ASV users: the everything ASV thread.

[ameriken]

I keep meaning (and forgetting) to ask you: have you obtained a a copy of your sleep study results from your doctor? If yes, would you mind posting it? If not, I'd suggest asking your doc for it. Seeing the study details can help figure out a whole bunch of stuff.

I keep meaning and forgetting to do that. I don't meet with the Dr until Aug 22 so I called about getting copies and was told I have to go down to the 'release of records' dept at the VA. And then who knows how long it may take after that. Stuff like this moves at a snails pace.

[jedimark]

Hi ASV guys & gals.

I just finished the ASV importer for SleepyHead (family 5 models anyway), and it needs brave willing testers to verify the loader works.

See the Sleepyhead v0.8 thread if your interested in trying it out.

[ameriken]

Drat, this explains my headache this morning. Obviously not the best night.

Incidentally, I did take methadone late in the afternoon, which I normally do not take it that late in the day. I wonder if this is the result. PTB's dropped and when they were the lowest, the machine kept me breathing at the minimum 10 BPM. Looks like a 20-25 minute stretch.

[ameriken]

Set Min EPAP 9. Leave everything else the same.

I was just going through this thread and realize I missed this. What is the rationale behind raising the EPAP as opposed to lowering it?

[adipasqu]

Set Min EPAP 9. Leave everything else the same.

I was just going through this thread and realize I missed this. I appreciate your input. What is the rationale behind raising the EPAP as opposed to lowering it?

Thanks

Raising your EPAP should reduce obstructive events (both apneas and hyponeas) but might increase central events (and PB?). I have found in my trials that lowering EPAPmin and PSmin helped increase my PTB from ~50% to the high 90's %, as well as reduced my hypopneas substantially. If your hypopneas are central (which we cannot really tell, unfortunately), lowering both your EPAPmin and PSmin may increase your PTB and decrease hypopneas, both good things looking at your last report.

-A

[ameriken]

Set Min EPAP 9. Leave everything else the same.

I was just going through this thread and realize I missed this. I appreciate your input. What is the rationale behind raising the EPAP as opposed to lowering it?

Thanks

Raising your EPAP should reduce obstructive events (both apneas and hyponeas) but might increase central events (and PB?). I have found in my trials that lowering EPAPmin and PSmin helped increase my PTB from ~50% to the high 90's %, as well as reduced my hypopneas substantially. If your hypopneas are central (which we cannot really tell, unfortunately), lowering both your EPAPmin and PSmin may increase your PTB and decrease hypopneas, both good things looking at your last report.

-A

Lowering EPAP is what Brian is suggesting as well, and I did lower my EPAP from 7 to 6 a couple of days ago. However as you saw, last night was not a good night. Subsequently, I had two naps today, both of which were also not good. The first for 45 minutes was on may back and I had an AHI of 17, all hypops. The second was 50 mins, on my side. AHI 7 with 1 FL and 6 VS. So I'm not sure what is going on, especially since my nights were doing pretty well prior to this. I was thinking about dropping my EPAP to 6 when I saw that other post that suggested raising the EPAP to 9.

[BrianinTN]

adipasqu is correct. -SWS explained this with a bit more geekspeak back in JIMCHI's thread too: viewtopic.php?f=1&t=60687&p=573999#p574405

As for anything said by the person posting under the name StillAnotherGuess (not to be confused with StillAnotherGuest, aka Muffy, aka NotMuffy -- who is a smart sleep professional with a sassy demeanor), read my threads or Paper_Nanny's, and you'll see why this community gives little to no credence to anything he says. He randomly throws out one-liners like that without any evidence or support and usually without sufficient data to support his conclusion. He has also been often proven to be completely wrong, despite stating things with a matter-of-fact tone. I think my earlier post, -SWS's that I linked, and adipasqu's all do a pretty decent job of explaining when and under what conditions an increase in EPAP could help you. But right now, without further data, the evidence doesn't support it, and because your ASV is not increasing your EPAP when you sleep, there's a strong argument to be made for taking min EPAP even lower rather than higher.

