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Shift Work Disorder

When your overnight shift becomes your morning after nightmare!

Thomas Edison’s invention of the light bulb in 1879 set in motion patterns of work that affect us to this day. Historically, mankind worked during the daylight hours, but the invention of electricity and light bulb laid the groundwork for today’s 24/7 society. Some estimate that up to 20% of Americans engage in some type of shift work, including doctors, nurses, construction workers, police officers, pilots, commercial drivers and many more.

What is “Shift Work”?

Shift work refers to any job that falls outside of a traditional nine to five work schedule, including those who start work before 6:30 a.m. or after 4:30 p.m.

Types of non traditional work shifts include:

Graveyard or night shift: 10pm to 6am;

Early morning shift: 6am to 2pm; and

Early evening shift: 2pm-10pm.

In addition, shifts can be permanent or rotating. Shifts can rotate forward (clockwise, from morning to afternoon to evening); or backward (anticlockwise: from night to afternoon to morning).

Rotating shifts cause more sleep difficulties than permanent shifts and counterclockwise rotation affects sleep negatively more that clockwise rotation. In addition, other factors like the speed of rotation and the length of shift also have an impact on the sleep wake schedule.

How does shift work affect sleep wake rhythm?

Every living cell in our body has a rhythm. In fact, our bodies have several different cycles/rhythms. Sleep wake cycle is one of the vital rhythms that follows a circadian pattern (from Latin circa means “about” and dian, meaning “day”). The control center for this rhythm lies in hypothalamus and is responsible for regulating our body temperature, appetite, hormone secretion, water intake and sleep wake cycle.Screen Shot 2015-05-23 at 6.13.18 PM

Environmental light helps to keep our circadian rhythm timing to a 24 hour period. The circadian rhythm is ingrained in each one of us causing our body’s natural desire to be asleep at night time, and to be awake during the daytime. Our body likes to operate on a routine schedule and know what to expect. When you expose yourself to sunlight at some times during the week, but not others — when you’re sleeping at nighttime some nights and then during daytime at others — the body has difficulty knowing what to anticipate and when to produce transmitters and neurochemicals responsible for sleep and digestion and proper body functioning..

Normally, we are adept at adjusting our sleeping schedules. Our brain makes note of the external cues (sunlight, time on the clock, other people up etc) and is able to keep us awake. However, for night shift workers, daytime hour is the period when they need to sleep. This disruption of their circadian rhythm leads to sleep disturbances and other metabolic disorders.

What are the main symptoms of Shift Work Disorder?

The hallmark of Shift Work Disorder are: Excessive sleepiness during working hours and an inability to fall asleep during the daytime sleep period. Workers with significant symptoms — including headaches, lack of energy and trouble concentrating — should talk to their doctors.

How common is Shift Work Disorder?

Roughly about 10% of shift workers report Shift Work Disorder. (14% amongst permanent night shift workers and 8% among rotating shift workers).

Overall, shift workers constitute about  6.4% of the work force in the US. This translates into 1% of working population in US having Shift Work Disorder.

Studies report that 30% of shift workers report dozing off about once a week during the working hours. And about 50% report falling asleep at some point while commuting home from work. These symptoms are greater in intensity and frequency, with an inability to function adequately, in those with Shift Work Disorder.

How does the physician make a diagnosis of Shift Work Disorder?

The diagnostic criteria according of American Academy of Sleep Medicine includes:

  1. Patient must have significant insomnia or excessive sleepiness that interferes with functioning and is associated with a work schedule that overlaps the usual sleep period.
  2. Symptoms must be associated with a shift work schedule over the course for at least one month
  3. Mis-alignment between the body clock and environmental clock manifested by loss of a normal sleep wake pattern has been documented by sleep log or diary and lab/home sleep recordings.
  4. Sleep disturbance is not explained by another sleep disorder, medical, neurological or psychiatric disorder, medication use or substance abuse disorder.

What are the assessment tools used in the diagnoses of Shift Work Disorder?

Complete medical, neurological, psychiatric, drug and alcohol history. Relevant past and family history.

Physical examination to exclude any other related conditions.

Detailed sleep log and diary for a period of 2 weeks to establish sleep wake pattern.

Administration of scales including the Modified Epworth Sleepiness Scale.

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  1. Sleep study: Polysomnography study to confirm the diagnosis and rule out other sleep disorders including sleep apnea, narcolepsy, restless leg syndrome and other circadian rhythm disorders.
  2. MSLT (Multiple Sleep Latency test): to determine the severity of sleepiness. Ideally, it should be done during the “normal” working hours of the patient to assess patient’s level of sleepiness.
  3. Actigraphy Recording: It involves wearing a watch like motion sensor device on the wrist or the ankle, and monitoring the body movements.

What are the goals of treatment of Shift Work Disorder?

A) To realign the internal body clock with the external altered sleep schedule by employing non pharmacological and behavioral measures so that one’s body adapts to the shift work schedule

B) Symptomatic treatment to improve sleep and maintain wakefulness.

What are some Non-pharmacological methods to combat Shift Work Disorder?

