Authored by: Peggy Pilon, BSN, MS, RN, VP of Clinical Success
Every ICU bedside nurse knows that working rotating day/night shifts and holidays/weekends are all part of what is required of them in Critical Care. But what are the ramifications of sleep deprivation on nurses who rotate shifts or work straight nights? The situation is complicated.
The Problem: Disrupted Circadian Rhythms
Everyone agrees that Critical Care Units have to be staffed 24 hours/day, 7 days/week, 365 days/year. Since the beginning of nursing, bedside nurses have worked around the clock to care for their patients. Straight night shift and rotating shift nurses can experience detrimental side effects, because their work hours disrupt their normal circadian rhythms. As discussed in the article “Sleep in the ICU…It’s Complicated,” Dr. Matthew P. Walker, PhD states that all humans, like most animals on the planet, have an internal circadian clock which produces daily (circadian) rhythms. These circadian rhythms help regulate numerous bodily functions such as body temperature, cognitive and physical performance, and the secretion of vital hormones and neurotransmitters. Our circadian clocks are synchronized to the 24-hour day cycle, by the 24-hour light-dark cycle. Human beings are diurnal animals, and we are programmed by our circadian clocks to feel sleepy and to sleep at night, and to be awake and alert during the day.
Side Effect: Shift Work Sleep Disorder
What happens when nurses’ circadian rhythms are disrupted during rotation between day and night shifts? A condition called Shift Work Sleep Disorder (SWSD) often occurs. This is when the circadian rhythm is disrupted, causing the sleep-wake cycle to be abruptly changed, thereby decreasing the amount and quality of sleep. In a study published in Sleep Journal in April 2019, about 49% of nurses averaged less than 7 hours of sleep per night, compared to 28% of the general population. In other studies, over half of the nurses working night shifts reported sleeping 6 hours or less per day. This in turn decreases critical REM sleep that all people need. Getting 6 or less hours of sleep significantly correlates with sleep disturbances and low sleep quality. The Zverev and Misiri study showed that by the end of the 3 consecutive night shifts, nurses have accumulated about 10 hours of sleep deprivation. It has also been shown that working three or more night shifts in a row is associated with the beginning of SWSD. Also, one in four night-rotating nurses resort to staying awake for at least 24 hours prior to their shift to try to adjust their sleep schedule to be able to work their night shift.
Other Outcomes: Medical Errors, Dozing, Physical Risks
The situation of insufficient sleep has been associated with medical errors and decreased quality of patient care. Staff nurses who are awake for 17 hours or more show performance similar to being under the influence of alcohol, and the effects increase with each additional hour of being awake. Research has shown that staying awake for 18 hours or more results in impairments similar to someone with a blood alcohol concentration (BAC) of 0.05; after 24 hours, this increases to a BAC of 0.10. In the U.S., a BAC of 0.08 is defined as legally drunk. Working 12.5-hour shifts also increases the risk of patient care errors by three times when compared with nurses working 8.5-hour shifts. The second half of a 12-hour night shift is associated with increased attention lapses and reduced reaction times. Fatigue can also lead to difficulty concentrating, irritability, decreased motivation, slowed reaction time, difficulty communicating, and increased errors and injuries. Besides patient safety concerns, overworked and tired nurses can lead to nurse burnout.
This fatigue and chronic sleepiness is also characterized by “involuntarily dozing” or microsleep. Microsleep occurs when a sleep-deprived person falls asleep for a few to several seconds. These episodes can happen during patient care or while documenting, without the nurses ever knowing that it occurred. Nurses try to fight the fatigue by ingesting caffeine to stay alert, but the effects of caffeine are short-lived.
Insufficient sleep also has physical risks that manifest themselves outside the hospital. Nurses driving home after shift work are found to have a higher likelihood of being involved in a car accident. Many nurses report feeling sleepy when driving home after a night shift, increasing the risk of motor vehicle crashes. When compared with individuals sleeping 8 hours or more per night, those who sleep 6 to 7 hours are twice as likely to be involved in a crash. While those who sleep 5 hours or less are four to five times more likely to be involved in a crash. Many nurses use the technique of not emptying their bladder after a long night shift so they can stay awake on the drive home, which has its own health ramifications.
Can nurses “catch up” on sleep between shifts? Research on chronic/partial sleep deprivation in healthy adults shows that after several days of not getting enough sleep, one day or more of ‘recovery sleep’ (or more than 10 hours in bed) may be needed to return to baseline functioning. But considering a nurse’s schedule, which often involves consecutive 12-hour shifts with only one or two days off in-between, the opportunity for complete recovery, or ‘catching up,’ is low, noted Dr. Witkoski Stimpfel.
