Why doesn't APAP respond to apneas?

SWS,
when I said I was being polite re the 25 CMs - I didn't suggest setting the machine to that - I was commenting of SD's range of suggestions & being polite re his suggestion of IpapMax of 25 whilst setting ipapMin to 1 over epap.

Also I thought we understood that the Bipap Auto SV maxes at 30 CMs. Dllfo's kept going to 30 CMs but I have his data & I know it was cycling when it ramped Ipap up to IpapMax. It didn't just go to 30 CMs and sit there. It cycled between his epap (I think that was around 10CMs but would need to check) and his IpapMax (30CMs) and his breathing had stopped for over 60 secs.

He really was needing a good Volume Ventilator I don't believe the Bipap SV was his best choice. But, that is really the RT's call and Dllfo's ability to fund the best machine, which from what I gather was a bit of an issue for him.

Cheers

DSM

Doug, thanks for that clarification!

snoredog wrote:Her 10/16/07 PSG Respiratory events nearly mimics the Encore Pro report pulled 10/13/07. Clearly on that PSG the centrals are the bad guys with her SAO2. While there ARE NRAH's showing up on the 10/13 Encore report, you have to also conclude that many of the obstructive apnea seen on that Encore report are Central and a mix of obstructive, maybe they are mixed apnea I don't know.

Snoredog, my best guess is also that Bev's Encore reports contain undifferentiated central and mixed events.

But I also lean toward thinking that many of the obstructive events are perhaps neurologically responsive, from that same repeated stimuli/sensitivity causing the central and mixed events. A waaaay out on a limb statement... for sure!

Dang it

Mea Culpa

I just double checked my refs to a 3-min window for tracking Peak Flow on a Bipap SV & Rate & realized it is 4 Mins & that it is the Vpap SV that does it in 3 mins.

So any refs I made to a 3 minute window re the Bipap SV should have been 4 mins.

DSM

SWS on page wrote:Now with that said, am I the only one who thinks Bev's bifurcation of central dysregulation may be a salient clue here? Some nights she has central dysregulation and other nights she does not. Do we think bumping up pressure a teensy bit is going to fix that? It might, but I doubt it. That bifurcation is potentially a central clue (pun intended) and it seems to be getting little or no consideration in this thread.

I'm thinking that a patient with that kind of central bifurcation tendency probably has an unresolved SDB problem that accounts for her daytime symptoms. Am I the only one in this thread who seems to think along these wacky lines? What's the nature of that central bifurcation?

Not wacky lines at all. You may very well be right that her EDS is caused more by complicated Sleep Disordered Breathing than by non-SDB related issues. Could be an ever changing combo... occasional central dysregulation that "cpap" can't do anything about on some nights, and other issues (hormones? stress? anxiety?) other nights when "cpap" treatment is going fine. I can easily buy the idea of "twitchy" defensive closure responses at times.

SWS wrote:I also lean toward thinking that many of the obstructive events are perhaps neurologically responsive from that same repeated stimuli/sensitivity causing the central and mixed events. A waaaay out on a limb statement... for sure!

No. Not way out on a limb at all, imho. I think you've been making a very good and insightful case all along for the many ways it can be possible for Bev's sleep to leave her feeling unrefreshed and still sleepy the next day.

Complicated, to be sure! Your thoughts, -SWS, on what may be going on, or what may be contributing the most to Bev's continued EDS are always most interesting. Not wacky. Interesting! And usually right on target.

dsm wrote:Dang it

Mea Culpa

Is third person for mea culpa pronounced youa culpa?

Either way, you're forgiven since I culpa quite often myself!

Goodnight all!

P.S. Rested Gal, I'll PayPal you the $20 as promised for those compliments! Expensive, but worth it IMO!

dsm wrote:SWS, I was being polite re the 25 IpapMAX suggestion. Also based on the data from Bev and my own experience I would 'guess' it won't. Do you believe from the data discussed this far that it will ? - if yes why ?

Actually IPAP Max=25 I posted is too high for the settings. I should have said IPAP Max=19 cm or 10 cm higher than EPAP. By the way the settings I posted are Respironics start up recommendations,

I was basing those settings on:

Knowing what her PSG reported as being a good EPAP pressure (you can use former CPAP pressure too), actually they suggest starting her EPAP=4 cm (if CPAP is unknown), well I know that will surely starve her of air, about 6.5 cm is the lowest I would ever go. They also don't recommend going over 13 cm with EPAP either. The setting of IPAP Min to 1 cm higher than starting EPAP pressure is also recommended until obstructive events are under control. The Adapt SV is a totally different machine than what she has used in the past, but it is not too hard to figure out what it is doing.

