Table of ContentsView AllTable of ContentsOverviewPrevalenceCausesEffectsTreatment
Table of ContentsView All
View All
Table of Contents
Overview
Prevalence
Causes
Effects
Treatment
Complex sleep apnea, also called treatment-emergent central sleep apnea, is a condition that develops from the use of CPAP (continuous positive airway pressure) to treatobstructive sleep apnea.
Sleep apneais a medical condition in which a person’s breathing stops and restarts many times while they sleep. There are two main types: chronic obstructive sleep apnea and central sleep apnea.Complex sleep apnea is a combination of both.
Learn about complex sleep apnea, its features and causes, how it is diagnosed, and the most effective treatments.
Juanmonino / Getty Images
Overview of Complex Sleep Apnea
Complex sleep apnea is also referred to as treatment-emergent central sleep apnea. Complex sleep apnea occurs when someone who previously hadobstructive sleep apneadevelopscentral sleep apneadue to treatment withcontinuous positive airway pressure (CPAP).Here’s an explanation of the terms:
Obstructive Sleep Apnea
First, obstructive sleep apnea occurs when the upper airway (or throat) collapses during sleep. This can trigger drops in the blood’s oxygen levels, as well as arousals or awakenings from sleep.
Once obstructive sleep apnea is identified, the most common and effective treatment is the use of CPAP therapy.This treatment delivers a constant flow of air through a facial mask.
This additional air keeps the airway from collapsing, or obstructing, and also resolves snoring. In some cases, it may trigger changes in breathing that result in breath holding, a condition called central sleep apnea.
Complex Sleep Apnea
By definition, complex sleep apnea occurs with the use of CPAP treatment.Obstructive events resolve with therapy, while central apnea events emerge or persist with CPAP treatment.
These central apnea events must occur at least five times per hour and constitute more than 50% of the total number of apnea and hypopnea events. Therefore, if you have a total of 100 apnea events noted while using CPAP therapy, and only 49 (or more likely fewer) are central apnea events, you do not have complex sleep apnea.
It is very common for some central apnea events to emerge, but they may not require any additional intervention beyond time.
Understanding the Types of Sleep Apnea
Prevalence of Complex Sleep Apnea
How common is complex sleep apnea?This is a difficult question to answer. The true incidence and degree of persistence are not well defined because the condition can resolve as treatment continues.
Complex sleep apnea is estimated to affect from 2% to 20% of people as they start using CPAP therapy and may be seen more often on the first or second night of use. Therefore, it may be over-identified as part of a titration study in a sleep center. Fortunately, it only persists with therapy in about 1.5% of people.
Complex Sleep Apnea Causes
The exact causes of complex sleep apnea are not fully understood. There may be a number of contributors to the condition, and not all are due to CPAP therapy.
If someone has more severe sleep apnea initially (with a higher apnea-hypopnea index, orAHI)or has more central apnea events noted prior to treatment, this may increase the risk. It also seems to occur more in men.
It is interesting to note that other treatments of sleep apnea also seem to increase the risk of developing complex sleep apnea.
Surgery and the use of anoral appliancelike a night guard have both been reported to trigger central sleep apnea. It may also occur if the pressures of the PAP therapy are either too high or too low, as set during a titration study or in subsequent home use.
Effects of Complex Sleep Apnea
Even though complex sleep apnea generally resolves over time, there are still 1.5% of people in whom the condition persists and there may be other consequences. Some of these people may requirealternative treatmentsto resolve the disorder.
Complex sleep apnea may be noted to persist on routine download of PAP compliance data. This will usually occur at a routine follow-up appointment with your sleep specialist in the first three months of use. If more than five central apnea events are occurring per hour, despite the obstructive sleep apnea events resolving, this might prompt changes.
Persistent complex sleep apnea associated with a high residual AHI may cause continued sleep fragmentation and oxygen desaturation (low oxygen levels in the blood). This may lead to daytime sleepiness and other long-term health effects. Importantly, this may also compromise PAP therapy: The user may report little benefit and have poor long-term adherence to the treatment.
