Jean, an emergency nurse with 15 years of experience, recently relocated from Florida to California, accepting a permanent
position at a high acuity medical center. Working overtime to train a replacement, selling her home, and packing until the
last minute had left her sleepless and stressed. Arriving the day before she was scheduled to start her new job, Jean had
little time to adjust to the different time zone, yet alone the idea of working nights instead of days.As she got into her car at the end of her first 12-hour shift, Jean mused, “It certainly has been a hectic month.” Driving
to her apartment in the early morning light, she didn’t realize she was nodding off…or that her car was easing over into oncoming
traffic…
Many healthcare professionals will attest that sleep deprivation (SD) from shift work may lead to occurrences that jeopardize
not only themselves, but also their patients. Fatigue from long shifts can reduce attention to detail, affecting critical
thinking and performance. Although sleep is not cumulative, SD is. The more hours a person works, the longer it takes to complete
a task. More mistakes are made, and alertness is markedly decreased.
Jean discovered, firsthand, that lack of sleep poses risks not only while at work, but also when driving home. Producing a
"drunken" effect, sleep deprivation is a leading cause of automobile accidents. This fact is underscored by results from the
2002 Sleep in America Poll, conducted by the National Sleep Foundation (NSF). Over half of its 1,010 adult respondents reported
driving while drowsy, with 17 percent admitting to dozing off on the road within the past year. As noted by the National Commission
on Sleep Disorders Research, falling asleep at the wheel is the most costly and devastating problem on American highways.
According to NSF, the percentage of individuals receiving less than six hours of sleep per night has steadily increased, from
12 percent in 1998 to 15 percent in 2002. At the time of the study, participants averaged 6.9 hours of sleep during weekdays
and 7.5 hours on weekends. When asked if daytime sleepiness interfered with daily activities, 37 percent replied in the affirmative.
Considering that people who get the least sleep include parents, males, individuals between 18 and 64, and those who work
untraditional shifts, it is imperative for mobile professionals to recognize the symptoms of sleep deprivation and take steps
to combat it before negative consequences result.
ETIOLOGY OF SLEEP Historically, experts have thought sleep to be a passive state, initiated through withdrawal of sensory input. Presently,
researchers believe the recession of sensory awareness is a factor in sleep. During this process, the creative part of the
brain-the prefrontal cortex-shuts down. If sleep time is reduced, there is a decrease in the functioning of the prefrontal
cortex, resulting in a lowered attention span and dampened critical thinking abilities. Experts consider the period of time
from 2:00 to 4:00 a.m. as the highest risk. It is then when people reach the lowest point of overall activation, are likely
to feel sleepy, and are most vulnerable to making mistakes.
Circadian rhythms, modulated by the hypothalamus, regulate all the major bodily functions, from temperature and hormones to
heart rate. This 24-hour internal clock is linked to cycles of light and dark. Notes Alex Lukeman, PhD, author of Sleep Well,
Sleep Deep, when circadian rhythms are operating without interference, individuals are in an easy and natural cycle of wakefulness
and sleep, rest and activity, tiredness and alertness. If these rhythms are disturbed, persons are suddenly fatigued, facing
sleeplessness and experiencing reduced mental capabilities.
STAGES OF SLEEP Four stages of sleep exist within a cycle. In general, people undergo four or five cycles a night, with each lasting approximately
90 minutes. In stage 1, or "light sleep," theta waves form, promoting relaxation, although individuals can be easily awakened.
The percentage of total sleep time devoted to this level increases with age. Stage 2 is characterized by sleep spindles where
brain waves increase in size and amplitude with bursts of electrical energy, while Stage 3 features slow-frequency delta patterns
mixed with theta waves. During Stage 4, also known as "deep sleep," theta waves disappear but delta waves remain. The most
difficult time to awaken individuals, this level promotes deep relaxation with a small amount of muscle activity and reduced
bodily function. As individuals age, the percentage of sleep time devoted to this stage decreases progressively.
According to Sandra Fielo, EdD, RNC, author of "The Mystery of Sleep: How Nurses Can Help the Elderly," a typical pattern
within the sleep cycle for any age group is Stages 1 through 4, followed by Stages 3, 2, and REM (rapid eye movement) sleep.
Occurring about an hour after individuals initially fall asleep, REM comprises 25 percent of total sleep time and is characterized
by increased brain activity, reduction in muscle activity often to the point of paralysis, and variable vital signs. Throughout
the night, the length of time devoted to REM sleep increases per cycle until the final phase lasts an hour. It is during this
stage that individuals experience dreams. Images appear in the mind, while respiration, heart rate, and blood pressure rise
and fall in response.
Though dreaming is believed to be significant, its exact function has not been determined. Dr. Lukeman states, "Scientific
thought tends to dismiss meaning and emphasize a role in memory retention and learning." It is also difficult to determine
how long an individual dream lasts, explains John Harvey, PhD, a licensed psychologist and author of Deep Sleep. For the person
dreaming, time perception can be quite distorted. He says that dreams may have multiple roles, including the neurological
processing of the day's sensory experiences and learning. Michael J. Breus, PhD, ABSM, faculty member of the Atlanta School
of Sleep Medicine, in Atlanta, Georgia, notes it is difficult to determine whether dreams mean anything; however, it is known
that recurring dreams likely revolve around themes that are meaningful to the individuals who have them.
While senses still function during every stage of sleep, they do so at a reduced level. According to Dr. Lukeman, a recent
study at Johns Hopkins University indicates there may be several different areas of the brain that monitor and evaluate sounds
when we sleep, ignoring some, waking us gently for others, or throwing us into a state of adrenaline panic when danger appears.
Internal warning systems, however, can be thwarted by drugs, alcohol, exhaustion, or medication.