The Adapt SV titration protocol is pretty simple to follow, take it in steps and it should work fine. The Adapt SV is going to report AI or OA so she will be able to see if EPAP is addressing those events. The only thing Automatic on the SV is Inspiration and calculating BPM or RR. It still has a backup mode which they recommend you set once spontaneous is stable. And if you follow those recommendations, not too difficult to see they want to slow her breathing down to reduce the CA's. That is what she has NOT gotten with all her other therapy modalities.

My guess is she has short rapid breathing (chronic hyperventilation syndrome), the SV will control that with correct settings. My other guess is she breathes like that during the day also and would do herself good addressing it through breathing training. Does she have asthma? Maybe. Any way you look at it, when the protocol for the machine calls for setting any backup mode with a slower BPM than spontaneous and specific settings for Inspiration and Rise times they are wanting to slow the breathing down.

But as simple as that machine works, they could make it in china, maybe they could lower the price too

Basic Startup settings (from Respironics):

EPAP=4 cm (or CPAP pressure that eliminated obstructive)
IPAP Min=(Same or 1 cm higher than EPAP until obstructive eliminated**)
IPAP Max=EPAP+10 cm (moves up as EPAP moves up)
BPM=Auto (backup = 10 BPM minimum)
IT=1.2 Seconds
Rise Time =2 or 3 (Automatic in Auto mode).

** May not make sense but that is what they recommend, they want you to find the EPAP pressure that eliminates the obstructive events. Once that is done, you can increase Pressure Support by moving IPAP Min up. IPAP addresses periodic breathing and Hypopnea. If in Auto SV mode this machine should pretty much eliminate any hypopnea and periodic breathing, in case it doesn't, you use the default backup mode settings which is 10 BPM (minimum) and IT=1.2 and Rise Time 2 or 3. The Auto mode would have to fail before the patient would switch to that mode, if they switch it will be like hitting a brick wall and slow breathing down when CA's subside and it reverts back to Spontaneous mode.

Granted the SV does a bit more than typical Bipap, it can manipulate inspiration automatically which causes the patient to retain more CO2 with every breath (2 to 6 breaths they claim).

From everything I've seen so far, Bev is over titrated and reason why she feels so bad during the day. Right now the Aflex reports is misleading sure her AHI is low but she went over the hill with that in my opinion. I'd sure like to have seen her on a 420e I don't think she would have had half the problems.

But now that she has a SV coming, that should do the trick. But she needs to be careful in interpreting what she is seeing with the Encore reports. Start low and work your way up, follow Respironics recommendations and it seems pretty simple to set up.

Good thing Bev has an RT

& good luck with the SV Bev.

DSM

-SWS wrote: Respironics clearly refers to their "SV" mode as "automatic pressure support". They clearly allow for that "automatic PS" to be applied not only to BiPAP mode (they call it "BiPAP + PS") but they also intend it to be applied to CPAP mode should etiology require (they call it "CPAP + PS"). And I explained that etiology would be a CSDB/CompSA patient who tends to destabilize less with CPAP modality than BiLevel modality.

No one is disputing Pressure Support, it is not even a consideration from my point of view at this stage. I thought you asked for suggested CPAP and BIPAP pressure(s) to transfer over to the SV and for discussion. Out of all the data I seen 9 cm was the value I would select to start with for EPAP. I based that on her PSG result, not Encore. Past Encore reports are in the toilet for setting up the SV in my opinion.

My suggestions for Initial Settings for Bev's SV in SV mode, I see no reason to set it up in any other mode:

1. When setting up the SV, you need to first provide the CPAP/EPAP pressure which eliminates obstructive apnea. After looking at her PSG titrations, Encore reports of which I discount the latter in providing the correct information, I resort back to the PSG titration data and since I want to start lower than current, that is 9 cm found on her 10/16/07 PSG. Zero events, it is the highest pressure seen before the train wrecks.

EPAP=9.0 cm

2. Next, I want to know if that EPAP of 9 is going to take care of her OA's, so IPAP doesn't influence that finding, I set IPAP Min to the same or 1 cm higher than EPAP maintaining a 1 cm delta (Respironics recommendation from their titration guide).

IPAP Min=10 cm

3. Next, I want to give the machine a broad range to work during this initial setup period, I don't want to hinder its auto operation at all, so I use the recommended 10 cm Pressure Support spread, that is 10 cm. So as a result, I set IPAP Max to:

IPAP Max=19 cm (EPAP +10 cm)

4. At this point I don't know what her Respiratory Rate or BPM is. None of her prior studies gave me that info, so I need to set the machine in Auto mode and let it find that automatically. SO BPM=Auto.

BPM=Auto

5. Backup mode. If the Auto mode fails, I need to set up some fail-safe parameters until I have the spontaneous data, so backup mode is set to default BPM=10, IT=1.2 sec, Rise Time=2 or 3. Rise time is a comfort setting.

