift schedule isn’t possible, sleep medicine providers can diagnose and treat SWSD with both behavioral (bright light, exercise) and short-term pharmacologic (melatonin, stimulants) interventions. (See Shift work and safety.)

Practice recommendations

Work-related interventions to eliminate or reduce the effects of shift work can be implemented by individual nurses, managers, and organizations.

Individual nurse interventions

Overall sleep hygiene is important for all nurses. The ideal sleep environment is cool (68° F to 72° F), dark (blackout shades or an eye mask can be used during the day), and quiet (white noise machine or ear plugs can help reduce ambient noise, especially during the day). To reduce exposure to sleep-suppressing blue light, the environment should be free from electronics (tablets, phones, and TVs). Nurses commuting home from the nightshift should consider wearing blue light–blocking sunglasses and using phone apps that reduce blue light stimulation.

Healthy eating is important for good sleep, as is limiting food intake 2 to 4 hours before bed. Caffeine, alcohol, and nicotine can impair sleep quality and shouldn’t be used 3 to 4 hours before sleep.

Nurses who work nightshifts need to make additional modifications to optimize their sleep. They should try to sleep directly after their shift. Even on days off, nurses may want to consider keeping a consistent anchor 4- to 5-hour sleep period in addition to a second 3- to 4-hour sleep period from, for example, 8:00 am or 9:00 am until noon or 1:00 pm. On nightshift workdays, a short nap combined with caffeine just before the shift begins can enhance alertness.

Manager interventions

Individual nurses and nurse managers can actively monitor scheduling and shift work practice. Mangers should strive to reduce the number of allowable consecutive shifts (no more than three in a row) and shift lengths (< 12 hours). Ensuring that the time off between shifts is at least 11 hours helps the body recover and allows for adequate sleep between shifts, and nurses should have at least 3 days off after working nightshift. When rotating shifts, nurses should be scheduled using a clockwise or forward rotation so that they move from day, to evening, to nightshift.

Managers should provide shift work awareness education that includes topics such as sleep hygiene, chronotype and shift work, strategic use of naps while working or on-call, and how to recognize signs of excessive sleepiness in colleagues. Management also should provide screening and referral to sleep medicine or occupational health for evaluation of SWSD. Free resources, such as the National Institute for Occupational Safety and Health Training for Nurses on Shift Work and Long Work Hours, can be used in these staff development sessions.

Organizations also might want to consider providing taxi vouchers or other incentives and support to promote safe commuting for nurses working extended or nightshifts.

Promote healthy sleep

Sleep is a crucial biologic need. Adequate sleep quality and quantity are necessary for optimal neurobehavioral functioning and on-the-job performance. Nurses traditionally don’t receive adequate, if any, pre-licensure education on sleep or shift work. To protect nurses and the patients in their care, individuals and organization leadership must take steps to promote schedules that limit circadian disruption and develop policies and practices to monitor workers for signs of sleep disorders and functional decline

Editor’s note: To learn more about the effects of shift work and how you can get a better night’s sleep, visit Nursing, night shift, and nutrition and In pursuit of a good night’s rest.

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