What causes hypopneas?

So ever since I started using a CPAP machine, my AHI has gone down very nicely, from around 50 (during my sleep test) down to usually below 1.0 per night. So I'm mainly satisfied. But I'm curious about my remaining AHI, and what's behind it. I have gotten a mix of the three types, central, obstructive, and hypop. But it's looking like the vast majority of the remainder AHI causes are now from hypos, the rest remain at zero most nights. Even the hypos are not that much either, maybe 1 or 2 a night, occasionally I won't even have those on some nights. So just wondering how to get more consistently zero hypos per night? What is the main cause of the hypos, like sleeping position, maybe eating and drinking regimens prior to sleep, etc.?

An apnea is an airway blockage of 70-100%. A hypopnia is a blockage of 40-70%. They are treated the same. When you get a few CAs during the night, it's common. A Ca is when there is a 10+ second breathing stop and there is no blockage...they usually come when you are partially awake. Don't beat yourself up trying to get zero events every night.

Yousuf wrote: ↑

Sat May 01, 2021 2:57 am

the vast majority of the remainder AHI causes are now from hypos

If your AHI is under 1.0, don't you think the use of "vast" is language abuse?

Yousuf, you are doing great! As LSAT and CG are saying, don't give those hypopneas a thought.

Just fyi, hypopneas can be central or obstructive in nature, meaning that they can reflect a dwindling of effort to breathe (central) or an episode with normal effort effort to breathe but a partial blockage to the flow of air (obstructive).

I am a fairly new CPAP user, not a sleep doc nor a sleep tech nor a professional of any kind. There are people on this board that are much smarter and more experienced than I am. May I suggest you read http://www.apneaboard.com/wiki/index.ph ... onal_Apnea carefully and several times. There is some great background there.

As I understand it, the machine calculates a moving average flow rate during the prior 5 minutes. When flow rate is <50% of the baseline moving average for 10 seconds, that is the definition of hyponoea. When flow rate is <10% of the baseline moving average for 10 seconds, that is the definition of obstructive. Hypopneas are wannabes.

As I understand it (remember my limitations), both obstructives and hypopneas tend to occur during the exhale phase and are therefore treated by increasing EPAP. Try increasing EPAP and IPAP by 1cm every couple nights and review again.

clownbell wrote: ↑

Sat May 01, 2021 1:23 pm

Try increasing EPAP and IPAP by 1cm every couple nights and review again.

His AHI is under 1.0. A pressure increase is not indicated. Now, if his AHI was 10.0, some analysis of his OSCAR detail might indicate a pressure increase.

EPAP and IPAP are terms for bilevel machines. There is no indication he has a bilevel machine.

It's good you are eager to help, but you need to build your knowledge base and experience level before making those kinds of recommendations.

Regards,

ChicagoGranny wrote: ↑

Sat May 01, 2021 6:04 am

Yousuf wrote: ↑

Sat May 01, 2021 2:57 am

the vast majority of the remainder AHI causes are now from hypos

If your AHI is under 1.0, don't you think the use of "vast" is language abuse?

I know, it sounds like I'm complaining over nothing, and I know that the numbers I'm getting are just fine. And I acknowledge that, it's just more of a "I want to know why it's happening" rather than a "I am worried about this" type of question.

But regarding the word "vast", I'm talking about over the course of a week, or a month, etc. Not really the nightly number. And also it refers to how hypos vastly outnumber all of the other types over the long-term course.

LSAT wrote: ↑

Sat May 01, 2021 5:50 am

An apnea is an airway blockage of 70-100%. A hypopnia is a blockage of 40-70%. They are treated the same. When you get a few CAs during the night, it's common. A Ca is when there is a 10+ second breathing stop and there is no blockage...they usually come when you are partially awake. Don't beat yourself up trying to get zero events every night.

Ah, okay, so a CA is calculated over the course of 10 seconds. Are the Obstructives and Hypos also calculated over 10 seconds too?

ChicagoGranny wrote: ↑

Sat May 01, 2021 3:02 pm

clownbell wrote: ↑

Sat May 01, 2021 1:23 pm

Try increasing EPAP and IPAP by 1cm every couple nights and review again.

His AHI is under 1.0. A pressure increase is not indicated. Now, if his AHI was 10.0, some analysis of his OSCAR detail might indicate a pressure increase.

EPAP and IPAP are terms for bilevel machines. There is no indication he has a bilevel machine.

Yeah, no I'm not looking to change any of my settings, they seem to be doing just fine right now, this is just an informational inquiry. And yes, I don't have a BiPAP machine, it's a standard CPAP machine.

But this brings up a secondary question. As I understand it, BiPAP's are prescribed to people who suffer a lot of problem with CA rather than obstructive apneas. A friend's husband has a CA problem, he simply sometimes doesn't bother to breathe a night. Now shouldn't a case like this have been prescribed a BiPAP? But they prescribed a CPAP instead.

clownbell wrote: ↑

Sat May 01, 2021 1:23 pm

As I understand it, the machine calculates a moving average flow rate during the prior 5 minutes. When flow rate is <50% of the baseline moving average for 10 seconds, that is the definition of hyponoea. When flow rate is <10% of the baseline moving average for 10 seconds, that is the definition of obstructive. Hypopneas are wannabes.

Okay, so that does answer a few things. An event is not logged unless it occurs for more than 10 sec over the course of 5 mins.

This is standard across all brands?

Yousuf wrote: ↑

Tue May 04, 2021 4:19 am

a lot of problem

Knowing how you define "vast", I have to ask what is "a lot".

Please keep it per night and not per century.

ChicagoGranny wrote: ↑

Tue May 04, 2021 10:43 am

Yousuf wrote: ↑

Tue May 04, 2021 4:19 am

a lot of problem

Knowing how you define "vast", I have to ask what is "a lot".

Please keep it per night and not per century.

In this case it just means, a lot, as in a lot. Like the CA being their primary apnea problem.

It is good that you are interested in getting the best therapy possible;
but the operative word is "possible".
What you are getting is awesome--some would practically kill for the numbers you report.
Relax and enjoy what you have.
Perspective is important.
Learn how to be content in the place you are.

All breathing obstructions, whether obstructive, hypopnea, or central, have to last for 10 seconds before the machine reports them as events.

Any attempt you make to reduce the number of hypopneas has a real risk of increasing something else, especially centrals. Reducing your AHI from 50 to less than 1 is a major improvement! General advice for an AHI of less than 1 is to leave things alone, though of course not everyone takes that advice.

What type of CPAP machine do you have and does OSCAR support it?