The Auto SV is going to have full control over IPAP. If it needs to add pressure support, working IPAP will rise off the Minimum setting to what ever it needs. It may even rise to 19 cm and bump into the Maximum. Now if she has a central apnea or periodic breathing while in that Auto SV mode it will switch to the backup mode where BPM will be 10 and Inspiration Time will be 1.2 seconds. That should stop any CA where once breathing is stabilized she will cycle back to spontaneous mode. If the machine is having to take over with the Timed backup values, that means the static settings are not set correctly in Spontaneous mode. If reports shows OA higher than wanted, EPAP gets increased. If I see zero OA on her report, I may even drop EPAP by 1 cm. I would hope to see 2 to 6 OA from a session. I want that EPAP pressure just where it eliminates the OA's and no more. Next, I expect the AutoSV mode to completely eliminate all Hypopnea. I'm wanting to see 99% or higher of User initiated breathing. Because if the machine is reporting that high a User Initiated breathing I know she isn't having any centrals or periodic breathing. Once I know what her avg. BPM is in the Spontaneous mode I input that value into the backup BPM field minus 2. You don't want it the same as the Spontaneous mode, you want it slower so it causes slight discomfort where the patient is encouraged to breathe on their own. The machine will automatically predict target volume half way through inspiration, if it doesn't see the target volume being met it will increase and extend inspiration (usually in 2 to 6 breaths).

So starting off I'm giving the SV a nice big range to work in. Once parameters are known values can be fine tuned for best therapy. You don't have to worry about Pressure Support at all. I'd want to see how she did after the initial settings before I'd go jacking her up to those higher pressures, she already has a aerophagia problem.

I also have the clinical and titration guide if you need it Bev let me know, it has easy to understand pictures and yes/no decision trees, I promise it is a whole lot easier to understand than this discussion.

FYI for SWS: You need to update your Marketing data dude, it goes to 30 cm, no wait 25 cm, see below, as pasted right out of their PDF guide

Some definitions
EPAP End Expiratory Positive Airway Pressure
IPAPmin Minimum Inspiratory Pressure
IPAPmax Maximum Inspiratory Pressure
BPM Back-Up Rate
Ti Inspiratory Time
Settings
EPAP: 4 to 25 cm H2O
- Should be adjusted to treat Obstructive
Component
IPAPmin: EPAP to 30 cm H2O
- Equal to EPAP for CPAP to treat OSA
- Add 2–3 cm above EPAP for comfort
IPAPmax: IPAPmin to 30 cm H2O
RATE - OFF
- Auto
- 4-30 bpm
DEFAULT SETTINGS - EPAP: 5 cm H2O
- IPAPmin: 5 cm H2O
- IPAPmax: 15 cm H2O
- RATE: Auto
Set to treat Obstructive
Component
- EPAP = IPAPmin: CPAP
- EPAP < IPAPmin: BiPAP®
Automatic Pressure
Support Maximum
Allows for clinician adjustments
to back-up rate
SETTINGS

-SWS wrote:FYI for SWS: You need to update your Marketing data dude, it goes to 30 cm, no wait 25 cm, see below, as pasted right out of their PDF guide

Yeah, I pulled both of my images from the original ASV thread that must be a couple years old by now. I think we might have to donate those to the Smithsonian. All the salient principles are still correct, though. Thanks for the updated specs!

Regarding the BiPAP AutoSV "Quick Start Guide to PSG Titrations in the Lab" that you propose extending to Bev's bedroom where she lacks titration equipment.... Respironics already has a suggested procedure to cover Bev's situation. And I highlighted that manufacturer recommendation a couple pages back:

earlier that wacky -SWS wrote:According to Respironics the initial settings can be based off a previously determined fixed CPAP pressure, or a previously determined fixed pair of BiLevel pressures: http://bipapautosv.respironics.com/

Respironics BiPAP AutoSV FAQ wrote: If the CPAP or BiPAP pressure is already determined in lab, the patient can be put directly on BiPAPautoSV. To assure that the patient is being properly treated it is a good idea to download the SmartCard data after 7-10 days.

Respironics BiPAP AutoSV FAQ wrote:For the set up of these patients it is advisable to use the CPAP or BiPAP pressure from the “old” unit,set the IPAPmax 10cmH2O above the CPAP or BiPAP pressure and set the back up Rate to Auto."

So I'm thinking this thread should probably entertain some discussion about what your previous best fixed CPAP pressure or best fixed BiLevel pressure happened to be. I would suggest coming up with some analysis and rational about what and why your previous best pressure(s) treated you the best. I would then suggest taking that "best" previous pressure setting and doing one of two things with it:

1) establish a data baseline by running at that best BiLevel or CPAP pressure (with BiFlex relief also set to match your current best CFlex/Aflex setting), or

2) use that previous "best" pressure setting as basis for your initial ASV pressure setting values as Respironics describes above (thus an "ASV free" data baseline for later comparison would not get established with this acceptable option)

It realy boils down to Respiroinics saying "Use procedures A" for titration in the lab but "Use procedures B" if you cannot manage to titrate the BiPAP AutoSV in a PSG lab. And procedure set A (the PSG titration procedures) require some very robust real-time measurements to follow those decision trees. So I'd say that Bev would be wise to follow the manufacturer recommendations above rather than attempting to follow a PSG titration guide in her bedroom. She can tweak from those starting points, if necessary, using the data card results as Respironics suggests.

