Newbie on AVAPS

Banned,

Again good results. Does the AHI data get broken out to HI & AI ?
Obviously you are pleased with the progress.


I reverted to the Vpap Adapt SV last night. I haven't tried it before with my Quattro mask. It was the best night I have ever had off that machine and good enough that I will continue with it. The quattro mask clearly solved the leak issues I previously was having with the UMFF on the Vpap Adapt SV.

I (as expected) did tend to wake up more while on the Vpap Adapt SV but felt fine whereas before I would wake up struggling with the mask & the pressure.

Settings I used were as before EEP=10 & PS=3.2

DSM

dsm wrote: I (as expected) did tend to wake up more while on the Vpap Adapt SV but felt fine whereas before I would wake up struggling with the mask & the pressure.

DSM,

I'm using Encore Viewer on my PC at work (Mac based at home). I think the Encore SW only depicts Total Apnea Count and does not break it down into HI and AI.

Glad to hear you are enjoying the Adapt SV with the Quattro. It's really an unbeatable combination.

Although I still wake up several times a night, and in light of my turbinate irregularities, I believe I sleep sounder with the AVAPS then the Adapt SV. The AVAPS does not have the wild swings with IPAP Min that probably created the arousals, keeping me just on the edge of deep sleep. Plus, AVAPS for some reason keeps my nasal passages and upper airway clear. And the AVAPS literature is correct as there are absolutely no positional change effect to my upper airway when I roll from side-to-side and on my back, etc.

Since I have no control over my dial-spin'in ways I'm going to try EPAP 15 and IPAP Min 20 tonight. And maybe EPAP 16 and IPAP Min 20 tomorrow night, while I search for the illusive <1AHi.

Banned

Banned,

The Encore Pro software should I imagine, break out the HI & AI as it does for the Bipap SV but perhaps the AVAPS is just an extension of the Bipap S/T & in that case, they may just stick to the average AHI for the night just as the Bipap S/T does.

One strange thing I have observed & don't yet know what to make of, is that about 3 weeks ago our weather changed markedly & at home we switched from a duvet to 1 blanket & progressively from then whilst getting good data from the Bipap SV, was starting to hit increasing bouts of daytime drowsiness.

I made a guess that the Adapt SV was actually going to be better & somehow to do with the change in temperature (it was quite a big jump).

Now wouldn't it be really funny (to me anyway) if it turns out that one brand of SV (Respironics) is far better in winter & the other Resmed is better in summer. It seems a bizarre thought but temperature change is the only common factor that I can pinpoint. There is of course the mask & maybe I need to go back & use the UMFF one night to see if it was the contributing factor, but, I am leaning towards temp change having some role to play.

I may have more thoughts on this if time shows that last night's excellent run with the Vpap SV is more than a flash-in-the-pan. My prior nights with the Vpap Adapt SV were pretty awful - it just seems so strange to think that a shift in the weather could be responsible for a significant improvement - if it weren't for the so obvious decline in Bipap SV effectiveness since summer hit, I would point the finger squarely at the mask as the cause ?

DSM

While the AVAPS Mode should really be restricted to volume-oriented therapy, I would imagine that one could (loosely) predict settings parameters, and, to a lesser extent, determine treatment efficacy, via an algorithm. There would be entry criteria for the algorithm, including some measurement of baseline CO2 and Sleep Fragmentation (stage shifts would achieve this).

Settings determination would then be accomplished utilizing the following methodology:

The Utilization of Average Volume Assured Pressure Support (AVAPS) in the Treatment of Primary Flow Limitation (PFL) Associated with SDB

SAG

StillAnotherGuest wrote:While the AVAPS Mode should really be restricted to volume-oriented therapy, I would imagine that one could (loosely) predict settings parameters, and, to a lesser extent, determine treatment efficacy, via an algorithm. There would be entry criteria for the algorithm, including some measurement of baseline CO2 and Sleep Fragmentation (stage shifts would achieve this).

