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jskinner wrote:

Snoredog wrote: I still think your EPAP needs to be lower at 9.0 cm.

EPAP=9.0 cm
IPAP Min=13 cm
IPAP Max=19 cm

Seems like we are thinking along the same lines. I had already set my machine to 20/19/12 for tonight. I will go with 13 IPAPmin instead as you suggest. Will leave BPM=Auto for tonight as I don't like to change to many settings as once as it becomes hard to tell what variable change produced the results.

Question: Does the AutoVS use square wave transitions from IPAP->EPAP->IPAP or is it more rounded like their Biflex provides?

By comparison to your pressure referenced, my suggestion would be 19/13/9 for comparison. Note: You do NOT want to increase EPAP to 12. You either set that to 9.0 or 10 cm and you leave it, it does NOT change. You only change EPAP when there are obstructive apnea, it is assumed when going to this machine you have already titrated for that. EPAP pressure is fixed it does NOT move on this machine at all. The "single" AP tic you are looking at on last night's report is a Central apnea not a obstructive.

Note: The EPAP=9 setting is critical, you cannot have that too high with your phenotype, this is the intolerance of CPAP with CSDB. IF you lower EPAP=10.0 to EPAP=9.0 and it is too low, IPAP working pressure would immediately be bumping into IPAP Max ceiling, we are compensating for that happening by increasing IPAP Min=13 or 4 cm higher than EPAP pressure. I don't know how else to stress how critical that EPAP pressure is. You have showed us a history with CPAP that 9.0 cm pressure produced the lowest AHI, and that is what you want the pressure that eliminates the obstructive apnea. Also understand that increasing EPAP by 1 cm is enough to send your breathing into dysregulation. We cannot expect to have the machine correct central dysregulation because EPAP is too high, it simply won't work.

jskinner wrote:http://james.istop.com/apnea/reports/AsvNov27.pdf

I bumped up IPAPmin last night by 3cm. Since the hypopneas didn't seem to respond could those remaining events be central hypopneas? (which I don't really understand)

I did end up sleeping an usually long time at these new settings.

James,

Your settings are pretty close to mine now (I ended up bumping 10 to 11 & 13 to 14) and your pattern of PS looks very much like what I usually see, here is my last nights data. The main difference being how many individual events we each scored.

http://www.internetage.ws/cpapdata/dsm- ... 9nov08.pdf

DSM

#2

James, just also wanted to mention I take pariet for GERD - in fact 2 tabs - 1 in morning & 1 at night. Also, when I set my gap greater than 4 CMs separation I was starting to increase events. Over time I keep coming back to 11/14/20 - my PS has never gone above 19/20 even when I set IpamMax for 24 for a week or so.

#2 Snoredog & SWS - I will see what I can dig up in the patent re BPM=AUTO as what SWS is saying is what I have also said in the past (cycling is the exclusive mechanism for central dysregulation) BUT, I am sure I read in the patent that when it detects a pattern of periodic breathing and the machine determines the sleeper starts to hyperventilate, it tries to slow that - the patent does state it will adjust epap during CSR episodes - it is particularly clear about doing this. I need to read it again.

DSM

dsm wrote: #2 Snoredog & SWS - I will see what I can dig up in the patent re BPM=AUTO as what SWS is saying is what I have also said in the past (cycling is the exclusive mechanism for central dysregulation) BUT, I am sure I read in the patent that when it detects a pattern of periodic breathing and the machine determines the sleeper starts to hyperventilate, it tries to slow that - the patent does state it will adjust epap during CSR episodes - it is particularly clear about doing this. I need to read it again.

DSM

SV does NOT adjust EPAP pressure, if you are reading that you are NOT reading the correct patent for the machine. EPAP IS the background CPAP modality for this machine, it does not fluctuate, it does not pad EPAP with PPAP, once set it stays there just like CPAP does.

Thanks for the input, Doug!

Patent descriptions are almost never the equivalent of low-level design documents. I can't think of any legal or financial incentive for patent descriptions to be the equivalent of highly accurate low-level design documents. But despite that general caveat about patent descriptions, none of the Respironics marketing literature, training literature, or technical literature so far has hinted at EPAP being automatically adjusted: http://bipapautosv.respironics.com/ .

