Central Sleep Apnea (CSA) is a sleep disorder where breathing repeatedly stops and starts because the brain fails to send the proper signals to the muscles that control respiration. Unlike Obstructive Sleep Apnea (OSA), which involves a physical blockage of the upper airway, CSA originates from a temporary dysfunction in the central nervous system’s respiratory control center. This lapse in communication results in periods of absent breathing, known as apneas, during sleep.
Treating the Underlying Medical Condition
Central Sleep Apnea is frequently a secondary condition, and the most effective treatment involves managing that primary health issue. The most common cause is severe heart failure, which often leads to a specific pattern of irregular breathing known as Cheyne-Stokes respiration. Optimizing the heart’s function through standard medical therapy, such as beta-blockers and angiotensin-converting enzyme (ACE) inhibitors, often improves CSA by stabilizing the circulatory system and reducing fluid overload.
Another significant contributor to CSA is the use of certain medications, particularly opioid pain relievers and other central nervous system (CNS) depressants. Drug-induced CSA occurs because these substances directly suppress the brain’s respiratory drive, leading to shallow or absent breaths during sleep. Treating this form typically requires a managed reduction or cessation of the causative agent, a process that must be overseen by medical professionals. For patients with kidney failure, metabolic imbalances like uremia can also destabilize the respiratory center. Addressing the renal dysfunction, often through dialysis, helps to correct the chemical environment that drives the central apneas.
Advanced Breathing Devices
When managing the underlying condition is not sufficient, specialized respiratory devices become the primary intervention for stabilizing nighttime breathing. Adaptive Servo-Ventilation (ASV) is generally the preferred device for many forms of central sleep apnea, especially those associated with Cheyne-Stokes breathing patterns in heart failure patients. ASV works by continuously monitoring the patient’s breathing and calculating the ideal ventilation needs. When it detects a pause or a shallow breath, the device provides precisely calculated pressure support to normalize the respiratory cycle.
This rapid response helps keep carbon dioxide levels stable and prevents the unstable cycle of hyperventilation followed by apnea. ASV is highly effective because it only intervenes when necessary. However, caution is necessary when considering ASV for a specific subset of patients with severe, symptomatic heart failure and very low ejection fractions, requiring a thorough cardiac evaluation before initiation.
Continuous Positive Airway Pressure (CPAP) and Bi-level Positive Airway Pressure (BiPAP) devices are the standard treatment for Obstructive Sleep Apnea but are less effective for pure central apnea. CPAP delivers a single, constant pressure that keeps the airway open but does not stimulate the respiratory drive. BiPAP delivers different pressures for inhalation and exhalation, offering benefit in specific cases of CSA that include an obstructive component, often termed “overlap syndrome.”
Supplemental oxygen therapy is used for patients experiencing significant drops in blood oxygen saturation, particularly those living at high altitudes. Providing oxygen can increase the physiologic apneic threshold—the carbon dioxide level at which the brain is stimulated to breathe. This therapy can reduce the frequency of apneas and hypopneas and is often used as an adjunct therapy alongside other devices.
Medications That Stabilize Breathing
Specific medications can be used to stimulate the central respiratory drive directly. These agents are generally reserved for patients whose CSA persists despite optimal management of their underlying conditions. Acetazolamide is one such medication, often employed in cases related to high-altitude periodic breathing or certain metabolic forms of CSA.
The drug works by inhibiting the enzyme carbonic anhydrase, which induces a mild metabolic acidosis. This slight increase in blood acidity acts as a respiratory stimulant, making the brain more sensitive to carbon dioxide levels and encouraging more consistent breathing. Acetazolamide can effectively lower the Apnea-Hypopnea Index (AHI) and improve oxygen saturation during sleep.
Theophylline, a methylxanthine compound, is another respiratory stimulant used in specific populations, such as infants with apnea of prematurity. In adults, it is occasionally used off-label for CSA, but its application is limited due to a narrow therapeutic window and potential side effects, including gastrointestinal distress and cardiac arrhythmias. Its use requires careful monitoring of blood levels.
For patients who experience residual daytime sleepiness as a consequence of their central sleep apnea, wakefulness-promoting agents like modafinil or armodafinil may be prescribed. These medications manage the symptom of sleepiness but do not address the underlying pathology of the apnea itself.
Supportive Lifestyle Adjustments
While lifestyle changes are not a primary fix for central sleep apnea, they serve as supportive measures that enhance the effectiveness of medical and device treatments. Strictly limiting or eliminating alcohol and sedative use is paramount, as these substances act as central nervous system depressants, suppressing the brain’s drive to breathe and worsening the severity of apneas.
Managing fluid and salt intake is particularly relevant for individuals whose CSA is linked to heart failure. High sodium intake contributes to fluid retention; this excess fluid can shift to the chest and neck when lying down, destabilizing the breathing pattern. Restricting sodium intake, often less than 2,000 milligrams per day, helps control volume overload and stabilize respiration.
General sleep hygiene practices also maximize treatment benefits. Maintaining a consistent sleep schedule, ensuring the bedroom is dark and quiet, and avoiding large meals close to bedtime promote better overall sleep quality, supporting the body’s natural sleep architecture.