Central sleep apnea is a type of sleep-related breathing disorder that involves apneas, or breathing interruptions, during sleep. In people with central sleep apnea, muscles that control breathing don’t work properly, causing breathing to stop and start during the night.
What is Central Sleep Apnea?
Central sleep apnea is a type of sleep-related breathing disorder that involves apneas, or breathing interruptions, during sleep. In people with central sleep apnea, muscles that control breathing don’t work properly, causing breathing to stop and start during the night. Central sleep apnea is seen more frequently during NREM sleep and is linked to a number of health conditions involving the heart and brain.
Symptoms of Central Sleep Apnea include:
Abrupt nighttime awakenings
Shortness of breath that is relieved by sitting up
Lack of focus and concentration
Types of Central Sleep Apnea
There are several abnormal breathing patterns, or dysrhythmias, that make up the group of central sleep apnea syndromes. One is Cheyne-Stokes respiration (CSR), a breathing abnormality that involves heavier breathing followed by rapid, lighter breathing, then a pause in breathing. This cycle continues, causing lower levels of oxygen in the blood. This is most frequently seen in patients with congestive heart failure.
Other disorders in this group include CSA resulting from high altitudes (generally altitudes over 2000 miles), CSA resulting from a medication, and primary or idiopathic central sleep apnea: Central sleep apnea that doesn’t appear to be caused by medication, sleep environment or another health condition. Primary central sleep apnea of infancy and primary central sleep apnea of prematurity are seen in newborns and premature infants.
Treatment-emergent central sleep apnea, also called complex sleep apnea, is sleep apnea that occurs during CPAP (continuous positive airway pressure) therapy. In a patient with obstructive sleep apnea, in which an airway obstruction causes nighttime breathing to stop, CPAP generally resolves the obstruction and restores breathing. In patients with treatment-emergent central sleep apnea, apneas (or breathing pauses) continue or emerge during CPAP treatment.
Treatment-emergent sleep apnea is more common when patients begin CPAP therapy, appearing in up to 20 percent of new CPAP patients. After the first few nights of CPAP therapy, only about 2 percent of patients show symptoms of treatment-emergent central sleep apnea.
Central Sleep Apnea vs. Obstructive Sleep Apnea
Central sleep apnea differs from obstructive sleep apnea (OSA), in which nighttime breathing is impaired because of an airway obstruction. In central sleep apnea, breathing interruptions are caused by faulty brain signaling, rather than an airway obstruction.
Central sleep apnea is less common than OSA, occurring in about 1 percent of the general population. Like OSA, Central Sleep Apnea appears more frequently in people with certain health conditions, including obesity. However, central sleep apnea occurs more often in people with certain cardiovascular and neurological conditions, including up to 40 percent of those with heart failure and 10 percent of people who have had a stroke.
What Causes Central Sleep Apnea?
In central sleep apnea, the brain’s control of nighttime breathing is impaired, so the brain can’t signal the muscles that control breathing. Conditions affecting the brainstem, the region of the brain that controls breathing, make CSA more likely. These include stroke, certain spinal conditions and severe obesity.
The use of some narcotic pain relievers may increase the risk of central sleep apnea. Narcotic pain relievers work by binding to brain receptors, and may influence the brain’s signaling process. These pain relievers include:
To diagnose central sleep apnea, a sleep specialist will evaluate your health history and symptoms. Your doctor may request a polysomnogram, or an overnight sleep study, to provide more information about your nighttime breathing patterns. During a sleep study, sleep specialists can monitor your heart, lung, and brain activity along with your limb movements and blood oxygen levels.
Your doctor may request a split-night sleep study, in which your sleep is monitored for the first half of the night. If your breathing patterns show that you have CSA, you can be treated with CPAP therapy during the second half of the night.
Because central sleep apnea is closely linked to disorders of the brain and heart, neurologists, cardiologists and other specialists may be involved in the diagnosis.
Because CSA is characterized by apneas (breathing interruptions) that appear or persist during traditional sleep apnea therapies, treatment for central sleep apnea can be complex.
Your doctor may begin by treating other conditions that increase the risk of CSA, such as heart failure.
Reducing the use of opioid pain medications can also reduce the risk of CSA.
Positive Airway Pressure (PAP) therapies for CSA
Although CSA can persist during CPAP therapy, this type of treatment is still effective in managing CSA. When CPAP is used to treat CSA, sleep specialists work closely with patients to ensure that the device fits well and works properly. Doctors can adjust the device’s air pressure if needed. If the device is uncomfortable or doesn’t resolve the apneas, alternative types of PAP are available.
Another treatment using pressurized air is adaptive servo-ventilation (ASV). This therapy adjusts respiratory pressure for each breath to smooth out the breathing pattern and can automatically deliver a breath if breathing stops for a period of time. This treatment isn’t recommended for patients with certain types of heart failure.
Bilevel positive airway pressure (BPAP) delivers a fixed, rather than variable, amount of airway pressure overnight. Unlike CPAP, which delivers one continuous level of airway pressure, BPAP delivers one level of pressure during inhalation, and a different level of pressure during exhalation.
Supplemental oxygen may also be used to increase blood oxygen levels overnight without the use of airway pressure.
Some people with CSA cannot tolerate the use or airway pressure therapies or supplemental oxygen. These patients may be helped by certain medications, such as theophylline or acetazolamide. These medicines may also be used to help prevent Central Sleep Apneas induced by high altitude.