Why? Your ASV at least thinks you are not having events and patterns that merit increasing your EPAP. Our ASVs are designed to auto-titrate for both the obstructive and central components. The min EPAP is precisely that -- a floor beneath which the ASV won't try. Having that floor high makes sense for people who consistently need it to be high, as the ASV makes changes to EPAP rather slowly (in contrast to IPAP, which it varies much more quickly). Might those hypopneas be obstructive and the ASV is not reading the inputs well enough to increase your floor? Yup. Is it also possible the ASV is doing its job and your current EPAP floor is either just right or even too high? Yup.

Back to your point: I would not put much stock at all in very brief periods of sleep. Going from an awake state to sleep is often subject to lots of disturbances for many people (central apneas come to mind especially). As for last night, it is a bit worse than previous nights, although your overall AHI isn't poor. The thing that's worse is your PTB, and higher pressure could have an exacerbating effect.

If you decide you want to try min EPAP=9 before going lower, I won't argue against it. Trial and error is the name of the game, and since we have very limited data with which to work, I wouldn't call it a wrong approach per se. (A blind man will hit a bullseye if he throws enough darts.) However, I would urge you to log at least a day or two more at your current settings unless you're totally miserable. AHI across nights is often highly variable for many of us. Even putting aside the argument that it takes our bodies a little time to acclimate to new settings, it's really hard to figure out your "true" AHI at a given set of settings with only a couple nights of data.

[adipasqu]

Set Min EPAP 9. Leave everything else the same.

I was just going through this thread and realize I missed this. I appreciate your input. What is the rationale behind raising the EPAP as opposed to lowering it?

Thanks

Raising your EPAP should reduce obstructive events (both apneas and hyponeas) but might increase central events (and PB?). I have found in my trials that lowering EPAPmin and PSmin helped increase my PTB from ~50% to the high 90's %, as well as reduced my hypopneas substantially. If your hypopneas are central (which we cannot really tell, unfortunately), lowering both your EPAPmin and PSmin may increase your PTB and decrease hypopneas, both good things looking at your last report.

-A

Lowering EPAP is what Brian is suggesting as well, and I did lower my EPAP from 7 to 6 a couple of days ago. However as you saw, last night was not a good night. Subsequently, I had two naps today, both of which were also not good. The first for 45 minutes was on may back and I had an AHI of 17, all hypops. The second was 50 mins, on my side. AHI 7 with 1 FL and 6 VS. So I'm not sure what is going on, especially since my nights were doing pretty well prior to this. I was thinking about dropping my EPAP to 6 when I saw that other post that suggested raising the EPAP to 9.

I'm willing to bet your hypopneas are central. Have you tried getting off of your back? I know my AHI skyrockets when I sleep on my back, so I am basically a 90% stomach sleeper/10% side sleeper now. I know its hard with a FFM, but with a CPAP pillow stomach sleeping is actually possible and has worked for me. It might take some getting used to, but it might be worth it. EPAPmin of 9 is a high start point in my opinion. I was at a EPAPmin of 8, PSmin of 4 for about 1 week and had all sorts of central problems, as well as aerophagia big time. I say go down to EPAPmin of 5 with PSmin of 3 and see how you do. Remember, if those settings are too low, the machine should bring them up to what you need at any given time to address the obstructive events. That's the beauty of the ASV.

-A

[ameriken]

@ Brian & Adipasqu, great posts. Looks like I've got some reading to do with some of these other threads, I'll probably be lowering my EPAP here shortly. I guess I'm a bit anxious today, feeling a bit crappier after last night.