Speaking of Respironics marketing literature, look at what modality the manufacturer decided to showcase treating Periodic Breathing:


Above Respironics is showcasing CPAP+SV modality to treat periodic breathing.

jskinner wrote:Seems like we are thinking along the same lines. I had already set my machine to 20/19/12 for tonight

Sorry that was a typo. I had set it to 19/12/9 for tonight. I seemed a little slow today from all that sleep last night

Snoredog wrote:By comparison to your pressure referenced, my suggestion would be 19/13/9 for comparison. Note: You do NOT want to increase EPAP to 12.

Agreed. It was a typo, not sure where my brain was when I typed that. My machine was actually already set to almost what you suggested with only 1cm difference on the IPAPmin.

It will be interesting to see how tonight goes at 19/13/9

http://james.istop.com/apnea/reports/AsvNov28.pdf

Actually ended up going with 20/12/9 as I found the IPAP->EPAP transition with 13 a bit strong.

The good news is you are not doing any worse on Bi-level SV than on CPAP SV. The bad news is you are also not doing any better. Your 1 Ap is fine, and you got the same Ap score at EPAP=9 as you did at EPAP=10. EPAP is not your problem. I recommend that you raise EPAP to 11. That may clear the pesky 1 Ap that seems to be bird-dogging you.

And EPAP=11 will let you raise IPAP Min to 14 (since you find a 4cm spread to steep). My feeling is you need an IPAP Min of 15cm to start addressing your 2 Hi in both Bi-Level SV or CPAP SV modes. Hopefully the higher IPAP Min can start addressing the 1% PB which has been the same in both modes (although yesterday's settings of 13/10 resulted in 2% PB).

You need to address IPAP Max. Both the 'recommended' IPAP max setting of EPAP to IPAP Max spread = 10, and dsm's EPAP to IPAP Max spread are incorrect. The correct spread for IPAP Max is IPAP Min to IPAP Max = 10cm. If you note on your chart, you clipped IPAP Max during your first H event last night. SV mode needs the correct 10cm in to function properly. If you do not maintain the 10cm IPAP Min to IPAP Max spread, you are (as demonstrated in your own data) following some ill-advised advice.

Someday, when you are ready:
EPAP = 11
IPAP Min = 14
IPAP Max = 24

Banned

Banned wrote:The correct spread for IPAP Max is IPAP Min to IPAP Max = 10cm... If you do not maintain the 10cm IPAP Min to IPAP Max spread, you are (as demonstrated in your own data) following some ill-advised advice.

The Resperonics AutoSV titration guide says IPAPmax: 10 cm H20 above EPAP.

jskinner wrote:

Banned wrote:The correct spread for IPAP Max is IPAP Min to IPAP Max = 10cm... If you do not maintain the 10cm IPAP Min to IPAP Max spread, you are (as demonstrated in your own data) following some ill-advised advice.

The Resperonics AutoSV titration guide says IPAPmax: 10 cm H20 above EPAP.

That 10 CM spread is a protection from excessive variation.

When I did my static tests on how far pressure would rise if an central occured, the machine always stopped raising PS after 12 CMs above epap. I had set IpapMax to 30 but it would never go higher than 22-23 CMs

I am sure the patent also mentions a ceiling on raising pressure.

DSM

I guess we know why they call it Complex SDB.

1. Obviously you don't do any better with greater PS of 3, I would stay below that or even move IPAP Min down to EPAP back to CPAP.
2.Compare your reports going back to 11/20, even though there is a train wreck in the center, last night was the first night you broke <H=2.0 all other reports show H: as high as 4.0. I think you did better at 9.0 EPAP, if you toss out that train wreck in the center you had fewer events before and after it.
3. You will notice that IPAP working pressure wanted to stay at the IPAP Min most of the night, IPAP Max was plenty high it only bumped into 1 time the whole night and if you look at what Peak and Tidal were doing you will see a big jump in those guys so that is why IPAP Max bounced off the ceiling.
4. the "AP" seen haven't really changed from night to night, your PB has come down to 1% and gone from triple tics to single tics. The same number of tics may seem to be appearing but they are skinnier.

