Sleep Related Breathing Disorders
Dr. Clete Kushida discusses Obstructive Sleep Apnea
Sleep Related Breathing Disorders (SRBDs) is an umbrella term used to describe disorders related to abnormal breathing during sleep where breathing is repeatedly interrupted. There are several different types of sleep disordered breathing disorders with varying degrees of severity.
Snoring
Description
Snoring is a very common condition and a symptom of obstructive sleep apnea (OSA). When a person’s airway becomes partially blocked, the restriction prevents some of the air that was inhaled from getting into the lungs. The “extra” air gets redirected into the mouth, creating a negative pressure which vibrates the soft tissue of the palate and creates snoring.
Not everybody who snores has OSA, and not everybody who has OSA has snoring. Snoring indicates that there is some resistance to the normal path of air from the outside to the lungs, and snoring is associated with disrupted sleep, daytime fatigue and sleepiness, and decreases in oxygen levels in the body. Snoring can also be extremely disruptive to the sleep of the bedpartner and can stress interpersonal relationships of couples.
Treating Snoring
There are several surgical procedures that can improve snoring, some of which can be performed on an outpatient basis, and that involve reducing the volume of excess tissue in the airway that produces snoring. Oral appliances, which are very similar to mouthguards or retainers which are placed in the mouth during sleep to either the move the lower jaw or tongue forward, can also improve snoring.
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Upper Airway Resistance Syndrome (UARS)
Description
Upper Airway Resistance Syndrome (UARS) is a condition that was first identified and described at Stanford University. It is very similar to OSA in that the soft tissue of the throat relaxes, reduces the size of the airway, and results in disturbed sleep and consequent daytime impairment, including excessive daytime sleepiness. Although the increase in upper airway resistance is not enough to meet criteria of the sleep disordered breathing that define obstructive sleep apnea, the resulting increase in breathing effort does cause a brief awakening from sleep that is often undetected by the affected individual. When this scenario repeats throughout the night, sleep is impaired, just like in obstructive sleep apnea.
The symptoms of UARS tend to be similar to OSA but may be less in severity. People with UARS usually complain of snoring, daytime sleepiness, cognitive impairment, un-refreshing sleep, and frequent arousals from sleep.
Treating UARS
Adults
Continuous Positive Airway Pressure (CPAP) is the most effective treatment for sleep apnea, however there are also surgical options, oral appliances, and behavioral approaches that can be used to treat OSA. Weight loss, although always a good idea in reducing obesity-related conditions (e.g., hypertension, diabetes), is considered supplementary or adjunctive therapy rather than primary treatment for OSA. Other underlying medical conditions, especially nasal allergies, should also be treated. A nasal steroid might help improve nasal obstruction associated with allergies as well as the OSA symptoms. For a more comprehensive explanation of the treatment options for this condition, go to the Treatments Section in the Tests and Treatments Section. The same treatments that are successful for OSA can be used to treat UARS. While CPAP remains the most effective treatment, this population may find it difficult to tolerate. Alternative treatments such as surgery, oral appliances, positional therapy (restricting the individual to sleeping on his/her sides), and weight loss may be effective in improving sleep disordered breathing in individuals with UARS.
Children
Surgery is usually the first line of treatment for children; removing a child's enlarged tonsils and adenoids by a tonsillectomy and adenoidectomy (or T&A) will often resolve the OSA. However, in some children, CPAP, further surgery, or specialized orthodontic treatment may be necessary to treat the OSA.
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Obstructive Sleep Apnea (OSA)
Description
Obstructive sleep apnea occurs when the airway completely or partially collapses repeatedly throughout the night. During sleep, the soft tissues in the throat relax. For someone with OSA, these tissues can block the upper airway enough to disrupt sleep related breathing.
When the airway is blocked, the oxygen levels in the body drop causing the person to wake up long enough to begin breathing normally again. These awakenings are often very brief, sometimes only a few seconds, and this is the reason that the affected individual is often not aware that they have these awakenings during sleep. This pattern repeats during the night, and someone with severe sleep apnea may wake up hundreds of times each night. Even though the awakenings are usually very short, they fragment and interrupt the sleep cycle. This sleep fragmentation can cause significant levels of daytime fatigue and sleepiness, which is a common symptom of sleep apnea.
There are 3 types of obstructive breathing events:
- Apnea: A period of at least 10 seconds during which there is a complete or near complete pause in breathing.
- Hypopnea: A decrease in airflow lasting at least 10 seconds.
- Respiratory Effort Related Arousal (RERA): A limitation in breathing that results in increased respiratory effort and culminates in an arousal; it does not meet the criteria from an apnea or hypopnea.
OSA is estimated to occur in approximately 18 million Americans; a quarter of men and one-tenth of women between the ages of 30 and 60 years have sleep study evidence of OSA, and the prevalence in children is estimated to be 1-3%. It is a treatable disease; however, if left untreated, it is associated with serious medical conditions.
Risk factors for OSA include:
- Obesity. The extra tissue caused by fat deposits around the throat, chest and abdomen create extra resistance which can hamper breathing. However, just because someone is overweight does not mean they have OSA. The opposite is also true: many thin people have OSA.
- Large neck size. A thick neck can narrow the airway, and increase the likelihood of OSA. Higher risk of OSA is associated with a neck circumference greater than 17 inches (43 centimeters) for men and 15 inches (38 centimeters) for women.
