Questions about my new ASV machine

[Pugsy]

That's wonderful that SH is working again. Probably those old weird files were confusing SH.
Some people with the 950 couldn't even get anything to show up...not even 1700 AHI.
I know JohnBFisher couldn't get it to work and he is a computer engineer and tried everything he could think of to fix it.
Which BTW I was hoping that he or SWS would stop by in your thread to offer their input. Both of them seem to have been absent from the forum for a while. Normally they zero in on threads with ASV in the subject line.

I don't know enough about ASV settings to figure out what is wrong with your settings...something isn't right but I can't put my finger on it. Your patient triggered breathing is way off and way more events than I would want to see but I don't know enough about those settings to know which does what on your machine.

I know we don't expect perfection immediately with this machine but something tells me there is more to "give it time" going on here.

[-SWS]

My numbers are virtually unchanged, same AHI (12.1), same number of CA's, OA's and Hypopneas.

Hi, tomma. What does "same number" mean---4 CA's/hour, 4 OA's/hour, and 4 hypopneas/hour during that AHI-of-12 night?

I did feel like I slept better, and I actually slept around 90 minutes longer than usual, so I guess that's good.

Well that part sounds good! Bear in mind that your body might need days or weeks to acclimate to ASV settings. Your AHI numbers might improve as you adapt to these settings.

My settings right now are:

Max Pressure 25
EPAP Min and Max are both 14
PS Min = 3
PS Max = 10

Is your backup rate set to auto or a fixed number? As a side note, your obstructive component is largely addressed by this IPAP/EPAP relationship: (PS Min plus EPAP Min) as your fixed IPAP, and EPAP Min as your fixed EPAP. But your central component is largely addressed by the PS Min through PS Max range in conjunction with backup rate. That first relationship, used for obstruction, is your fixed pressure. And that second relationship, used for central undershoot, is your per-breath ventilatory-type pressure. So when there are too many residual obstructive events compared to central, that first obstructive-treating relationship is commonly tweaked. Conversely, when there are too many central events compared to obstructive, then that second central-treating relationship is often tweaked. But backup rate is important for central apneas as well. That's why I'm wondering what your machine's backup rate is set to.

Any words of wisdom, suggestions, a rope?

Include plenty of numbers and details as you post, looking for advice. ASV doesn't always click during the first or second night of use. Some people need to adapt, and others need to tweak settings. As you offer details, and even graphs, people will gain a better idea of where problems might lie with your settings, leaks, etc.----or if sitting tight with these settings make sense. In any event, I'd suggest keeping your doctor in the loop should you want to try any new settings.

[tomma]

Thanks for all the info SWS, while I used XPAP for a few months and got used to what to look for, what to tweak etc, I'm just now starting to understand the ASV end of things. I couldn't agree more with Pugsy, I know I need to give this some time, but I think there's more to it.

My settings are:

EPAP min and max = 14
PSmin = 3
PSMax = 11 (this was 10 up until a couple hours ago, so tonight will be my first night at 11)
BPM =Auto

Here's a screen shot from last night. I'm mainly concerned with the number of hypopneas. Any suggestions for what to look at or try? My next sleep doc appointment is 6 months out. No idea why a doctor would prescribe me this kind of machine and say see me in 6 months. If I can't figure it out on my own (well, with the forums help) I will definitely hounding her for a much earlier appointment

[Taringa542]

After 2 months of futzing with my settings, using painful devices to stay off my back, being awake half the nite, being discouraged because nothing seemed to help, I was finally able to see my doctor this morning. The DME was supposed to have sent her my data a week or so ago, but since they still haven't sent me my card back I knew something wasn't right so I brought my laptop with me so I could show her my SleepyHead graphs. Good thing I did, she still hasn't gotten the latest report from the DMS yet.

So, after talking through things and looking at my data, she thinks I may need an ASV. Good, but potentially expensive news. She's ordering me another sleep study. 1/2 night BiPap and half nite ASV. I guess we'll see what happens from there. While I'm not thrilled with the idea of another study, or the expense of the machine (I have a very,very high deductible which I haven't even started to rack up yet for this year) I am glad to have a new direction to go in since things really aren't working all that well as is.

