Sleep-related breathing disorders
Treatment-Emergent Central Sleep Apnea (Complex Sleep Apnea)
Central breathing pauses that appear when obstructive sleep apnea is treated, most often when starting CPAP. It frequently settles with continued treatment.
Overview
Treatment-emergent central sleep apnea, often called complex sleep apnea, describes people diagnosed with obstructive sleep apnea who develop central apneas once their airway is held open, most commonly with CPAP. The obstructive events disappear, but pauses with no breathing effort appear in their place.
In many people these central events are temporary and fade over the first weeks to months of regular CPAP use as breathing control stabilises. In others they persist, and a different device may be needed. Researchers think it reflects an unstable breathing control system that the obstructive events had been masking.
If your CPAP data show a high residual AHI, or you still feel unrefreshed despite good use, ask your clinician whether central events could be the reason.
Common symptoms
- Persistent sleepiness despite regular CPAP use
- A high residual AHI or many central events on your machine report
- Waking frequently or feeling unable to settle on CPAP
- Air hunger or waking short of breath
- Poor CPAP tolerance
Causes and risk factors
- Starting CPAP or bilevel therapy for obstructive sleep apnea
- Pressure set higher than needed
- Heart failure or atrial fibrillation
- Opioid medicines
- Male sex and higher severity of the original apnea
- Occasionally after other OSA treatments such as surgery or oral appliances
How it is diagnosed
It is diagnosed when a sleep study done on positive airway pressure, or ongoing device data reviewed by your clinician, show that obstructive events have resolved but central apneas or hypopneas persist at five or more per hour and make up more than half of remaining events, in someone whose original diagnosis was obstructive sleep apnea.
Because many cases resolve on their own, clinicians often monitor device data over several weeks before changing treatment. An attended in-lab titration study may be used to confirm the pattern and test other devices.
Treatment options
Continued CPAP with monitoring
Many people see central events fall over the first weeks to months of consistent use.
Pressure adjustment
Avoiding unnecessarily high pressure can reduce central events.
Adaptive servo-ventilation (ASV)
Suggested by AASM guidance for persistent treatment-emergent CSA, after assessing heart function.
Addressing contributing factors
Reviewing opioid use and treating heart conditions can help.
What you can do yourself
- Keep using your CPAP unless your clinician tells you otherwise
- Check your device report and share the data with your care team
- Report persistent sleepiness or new symptoms rather than giving up on therapy
- Avoid alcohol and sedatives before bed
When to see a doctor
- Your device shows a residual AHI that stays high after the first few weeks
- You feel no better or worse after starting CPAP
- You wake gasping or feel air hunger on the mask
- You have heart disease or use opioids and recently started CPAP
Frequently asked questions
Did CPAP cause my central apneas?
CPAP reveals or triggers them in some people rather than creating a new disease. Once the airway stops collapsing, an underlying instability in breathing control can show up as central pauses. In many people this settles with continued regular use.
Should I stop using CPAP if my report shows central events?
No, not without talking to your clinician. Stopping brings back the obstructive apnea, and central events often decrease over the first weeks to months. Your clinician can review the data and adjust pressure or change devices if they persist.
What does CA mean on my CPAP report?
Many machines label events as obstructive (OA), clear airway or central (CA), and hypopneas. A rising number of CA events is worth showing your sleep team, though home device scoring is an estimate rather than a formal sleep study result.
What is ASV and when is it used?
Adaptive servo-ventilation is a bilevel device that varies support breath by breath to smooth out unstable breathing. It is used when central events persist despite CPAP, after checking heart function, because it is not appropriate for everyone with heart failure.
Sources
This page is general information, not a diagnosis or medical advice. Read our medical disclaimer.