It is important to recognize that there may be night-to-night variability. In the context of your initial condition, some elevations in the AHI may be tolerated if the overall response to therapy is favorable. Though the devices can provide a rough measure of central apnea events, these are not perfect, and this may be better assessed via a standard polysomnogram.
Can Complex Sleep Apnea Be Cured?
Resolution of complex sleep apnea may depend on addressing the underlying causes. For example, if the pressures used are simply too high (or, less often, too low), a simple adjustment may resolve the matter. If awakenings are occurring due to mask leaks, a proper fitting may help.
In some cases, it may be necessary to switch to bilevel ST (with a timed breath rate that can be delivered during breath pauses) or adaptive servo-ventilation (ASV) therapy.Thesetherapy modalitieswill often require a titration study to find the optimal device settings.
The most prudent treatment is often the most effective: time. Complex sleep apnea will usually improve in 98% of cases as therapy continues (after about eight weeks).It may not require any further intervention beyond waiting and watching the remaining events resolve on their own.
Summary
Complex sleep apnea is a condition that develops during the use of CPAP to treat obstructive sleep apnea. It is a combination of obstructive sleep apnea and breath-holding (known as central sleep apnea). Complex sleep apnea resolves over time in the majority of people, but the condition persists in about 1.5% of people which could have other health consequences. These people may require alternative treatments.
7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Heart, Lung, and Blood Institute.What is sleep apnea?Wang J, Wang Y, Feng J, Chen BY, Cao J.Complex sleep apnea syndrome.Patient Prefer Adherence. 2013;7:633-641. doi:10.2147/PPA.S46626MedlinePlus.Polysomnography.Javaheri S, Smith J, Chung E.The prevalence and natural history of complex sleep apnea. J Clin Sleep Med. 2009 Jun 15;5(3):205-11. PMID: 19960639Muza RT.Central sleep apnoea—a clinical review.J Thorac Dis. 2015;7(5):930-937. doi:10.3978/j.issn.2072-1439.2015.04.45Division of Sleep Medicine at Harvard Medical School.Apnea hypopnea index (AHI).Khan MT, Franco RA.Complex sleep apnea syndrome. Sleep Disord. 2014;2014:798487. doi: 10.1155/2014/798487. Epub 2014 Feb 16. PMID: 24693440Additional ReadingAmerican Academy of Sleep Medicine.International classification of sleep disorders. 3rd ed. American Academy of Sleep Medicine;Lehman S, Antic NA, Thompson C, Catcheside PG, Mercer J, McEvoy D.Central sleep apnea on commencement of continuous positive airway pressure in patients with a primary diagnosis of obstructive sleep apnea-hypopnea.J Clin Sleep Med.2007;3:462-466. doi:10.5664/jcsm.8424Westhoff M, Arzt M, Litterst P.Prevalence and treatment of central sleep apnea emerging after initiation of continuous positive airway pressure in patients with obstructive sleep apnoea without evidence of heart failure.Sleep Breath.2012;16(1):71-78. doi:10.1007/s11325-011-0486-0
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Heart, Lung, and Blood Institute.What is sleep apnea?Wang J, Wang Y, Feng J, Chen BY, Cao J.Complex sleep apnea syndrome.Patient Prefer Adherence. 2013;7:633-641. doi:10.2147/PPA.S46626MedlinePlus.Polysomnography.Javaheri S, Smith J, Chung E.The prevalence and natural history of complex sleep apnea. J Clin Sleep Med. 2009 Jun 15;5(3):205-11. PMID: 19960639Muza RT.Central sleep apnoea—a clinical review.J Thorac Dis. 2015;7(5):930-937. doi:10.3978/j.issn.2072-1439.2015.04.45Division of Sleep Medicine at Harvard Medical School.Apnea hypopnea index (AHI).Khan MT, Franco RA.Complex sleep apnea syndrome. Sleep Disord. 