There has been a new type identified of sleep apnea which has been called complex sleep apnea. Until now, we have all known only about two types of sleep apnea, obstructive sleep apnea and central sleep apnea. If a person deals with obstructive sleep apnea, which is the more common type, their throat muscles relax and the airway is narrowed which causes breathing breaks and loud snoring. On the other hand, central sleep apnea means that the brain does not send proper signals to the muscles that control breathing. The newly discovered, third type, is a mix of both obstructive and central sleep apnea.

Patients who have complex sleep apnea look like they have obstructive sleep apnea, but their breathing issue isn’t completely alleviated by a CPAP machine. Instead, as soon as these patients get CPAP, the obstruction seems to disappear, but there is no improvement in breathing. The symptoms of central sleep apnea occur and there is fragmented sleep due to the frequent pauses in breathing. In fact, when obstructive sleep apnea patients put on a CPAP machine, they start to look like central sleep apnea syndrome patients. This phenomenon has been observed and analyzed for years and it was about time that scientist and researchers came into conclusion that this is a new sleep apnea type.

Complex Sleep Apnea Syndrome

This condition is a pattern consistent with simultaneous upper-airway obstruction and increased breathing control-related fluctuation. Complex sleep apnea syndrome happens mostly in non-rapid eye movement sleep, which is a deep, restorative phase. This condition also occurs during CPAP titration or early phases of CPAP treatment.

In order to diagnose complex sleep apnea, there have to be 50% of all central events, less than 5 per hour of sleep obstructive events, and 5 or more of the central apnea-hypopnea index. This condition is quite common during the initial treatment period with CPAP. Moreover, a person who has complex sleep apnea is likely to experience a high number of arousals from sleep and each awakening may be followed by a post-arousal central.

It’s very challenging to determine how common this condition is. It is estimated that 2% to 20% of people who start using CPAP therapy start experiencing symptoms of complex sleep apnea syndrome. Luckily, only 2% of people will continue experiencing this condition with the therapy.

Why complex sleep apnea syndrome is still unknown. There are probably many causes for this condition and not all of them have something to do with CPAP therapy. Some people might be predisposed towards complex sleep apnea syndrome and it has shown to be more common in people who suffer from insomnia. Likewise, the condition seems to occur due to low carbon dioxide levels and in people who have more severe sleep apnea initially. This condition is more prevalent in men.

Besides CPAP therapy, there are other treatments of sleep apnea which increase the risk of developing complex sleep apnea, including the use of an oral appliance, surgery, and PAP therapy. This condition resolves on its own over time, but in about 2% of people the condition persists and there may be other consequences. Nevertheless, complex sleep apnea syndrome will improve in 98% of cases as therapy continues.