Thank goodness for SleepyHead, it was very helpful to have all that data right there with me.

Time to read up on ASV, and oh yeah, call my DME and find what they did with my card.

Do yourself a favor & buy this machine off STL Mark: viewtopic.php?f=1&t=86737 You won't regret it or get one for a better price, Ive been on the S9 Adapt since Oct 2012 (Self prescribed) & except for the first month I haven't looked back
The machine in my case was very difficult to get use to but once I did it has been great, I can show you SH graphs where I have gone 11 days straight with 0.00 Ahi's & no its not the S9 firmware bug as I reboot daily

[tomma]

My little experiment of increasing PSmax from 10 to 11 didn't make any difference at all. Speaking of PS, the average last night was 4, it looks like it never went up, does that make sense?

I'm not having any real problems acclimating, maybe a little longer to fall asleep but other than that I haven't had any problems so I don't think it's that, maybe part of it but almost certainly not all. I don't know if this is worth mentioning, but I'll throw it out there just in case. My very first night on this machine the BPM was turned off.That night I of course had a ton of centrals, but virtually no H's. Now with the BPM on auto, the centrals are almost gone but the H's are through the roof.

Here's some data from last night, all ideas, suggestions, or anything else are welcome:

[-SWS]

Well, tomma, your leaks appear acceptable at first glance. You might want to zoom-in to take a closer look at detailed graphs in SH, to make sure brief, transient leaks aren't precipitating some of the hypopnea events. Assuming leaks are fine immediately before hypopnea events, the next thing to look for is whether PS max is bumping the ceiling too often. Assuming PS max is not bumping the upper-limit too often, then consider exploring a trade-off between EPAP min and PS min by creating a search matrix. Here's an example (using different values than you would explore):

viewtopic.php?f=1&t=60687&st=0&sk=t&sd= ... 90#p572497

If you'd rather not explore an automatic EPAP range just yet, then consider exploring how increasing PS min -vs- decreasing PS min affects these two output variables: 1) AHI (especially HI), and 2) percent of patent-triggered breaths. Also....


****bump for thoughts/ideas from other ASV users************

[tomma]

Well, tomma, your leaks appear acceptable at first glance. You might want to zoom-in to take a closer look at detailed graphs in SH, to make sure brief, transient leaks aren't precipitating some of the hypopnea events. Assuming leaks are fine immediately before hypopnea events, the next thing to look for is whether PS max is bumping the ceiling too often. Assuming PS max is not bumping the upper-limit too often, then consider exploring a trade-off between EPAP min and PS min by creating a search matrix. Here's an example (using different values than you would explore):

viewtopic.php?f=1&t=60687&st=0&sk=t&sd= ... 90#p572497

Funny, I was reading through that thread just an hour or so ago.

Leaks look ok, I don't see anything excessive when I zoom in and look closer. Can you elaborate a little on the 'PS max bumping the ceiling' comment? Not sure I know what you mean.

[-SWS]

Can you elaborate a little on the 'PS max bumping the ceiling' comment? Not sure I know what you mean.

PS is the difference between IPAP and EPAP. So at fixed EPAP 14cm and PS Max 11cm, you're looking to see how often your IPAP hits the 25cm ceiling. Judging from your high-level graphs above, your IPAP delivery doesn't appear to hit 25cm often, if at all. Still, I'd suggest taking a peek at detailed graphs to make sure IPAP isn't briefly maxing out at 25cm around the time hypopneas manifest. If that were the case, then you might consider experimentally reducing EPAP to allow enough headroom for more PS delivery----perhaps opening an EPAP auto-range rather than using 14cm fixed, or perhaps exploring a fixed EPAP lower than 14cm.

Assuming your IPAP isn't hitting 25cm during hypopneas, then I'd suggest either: a) exploring your output variables using more PS Min -vs- less PS Min (while leaving EPAP fixed at your Rx of 14cm), or b) opening an auto-EPAP range to explore an EPAP Min -vs- PS Min trade-off relative to AHI and % patient-triggered output variables (subjective assessment as well).

