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A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
#1
A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
I’ve been using my ResMed AirCurve 10 ASVAuto machine for about 7 months now.  I think I am getting closer to understanding more of how to read the SH data and what to adjust and why.  There were a few changes that I made recently of which I think I am addressing correctly.  But please correct me if I am barking down the wrong path.  (Sorry for the bad pun.)  Oh-jeez

First, I like to maintain any setting adjustments for about 2 weeks to validate those changes with consistency in SH data.  Then I would consider making another tweak to the settings.

My overall treatment has been pretty good but sometimes my AHI bumps up above 5 and occasionally I have experienced some comfort issues.

I keep in mind what Fred had said in another post:
———————————————————
RE: Centrals - help needed
With your machine you want to find a balance. 
Goal 1: reduce centrals by reducing both pressure and pressure variance and at the same time increase hypopneas and flow limitations with setting a fixed pressure at the lowest value you can tolerate.
Goal2: reduce hypopneas by increasing pressure variance with pressure support and increase in max pressure with likely small increases in epap which will increase centrals.

The only way to do both is with an ASV.
Fred Bonjour - Project Manager and Lead Tester for OSCAR - Open Source CPAP Analysis Reporter 
———————————————————

First, comfort change - When I was trying to get to sleep a couple nights ago, the pressure kept quickly elevating to the point of pushing air into my stomach.  This of course prevented me from falling to sleep.  So I changed the Ramp from Off to 5m and reduced the PS max from 15 to 13 cmH2O.  This did the trick.

Second, EPAP min - I am nibbling upward the EPAP min to see if there is a sweet spot of minimizing hypopneas and maintaining a reasonable level of comfort.  I was at 4.0 cmH2O for quite a while and have been testing 5.0 for some time now.  I will bump it to 6.0 soon.  The ASV algorithms so far (the entire 7 months) have not directed the machine to hit my EPAP max of 8, so 8 is where I have left the max setting.

I have been adjusting EPAP min based on what Sleeprider recommended in a prior post…
———————————————————
Sleeprider wrote -
RE: Fine Tuning my Resmed ASV Machine with Incremental Wins
Your images are pretty revealing. The results on the Vauto are what I would have expected for complex apnea with PS 6.0...terrible central apnea! Impressive. Your current results on the Aircurve 10 ASV are much better and AHI is entirely hypopnea. Current settings are EPAP min 4, EPAP max 8 and PS 4-15. This does resolve all of the apnea. I think a lot of the issue here is your low respiration rate of 10 BPM, but your tidal volume is good and results in a decent minute vent. As you note in your graphs, the hypopnea seem to occur in clusters, and this may be a positional apnea issue that we often address with the use of a soft cervical collar. Don't confuse "positional" with the idea of sleeping on your back, we are talking about tucking the chin which can restrict the airway. Read the Positional Apnea section of this wiki article http://www.apneaboard.com/wiki/index.php...onal_Apnea 

It's possible you need a higher EPAP pressure. These events seem to extinguish when your pressure is at 5.6 to 6.0, so an increase in EPAP min to that range may resolve the problem. I would try that first, and if they continue to recur, then consider using a soft cervical collar to prevent your airway from being restricted. You can probably test this by sitting and relaxing in a comfortable chair and letting your chin drop to your chest. If you notice air restriction, that is the mechanism of your hypopnea. We can see the flow limitations correspond with the hypopnea events, and either EPAP pressure or a collar should avoid this. The other problem is simply short therapy time. Your therapy is extremely fractured as shown in the summary overview graph. Recently, this has been improving, but we need to understand what causes you to break therapy and not sleep with the machine.
———————————————————

On to the the screenshots.
My Session Times are getting longer and less fragmented.  My record is 4-1/2 hours- yeah!.  My max before treatment was about 2 hours.

   

On the Overview graph of Pressure and IPAP, this shows that on 3/20/19, SH hiccuped and reared its ugly bug of not recognizing IPAP in the Daily and Overview charts anymore.  Up to that date, every Daily chart reported IPAP correctly with a nice graph.  After that date, every chart moving forward and random ones historically changed from “IPAP” to “Pressure” and default to having “Pressure” unchecked on the Daily charts.  And as noted in other posts, the check box unchecks whenever you move to another day.  I hope this gremlin will be tracked down in OSCAR.

The first and second Daily charts show what Sleeprider noted - that my apneas seem to resolve when the EPAP pressure increases.  I’ll continue upping my EPAP min to find that sweet spot.

[attachment=11052][attachment=11053]

The last Daily chart shows 4 instances of distinctly different Flow Rate waveforms.  The first and third are pretty typical of what I see every day.  The second one is a little different and I see it occasionally.  The fourth one has me puzzled.  I’m guessing it is possibly a positional anomaly.  I normally sleep on my side - rarely on my back.  The little flat pause and ripple I would think is either me sleeping on my back and snoring or the ASV machine bumping the pressure to see if there is an open airway and a central apnea occurrence.  This is completely new to me after 7 months.  Any ideas?

