Aircurve OA Flagging

[bossfan]

I am on day 8 of using an Aircurve ASV. Previously I've used Respironics machines. The Respironics always flagged some obstructive events. The Respironics has not flagged even one OA event in 8 days. Is that possible that the Aircurve treats an OA event so much better than Respironics that I would not have even one OA event? I do get a couple of Uncalssified events but not that many of those either.

[GrumpyHere]

Aircurve ASV does not differentiate between OA and CA.
They are both classified as UA.

[Julie]

Well, the algorithms are a bit different in the machines so settings need to be adjusted when changing, but if you post 1-2 Oscar nights in this thread you'll probably get more info.

[bossfan]

Well, the algorithms are a bit different in the machines so settings need to be adjusted when changing, but if you post 1-2 Oscar nights in this thread you'll probably get more info.

Here are charts from last 2 nights.

oscar20210626.png (126.71 KiB) Viewed 640 times

oscar20210627.png (125.02 KiB) Viewed 640 times

[Pugsy]

ResMed machines with back up rates (ASV and a few others) don't use the FOT thing to differentiate between OAs and central apneas.
It's never really been fully explained as to why they don't but since they don't use FOT they lump all apneas in the UA unclassified apnea basket. It's just the way they report things.
Now according to ResMed the central apneas are usually dealt with (assuming the settings don't tied the machine's hands) so there really shouldn't be any central apneas. From this we can deduce that if we see a UA flagged event on the ASV that it is most likely an obstructive apnea.

Anyhow....your UA flagged events are very minimal and no matter what category they might fall in not enough to worry about.

The only thing I see on your reports that might need some work are the leaks (if they wake you up).
With so much leak going on the chances of false positive flagging is greatly increased even if you don't remember an arousal.
Example...the cluster of hyponea events right at the beginning of the night on the June 27 report....I would bet my last dollar you weren't asleep when those were flagged.
And remember...we can have false positive flagged events in any category.

But that's why you don't/won't see OA flags or central flags...your machine doesn't separate them. They both go in the UA basket.

[bossfan]

ResMed machines with back up rates (ASV and a few others) don't use the FOT thing to differentiate between OAs and central apneas.
It's never really been fully explained as to why they don't but since they don't use FOT they lump all apneas in the UA unclassified apnea basket. It's just the way they report things.
Now according to ResMed the central apneas are usually dealt with (assuming the settings don't tied the machine's hands) so there really shouldn't be any central apneas. From this we can deduce that if we see a UA flagged event on the ASV that it is most likely an obstructive apnea.

Anyhow....your UA flagged events are very minimal and no matter what category they might fall in not enough to worry about.

The only thing I see on your reports that might need some work are the leaks (if they wake you up).
With so much leak going on the chances of false positive flagging is greatly increased even if you don't remember an arousal.
Example...the cluster of hyponea events right at the beginning of the night on the June 27 report....I would bet my last dollar you weren't asleep when those were flagged.
And remember...we can have false positive flagged events in any category.

But that's why you don't/won't see OA flags or central flags...your machine doesn't separate them. They both go in the UA basket.

Thank you Pugsy. As a long time Respironics user I guess that I am still getting used to the way Resmed reports things. My AHI has been great since switching so I think that Resmed is treating the centrals and hypopneas better than Respironics.

The leaks have been an issue since I switched from Respironics. I saw on another thread from someone having the same leak issue after switching from Respironics to Resmed that you told that person to turn on EPR. With ASV I guess I have to adjust EPAP? My machine settings are set to what my doctor prescribed. Is there a change that you can suggest to address the leak issue? I'd like to stay with the nasal pillow since I have trouble tolerating a fuller face mask.

[Pugsy]

I am very hesitant to change the settings to try to fix a leak issue with your machine because of your problem.
The person I suggested adding EPR in...that was to more mimic what he had been using on the Respironics machine since he was using Flex.
With your ASV machine it's the PS that is similar to EPR and it's already doing a primary job of dealing with the centrals with the range in PS (EPR doesn't have a range). So your situation is different.

First of all...I don't know that you need more EPAP anyway....EPAP is mainly for OAs and hyponeas...and there's a good chance some of your flagged events are arousal related....and even if every single flagged event was a real asleep event there aren't enough of them to be a big problem.

The leak...we don't know for sure that it is mouth breathing or just mask movement. I don't want to go screwing with settings on an ASV machine to try to fix a leak that we don't know for sure the cause.
ASV machines need to be able to go up fast to breathe for you....that going up fast can cause leaks....maybe sort of blow the mouth open a bit or maybe the leak is mask movement....but not treating the centrals by limiting the machine just to fix leaks....not a good compromise IMHO. The centrals are a worse foe than the leaks unless the leaks wake you up all the time.

