High Clear Airway Apneas Despite CPAP – Should I Be Worried?

Hi everyone,

I’ve been using my DreamStation 2 CPAP and reviewing my therapy data, and something’s really concerning me.

My AHI has been consistently in the 8–13 range over the past several nights, but what stands out is that the majority of these events are Clear Airway Apneas, not obstructive. Below are my daily results (screenshots included):

⸻

May 14–15
• AHI: 13.0
• Clear Airway Apneas: 72
• Obstructive Apneas: 19
• Hypopneas: 21

May 15–16
• AHI: 9.7
• Clear Airway Apneas: 56
• Obstructive Apneas: 5
• Hypopneas: 7

May 16–17
• AHI: 12.6
• Clear Airway Apneas: 65
• Obstructive Apneas: 5
• Hypopneas: 12

May 17–18
• AHI: 11.8
• Clear Airway Apneas: 44
• Obstructive Apneas: 3
• Hypopneas: 4

May 18–19
• AHI: 8.4
• Clear Airway Apneas: 35
• Obstructive Apneas: 4
• Hypopneas: 9

May 19–20
• AHI: 8.7
• Clear Airway Apneas: 49
• Obstructive Apneas: 7
• Hypopneas: 3

As you can see, the Clear Airway Apneas are very high almost every night. I barely have obstructive apneas, which makes me wonder:
• Could this be treatment-emergent central sleep apnea?
• Is my pressure too high, triggering central events?
• Should I be considering a different machine (BiPAP, ASV)?
• Did anyone else experience this early on, and did it improve with time?

I’m planning to speak with my doctor, but I’d really appreciate hearing from anyone who’s experienced something similar or has advice on what worked for them.

Thanks so much in advance!

Mrsafety wrote: ↑

Tue May 20, 2025 10:36 pm

Could this be treatment-emergent central sleep apnea?

Entirely possible.

Mrsafety wrote: ↑

Tue May 20, 2025 10:36 pm

Is my pressure too high, triggering central events?

Don't know. For one thing you didn't tell us what your pressure settings are but it doesn't have to necessarily be a "high" pressure. Treatment emergent central apneas can be triggered by as little as 5 cm pressure.

Mrsafety wrote: ↑

Tue May 20, 2025 10:36 pm

Should I be considering a different machine (BiPAP, ASV)?

Too soon to make that determination. It depends on just what might be triggering the centrals and can we get lucky and have the centrals either reduce on their own or with minor tweaking of the settings.

Where are you located? Phillips Respironics machines are unavailable in the USA....how did you get one?

Pressure is 10.00

Location- Canada

Are you using the Flex exhale relief? If so, at what setting?

Which model machine? Which mode?
There is more than one and what you get as details depends on model and mode.

Can you share the detailed report from one of your typical nights?
http://www.cpaptalk.com/viewtopic/t1585 ... eview.html


How long have you been on this machine at these settings?

Where in Canada? Does your province offer any cpap coverage to lessen you expense?

I’m using the Dreamstation 2 advanced

Mrsafety wrote: ↑

Wed May 21, 2025 7:36 am

I’m using the Dreamstation 2 advanced

In what mode? Fixed cpap mode or auto adjusting mode?

And again....answer the Flex question please. If you are using Flex exhale relief try turning it off or way down and see if that affects the central numbers or not. Exhale relief can trigger centrals in a very small subset of cpap users....that's why it is important to know ALL the settings.

I'm using the Dreamstation 2 Auto CPAP advanced. Ramp + is 45 minutes with Pressure at 10 cmH2O, Humidity 4, Heated tube 2, and Flex 3. So, with the pressure, I have the ability to reduce and not increase from the machine.

Try turning Flex setting to OFF or at least reduce it to 1 and see if it makes any difference in the number of central/Clear airway apnea flagging.
No other changes at this time.

Thanks will do

I don't know that Flex is the trigger for the centrals but it is very possible and it's an easy modification to make...and cheap.

Once you get a night without Flex then we need to see the OSCAR detailed report and maybe SleepHQ unless we have a miracle with just altering the Flex setting.

It’s 3:03 a.m., and I’m still unable to sleep. I keep experiencing a sensation that I stop breathing just as I’m about to fall asleep, which is preventing me from getting any sleep

You need to talk to a doctor, whether 'only' medical or possibly also psychiatric/psychological about sleeping.

Hi I took am on dreamstation 2 auto
Been on it for 9 days
My numbers for csa are also abnormal
From 81 to 17 in 9 days with an average sleep time of 7 hours
Hypopneas are in average 40 for 9 days
And osa on average are 15 for 9 days
So my inhalotherapist called me and said threshold is 5 for csa as is ahi,
He removed the ramp which was set at 4 and last night I slept with a start of 6,my csa was 17 in 7 hours, so in mild range, he also stated that in can resolve on its own, in time but if it doesn't, a different machine will be needed.

Segal_mtl wrote: ↑

Sat May 24, 2025 9:25 am

So my inhalotherapist called me and said threshold is 5 for csa as is ahi,
He removed the ramp which was set at 4 and last night I slept with a start of 6,my csa was 17 in 7 hours, so in mild range, he also stated that in can resolve on its own, in time but if it doesn't, a different machine will be needed.

True...a reduction in centrals can happen on its own with time....also they can reduce if you are having a lot of post arousal centrals where you aren't sound asleep and with time and experience and just simply sleeping more soundly and not causing post arousal centrals.

You MUST be asleep for a central to really matter in terms of going along with central sleep apnea diagnosis...and must have at least 5 per hour every night hourly average.

So let's figure out if your centrals are asleep centrals....or post arousal SWJ (sleep/wake/junk) centrals or simple a nice normal sleep transition central. A handful of real asleep centrals is normal and nothing to worry about.

BTW stick with your other thread/topic that you started and don't continue to hijack this thread. Thank you.

viewtopic/t172378/StickyIf-you-want-CPA ... Gquot.html