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 under-diagnosed 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 the following:
- irregular heartbeat
- high blood pressure (hypertension)
- heart attack
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 - 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 - 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:
- snore loudly
- are overweight
- 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 - may be as many as 20 to 30 or more events per hour. These events are almost always accompanied by snoring between apneic 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 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 causes 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/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 care physicians, pulmonologists, neurologists, or other physicians 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 the following:
- 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.
- Multiple sleep latency test (MSLT) - A test that measures the speed of falling asleep. 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 type of treatment for 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.
Treatment for sleep apnea:
Specific treatment for sleep apnea will be determined by your physician based on:
- your age, overall health, and medical history
- extent of the condition
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the condition
- 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 - 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.
- Behavior and lifestyle changes - 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 - 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 forces air through the nasal passages.
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.
- Surgery - Some patients with sleep apnea may need surgery. Examples of these procedures include the following:
- 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) - 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 (sometimes recommended for sleep apnea patients who are morbidly obese)