Settings determination would then be accomplished utilizing the following methodology:

The Utilization of Average Volume Assured Pressure Support (AVAPS) in the Treatment of Primary Flow Limitation (PFL) Associated with SDB

SAG

SAG

What processes over time did you go through to reach this insight

DSM

dsm wrote: SAG

What processes over time did you go through to reach this insight

I'm guessing SAG's more relaxed demeanor toward the recreational use of BiPAP AVAPS is that dispensing of volume-oriented therapy devices for COPD, Neuromuscular Disease, Amyotrophic Lateral Sclerosis, Obesity, Chest Wall Deformity, etc. may preclude the use of BiPAP AVAPS in favor of more traditional NPPV devices. Most SDB/COPD/Obesity therapies are probably of the, "Give them a BiPAP, a little O2, and leave them smiling", variety. For more serious volume-oriented issues, give them a traditional NPPV device.

That notwithstanding, it took what I learned from everyone on this forum including Slinky, RG, the Fab Four, sleepy55 (who inspired me to take the AVAPS that I had given up on, back out of the closet) and the myriad of threads on this forum that I have learned from, for me to go from a completely automatic Adapt SV, to set-everything BiPAP AVAPS. And to everybody on the board, I'm eternally grateful!

Last night at EPAP 16 and IPAP Min was a wash.

11-6-08 settings:
Mode: S/T AVAPS
EPAP: 16
IPAP Min: 20
IPAP Max: 25
Tidal Volume: 530 ml

Encore results:
Apnea Count: 12
Average EPAP: 16
Average IPAP: 20.5
Average (Exhaled) Tidal Volume: 555.7 ml

The only thing I have left to try is EPAP 15, IPAP Min 20 tonight.

Banned

So, last night I'm at EPAP 15cm and IPAP Min 20cm. The Apnea Count of 10 sucked, but interestingly the Average Tidal Volume increased to 583.1ml (which is higher than my constant 530ml Tv AVAPS setting that usually results in 558ml). Perhaps the further you increase IPAP Min from EPAP results in increased Average Tidal Volume?

Tonight is my last trial at EPAP 15cm, and IPAP Min 18cm which is slightly tighter then the AVAPS recommended 4cm separation.

If that fails to show any improvement, then EPAP 15cm and IPAP Min 19cm at <5AHi may be the best I can hope for on AVAPS.

I took Snoredogs thought and increased BPM to 8. Not that I may even need a timed mode at this point as I believe the increased volume and 'open' airway may facilitate a reduction/elimination of my periodic breathing issue?

Banned

Thanks for the flow of data - alweays interesting to see what tweaks cause what results.

As for me - its off the Vpap Adapt SV again after 3 nights & back to the Bipap SV (on which I will change risetime from 3 to 2).

I am not sleepy during the day with the Vpap Adapt SV but just don't feel I get any deep sleep. If I could guess at what the issue is with this model it is the possibility its 'tight' control may eliminate more CO2 than it should. I know of others who have had CO2 issues with it so am wondering if I am having the same. One night I woke up wide awake thinking good sleep, time to get up, then looked at the clock & it was 2 AM !!!. It is a strange feeling to describe it where you don't feel tired in the day but you do feel you never really got to sleep. It sort of fells like too much REM sleep & regularly waking as if having only been very lightly asleep.

DSM

After numerous trials the sweet spot in S/T AVAPS mode seems to be EPAP 15cm and IPAP Min 19cm at 530 ml Tidal Volume. As it stands, the resulting 4 AHi is very stable and probably the best obtainable at these settings.

11-9-08 settings:
Mode: S/T AVAPS
EPAP: 15
IPAP Min: 19
IPAP Max: 25
Tidal Volume: 530 ml

Encore results:
Apnea Count: 4
Average EPAP: 15
Average IPAP: 19.3
Average (Exhaled) Tidal Volume: 561.1 ml
Average Peak Flow: 39.1
Average Minute Ventilation: 9

So interestingly enough, my last gasp chance to lower the 4 AHi with this hybrid may be in lowering the Tidal Volume. Talk about fine tuning!

