Central Sleep Apnea in Singapore

Primary CSA, also known as idiopathic central sleep apnea, occurs without an identifiable underlying cause. This form may affect adults and is characterised by a low respiratory drive during sleep. Patients with primary CSA often have normal daytime breathing but may experience breathing disruptions during sleep.

This breathing pattern involves periods of deep breathing alternating with shallow breathing or complete cessation. It’s commonly associated with heart failure or stroke and follows a crescendo-decrescendo pattern. The cycle may last varying durations and can be more pronounced during non-REM sleep stages.

Exposure to high altitudes can trigger central sleep apnoea in otherwise healthy individuals. Lower oxygen levels at high altitudes may cause hyperventilation, followed by periods of apnoea. This type may resolve upon returning to lower altitudes, but could require treatment during altitude exposure.

Various medical conditions can trigger central sleep apnoea, including heart failure, stroke, brain tumours, and brainstem lesions. Each underlying condition may affect the brain’s respiratory control centres differently, requiring tailored treatment approaches.

Long-term use of opioid medications can suppress the brain’s respiratory drive, potentially leading to central sleep apnoea. This type has become increasingly recognised with the use of opioid pain medications and may require careful medication management alongside sleep apnoea treatment.

• Observed episodes of stopped breathing during sleep
• Abrupt awakenings accompanied by shortness of breath
• Difficulty staying asleep (insomnia)
• Abnormal breathing patterns during sleep
• Frequent nighttime urination
• Night sweats without apparent cause

• Excessive daytime sleepiness despite adequate sleep time
• Morning headaches
• Difficulty concentrating or memory problems
• Mood changes, including irritability or depression
• Fatigue distinct from sleepiness
• Decreased exercise tolerance

• Chest pain during sleep or upon waking
• Irregular heartbeat or palpitations
• Severe shortness of breath when lying flat
• Swelling in legs or ankles
• Confusion or difficulty thinking clearly
• Falling asleep during critical activities like driving

Central sleep apnoea symptoms often develop gradually and may be attributed to ageing or other conditions. Unlike obstructive sleep apnoea, loud snoring is typically absent, making CSA harder to detect without proper sleep evaluation.

• Adaptive Servo-Ventilation (ASV): ASV represents a modern positive airway pressure therapy for central sleep apnoea, particularly for Cheyne-Stokes breathing patterns. The device continuously monitors breathing patterns and automatically adjusts pressure support to stabilise ventilation. Treatment involves wearing a mask during sleep, with the machine learning your breathing patterns over time. Patients may require time to adapt, with regular follow-ups to optimise settings. ASV is contraindicated in certain heart failure patients with reduced ejection fraction.
• Bilevel Positive Airway Pressure (BiPAP): BiPAP devices deliver two pressure levels – higher during inhalation and lower during exhalation. This approach may suit patients who cannot tolerate continuous pressure or need ventilatory support. The backup rate feature aims to achieve a minimum breathing frequency, which may be beneficial for central apnoea events. Treatment customisation involves sleep laboratory titration to determine optimal pressure settings and backup rate.
• Continuous Positive Airway Pressure (CPAP): While primarily used for obstructive sleep apnoea, CPAP may benefit select CSA patients, particularly those with mixed apnoea patterns. The continuous air pressure can stimulate breathing in mild cases. Some patients initially treated with CPAP for obstructive apnoea develop central events, requiring transition to other devices.

• Nocturnal Oxygen Supplementation: Supplemental oxygen during sleep can reduce hypoxaemia and may decrease the frequency of central apnoea. Treatment involves wearing a nasal cannula delivering oxygen throughout sleep. Oxygen therapy may particularly benefit patients with heart failure-related CSA or high-altitude periodic breathing. Regular monitoring helps with appropriate oxygen levels without suppressing respiratory drive.

• Acetazolamide: This carbonic anhydrase inhibitor stimulates breathing by inducing mild metabolic acidosis. Dosing typically starts at a low level before bedtime, with gradual adjustments based on response. The medication may particularly help high-altitude periodic breathing and idiopathic CSA. Side effects can include tingling sensations and increased urination, which may improve with continued use.
• Theophylline: A respiratory stimulant that enhances diaphragm contractility and increases respiratory drive. Low-dose treatment may help reduce central apnoea events. Regular blood level monitoring helps with therapeutic dosing while avoiding toxicity. The medication requires careful use in patients with cardiac arrhythmias.
• Opioid Reduction or Substitution: For medication-induced CSA, carefully supervised opioid tapering or switching to non-opioid pain management may improve breathing patterns. The process requires coordination between ENT specialists and pain management physicians. Alternative pain treatments can include non-opioid medications, nerve blocks, or physical therapy approaches.

• Implantable Nerve Stimulator: This treatment involves surgically implanting a device that stimulates the phrenic nerve, thereby causing diaphragm contraction. The system activates during sleep, aiming to maintain regular breathing patterns. Suitable candidates undergo a thorough evaluation, including phrenic nerve function testing. The procedure requires specialised surgical knowledge with programming adjustments over time.

Whilst some causes of central sleep apnoea cannot be prevented, risk reduction strategies may help minimise the likelihood of development or progression. Managing cardiovascular health through regular exercise, maintaining a healthy weight, and controlling blood pressure may reduce the risk of heart failure, a contributing factor to CSA. Patients with heart conditions may need to optimise medical management and attend regular cardiac follow-ups to detect early signs of sleep-disordered breathing.

Medication awareness involves discussing opioid alternatives with healthcare providers when possible. Patients requiring long-term opioid therapy need regular sleep assessment monitoring. Altitude acclimatisation may help prevent high-altitude periodic breathing by ascending gradually and allowing time to adjust at intermediate elevations. Portable oxygen or acetazolamide prophylaxis may benefit susceptible individuals.

Lifestyle modifications supporting respiratory health include avoiding alcohol and sedatives before bedtime, as these substances can suppress breathing drive. Maintaining regular sleep schedules may help optimise natural breathing rhythms. Sleeping position adjustment, particularly avoiding the supine position, may reduce apnoea severity in some patients. Prompt treatment of respiratory infections may prevent additional stress on compromised breathing control systems.