Other factors that affect night nurses’ sleep are stressful work environments. Many nurses return home not being able to sleep, because they are plagued by the beeping sounds that are in their heads. Nurses are led to believe that “hearing the beeping in your head” is all part of the job. However, nurses that have intrusive thoughts of alarms going off while they sleep or nightmares and flashbacks of noisy ICUs, are in fact showing signs of Post Traumatic Stress Syndrome (PTSD). It then becomes more than not being able to sleep, for they’re re-experiencing their traumatic work environment. Couple that noisy, alarm ridden-environment with having to juggle sleep, work, and meeting your family obligations. I vividly remember taking my young children to church on Sunday mornings, after working a 12-hour night shift, only to fall asleep in the pew and then being awoken to ugly stares from other parishioners!
Long-Term Effects
What happens if a nurse develops a Shift Work Sleep Disorder? It is important to examine the effects of long-term sleep deprivation, because there is a lot more at stake than just feeling tired all the time. Researchers have found correlations between SWSD and some serious medical conditions. The American Academy of Sleep Medicine (AASM) lists evidence-based outcomes of chronic sleep deprivation:
- Alzheimer’s Disease: Gradual toxic accumulation of beta-amyloid, a brain protein that is linked to Alzheimer’s, which leads to memory and learning impairment. Normal sleep time allows beta-amyloid to be flushed out; insufficient sleep increases the risk for dementia. Repetitive sleep disturbances are associated with sleep apnea and low oxygen levels that can also contribute to Alzheimer’s disease.
- Cardiovascular Disease: Sleeping less than 5 hours a day more than doubles the risk of developing a cardiovascular condition, especially for adults under the age of 60.
- Metabolic Syndrome/Diabetes: Sleep deprivation can impair glucose tolerance, reduce insulin sensitivity, and increase weight gain, leading to type 2 diabetes.
- Depression/Mood Disturbances: Harvard Health reports that sleep disorders increase the risk of developing depression. A longitudinal study of 1,000 adults found that a history of insomnia led to four times more major depression compared to normal sleepers. Depressed patients with insomnia are also more likely to contemplate and die by suicide, than depressed patients who could sleep without difficulty.
- Immune system issues: Consistent, good-quality sleep strengthens and balances the immune response. SWSD increases the risk of infection and inflammation.
- Weight Gain/Obesity: With SWSD, a nurse is simply too tired to exercise and burn extra calories. Second, lack of sleep affects leptin and ghrelin. These two hormones affect the sensations of fullness and hunger. Leptin signals the brain that you’re full. However, without enough sleep, leptin levels drop and the levels of ghrelin (the appetite stimulant) increase.
- Cancer: Night nurses have a 25% risk of dying from lung cancer, a 33% risk of dying from colon cancer and a “remarkable” 58% increased risk for breast cancer.
- Premature Death: Scientists led by Dr. Eva Schernhammer, found that nurses who worked on rotating night shifts for more than 5 years were up to 11% more likely to die early, when compared to other day-shift nurses.
Combatting Nurse Sleep Deprivation
What can nurses do to combat SWSD? The American Academy of Sleep Medicine and the American Nursing Association recommends:
- Avoid caffeine several hours before you are scheduled to sleep.
- If one can not get 7 hours of sleep in, take a 2-3 hour nap prior to going to work.
- Hospitals should allow scheduled uninterrupted naps during the night shift for night nurses.
- Eliminate mandatory overtime.
- Minimize rotating between days and nights within the same scheduling block.
- Eliminate “doubling backing” to a different shift.
- Provide a transport service for nurses that are too tired to drive home.
Even though these recommendations are powerful, they still lack an important intervention. What about making the environment better for nurses working at night? Isn’t it time that we use AI-backed technology to help drive out the unnecessary noise and signal the nurse to where he/she is really needed? Enter: CalmWave. We at CalmWave use AI technology to make every alarm actionable for the nurse to respond to. Fewer alarms means a quieter environment that can help patients sleep and make it easier for nurses to sleep once they get home. Quieter environment…more sleep…rested nurses who are not burnt out…that’s what everyone wants and needs.
Some casual observers might say…“Just stop working nights.” It is important to note that when nurses work night shifts for a prolonged period, their bodies become accustomed to being awake during the night and sleeping during the day. This disrupted pattern makes it challenging to switch back to a regular night sleep schedule. Even after stopping night shift work, many former night nurses continue to experience sleep disturbances, such as difficulty falling asleep, waking up frequently during the night, and feeling tired during the day. I am one of those nurses. Isn’t it time to care for the people that care for us? We at CalmWave understand, and we can help! Contact us to learn how we can help you turn your ICU into a more optimal place for nurses and patients…nurses are yearning for our help.