Recall, there are two ways to set Tidal Volume with AVAPS: 1) Dial in the desired Tv directly, or 2) Dial in 200 ml to facilitate a small increase in 'regular' Tv.

Tonight I will dial in a Tidal Volume of 520 ml rather than the usual 530 ml (AVAPS adjusts Tidal Volume in 10 ml increments). My hope is that a reduction of Tv may (or may not) lower the AHi.

Banned

Good that you have the results so tight

Now swap the mask

DSM

PS
I changed the risetime on my Bipap Auto SV to 1 last night (100 milliseconds) & woke up fine but did feel I slept lightly just like
when using the Vpap Adapt SV. The night before I had set risetime to 2 (I normally use 3). That showed some improvement in
the daytime drowsiness but with it at 1 the day has been very good with no trace of drowsiness.

So the interesting part to me is that the Bipap SV now feels very similar to the Vpap Adapt SV and to get this to happen I
made the risetime as fast as it will run on the Bipap Autop SV. So am now of the opinion that the Vpap Adapt SV because it has
no manually settable risetime, runs its risetime continually at a fast rate.

For me it seems it is a lower (faster) rise time that contributes to less deep sleep even though REM sleep & daytime drowsiness
seem to be well addressed. If this is the case then I have solved a long standing mystery for myself.


D

dsm wrote: So am now of the opinion that the Vpap Adapt SV because it has
no manually settable risetime, runs its risetime continually at a fast rate.

Well, that may be part of it, but try this..

I believe there is a causal link between pressure controlled CPAP/Bi-Level's inability to control Tidal Volume and folks inability to get a good night sleep due to arousals caused by changes in Tidal Volume.,

Case in point, I just lowered my Apnea Count from 4 to 2 merely by decreasing Tidal Volume 10 ml! That may not seem like a big deal, but it does prove that a factor contributing to AHi can be Tidal Volume. If that is the case, I could envision an argument that could support fluctuating Tidal Volume as a factor for arousals/poor sleep (even in light of good AHi). But, I digress.

11-10-08 settings:
Mode: S/T AVAPS
EPAP: 15
IPAP Min: 19
IPAP Max: 25
Tidal Volume: 520 ml

Encore results:
Apnea Count: 2
Average EPAP: 15
Average IPAP: 19.2
Average (Exhaled) Tidal Volume: 553.6 ml
Average Peak Flow: 36.1
Average Minute Ventilation: 8.5

I even had dreams last night. It was a beautiful thing!

So, it appears after you have established your Tidal Volume in S/T (only) mode, you can then rough-in AHi with EPAP and IPAP Min in S/T AVAPS mode, then fine-tune the Apnea Count with the Tidal Volume.

Tonight, I will further reduce Tidal Volume another 10 ml from 520 ml to 510 ml in attempt to obtain AHi <1.

Remember, my S/T (only) Tidal Volume registered between 512 ml and 523 ml. Dialing in 510 ml will still target an Average Tidal Volume well above the S/T (only) Tv results of 512 ml to 523 ml while staying well within the AVAPS 110% of S/T (only) Tv.

That basically means I'm contolling AHi while being on a (NPPV) ventilator all night.

It is hard to put into words how pleasant it is to be able to address AHi while essentially spending your entire sleeping period on a ventilator. I don't know if there is any particular advantage to being on a NPPV while you sleep. I have no idea if it takes additional loads off your heart. Perhaps a sleep specialist could answer that.

I do know the extremely stable Tidal Volume and low AHi of AVAPS, that allows for open airways, positional changes, mask leaks, and perhaps mitigation of arousals generated by uncontrollable Tv changes in pressure controlled CPAP/Bi-level therapy, is very nice indeed.

Banned

Banned,

You may well be on to something.

I certainly feel that tidal volume is very important to how good I feel next day (all things being equal).
If it drops noticably (50ml) night to night then even though the AHI may look good, the 'dullness' can
return (after a day or two the dozing bouts at midday).