   

Many thanks to the group, especially Sleeprider and Fred of whom I have learned so much from and am very grateful.

Ray
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#2
RE: A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
Ray, you are aware SH 1.1.0 has display problems with resmed asv. sounds like you may also already know what I'm about to say, but just in case:

SH 1.0.0 beta2 broken gl works fine with my resmed asvauto. I started using the broken gl after the open gl started giving me trouble a year into using it with a resmed autoset apap (maybe it was always funky but that's when I noticed it wasn't displaying everything properly). because of the issue you mention, I gave up on SH 1.1.0 with the asv after 1 use.

also, if you are not using a soft cervical collar, you should try one. I see clustered events in your charts that the collar should help avoid.
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#3
RE: A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
I'd turn off the ramp. I'd try min epap 7 or may need 8, I'd have the max epap at 15 and out of the way.
You won't notice the change in pressure to 7, when you are often running over 20. Then review if it clears up some OA/H. Resmed say the CA are 100% treated and it's just a matter of enough PS available to give a full breath and your available max PS13 should be enough. So all UA and H are obstructive and would be treated with more min epap, or positional therapy.

I don't know what the min backup rate is on the ASV, it is probably 10? You are low across the 95% and max too. It may be perfectly normal for you. What is your breath rate when you are awake, now? Have someone else count it if you can, when you are aware and focused, it changes. Perhaps Min PS5 is too high, there would be charts for your Med tidal volume, minute vent for your height and build. The med TV of 560 may be what it is? The minute vent of 5.5 would indicate a smaller person. Do you have a recording o2 meter to check o2 levels?
mask fit http://www.apneaboard.com/wiki/index.php...ask_Primer
For auto-cpap, from machine data or software. You can set the min pressure 1 or 2cm below 95%. Or clinicians commonly use the maximum or 95% pressure for fixed pressure CPAP, this can also be used for min pressure.
https://aasm.org/resources/practiceparam...rating.pdf
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#4
RE: A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
Thanks ajack.

I will up the EPAP and see how that goes.  Thanks for the ResMed info too.

My awake, resting resp rate is a crazy slow 7 BPM.  I don't know what the average rate is, but I'm thinking this is crazy slow, but it is what it is.  My mother's resp rate was really slow too.  Inherited from her???

Ray
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#5
RE: A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
If your awake is slower than asleep. It is the way you are built and likely, given your mother is similar.
Normally the awake rate is a little bit faster. I was thinking you would be 11-12. If you had 14 or 16 awake and 10 asleep, I would then ask the doctor.
If you get bored one day, you could put the asv on while watching television and see what the column stats are. just curious.
mask fit http://www.apneaboard.com/wiki/index.php...ask_Primer
For auto-cpap, from machine data or software. You can set the min pressure 1 or 2cm below 95%. Or clinicians commonly use the maximum or 95% pressure for fixed pressure CPAP, this can also be used for min pressure.
https://aasm.org/resources/practiceparam...rating.pdf
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#6
RE: A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
(03-31-2019, 08:37 PM)sheepless Wrote: Ray, you are aware SH 1.1.0 has display problems with resmed asv.  sounds like you may also already know what I'm about to say, but just in case:  

SH 1.0.0 beta2 broken gl works fine with my resmed asvauto.  I started using the broken gl after the open gl started giving me trouble a year into using it with a resmed autoset apap (maybe it was always funky but that's when I noticed it wasn't displaying everything properly).  because of the issue you mention, I gave up on SH 1.1.0 with the asv after 1 use.

also, if you are not using a soft cervical collar, you should try one.  I see clustered events in your charts that the collar should help avoid.

Thanks sheepless.  I guess I was hoping that SH 1.1.0 would miraculously start working again.  It actually behaved for a little while - not sure how long though. I did read in this forum of the issues with SH 1.1.0 not playing well in the ResMed ASV sandbox. Oh well. I just dusted off SH 1.0.0 beta2, and it seems to work quite well for me and my ASV.  I also like that the light gray apnea events show in the Time at Pressure graph again.

Thanks for the info on the soft cervical collars too.  I have been looking into them over the past week.  And I'll pick one up when I get back from vacation.  I didn't know they would help with the event clusters.  I do tuck my chin down - kind of like hibernating like a bear when I sleep on my side.  I'm sure that would be corrected with a soft cervical collar.  I didn't see any soft cervical collar reviews in the Product Review Forum.  So I was just looking on Amazon at the products that had higher customer reviews.  I suppose this is a rather personalized item and not a one-size-fits-all.  I'll measure my neck and order something that should work.

Ray
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#7
RE: A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
(03-31-2019, 09:46 PM)ajack Wrote: If your awake is slower than asleep. It is the way you are built and likely, given your mother is similar.
Normally the awake rate is a little bit faster. I was thinking you would be 11-12. If you had 14 or 16 awake and 10 asleep, I would then ask the doctor.
If you get bored one day, you could put the asv on while watching television and see what the column stats are. just curious.

