Need Help Understanding ASV Response

[chrotteg]

Hi all, 

I have been trying to get back into using my ASV after about a year. This attempt is going pretty well as my main discomfort the first time was aerophagia, so I decided to reduced my PS max to 8 this time. I have great AHI with ASV but during the day I don't notice any drastic change in my tiredness. I noticed in my charts that my PS is almost always above min and fluctuates a ton as expected, however, my EPAP almost never changes. It may increase a bit but its always near the minimum. I started with an EPAP min of 6 and thought I should try an EPAP of 7 and of course I woke up with aerophagia and insane burping. Am I just screwed or can I get used to a pressure and lose the aerophagia? 

Anyone have any thoughts on why the ASV is acting this way and whether I should change any settings? Thank you for your time and help!

[SarcasticDave94]

Due to EPAP using a minimal range via ASV control, why not limit it to Max 8? I would try to move those 4 pressure units over to PS Max in part at least.

With PS range, maybe use minimum 2 PS, and then try increasing PS Max a bit at a time up to 12 from the current 8.

I think you can edit both the EPAP range reduction and the PS Min down to 2 at the same time. Then do the PS Max increase on its own, once you see if the first step helps.

Your left panel user data needs updated to reflect an ASV to allow others to know what you're working on.

[chrotteg]

Sounds good Dave, thank you for the info! I will try those steps and let you know the results.

[SarcasticDave94]

Welcome. Try those but if it makes things worse just revert back to known good.

[Jay51]

Dave is spot on. 

Your question about why your ASV is behaving this way:  I have an ASV and have used several ventilators.  

When epap remains the same, that usually means few problems with OA's, etc.  

When the pressure support (PS) fluctuates a lot, then it is mainly dealing with CA's - trying to get you to breathe when you stop breathing.  I noticed using my ASV, when I stopped breathing because of CA's, the pressure would ramp up to the max to get me to breathe.  When I was breathing on my own, the PS stayed low.  

Just my experience.

[Sleeprider]

I’m on board wit the others, but given these results am inclined to recommend EPAP min 4.0,EPAP max 6.0, and leave PS alone for now.

[chrotteg]

Hi all, 

Thank you for all the suggestions. I went with Daves initial suggestion and lowered EPAP max and PS min to 2 and am increasing PS max by 1. I am providing the data for PS max of 9 from last night. I feel like I didn't sleep super great even though AHI is 0. I have issues waking up a lot and I remember waking up quite a few times. Is there any new recommendations based on these results? Or should I continue with increasing PS max?

I am also providing a zoomed version of weird events that show up pretty commonly in my data, if anyone is able to help me understand what it is or if its something I don't have to worry about, that would be fanatastic.

Thanks for all the help as always!

[SarcasticDave94]

How about trying EPAP 4 min, EPAP Max 7. It appears the EPAP just dropped in the chart, basically wherever you set EPAP that's what you'll get. Interpretation, you don't seem to need much Obstructive therapy.

[Jay51]

Pretty good, clean looking chart IMO.  

What I see happening from your OSCAR full night and zoomed in view and from your statistics (particularly your min, median, and max respiratory rate and tidal volume stats) is that at times during the night, your respiratory rate gets very low (3 min I think from stats).  ASV then immediately ramps up pressure, which causes you to take some deeper breaths to get back on track.  

Same thing happens when your tidal volume gets low - (150 min or so if I remember) - ASV ramps up pressure support to help get it higher (which shows in the larger, deeper breaths in your close up).   

They both line up with the pressure increases in your pressure chart.  

This is just the way the ASV works.  I see it in my OSCAR as well.  My tidal volume and respiratory rate look like a see saw (up and down and up and down, etc.).  The ASV is just doing it's job.  

If you can sleep through this (or learn to sleep through it), your therapy would be good.  If you can't ever learn to do it, we can keep making little tweaks like Dave suggests to make it more comfortable with the trade off of a little bit of effective therapy.

[chrotteg]

Thanks for all the help again and the useful information. I took Daves suggestion and tried EPAP 4-7 and am adding the chart below. EPAP didn't fluctuate too much so it seems even at 4, it covers the majority of events but does have to ramp up if I get obstruction. My overall breathing seems shallower with these settings compared to previously, will this matter at all? 

I think we are relatively close to figuring out my settings as last night was the longest I had the mask on and didnt have any annoying symptoms. The only "issue" I had was when trying to fall asleep, the pressure is so low compared to what I am used to, it felt like I wasn't getting enough air when inhaling. Should I get used to it and just leave these settings or fix that? And if I was to fix it, would I increase PS min to 3 or EPAP min to 5? 

Thanks for all the help again!