FOR
MORE INFORMATION
WHAT
IS SLEEP APNEA?
Sleep apnea is a serious, potentially life-threatening
condition that is far more common than generally understood.
First described in 1965, sleep apnea is a breathing disorder
characterized by brief interruptions of breathing during
sleep. It owes its name to a Greek word, apnea, meaning
"want of breath." There are two types of sleep
apnea: central and obstructive. Central sleep apnea, which is
less common, occurs when the brain fails to send the
appropriate signals to the breathing muscles to initiate
respirations. Obstructive sleep apnea is far more common and
occurs when air cannot flow into or out of the person's nose
or mouth although efforts to breathe continue.
In a given night, the number of involuntary breathing
pauses or "apneic events" may be as high as 20 to 30
or more per hour. These breathing pauses are almost always
accompanied by snoring between apnea episodes, although not
everyone who snores has this condition. Sleep apnea can also
be characterized by choking sensations. The frequent
interruptions of deep, restorative sleep often lead to early
morning headaches and excessive daytime sleepiness.
Early recognition and treatment of sleep apnea is important
because it may be associated with irregular heartbeat, high
blood pressure, heart attack, and stroke.
WHO
GETS SLEEP APNEA?
Sleep apnea occurs in all age groups and both sexes but is
more common in men (it may be underdiagnosed in women) and
possibly young African Americans. It has been estimated that
as many as 18 million Americans have sleep apnea. Four percent
of middle-aged men and 2 percent of middle-aged women have
sleep apnea along with excessive daytime sleepiness. People
most likely to have or develop sleep apnea include those who
snore loudly and also are overweight, or have high blood
pressure, or have some physical abnormality in the nose,
throat, or other parts of the upper airway. Sleep apnea seems
to run in some families, suggesting a possible genetic basis.
WHAT
CAUSES SLEEP APNEA?
Certain mechanical and structural problems in the airway
cause the interruptions in breathing during sleep. In some
people, apnea occurs when the throat muscles and tongue relax
during sleep and partially block the opening of the airway.
When the muscles of the soft palate at the base of the tongue
and the uvula (the small fleshy tissue hanging from the center
of the back of the throat) relax and sag, the airway becomes
blocked, making breathing labored and noisy and even stopping
it altogether. Sleep apnea also can occur in obese people when
an excess amount of tissue in the airway causes it to be
narrowed. With a narrowed airway, the person continues his or
her efforts to breathe, but air cannot easily flow into or out
of the nose or mouth. Unknown to the person, this results in
heavy snoring, periods of no breathing, and frequent arousals
(causing abrupt changes from deep sleep to light sleep).
Ingestion of alcohol and sleeping pills increases the
frequency and duration of breathing pauses in people with
sleep apnea.
Effects
of Sleep Apnea
This roller coaster sleep pattern leads to a loss of
energy, concentration, productivity, and an inability to stay
awake during less active tasks like reading, watching
television, and driving. In serious cases, the continuous
oxygen deprivation caused by sleep apnea can lead to high
blood pressure, heart attacks, strokes, and even sudden death.
There may be a genetic component to this disorder as it often
occurs within families.
What can be done to reduce or cure sleep apnea? In
less-severe cases, weight loss and a reduction in alcohol and
other sedative use before bedtime has been a very successful
remedy. Sleep experts also recommend that people with sleep
apnea should not sleep on their backs; sometimes sewing a
tennis ball into the back of a night- shirt can prevent this
from occurring. In more serious cases like yours, continuous
positive airway pressure (CPAP) machines blow air through a
mask into the body during sleep. Although this treatment has
also helped many people, some cannot tolerate this method, and
may benefit from oral devices that change the position of
mouth structures during sleep.
Seeking treatment for sleep apnea usually involves visiting
a sleep lab where heart, blood oxygen levels, and other vital
signs are monitored by professionals. For more information on
sleep apnea and resources for help, you can write the National
Sleep Foundation at 1367 Connecticut Avenue, NW, Washington,
D.C. 20036.
It is good to hear your acknowledgment of improvement with
the aid of CPAP, and your discomfort and fears are certainly
understandable. If you haven't done so already, Alice suggests
discussing these issue with your health care provider, experts
at these agencies, or a counselor. Your ability to cope with
this illness for all of these years gives new meaning to the
word, patience.
