Question: ASV and hypopneas

I finally got my ASV this week and I love it! I have 0 centrals and 0 obstructions, but quite a few hypopneas (last night AHI 2.49). I also have a lot of flow limitations. My min EPAP is 8. Do I need to give it some time to even out, or is my min EPAP a little too low?

M'ohms wrote:I finally got my ASV this week and I love it! I have 0 centrals and 0 obstructions, but quite a few hypopneas (last night AHI 2.49). I also have a lot of flow limitations. My min EPAP is 8. Do I need to give it some time to even out, or is my min EPAP a little too low?

As with anything in this therapy, give it some time and study the trends before making changes. I'm not really familiar with ASV machines, but with Bi-PAP/Bi-level machines, the EPAP setting is supposed to eliminate the Apneas and the IPAP setting should eliminate the Hypopneas.


Den

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Welcome to the club.

I got my ASV machine last September and made no changes for three months.
Then I discussed with my sleep doctor what issues I had and what experiments I was proposing to improve the results.
When we both agreed on the range of pressure changes that might help and I was assured that changes in that range were safe for me, then I went ahead.

I made modest changes and got my OSA's down to zero from a couple per night.
The hypopneas didn't improve.

A new discussion on what additional I might try followed and a second set of experiments were done.
Again, no significant change in hypopneas

So the numbers were set back to the first set and that's where I've been ever since.
I've done quite a bit of reading about these machines and it seems that they don't resolve hypopneas very well.
They seem to be just part of the game and not harmful.

Are you feeling better on this machine? I spent almost three years on an Auto BiPap machine and by diligence ( coordinated with my sleep doctor ) I got the hypopneas done to near zero, the obstructives down to zero, and, of course, centrals were uncontrolled by that technology. Most days I didn't feel better. New sleep study and I switched to ASV.

Now I do feel better and people around me comment on how much better I seem to be.

So, the bottom line is, take it easy and don't rush things. Do talk to your doctor before making any changes. It's my feeling that changes that will eliminate hypopneas will, at the same time, reduce the effectiveness of the machine to deal with the periods in which you are not breathing on your own. In that mode, the machine needs to be able to have really large pressure swings so that you maintain effective air exchange in your lungs. In my case, that means the pressure can sometimes swing between EPAP=10 and IPAP=25. Your current numbers appear as if your machine can have EPAP=8 and IPAP=25 and having that range available means the machine can protect you very well.

Since your machine type didn't show up, I assume that you got a Respironics 950 ASV machine and not the 960.

I hope all goes well and will try to help if you need anything else.

Thanks for the comments. I wasn't planning to make any changes yet, but was wondering if things would level out or if I should have a plan in mind when I see my sleep doctor next month. JDS74, I appreciate you telling me about your experience with hypopneas. Because of that, I won't pay so much attention to them.

JDS74 said:

Are you feeling better on this machine? I spent almost three years on an Auto BiPap machine and by diligence ( coordinated with my sleep doctor ) I got the hypopneas done to near zero, the obstructives down to zero, and, of course, centrals were uncontrolled by that technology. Most days I didn't feel better. New sleep study and I switched to ASV.

Now I do feel better and people around me comment on how much better I seem to be.

My story is similar to yours, but I was on BiPap for only 1 year. My ASV titration was successful and I went home feeling better than I had since starting pap therapy. It took me 2 months and some creative problem-solving to finally get the machine. Now I am giddy about how much it has improved my nights. I have taken to it very well.

...and

Since your machine type didn't show up, I assume that you got a Respironics 950 ASV machine and not the 960.

I received the PRS1 960 ASV, and it is sweeeeeeeeet!

Thanks for the support!

Glad you are doing so well.
How is your Patient Triggered Breaths statistic working out?
Mine hovers around 80% but has dropped to 50% and peaked at 96% on occasion.
My breathing is quite unstable in terms of breaths per minute from breath to breath and my 960 really reacts to that.

My patient triggered breaths hover around 93%. I am thrilled to see the machine's reaction to my events. I wonder why we still have hypopneas when the ASV reacts to everything else so well.

Your AHI was less than 3.0 per hour and even if primarily all hyponeas...that's still very good especially considering where you came from. Now if your hyponeas per hour was 30.0 then we get a different discussion.
Were you expecting 0.0 for all categories?

Give it time...your body has to learn to be okay with this machine.

M'ohms wrote:My patient triggered breaths hover around 93%. I am thrilled to see the machine's reaction to my events. I wonder why we still have hypopneas when the ASV reacts to everything else so well.

It may simply take you a while to adjust to it and vice versa.

When I first got my ASV, I was around 1-4 AHI, all hypopneas. (In fact, all of my OSA was hypopnea until they put me on pressure, at which point centrals started cropping up.)

When I switched from FFM to a hybrid mask, the pressure going up my nose instead of the mask pressing against the bridge of my nose really opened my nasal airways, and I'm now typically at 0-1 hypopnea events per _night_ (0.0 to 0.1 AHI).

Depending on your PSmin/max, it wouldn't surprise me if there are a few hypopneas that linger. It tries to increase pressure as gently as possible to keep your airway open. That might turn a full-on apnea into a hypopnea. Or it may take a few breaths for the IPAP to get to the point where it splints your airway open enough to resolve the hypopnea. Either way, as long as it isn't waking you up and you're not having O2 desat during those events, it's working great.

Where the machine goes bananas with IPAP is if it thinks you're having a central: in three breaths it can ramp up to max IPAP. (So even then, it's not instantaneous.)

It's possible that you could benefit from a tweak to PSmin, but I'd give the current settings a few months to settle in before tweaking, and then in consultation with your dr.

Thanks for the advice/encouragement! It's comforting to know that others have the same experience as I have. While not really expecting a 0 AHI, I was curious as to why the ASV didn't wipe out the hypopneas like it does the OA's and the CA's. I'll wait and watch...

JDS74 wrote:I've done quite a bit of reading about these machines and it seems that they don't resolve hypopneas very well.
They seem to be just part of the game and not harmful.

x2. I am fairly new to the game at three months so things may change but obstructives and centrals are consistently <1; hypopnea index ranges between 3 and 6. I thought about dorking with the settings but not sure that the juice is worth the squeeze.