I know it's weird.  I guess I'm weird.  Been called that before. Big Grin  My resp rate has always been freakishly slow as my mothers was when she was alive.  Doesn't seem to be that big of a problem otherwise.  My SpO2 levels have always been good.  It may have compounded other health issues with the undiagnosed OSA that I have had for who knows how long, but on its own, probably not a big deal.  I can say that I feel sooo much better with using the machine.
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#8
RE: A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
(03-31-2019, 09:00 PM)ajack Wrote: I don't know what the min backup rate is on the ASV, it is probably 10? You are low across the 95% and max too. It may be perfectly normal for you. What is your breath rate when you are awake, now? Have someone else count it if you can, when you are aware and focused, it changes. Perhaps Min PS5 is too high, there would be charts for your Med tidal volume, minute vent for your height and build. The med TV of 560 may be what it is? The minute vent of 5.5 would indicate a smaller person. Do you have a recording o2 meter to check o2 levels?

My TV and MV are on the lowest end of OK for my size. I'd like to see those numbers rise. Maybe a TD med of 700 or so would be nice. Should I hope to see that increase with higher EPAP min settings?

Also been looking into the multi-session CMS50i from China on eBay. I was going to order one of those when I get back from vacation too.  Been reading up on how to import data on the thread "importing from CMS50D+ to sleepyhead on mac".  Lots of great info there.

"Minute Vent of 5.5 would indicate a smaller person" - yup, not me.
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#9
RE: A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
Your tidal volume is normal, but since your respiration rate is so slow, your minute vent is really low. I think it would be worth using a recording pulse-oximeter to verify oxygen saturation. I have no idea how to increase your resp rate, but the default target rate on a Resmed ASV is 15 BPM, however it does seem to adapt to a wide variation.

I agree with earlier advise to increase EPAP min to resolve the remaining hypopnea and UA, and it is also possible that the clusters of hypopnea are a positional issue that might respond to a soft cervical collar. I would try the higher pressure first, however the clusters are a strong signature of chin tucking.

In your close-up charts and summary statistics, you are experiencing pressure support above the minimum almost all the time in the range of 6-8 cm. I think a higher PS min may be useful to keep the tidal volume up. I suspect this is a byproduct of the slow respiration rate. It's worth noting the breaths do not appear flow limited, they just take a fairly long time to complete. In the closeup graphs we see a period at 03:25:15 where PS drops back from 8 to 6 in what looks like a sleep transition period. Most of your closeup flow graphs show a flow rate of about 20-26 mL/sec, however the last one is very high at 36 mL/sec and is accompanied by pressure support over 10 cm. This appears to be mostly the machine taking over the breathing and maintaining rate and volume. I don't know what the small fluctuations are, but suspect we are seeing a pulse rate of about 65 bpm if my count is correct. We often see the heart rate show up in the flow rate wave form, especially when resp rate is slow like this. Note these observations have a lot of uncertainty and are my best interpretation of what is in the graphs. I would not suggest changes based on these observations, but they may be useful to you to understand what we're looking at.
Sleeprider
Apnea Board Moderator
www.ApneaBoard.com

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#10
RE: A Few Tweaks, A New Flow Rate Waveform, And A Few Questions
Been playing around with my settings trying to find my sweet spot.  Sleeprider and Bonjour both suggested increasing my Min EPAP settings to possibly reduce my apnea events, so I finally did that last night.  I want to get at least a few nights of this tested before I head out on vacation soon.  I had my EPAP setting around 5 min, 8 max and PS 5 min, 15 max.  Those were approximate settings, so +/- 1-2 cm.  I was varying them only a little to see if my AHI would bump up or down accordingly and see how my comfort level was with any small changes too.

I noticed whenever my IPAP pressure hit 21-22 cm and above, it would consistently push air into my stomach causing discomfort.  And it made it highly unlikely that I would be able to fall asleep.  So I proceeded to make the bigger change and tested out EPAP 8 min, 10 max, PS 3 min, 10 max.  EPAP 8 min would potentially reduce my apnea events, 10 max would give it a little wiggle room.  PS min of 3 was comfortable and natural, and by limiting my IPAP max to 20, that would hopefully keep me well out of my uncomfortable bloat-zone.

Last night seemed pretty promising.  My comfort level was probably one of my best in a very, very long time. like  And my AHI was 2.71.  I believe the two event clusters would qualify as SWJ.  So discounting the SWJ, my adjusted AHI of 0.32 was astounding.

I'm going to test these settings for the next few nights and if all goes well, just keep them as-is while on vacation.  I can also keep the Ramp off without having any problems of falling asleep with these settings.

Here's a couple screenshots of April 2 that are typical of the "old" settings.  And two more with the new settings from April 4.  The last one is a zoomed in screenshot of what I think is SWJ.

[attachment=11124][attachment=11125][attachment=11126][attachment=11127]    

Note - I modified the scale of some of the charts to improve upon the resolution displayed.
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