HOW
IS NORMAL BREATHING RESTORED DURING SLEEP?
During the apneic event, the person is unable to breathe in
oxygen and to exhale carbon dioxide, resulting in low levels
of oxygen and increased levels of carbon dioxide in the blood.
The reduction in oxygen and increase in carbon dioxide alert
the brain to resume breathing and cause an arousal. With each
arousal, a signal is sent from the brain to the upper airway
muscles to open the airway; breathing is resumed, often with a
loud snort or gasp. Frequent arousals, although necessary for
breathing to restart, prevent the patient from getting enough
restorative, deep sleep.
WHAT
ARE THE EFFECTS OF SLEEP APNEA?
Because of the serious disturbances in their normal sleep
patterns, people with sleep apnea often feel very sleepy
during the day and their concentration and daytime performance
suffer. The consequences of sleep apnea range from annoying to
life-threatening. They include depression, irritability,
sexual dysfunction, learning and memory difficulties, and
falling asleep while at work, on the phone, or driving. It has
been estimated that up to 50 percent of sleep apnea patients
have high blood pressure. Although it is not known with
certainty if there is a cause and effect relationship, it
appears that sleep apnea contributes to high blood pressure.
Risk for heart attack and stroke may also increase in those
with sleep apnea. In addition, sleep apnea is sometimes
implicated in sudden infant death syndrome.
WHEN
SHOULD SLEEP APNEA BE SUSPECTED?
For many sleep apnea patients, their spouses are the first
ones to suspect that something is wrong, usually from their
heavy snoring and apparent struggle to breathe. Coworkers or
friends of the sleep apnea victim may notice that the
individual falls asleep during the day at inappropriate times
(such as while driving a car, working, or talking). The
patient often does not know he or she has a problem and may
not believe it when told. It is important that the person see
a doctor for evaluation of the sleep problem.
HOW
IS SLEEP APNEA DIAGNOSED?
In addition to the primary care physician, pulmonologists,
neurologists, or other physicians with specialty training in
sleep disorders may be involved in making a definitive
diagnosis and initiating treatment. Diagnosis of sleep apnea
is not simple because there can be many different reasons for
disturbed sleep. Several tests are available for evaluating a
person for sleep apnea.
Polysomnography is a test that records a variety of body
functions during sleep, such as the electrical activity of the
brain, eye movement, muscle activity, heart rate, respiratory
effort, air flow, and blood oxygen levels. These tests are
used both to diagnose sleep apnea and to determine its
severity.
The Multiple Sleep Latency Test (MSLT) measures the speed
of falling asleep. In this test, patients are given several
opportunities to fall asleep during the course of a day when
they would normally be awake. For each opportunity, time to
fall asleep is measured. People without sleep problems usually
take an average of 10 to 20 minutes to fall asleep.
Individuals who fall asleep in less than 5 minutes are likely
to require some treatment for sleep disorders. The MSLT may be
useful to measure the degree of excessive daytime sleepiness
and to rule out other types of sleep disorders.
Diagnostic tests usually are performed in a sleep center,
but new technology may allow some sleep studies to be
conducted in the patient's home.
HOW
IS SLEEP APNEA TREATED?
The specific therapy for sleep apnea is tailored to the
individual patient based on medical history, physical
examination, and the results of polysomnography. Medications
are generally not effective in the treatment of sleep apnea.
Oxygen administration may safely benefit certain patients but
does not eliminate sleep apnea or prevent daytime sleepiness.
Thus, the role of oxygen in the treatment of sleep apnea is
controversial, and it is difficult to predict which patients
will respond well. It is important that the effectiveness of
the selected treatment be verified; this is usually
accomplished by polysomnography.
Behavioral
Therapy
Behavioral changes are an important part of the treatment
program, and in mild cases behavioral therapy may be all
that is needed. The individual should avoid the use of
alcohol, tobacco, and sleeping pills, which make the airway
more likely to collapse during sleep and prolong the apneic
periods. Overweight persons can benefit from losing weight.
Even a 10 percent weight loss can reduce the number of
apneic events for most patients. In some patients with mild
sleep apnea, breathing pauses occur only when they sleep on
their backs. In such cases, using pillows and other devices
that help them sleep in a side position is often helpful.