And if all else fails she can follow that Respironics titration sheet by going into the lab where those procedures are really intended to occur---with all that PSG equipment that supports following those various decision trees.

ozij wrote:Can you tell us at which pressure you're getting your best subjective results?

Bev, my hunch is that the above question just may be difficult for many of us to answer. But do you have any thoughts about which pressure(s) "feel" best? Or perhaps which pressure(s) feel the least uncomfortable or disruptive?

Then, if possible, I'd suggest that we look at some Encore graphs containing data segments at that best pressure guess (or pressure range).

If a best or even viable pressure is known, then we can plug in the manufacturer-recommended values that I have highlighted in red below:

Respironics BiPAP AutoSV FAQ wrote:For the set up of these patients it is advisable to use the CPAP or BiPAP pressure from the “old” unit,set the IPAPmax 10cmH2O above the CPAP or BiPAP pressure and set the back up Rate to Auto."

In addition to determining the red values above, the manufacturer also suggests setting the backup rate to Auto.

So let's figure out your best fixed pressure or best BiLevel pressure, Bev. You can even take a determined single-best pressure, called "P" and extend that into a minimum 3 cm PS spread applying the above manufacturer recommendations as follows:

EPAP=P cm (or best CPAP/single pressure)
IPAP min=(P+3) cm
IPAP max=(P+10) cm
Backup Rate=Auto

If a best fixed BiLevel pressure from the past was known, on the other hand, then manufacturer recommendations would yield:

new EPAP= old EPAP
IPAP min = old IPAP
IPAP max = old EPAP + 10c m
Backup Rate=Auto

(note in both cases above "IPAP peak"---which is a dynamic per-breath IPAP value---is allowed to fluctuate as high as 10 cm above EPAP according to manufacturer recommendations)


From there tweaks can be performed based on Encore Pro data results as well as subjective feeling.

My best pressure range for AHI is what I was using 14-17. I don't have discomfort breathing, but I can feel my chest filling up and then my stomach and on down the line. I should have data from last night when I get home from work. With no change in sleep "hygiene" (Thanks, Rested Gal, but I do take a shower every night before going to bed ), my numbers can vary widely from day to day. I keep notes every day as to what mask I'm using, what medication I have taken, chinstrap, tape, etc. My hard drive crashed on me in June, and I didn't have a back up for my data, so I only have from June to present and a few reports that I had printed out from before.

Bev

OutaSync wrote:My best pressure range for AHI is what I was using 14-17.

Alright. I just looked at your Encore results on page one of this thread. With pressure endlessly sitting at 14 cm you appear to get a very acceptable AI and HI. There's a slight chance with BiPAP AutoSV that you just may be able to eventually drop below that 14 cm, however.

But if I were in your shoes, I would initially plug that very acceptable 14 cm into the following guidelines:

EPAP=P cm (or best CPAP/single pressure)
IPAP min=(P+3) cm
IPAP max=(P+10) cm
Backup Rate=Auto

the above yielding:

EPAP = 14 cm
IPAP min = 17 cm
IPAP max = 24 cm
Backup Rate=Auto

Well, actually I lied. If I were in your shoes I would somehow try very hard to arrange an in-lab PSG titration on the BiPAP AutoSV. But if I couldn't manage an in-lab BiPAP AutoSV titration, then I think I would tentatively start with the above numbers---and then evaluate/tweak from there. If after viewing the initial data I saw great results but slept uncomfortably, as if pressure was too high---then I would experimentally subtract 1 cm from each value for the next night. ...and so on.

Suggestions, thoughts, comments, questions?

Another titration would be out of pocket, for me. I've had some big expenses this past month. If the economy doesn't pick up, my job is in jeopardy.

My SV didn't ship today. Durn that Columbus!

Hey, guys, if I die my first night on the SV, I've instructed my SO to pull the reports and send them to you!

Bev

Well, Bev, if your doctor thought you were at risk of death using the BiPAP AutoSV, then he wouldn't have written the script for one. And similarly, if Respironics thought your home based BiPAP AutoSV experiment imposed the risk of death, then their FAQ wouldn't have explicitly described how to use those previous CPAP or BiLevel values as a starting point.

I think it's darn nice of you and your S.O. to get those reports to us no matter what! But if it boils down to that, can I have your BiPAP AutoSV machine?

Changing my will, now.

Bev