[ameriken]

I'm willing to bet your hypopneas are central. Have you tried getting off of your back? I know my AHI skyrockets when I sleep on my back, so I am basically a 90% stomach sleeper/10% side sleeper now. I know its hard with a FFM, but with a CPAP pillow stomach sleeping is actually possible and has worked for me. It might take some getting used to, but it might be worth it. EPAPmin of 9 is a high start point in my opinion. I was at a EPAPmin of 8, PSmin of 4 for about 1 week and had all sorts of central problems, as well as aerophagia big time. I say go down to EPAPmin of 5 with PSmin of 3 and see how you do. Remember, if those settings are too low, the machine should bring them up to what you need at any given time to address the obstructive events. That's the beauty of the ASV.

-A

I am primarily a sidesleeper, the only time I sleep on my back is during a nap. At night though, it's always on my side. I'd love to go back to stomach sleeping, however I want to give this new buckwheat/millet pillow a try before I get another pillow. I'll see if I can make stomach sleeping work with it.

I just dropped the EPAP to 4 so we'll see what that yields.

[ameriken]

Last night i dopped the EPAP min to 5, results are somewhat better. AHI still 6, but PTB is up, and I'm feeling far better than yesterday.

[BrianinTN]

Looks good. You continue to lower your min EPAP, and the ASV continues to indicate that it agrees with that course of action (evidenced by the fact that it isn't increasing it on you). Most of all, I'm glad you're feeling a lot better.

One little tidbit/tangent on AHI calculations in Encore: for reasons I don't understand, their engineers still haven't fixed a long-standing bug in reporting. You'll notice how AHI -- as well as the component index scores like CA, OA, and HI -- is represented as a number with a single decimal place. Mathematically that is supposed to indicate a particular level of precision, but Encore thinks it's too special for math conventions. The only area where a decimal comes to play is in multi-day calculation of averages. Within a single day, everything is rounded, and for 0 < i < 1, i is often rounded up. Case in point? Your "CA" index last night of 1.0, where you had only one event the whole night. The proper calculation would be CA=0.1

Implication? There is a positive bias found in statistics obtained from Encore, so when you're close to cusp points between things like, say, mild and moderate apnea, keep that in mind.

[adipasqu]

Last night i dopped the EPAP min to 5, results are somewhat better. AHI still 6, but PTB is up, and I'm feeling far better than yesterday.

Looking much better! Note, however, your EPAP is almost always at your EPAPmin. That would indicate to me that you want to go even lower on your EPAPmin setting. You can give it a few more nights at EPAPmin of 5 to confirm last nights data or go down to 4 and see what happens. What is your PSmin? Looks like 4 from your graph, but it is a little hard to tell. If it is 4, you might want to consider reducing that as well (now or after you find a good EPAPmin). If PS is too high, it can reduce PTB and induce clear airway events, in my personal experience.

-A

[BrianinTN]

I believe ameriken said his min PS is 5. "Ditto" to pretty much everything you just said.

[jedimark]

Looks good. You continue to lower your min EPAP, and the ASV continues to indicate that it agrees with that course of action (evidenced by the fact that it isn't increasing it on you). Most of all, I'm glad you're feeling a lot better.

One little tidbit/tangent on AHI calculations in Encore: for reasons I don't understand, their engineers still haven't fixed a long-standing bug in reporting. You'll notice how AHI -- as well as the component index scores like CA, OA, and HI -- is represented as a number with a single decimal place. Mathematically that is supposed to indicate a particular level of precision, but Encore thinks it's too special for math conventions. The only area where a decimal comes to play is in multi-day calculation of averages. Within a single day, everything is rounded, and for 0 < i < 1, i is often rounded up. Case in point? Your "CA" index last night of 1.0, where you had only one event the whole night. The proper calculation would be CA=0.1

Implication? There is a positive bias found in statistics obtained from Encore, so when you're close to cusp points between things like, say, mild and moderate apnea, keep that in mind.

Encore rounds up when the fractional component >= .4 Makes it nightmarish to match it's calculations, so I don't even bother any more with my stuff - I prefer accuracy over familiarity..

If you look closely at his CA, it's thicker.. There's a few events there crammed together, which up's the CA indice value a bit.. Still not enough for Encore to make any sense.