1) Limit the number and duration of shifts in a row. You may become increasingly more sleep-deprived over several nights on the job. You’re more likely to recover if you can limit night shifts and schedule days off in between

2) Avoid frequently rotating shifts. If not possible, ask for a schedule that rotates from day shift to evening to night rather than the reverse order.

3) Limit caffeine. Drinking a cup of coffee at the beginning of your shift will help promote alertness. But don’t consume daytime-sleeping-tips-no-coffeinecaffeine later in the shift, or you may have trouble falling asleep when you get home.

4) Keep your workplace brightly lit to promote alertness.

5) Avoid excessive overtime hours.

6) Arrange short breaks during the work hours.

7) Try to avoid long commutes that take time away from sleeping and increase the risk of accidents.

8) Avoid bright light on the way home from work, which will make it easier for you to fall asleep once you hit the pillow. Wear dark, wraparound sunglasses and a hat to shield yourself from sunlight.

9) Don’t stop to run errands. Takes time away from sleeping.daytime-sleeping-tips-restful-environment

10) Exercise common sleep hygiene habits during the daytime sleeping hours.

11) Keep a consistent sleep wake schedule even on days off from work.

12) During the daytime sleep, turn off all phone ringers and ask callers to leave a voice message.

13) Darken the room by using heavy drapes and curtains.

14) Educate family, friends and neighbors about your need for uninterrupted sleep and forbid them to disturb you.daytime-sleeping-tips-no-noise

15) Put up “Do not Disturb” signs on your bedroom door and the main door of the house.

16) Consider using a white noise machine and ear plugs to maintain a quiet environment.

17) Maintain a regular schedule of exercise. Plan for exercise after you wake up instead of doing it prior your sleeping.

18) Eat healthy food , reduce the consumption nicotine or alcohol.

19) Expose yourself to bright light when you wake up using special light boxes.

20) If possible, allow your body a second sleep episode of 1 to 1 and 1/2 hour  in the late afternoon or early evening (prophylactic nap) to improve wakefulness and performance.

Use of Light therapy in Shift Work Disorder:

Circadian rhythms are controlled by a part of the brain that is influenced by light.

When you wake up: Expose yourself to bright light from special light boxes or lamps. Exposure to bright light when you start your “day” can help train your body’s internal clock to adjust. Also, keep your workplace brightly lit to promote alertness. Bright light has an alerting effect that improves wakefulness, attention, memory, and concentration during the working hours in night shift workers. Generally a bright light with intensity varying from 2500 lux to 10,000 lux  is used in early part of night. Sometimes it can be given intermittently during the first 6 hours of work, each session lasting 15-20 min at 45 minute intervals.

When you finish work: Avoid bright light which will make it easier for you to fall asleep once you hit the pillow. Wear dark, wraparound sunglasses and a hat to shield yourself from sunlight during your commute home from work. At home, do not allow sunlight to peek through curtains or shades. Sunlight is a potent stimulator of the circadian rhythm. Even if your eyes are closed, the sunlight coming into the room tells your brain that it’s daytime making it harder for you to fall asleep.

What are the Pharmacological interventions used in Shift Work Disorder?

There are no medicines to cure Shift Work Disorder. If behavioral changes don’t help, doctors can prescribe medications to help people stay alert when they need to be awake and help shift workers fall asleep. But the role for sleep medications or wake promoting agents is limited.               daytime-sleeping-tips-sleeping-pills

Stimulant medications such as Nuvigil and Provigil can relieve sleepiness when people need to be awake. These drugs are approved for the treatment of excessive sleepiness related to shift work disorder, among other conditions.

Sleep aids such as Ambien, Lunesta, and Sonata may be prescribed to help with falling asleep. Certain antidepressants and benzodiazepines may also be used to help with sleep.

The medication need to be carefully monitored and used cautiously as they only treat the symptoms not the disease itself.

What are some of the risks associated with Shift Work Disorder?

Regular, restful sleep is crucial for the body’s repair. The body’s ability to recover and recuperate from the damage done during the daytime on a cellular level is affected by the night shift.  It causes our sleep schedule to become erratic or irregular, causing a wrench in the  repair process leading to potential short term and long term consequences of shift work causing nearly 25% higher healthcare costs.

People with shift work disorder have higher rates of absenteeism due to illness. Increased incidence of accidents related to sleepiness poses a considerable public health risk.

Shift work disorder imposes a considerable stress for a variety of reasons, such as sleep disturbance, disruption of family and social life, insufficient quality time spent with children and spouse, job stress, etc.

Chronic sleep deprivation due to insomnia in shift workers causes impairment in their memory and ability to focus. Shift workers who are sleep-deprived often get irritable or depressed.

Shift workers are at an increased risk for gastro-duodenal ulcers due to increased release of certain hormones like gastrin and pepsinogen.

Some studies have shown that shift work is associated with increased rate of heart disease and high blood pressure due to a myriad of behavioral, psychosocial and physiological factors.

In 2007, WHO announced that overnight shift work that involves circadian disruption would be classified as a probable cause of cancer. Increased risk of developing breast and endometrial cancer in women, prostate cancer in men, and colorectal and non Hodgkin’s lymphomas have been noted in several studies. Further research is need to confirm this correlation.

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