What is sleep apnea?
Sleep apnea is a serious, potentially life-threatening condition that is far more common than generally understood. Sleep apnea occurs in all age groups and both genders. It is more common in men, although it may be underdiagnosed in women and young African-Americans. It is estimated that as many as 18 million Americans have sleep apnea.
Early recognition and treatment of sleep apnea is important, as it may be associated with:
High blood pressure
Increased risk of motor vehicle and work accidents
What are the different types of sleep apnea?
Sleep apnea is a breathing disorder characterized by brief interruptions of breathing during sleep. There are two types of sleep apnea:
Central sleep apnea occurs when the brain fails to send the appropriate signals to the muscles to initiate breathing. Central sleep apnea is less common than obstructive sleep apnea.
Obstructive sleep apnea occurs when air cannot flow into or out of the person's nose or mouth although efforts to breathe continue.
Who is affected by sleep apnea?
Sleep apnea seems to run in some families, suggesting a possible genetic basis. People most likely to have or develop sleep apnea include those who:
Have high blood pressure
Have some physical abnormality in the nose, throat, or other parts of the upper airway
Use of alcohol and sleeping pills increases the frequency and duration of breathing pauses in people with sleep apnea.
What are the characteristics of sleep apnea?
Sleep apnea is characterized by a number of involuntary breathing pauses or "apneic events" during a single night's sleep. Typically, there are at least 5 events per hour. Severe sleep apnea is diagnosed when someone has 30 or more events per hour. These events are almost always accompanied by snoring between apnea episodes (although not everyone who snores has sleep apnea). Sleep apnea may also be characterized by choking sensations. The frequent interruptions of deep, restorative sleep often lead to early morning headaches, slowed thinking and poor attention, and excessive daytime sleepiness.
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 a person from getting enough restorative, deep sleep.
What are the causes of sleep apnea?
Certain mechanical and structural problems in the airway cause the interruptions in breathing during sleep. 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 relax and sag, the airway becomes blocked, making breathing labored and noisy and even stopping it altogether.
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.
How is sleep apnea diagnosed?
Diagnosis of sleep apnea is not simple because there can be many different causes. Primary health care providers, pulmonologists, neurologists, or doctors with specialty training in sleep disorders may be involved in making a definitive diagnosis and initiating treatment. Several tests are available for evaluating a person for sleep apnea, including:
Polysomnography. 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.
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?
Specific treatment will be determined by your health care provider based on:
Your age, overall health, and medical history
Severity of the disease
Your tolerance for specific medications, procedures, or therapies
Expectations for the course of the disease
Your opinion or preference
Medications are generally not effective in the treatment of sleep apnea. Therapy for sleep apnea is specifically designed for each individual patient, and may include the following:
Oxygen administration may safely benefit certain patients, but does not eliminate sleep apnea or prevent daytime sleepiness. Its role in the treatment of sleep apnea is controversial.
Behavioral changes are an important part of a treatment program, and in mild cases of sleep apnea, behavioral therapy may be all that is needed. The patient may be advised to:
Avoid the use of alcohol.
Avoid the use of tobacco.
Avoid the use of sleeping pills.
Lose weight if overweight (even a 10 percent weight loss can reduce the number of apneic events for most patients).
Use pillows and other devices to help sleep in a side position.
Physical or mechanical therapy options are also available. Nasal continuous positive airway pressure (CPAP) is a procedure in which the patient wears a mask over the nose during sleep, and pressure from an air blower produces a mild increase in upper airway pressure, allowing airflow through the nasal passages and upper airway. Dental appliances that reposition the lower jaw and the tongue forward to open the upper airway have been helpful to some patients with mild sleep apnea, or who snore but do not have apnea.
Some patients with sleep apnea may need surgery. Examples of these procedures include:
Common surgical procedures to remove adenoids and tonsils, nasal polyps, or other growths or tissue in the airway, and correction of structural deformities.
Uvulopalatopharyngoplasty (UPPP) is a procedure used to remove excess tissue at the back of the throat (tonsils, uvula, and part of the soft palate).
Surgical reconstruction for deformities of the lower jaw may benefit some patients.
Surgical procedures to treat obesity are sometimes recommended for sleep apnea patients who are morbidly obese.