Complex sleep apnea
Complex sleep apnea (or mixed sleep apnea) is a form of sleep apnea in which central apneas persist or emerge during attempts to treat obstructive events with a continuous positive airway pressure (CPAP) or bilevel device.
Complex sleep apnea is characteristics
- The persistence or emergence of central apneas or hypopneas upon exposure to CPAP or bilevel when obstructive events have disappeared
- Complex sleep apnea patients have predominately obstructive or mixed apneas during the diagnostic sleep study, occurring at least 5 times per hour
- With use of a CPAP or bilevel, they show a pattern of central apneas and hypopneas that meets the Centers for Medicare Services (CMS) definition of CSA
A diagnosis of central sleep apnea (CSA) requirements
- An apnea index > 5
- Central apneas/hypopneas > 50% of total apneas/hypopneas
- Central apneas or hypopneas occurring at least 5 times per hour
- Symptoms of either excessive sleepiness or disrupted sleep
The difference between central, mixed and complex sleep apnea
CSA is a form of sleep-disordered breathing (SDB) caused by the temporary absence of a signal from the brain’s respiratory center. Without this signal, there is no effort to breathe. Mixed sleep apnea is fairly common and consists of both central and obstructive components. On the other hand, complex sleep apnea consists of all or predominantly obstructive apneas which convert to all or predominantly central apneas when treated with a CPAP or bilevel devices.
The challenge to treat complex sleep apnea
Patients with complex sleep apnea cannot be adequately treated with CPAP or bilevel device. The clinical consequences are residual symptoms (fatigue, sleepiness, depressed mood) and intolerance to therapy.
Patients with complex sleep apnea may be seen as those who cannot tolerate conventional CPAP or bilevel therapy both during lab titration and at home. Neither CPAP nor bilevel therapy seems to alleviate their sleep disorders. For complex sleep apnea patients, treatment with CPAP or bilevel therapy will leave them with a somewhat elevated AHI, and their disorder will not be completely resolved.