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.
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WHO GETS
SLEEP APNEA?
Sleep apnea occurs in all age groups and both sexes but is
more common in men (it may be under-diagnosed 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.
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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.
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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.
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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.
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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 working, or
talking). The patient often does not know he or she has
problem and may not believe it when told. It is important
that the person see a doctor for evaluation of the sleep
problem.
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WHAT ARE
THE SIGNS AND SYMPTOMS OF OBSTRUCTIVE SLEEP APNEA?
If you or someone you know snores regularly and has one or
more of the following symptoms, it may be Obstructive
Sleep Apnea. The following are some common signs and
symptoms of Sleep Apnea:
- Snoring, interrupted by
pauses in breathing
- Gasping or choking
during sleep
- Restless sleep
- Excessive sleepiness or
fatigue during the day
- Poor judgment or
concentration
- Irritability
- Memory loss
- High blood pressure
- Depression
- Obesity
- Large neck size (>17''
in men; >16'' in women)
- Crowded airway
- Morning headache
- Sexual dysfunction
- Frequent urination at
night
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WHAT
SHOULD YOU DO IF YOU SUSPECT YOU MAY HAVE OBSTRUCTIVE
SLEEP APNEA?
- See your doctor;
evaluation by a doctor specializing in sleep disorders
is recommended.
- Have a sleep study
done; a sleep study can provide the doctor with
information about how you sleep and breathe. This
information will help the doctor to determine your
diagnosis and treatment options.
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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.
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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
helpful to some patients with mild 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
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.
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CHILDREN
WITH OSA
Children who are treated for obstructive sleep apnea (OSA)
show improvements in behavioral and emotional problems,
according to a new study published in the January issue of
the Archives of Otolaryngology - Head and Neck Surgery.
The study, conducted by researchers at the State
University of New York Downstate Medical Center, found
that children with OSA had a higher rate of behavioral
and emotional problems (29 percent in the study's group)
than children without OSA (10 percent). Following
tonsillectomy and adenoidectomy, only 12 percent of the
children in the OSA group scored in the abnormal or
borderline range for behavioral and emotional problems.
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U.S.
DEPARTMENT OF HEALTH AND HUMAN SERVICES
Public Health Service - National Institutes of Health
National Heart, Lung, and Blood Institute
NIH Publication No. 95-3798, September 1995
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