You need to first figure out exactly what the leak is being caused by and THEN you get to decide what you want to do about it or even IF you want to do anything about it.
Fixing a mouth opening leak is totally different than fixing a mask movement leak.

As for not wanting to go the full face mask route...don't blame you because sometimes that full face mask fixing a mouth opening leak ends up causing more sleep problems or leak problems than the original leak was causing.

ResMed machines flag leaks a lot sooner than Respironics machines and IMHO are a bit too conservative.
My personal experience with ResMed large leaks has been that up to around 35 L/min excess leak the machine actually does a fairly decent job of things. So I don't even bat an eye with leaks until I see much time spent above 35 L/min
AS LONG AS THE LEAKS DON'T WAKE ME UP
So my criteria....do they wake me up and how far above 35 L/min did I go and how long was I up there....doesn't matter if it was mask movement or open mouth.

You have to decide your own criteria but with the ASV machine and how it works to deal with the central apneas...we might have to make some compromises because the go to fix of maybe limiting pressure swings isn't a good idea when a person needs big pressure swings to deal with central apneas.

[bossfan]

I am very hesitant to change the settings to try to fix a leak issue with your machine because of your problem.
The person I suggested adding EPR in...that was to more mimic what he had been using on the Respironics machine since he was using Flex.
With your ASV machine it's the PS that is similar to EPR and it's already doing a primary job of dealing with the centrals with the range in PS (EPR doesn't have a range). So your situation is different.

First of all...I don't know that you need more EPAP anyway....EPAP is mainly for OAs and hyponeas...and there's a good chance some of your flagged events are arousal related....and even if every single flagged event was a real asleep event there aren't enough of them to be a big problem.

The leak...we don't know for sure that it is mouth breathing or just mask movement. I don't want to go screwing with settings on an ASV machine to try to fix a leak that we don't know for sure the cause.
ASV machines need to be able to go up fast to breathe for you....that going up fast can cause leaks....maybe sort of blow the mouth open a bit or maybe the leak is mask movement....but not treating the centrals by limiting the machine just to fix leaks....not a good compromise IMHO. The centrals are a worse foe than the leaks unless the leaks wake you up all the time.

You need to first figure out exactly what the leak is being caused by and THEN you get to decide what you want to do about it or even IF you want to do anything about it.
Fixing a mouth opening leak is totally different than fixing a mask movement leak.

As for not wanting to go the full face mask route...don't blame you because sometimes that full face mask fixing a mouth opening leak ends up causing more sleep problems or leak problems than the original leak was causing.

ResMed machines flag leaks a lot sooner than Respironics machines and IMHO are a bit too conservative.
My personal experience with ResMed large leaks has been that up to around 35 L/min excess leak the machine actually does a fairly decent job of things. So I don't even bat an eye with leaks until I see much time spent above 35 L/min
AS LONG AS THE LEAKS DON'T WAKE ME UP
So my criteria....do they wake me up and how far above 35 L/min did I go and how long was I up there....doesn't matter if it was mask movement or open mouth.

You have to decide your own criteria but with the ASV machine and how it works to deal with the central apneas...we might have to make some compromises because the go to fix of maybe limiting pressure swings isn't a good idea when a person needs big pressure swings to deal with central apneas.

On the charts I posted 95% leak was 25.2 and 22.8. Is this what I want to look at for being 35 or below? Or is it on the machine's sleep report that I want to monitor for 35 or below?

The leaks do not wake me up unless I am unaware of being woken up. Sounds like ASV settings can be complicated so I'll leave things alone and when I next see my doctor I'll ask her about the leaks.

[Pugsy]

On the charts I posted 95% leak was 25.2 and 22.8. Is this what I want to look at for being 35 or below? Or is it on the machine's sleep report that I want to monitor for 35 or below?

I look at the leak graph itself for that 35 L/min line.
95% numbers...just means that for 95% of the time you were at or below that number and doesn't really tell you much about the other 5 % of the time. The max leak number tells you a little bit but to be honest...5 % isn't enough to worry about no matter how high it might have gone.

Your max...30 and 33 L/min....so very short lived and if the leaks don't wake you up then I would shrug my shoulders and move on.
Give yourself some time with the new machine. It does go about doing it's job a little differently and your brain and body needs a bit of time to adjust.

[babydinosnoreless]

Just a thought on the leak. I recently noticed my leaks going up, didn't think much about it till my husband complained of a whistling noise. After making sure everything was plugged in as normal I discovered a little tear in the silicone of the mask cushion and realized its been a while since I had inspected and changed out my cushion. Just my daily quick wipe down when I'm still half asleep in the morning I didn't notice it. And it apparently didn't leak all the time just occasionally. If you haven't changed your cushion in a while, maybe take a closer look at it and see if it needs replacing.