Last night I dropped risetime back to 2 (from 1 the night before) & raised ipap from 14 to 15 to compare
the results - today there is a slight dull feeling so tonight I'll revert risetime to 1 and ipap to 14 and see
if that provides the clear headedness that was noticeable yesterday. I noted that the tidal volume
improved markedly with a faster risetime. Less so (but still an increase) when bumping Ipap in lieu of
risetime.

Your testing is very informative even if relative to you and your particular respiration.

DSM

dsm wrote: Your testing is very informative even if relative to you and your particular respiration.

I agree my particular respiration is void of the unique constructs for which AVAPs was designed. As you and I know, these machines have capabilities to serve populations well beyond their design classification. This is where you and I find the incredible fascination in this stuff. What's next.. what's better.. AVAPS is better!

When I bought the AVAPS some months ago I wrongly assumed I was buying it to increase my Tidal Volume. Heck, I originally wanted to have a 650 ml Tidal Volume just like you.

What I learned was that while AVAPS can be about getting more Tidal Volume, the excellence in the AVAPS design comes in it's ability to control all facets breathing. It has little to do with Tv, and everything to do with STABLE BREATHING under all conditions. It took me 238 hours of self-titration on AVAPS to come to that conclusion!

The fact that I am admonishing AVAPS capabilities on a relatively healthy population shows that AVAPS is a machine that can benefit us all. And no, maybe you don't have to have a life threatening malaise to benefit from AVAPS therapy.

So, dsm, you need AVAPS! You will be amazed. I think you would toss your BiPAP SV just as I have tossed the Adapt SVs.

Banned

Banned,

I'll keep an eye out on cpapauction for an AVAPS - I'll try anything for the heck of it

DSM

#2 Just noticed someone has a newish looking Vpap Adapt SV listed - starting bid $1200.

Lowering the Tidal Volume to 510 ml last night still left me with an Apnea Count of 3.

Fortunately, with AVAPS there is no running out of dials to spin.
And, there are two more options.

Option 1: Goto S (spontaneous) AVAPS mode and eliminate BPM and Inspiration Time, altogether (Rise Time still remains).
Option 2: Goto PC (pressure control) AVAPS mode where BPM, Inspiration Time and Ride Time remain, however, Inspiration Time is very tightly controlled (much more so than in S/T AVAPS mode).

If it is a purpose of AVAPS is to stabilize breathing, perhaps there is more stability in PC (pressure control) AVAPS mode than S/T (spontaneous/timed) AVAPS mode.

-SWS wrote: Also, you were wondering about the difference between S/T mode and PC mode.

S/T mode allows either the patient or machine to cycle from IPAP to EPAP, based on the IT setting as a time limit. That means if the patient triggers the EPAP transition before the IT limit, that the patient and not the machine triggers that IPAP-to-EPAP cycling. Alternately in that same S/T mode the machine may initiate that cycling from IPAP to EPAP, if the IT time limit is reached before the patient initiates expiration.

PC mode still allows for the patient to trigger the very beginning of inspiration, exactly as S/T mode above allows. However, PC mode will hold the duration of each IPAP pulse width at exactly IT seconds before cycling to EPAP (for each breath). So in PC mode, the patient is not allowed to cycle the machine over to EPAP. Rather the IT setting cycles each breath over to EPAP according to that set time.

S/T mode: IT is an upper inspiratory time limit (thus patient-variable pulse width limited by IT)
PC mode: IT is a fixed time for inspiration (fixed IPAP pulse width)

PC and S/T modes treat the beginning of Inspiration alike (patient or machine will trigger EPAP-to-IPAP transition according to backup rate). The difference lies in how the end of inspiration and thus IPAP pulse width is handled according to the IT setting.

Currently, in S/T AVAPS mode I have used a BPM of 6. Inspiration Time of 3 sec, and Rise Time of 6.

Tonight I will switch to PC AVAPS mode and use a BPM of 6, Inspiration Time of 1.8 sec, and a Rise Time of 6.

Banned