[tomma]

Thanks.

Ok, one more question before I head off into a corner and try to understand all this.

From looking around the web and the forum I see what EPAPmin/max, PSmin/max mean, as far as the words definitions. What I can't find is what they do, and how they relate to each other. So, in other words, EPAP. Is that analogous to the min/max pressure settings on an APAP? On my APAP I had a range of 14 to 17, on my ASV EPAPmin/max are both set to 14, does that mean it's working as a straight CPAP? How does the PS and BPM come into play? I guess what I'm asking is, how do these machines work, what setting is responsible for what?

[StillAnotherGuess]

Assuming your IPAP isn't hitting 25cm during hypopneas, then I'd suggest: a) exploring your output variables using more PS Min (while leaving EPAP fixed at your Rx of 14cm)

Tomma, you really need to listen to SWS. SWS is suggesting you raise PS Min = 4. Leave everything else the same. Stop messing with PS Max. Stop asking so many questions that you get totally confused and loose sight loose sight of what you are trying to achieve. Just work on getting on your AHi down. Set PS Min = 4.

[tomma]

Yeah, right, sorry I asked how things work.

All I'm asking for right now is for an explanation of how all this works. As far as 'messing' with PSmax, if you read everything you would have seen I changed it once, from 10 to 11.

Thanks for offering such great advice.

[-SWS]

From looking around the web and the forum I see what EPAPmin/max, PSmin/max mean, as far as the words definitions. What I can't find is what they do, and how they relate to each other.

IPAP is the pressure delivered during inhale. EPAP is the pressure delivered during exhale. IPAP is the higher of the two pressures.

So, in other words, EPAP. Is that analogous to the min/max pressure settings on an APAP?

EPAP min and EPAP max are analogous to the min/max settings on an APAP. The one thing EPAP, CPAP, and APAP pressures all have in common, is that they employ static pressure to treat obstruction. Think of a long, skinny balloon that is inflated. Thanks to static pressure, the balloon's diameter is held wide and open instead of collapsed. Similarly, EPAP, CPAP, and APAP all apply static pressure for the purpose of holding your collapse-prone upper airway open.

On my APAP I had a range of 14 to 17, on my ASV EPAPmin/max are both set to 14, does that mean it's working as a straight CPAP?

That's close. When you throw a fixed PS Min value into the equation, then that means your machine's baseline operates as a fixed BiLevel rather than CPAP. Recall PS is the pressure difference between IPAP and EPAP. If your EPAP Min, EPAP Max, and PS Min values were all the same, then your machine's baseline would operate as a CPAP. As a side note, some CompSAS patients fare better with CPAP as their ASV machine's baseline, while others fare better with BiLevel as their ASV's baseline. So I would encourage you to look for efficacy patterns as you explore PS Min values greater than 3cm, but also less than 3cm----exploring your way down to CPAP as ASV's baseline modality in that latter part of your search.

How does the PS and BPM come into play?

Your fixed EPAP and PS Min values mean that your machine's baseline modality will behave like an ordinary BiLevel machine. So during most or many breaths, you will receive (PS Min plus EPAP) pressure during inhalation and EPAP pressure during exhalation. But the ASV algorithm is waiting in the wings----for breaths that are either too small or too late. When breath volumes are too small, then the ASV will deliver a proportionate increase in PS, but no more than PS Max. Delivering more PS translates to delivering more IPAP on top of that 14cm EPAP. When your breath is too late getting started, then the ASV machine will deliver IPAP as a nudge to get you started. The timing of that nudge is determined by your BPM setting, and it's referred to as your backup rate...

[tomma]

Perfect! That's exactly what I was looking for, ASV 101. Thanks, very helpful.

So, after looking thru my notes I saw that the 2nd night on this machine I did actually change PSmin from 3 to 4. I did have a somewhat lower AHI that night, (8.2 vs 9.7) mostly due to fewer hypops. That led me to think I may be going in the right direction so last night I bumped it up to 5. I had an absolutely horrible night. In fairness to my trusty machine it may not have been due to the change at all, I think it was just plain old insomnia, although on top of that I had so much gas I could have fueled the space shuttle. I got up after a couple hours and backed it down to 4.5, and then again later to 4.0.