2014;2014:798487. doi: 10.1155/2014/798487. Epub 2014 Feb 16. PMID: 24693440Additional ReadingAmerican Academy of Sleep Medicine.International classification of sleep disorders. 3rd ed. American Academy of Sleep Medicine;Lehman S, Antic NA, Thompson C, Catcheside PG, Mercer J, McEvoy D.Central sleep apnea on commencement of continuous positive airway pressure in patients with a primary diagnosis of obstructive sleep apnea-hypopnea.J Clin Sleep Med.2007;3:462-466. doi:10.5664/jcsm.8424Westhoff M, Arzt M, Litterst P.Prevalence and treatment of central sleep apnea emerging after initiation of continuous positive airway pressure in patients with obstructive sleep apnoea without evidence of heart failure.Sleep Breath.2012;16(1):71-78. doi:10.1007/s11325-011-0486-0
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Heart, Lung, and Blood Institute.What is sleep apnea?Wang J, Wang Y, Feng J, Chen BY, Cao J.Complex sleep apnea syndrome.Patient Prefer Adherence. 2013;7:633-641. doi:10.2147/PPA.S46626MedlinePlus.Polysomnography.Javaheri S, Smith J, Chung E.The prevalence and natural history of complex sleep apnea. J Clin Sleep Med. 2009 Jun 15;5(3):205-11. PMID: 19960639Muza RT.Central sleep apnoea—a clinical review.J Thorac Dis. 2015;7(5):930-937. doi:10.3978/j.issn.2072-1439.2015.04.45Division of Sleep Medicine at Harvard Medical School.Apnea hypopnea index (AHI).Khan MT, Franco RA.Complex sleep apnea syndrome. Sleep Disord. 2014;2014:798487. doi: 10.1155/2014/798487. Epub 2014 Feb 16. PMID: 24693440
National Heart, Lung, and Blood Institute.What is sleep apnea?
Wang J, Wang Y, Feng J, Chen BY, Cao J.Complex sleep apnea syndrome.Patient Prefer Adherence. 2013;7:633-641. doi:10.2147/PPA.S46626
MedlinePlus.Polysomnography.
Javaheri S, Smith J, Chung E.The prevalence and natural history of complex sleep apnea. J Clin Sleep Med. 2009 Jun 15;5(3):205-11. PMID: 19960639
Muza RT.Central sleep apnoea—a clinical review.J Thorac Dis. 2015;7(5):930-937. doi:10.3978/j.issn.2072-1439.2015.04.45
Division of Sleep Medicine at Harvard Medical School.Apnea hypopnea index (AHI).
Khan MT, Franco RA.Complex sleep apnea syndrome. Sleep Disord. 2014;2014:798487. doi: 10.1155/2014/798487. Epub 2014 Feb 16. PMID: 24693440
American Academy of Sleep Medicine.International classification of sleep disorders. 3rd ed. American Academy of Sleep Medicine;Lehman S, Antic NA, Thompson C, Catcheside PG, Mercer J, McEvoy D.Central sleep apnea on commencement of continuous positive airway pressure in patients with a primary diagnosis of obstructive sleep apnea-hypopnea.J Clin Sleep Med.2007;3:462-466. doi:10.5664/jcsm.8424Westhoff M, Arzt M, Litterst P.Prevalence and treatment of central sleep apnea emerging after initiation of continuous positive airway pressure in patients with obstructive sleep apnoea without evidence of heart failure.Sleep Breath.2012;16(1):71-78. doi:10.1007/s11325-011-0486-0
American Academy of Sleep Medicine.International classification of sleep disorders. 3rd ed. American Academy of Sleep Medicine;
Lehman S, Antic NA, Thompson C, Catcheside PG, Mercer J, McEvoy D.Central sleep apnea on commencement of continuous positive airway pressure in patients with a primary diagnosis of obstructive sleep apnea-hypopnea.J Clin Sleep Med.2007;3:462-466. doi:10.5664/jcsm.8424
Westhoff M, Arzt M, Litterst P.Prevalence and treatment of central sleep apnea emerging after initiation of continuous positive airway pressure in patients with obstructive sleep apnoea without evidence of heart failure.Sleep Breath.2012;16(1):71-78. doi:10.1007/s11325-011-0486-0
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
