Obstructive Sleep Apnea
What is Sleep Apnea?
Obstructive Sleep Apnea is very common and affects millions of Americans. It is caused by a blockage of the airway, usually when the soft tissue in the rear of the throat collapses and closes during sleep. Sleep is fragmented and of poor quality. Loud snoring, snorting and periods of silence are typical symptoms of sleep apnea but are not always present, especially in children.
Sleep Apnea is a serious, potentially life threatening condition that is far more common than generally understood. 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 the 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 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 two 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 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 altogether. Sleep apnea also can occur in overweight people when an excess amount of tissue in the airway causes it to be narrowed. Ingestion of alcohol and sleeping pills increases the frequency and duration of breathing pauses in people with sleep apnea.
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 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.
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. Co-workers 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). 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. 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.
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 effective treatment for sleep apnea. In this therapy, 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 persons 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 sleep apnea. A dentist or orthodontist is often the one to fit the patient with such a device.
What are the risks of Sleep Apnea if left untreated?
In addition to a feeling of tiredness during the day, untreated Sleep Apnea can cause high blood pressure, and potentially increase the risk of heart attack or stroke. Other consequences include falling asleep at inappropriate times, memory problems, acid reflux and frequent nighttime urination.
* Adapted from the American Academy of Sleep Medicine