What's interesting is that looking at the detail in SH, my first few hours (when PSmin was at 5) I had very few events, much fewer than normal, although some of it might be misleading since I'm not really sure if was asleep that whole time. I guess the bottom line is, at least for now, it looks like PSmin is the place to focus. I think I would have been ok at 4.5 or 5 if it wasn't for the....let's just call it.....bloating.

After messing with my APAP for 2-3 months I was really hoping to not have to go through it all again, but it looks like I will. Hopefully for a much shorter time at least.

[-SWS]

Great, tomma! Okay, a correction in red text below:

If your EPAP Min, EPAP Max, and [the IPAP value yielded by] PS Min were all the same, then your machine's baseline would operate as a CPAP. As a side note, some CompSAS patients fare better with CPAP as their ASV machine's baseline, while others fare better with BiLevel as their ASV's baseline. So I would encourage you to look for efficacy patterns as you explore PS Min values greater than 3cm, but also less than 3cm----exploring your way down to CPAP as ASV's baseline modality in that latter part of your search.

In other words, EPAP Min at 14cm, EPAP Max at 14cm, and PS Min at 0cm would yield 14cm for all three values---and thus 14cm CPAP as your ASV machine's baseline modality. I'd suggest first exploring efficacy trends with PS Min values larger than 3cm, before exploring PS Min values all the way down to CPAP as baseline modality (PS Min 0=CPAP).

[old64mb]

I did actually change PSmin from 3 to 4. I did have a somewhat lower AHI that night, (8.2 vs 9.7) mostly due to fewer hypops. That led me to think I may be going in the right direction so last night I bumped it up to 5. I had an absolutely horrible night....I got up after a couple hours and backed it down to 4.5, and then again later to 4.0.

I'm highlighting this to point out once again that repeatedly changing settings on the fly without any substantial data to support them isn't going to provide you with good results. I know you want better results now-immediately-ASAP-flash-don't-pass-go. Problem is that there's no shortcut, and it seems by your repeated postings you're trying to take one.

Spend at least a week at a setting. Let the machine record your results. Analyze those results. Rinse, repeat.

That said, a simpler explanation for you that I was hoping to avoid until you actually had data to crunch: IPAP on a Bipap is the setting used to eliminate obstructive hypopneas. It is equivalent to PS on an ASV. A PSMin setting should provide a IPAP that eliminates most hypopneas, and allowing the machine using the range of the PS Max should eliminate the rest.

The point I was trying to make - and why I'm so persistent in my message - is that I am not at all convinced by your data so far that those hypopneas are obstructive in nature. It's entirely possible they're centrals (and yes, central hypopneas do exist, they're just a pain to differentiate from obstructives even within a lab). If so, they may resolve themselves without any change after a while, since you've had less than a week of effective treatment after what could be 35 or 40 years of centrals and your body is going to take a while to adapt.

If they don't, changing PS is only part of the solution, and backup rate and tidal volume may come into play. It may even be that a different machine is worth trying, since the Resmed Adapt SV algorithms sometimes work better for some central-predominant people than the Respironics ASV ones. Or it could very well be they're obstructive, and changing PS Min and/or EPAP will fix things - but you simply aren't going to figure this out if you change PS Min around several times a night and can't figure out if it's insomnia or gastric insufflation or something else. The matrix -SWS suggests only works if you have enough data to analyze it.

I'm sorry the doctor and/or the DME screwed up your initial settings on the ASV, and I know it's frustrating to have spent a couple months on different ineffective machines only to find the ASV isn't reducing your numbers. Don't take this the wrong way, but 3 months on the wrong machine is nothing compared to what many people have gone through here. Frankly, you're lucky that your doctor actually pushed you up to an ASV this quickly.

Spend a week at 4 PS Min. Then spend next week at 4.5. Then spend the week after at 5. Then come back and post the results, and please do get your titration study.