Physical
or Mechanical Therapy
Nasal continuous positive airway pressure (CPAP) is the
most common effective treatment for sleep apnea. In this
procedure, the patient wears a mask over the nose during
sleep, and pressure from an air blower forces air through
the nasal passages. The air pressure is adjusted so that it
is just enough to prevent the throat from collapsing during
sleep. The pressure is constant and continuous. Nasal CPAP
prevents airway closure while in use, but apnea episodes
return when CPAP is stopped or used improperly.
Variations of the CPAP device attempt to minimize side
effects that sometimes occur, such as nasal irritation and
drying, facial skin irritation, abdominal bloating, mask
leaks, sore eyes, and headaches. Some versions of CPAP vary
the pressure to coincide with the person's breathing
pattern, and others start with low pressure, slowly
increasing it to allow the person to fall asleep before the
full prescribed pressure is applied.
Dental appliances that reposition the lower jaw and
the tongue have been very helpful to some patients with mild
to moderate sleep apnea or who snore but do not have apnea.
Possible side effects include damage to teeth, soft tissues,
and the jaw joint. A dentist or orthodontist is often the
one to fit the patient with such a device.
Surgery
Some patients with sleep apnea may need surgery. Although
several surgical procedures are used to increase the size of
the airway, none of them is completely successful or without
risks. More than one procedure may need to be tried before
the patient realizes any benefits.
Some of the more common procedures include removal of
adenoids and tonsils (especially in children), nasal polyps
or other growths, or other tissue in the airway and
correction of structural deformities. Younger patients seem
to benefit from these surgical procedures more than older
patients.
Uvulopalatopharyngoplasty (UPPP) is a procedure used to
remove excess tissue at the back of the throat (tonsils,
uvula, and part of the soft palate). The success of this
technique may range from 30 to 50 percent. The long-term
side effects and benefits are not known, and it is difficult
to predict which patients will do well with this procedure.
Laser-assisted uvulopalatoplasty (LAUP) is done to
eliminate snoring but has not been shown to be as effective
in treating sleep apnea. This procedure involves using a
laser device to eliminate tissue in the back of the throat.
Like UPPP, LAUP may decrease or eliminate snoring but not
sleep apnea itself. Elimination of snoring, the primary
symptom of sleep apnea, without influencing the condition
may carry the risk of delaying the diagnosis and possible
treatment of sleep apnea in patients who elect LAUP. To
identify possible underlying sleep apnea, sleep studies are
usually required before LAUP is performed.
Tracheostomy is used in persons with severe, life-
threatening sleep apnea. In this procedure, a small hole is
made in the windpipe and a tube is inserted into the
opening. This tube stays closed during waking hours, and the
person breathes and speaks normally. It is opened for sleep
so that air flows directly into the lungs, bypassing any
upper airway obstruction. Although this procedure is highly
effective, it is an extreme measure that is poorly tolerated
by patients and rarely used.
Other procedures. Patients in whom sleep apnea is due to
deformities of the lower jaw may benefit from surgical
reconstruction. Finally, surgical procedures to treat
obesity are sometimes recommended for sleep apnea patients
who are morbidly obese.
NATIONAL
CENTER ON SLEEP DISORDERS RESEARCH (NCSDR)
The mission of the NCSDR is to support research, training,
and education about sleep disorders. The center is located
within the National Heart, Lung, and Blood Institute (NHLBI)
of the National Institutes of Health. The NHLBI supports a
variety of research and training programs focusing on
cardiopulmonary disorders in sleep, designed to fill critical
gaps in the understanding of the causes, diagnosis, treatment,
and prevention of sleep-disordered breathing.
FOR
MORE INFORMATION
Information about sleep disorders research can be obtained
from the NCSDR. In addition, the NHLBI Information Center can
provide you with sleep education materials as well as other
publications relating to heart, lung, and blood diseases.
National
Center on Sleep Disorders Research
Two Rockledge Centre Suite 7024
6701 Rockledge Drive MSC 7920
Bethesda, MD 20892-7920
(301) 435-0199
(301) 480-3451 (fax)
NHLBI
Information Center
P.O. Box 30105
Bethesda, MD 20824-0105
(301) 251-1222
(301) 251-1223 (fax
