Complex Sleep Apnea in Singapore

Primary complex sleep apnoea presents from the onset with both obstructive and central components co-occurring. Patients may experience periods in which the airway physically collapses, as well as episodes in which the brain fails to signal the breathing muscles. This type can manifest in individuals with underlying cardiac conditions or neurological disorders that affect the respiratory control centres.

This form can develop during CPAP therapy for obstructive sleep apnoea. Initially presenting as pure OSA, central apnoeas may emerge once positive airway pressure eliminates the obstructive component. The mechanism involves complex interactions between ventilatory control, carbon dioxide sensitivity, and pressure-induced changes in breathing patterns. Some patients may develop this during CPAP therapy.

Some patients may continue experiencing both types of apnoeas despite various treatment attempts. This persistent form may require a comprehensive management approach, often involving multiple treatment modalities. These cases can have underlying medical conditions such as heart failure, stroke history, or chronic opioid use that may complicate respiratory control.

• Witnessed breathing pauses lasting 10 seconds or more
• Gasping or choking upon breathing resumption
• Frequent position changes throughout the night
• Irregular breathing patterns with variable depths
• Periods of very shallow breathing
• Partner reports concerning breathing irregularities

• Excessive daytime sleepiness despite adequate sleep hours
• Morning headaches
• Difficulty concentrating or memory problems
• Mood changes, including irritability or depression
• Decreased libido or sexual dysfunction
• Falling asleep during routine activities

• Changes in sleep quality after starting CPAP
• Increased awakenings compared to pre-treatment
• Feeling short of breath upon waking
• Difficulty tolerating prescribed CPAP pressures
• Persistent fatigue despite CPAP compliance

Complex sleep apnoea symptoms may persist or change despite initial CPAP therapy, which can help distinguish it from pure obstructive sleep apnoea. Patients may report different experiences after starting treatment.

Adaptive servo-ventilation is a treatment for complex sleep apnoea that uses algorithms to provide variable pressure support. The device monitors breathing patterns and adjusts pressure delivery to help manage both obstructive and central events. ASV machines can learn each patient’s breathing patterns and provide support to help maintain stable ventilation. Treatment may require several weeks of adjustment as the device adapts to individual breathing patterns.

BiPAP-ST (spontaneous/timed) devices deliver different pressures for inhalation and exhalation while maintaining a minimum breathing frequency. This mode may benefit patients with predominant central components or those requiring ventilatory support. The backup rate aims to help prevent central apnoeas by initiating breaths when spontaneous effort is absent. Pressure settings require careful titration to balance comfort with efficacy.

Supplemental oxygen therapy addresses hypoxaemia and may help stabilise breathing patterns in some cases of complex sleep apnoea. Low-flow oxygen delivered via the PAP circuit can help reduce fluctuations in hypoxic respiratory drive. This adjunctive treatment may help improve central apnoea when combined with positive pressure therapy. Monitoring helps with appropriate oxygen levels without suppressing respiratory drive.

Acetazolamide, a carbonic anhydrase inhibitor, may help reduce central apnoeas by inducing mild metabolic acidosis and stimulating breathing. This medication may particularly help patients with high loop gain or altitude-related central apnoeas. Theophylline may occasionally provide benefit through respiratory stimulation, though side effects can limit its use. Medication adjustments for underlying conditions, particularly cardiac medications and opioids, can significantly impact sleep-disordered breathing patterns.

VAPS technology combines the comfort of pressure support with the delivery of ventilation. The system automatically adjusts pressure support to help maintain target tidal volumes despite changing patient needs. This approach addresses both obstructive and central components while maintaining patient-device synchrony. Optimising settings requires sleep laboratory titration to achieve outcomes.

This therapy uses an implanted device to stimulate the phrenic nerve, triggering diaphragm contraction during central apnoeas. The system monitors breathing patterns and delivers stimulation when needed. Suitable candidates undergo a thorough evaluation, including phrenic nerve function testing. While invasive, this option may provide physiologic breathing restoration for selected patients.

Untreated complex sleep apnoea may increase cardiovascular risks, including hypertension, atrial fibrillation, and heart failure progression. The combination of low blood oxygen and sleep fragmentation can strain the cardiovascular system. There may be an increased stroke risk compared to simple obstructive sleep apnoea.

Cognitive function may be affected by chronic sleep disruption and intermittent hypoxia. Patients may experience memory impairment, decreased executive function, and increased risk of accidents. Work performance may deteriorate, relationships can be affected, and quality of life may decline. The metabolic consequences can include insulin resistance, weight gain, and the development of. Untreated complex sleep apnoea may create a cycle where complications can worsen the underlying sleep disorder, potentially making treatment more challenging.