- Narrowed upper airway. A small jaw or enlarged tongue can narrow the upper airway and predispose individuals toward the development of OSA. Enlarged tonsils and/or adenoids can also restrict the size of the upper airway.
- Positive OSA family history. If you have family members with sleep apnea, you may be at increased risk. Like eye color, the shape and size of the airway and cranial facial features may be inherited from our parents and can have an impact on the likelihood of developing OSA.
- Old age, male gender, post-menopausal women, and minorities. OSA is more common in adults over the age of 65 years, men, post-menopausal women, and, among those under the age of 35 years, some minority groups (blacks, Latino and Pacific Islanders).
- Smoking and use of alcohol or tranquilizers. Smokers are nearly three times more likely to have OSA, and alcohol or tranquilizers can relax the muscles in your upper airway and predispose it to collapse.
- High blood pressure (hypertension) and diabetes. OSA is more likely in people who have hypertension and up to three times more common in those with diabetes.
- Chronic nasal congestion. OSA occurs twice as often in those with consistent nasal congestion at night, regardless of cause.
- Enlarged tonsils or adenoids. In children, OSA is most often associated with sizeable tonsils or adenoids.
A typical OSA patient is a middle age, obese male; however anyone can develop OSA, and the symptoms can vary from person-to-person, increase with age, and have different levels of severity. Common symptoms of OSA in adults may include:
- Snoring (usually loud and disruptive)
- Choking or gasping during sleep
- Observed pauses in breathing
- Daytime fatigue and/or sleepiness
- Dry mouth/sore throat in morning
- Morning headaches
- Night sweats
- Insomnia
- Poor concentration and attention
- Memory problems
- Anxiety
- Irritability
- Sleep walking or night terrors
OSA in Children
While some types of snoring can be considered benign in adults, snoring or noisy breathing is never normal in children. OSA is often overlooked in kids because the symptoms are more different in children than they are in adults and they tend to be more subtle. Not all children with OSA snore, and when they are tired they rarely nap, instead they become hyperactive (and may mimic those children with attention deficit-hyperactivity disorder) or develop behavioral problems. These behavioral problems may manifest themselves as irritability, lack of concentration, easy distractibility, and acting out which can lead to problems at school. Additionally, many children with OSA are not overweight, so they don’t fit the stereotypical picture of some with sleep apnea.
Children with medical conditions impacting the shape of their face, nose and airway or neuromuscular system are at a higher risk of developing sleep apnea. Parents of children with disorders such as Down Syndrome should be aware of the elevated risk and should be evaluated when there has been a change in behavior that may be related to OSA. Common symptoms of sleep apnea in children may include:
- Snoring
- Daytime cognitive and behavior problems, including problems paying attention, easy distractibility, aggressive behavior and hyperactivity
- Mouth breathing
- Enlarged tonsils and adenoids
- Problems sleeping and restless sleep
- Parasomnias such as sleep walking or night terrors
- Bed wetting
- Failure to thrive (weight loss or poor weight gain)
- Excessive daytime sleepiness
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Other Sleep Related Respiratory Conditions
Description
Other sleep related respiratory conditions include such disorders such as Central Sleep Apnea (CSA) and Sleep Related Hypoventilation/Hypoxemic Syndromes. CSA occurs when you repeatedly stop breathing during sleep because your brain does not cue your body to breathe. This differs from Obstructive Sleep Apnea since in CSA, there is no breathing effort because there is no drive to breathe. In its primary form, CSA is the result of instability of the breathing control system as the individual transitions from wakefulness to sleep. Sleep Related Hypoventilation/Hypoxemic Syndromes may be the result of a decreased response to low oxygen or high carbon dioxide during wakefulness and sleep and are characterized by frequent episodes of shallow breathing lasting longer than 10 seconds during sleep.
Treating Other Conditions
Continuous Positive Airway Pressure (CPAP) is typically ineffective at resolving these conditions, though Bilevel Airway Pressure (BPAP) or Auto Servo-ventilation (ASV) devices may help to normalize sleep related breathing in patients with Central Sleep Apnea or Sleep Related Hypoventilation/Hypoxemic Syndromes.
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Diagnosis
A comprehensive history and physical examination by a sleep physician followed by an overnight sleep study or polysomnogram, is absolutely necessary to diagnose a sleep related breathing disorder in children or adults.
Based on the results of the overnight sleep study, your sleep physician will be able to determine whether or not you have a sleep related breathing disorder that warrants treatment.
To learn more about the sleep diagnostic tests, visit the Tests section.
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Current Research
Stanford has conducted many research studies related to Sleep Related Breathing Disorders, such as the Apnea Positive Pressure Long-term Efficacy Study (APPLES). APPLES was an NIH-sponsored research study examining the long term efficacy of CPAP (Continuous Positive Airflow Pressure) therapy, a treatment for obstructive sleep apnea. APPLES was a placebo-controlled study that collected data from 2003 through 2008, with individual participation lasting 6-9 months in five sites throughout the United States. The purpose of APPLES was to evaluate the effect of CPAP on neurocognitive functioning, alertness, mood, and quality of life. The data are still being analyzed and the baseline and primary outcome articles are pending publication.
See the Research Section for a list of studies that are currently open for enrollment.
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Additional Resources
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