I'm more inclined to suggest:

EPAP=9.0 cm
IPAP Min=10.0 cm
IPAP Max=19.0 cm
BPM=Auto
And if this doesn't work any better than seen on 11/23 report, I would try:
=================
If it was me, I would want to avoid the train wreck in middle, less PB seen and therefor I would have tried:

EPAP=8.0 (not a typo)
IPAP Min=10.0 cm
IPAP Max=18
BPM=12 (it is what it says to do when PB and HI are seen)
IT=1.7 or 1.8 (got to be less than 2, 1.2 is the "minimum")
Rise Time=2 (don't see any obstructive apnea, so lower Rise is better for resistive breathers)

So far, you have done the best on 11/23 (filename: AsvNov22.pdf) and those settings were:

EPAP=10
IPAP Min=10
IPAP Max=20
BPM=Auto

Patient Triggered Breaths were 99.5%

Is 11/23 the best you can get? Might be but you don't know for sure until you experiment. I would also follow the guide
and do what they suggest when Hypopnea and Periodic Breathing are present, they say move away from BPM=Auto to fixed
settings. Take your Avg. BPM from like last night it was 14.5, subtract 2 from that is 12.5, so that is what BPM=12.5, next
figure out what IT time should be, 60 /14.5=4.13 sec breaths, for a 1:1 ratio of I:E that would be: 2.06 IT time and the
rest left over for exhale and Rise time. So right there it says you cannot use 3 as Rise time, since 2 is about as close to 2.06
as you are going to get I would use a 2 as Rise time.

So if you took the 11/23 report settings above, then applied a Fixed backup as shown in the center of the guide, you would
end up with:

EPAP=10 cm
IPAP Min=10
IPAP Max=20
BPM=12.5
IT=2.05 (I think this is high but formula says it is not, I would use like a 1.7 or 1.
Rise Time=2

Using the above settings, I would expect to see fewer PB's, fewer H's. If you are only getting 2 or 3 AP's per night I would NOT worry
about them, those can be transitional centrals. Remember: CSDB likes stead pressure as opposed to rapidly changing pressure, it
also likes lower pressure as opposed to higher. You will notice on most of your reports stable sleep was seen when IPAP working pressure
was down near the IPAP Min floor pressure.

jskinner wrote:

Banned wrote:The correct spread for IPAP Max is IPAP Min to IPAP Max = 10cm... If you do not maintain the 10cm IPAP Min to IPAP Max spread, you are (as demonstrated in your own data) following some ill-advised advice.

The Resperonics AutoSV titration guide says IPAPmax: 10 cm H20 above EPAP.

If you look at the Titration Guide it only references, "IPAPmin: same as EPAP, IPAPmax: 10 cm H20 above EPAP", which is CPAP SV mode.
It is not recommending a spread of 10 cm from EPAP to IPAP Max as a life style in Bi-Level SV mode..

Banned

I interpret the titration guide says don't set IpapMax greater than 10 over Epap. Foe either type of set up.

As mentioned before. the machine itself when I tested it. Would not raise IpapCurrent greater than 12-13 CMs even if IpapMax was set at 30 & Epap at 10.

I really don't believe the vendor wants the machine delivering an epap or epap=IpapMin) to IpapCurrent with a gap higher than 10 - also we have discussed elsewhere (SWS posted) that the current recom from one of the influential sleep assocs says 4-8 as the recommended gap range - even though a number of us are happy with 3 as a gap & a lot of Bipap Auto (Biflex) users are happy with a 2 CMs gap.

DSM

Here's the other 4cmH2O to 10cmH2O recommended gap Doug mentioned in his post above:

2008 AASM PAP titration clinical guideline wrote: 4.3.1.6 The recommended minimum IPAP-EPAP differential is 4 cm H2O and the maximum IPAP-EPAP differential is 10 cm H2O (Consensus).

http://www.aasmnet.org/Resources/Clinic ... 040210.pdf

http://www.pubmedcentral.nih.gov/articl ... id=2335396

-SWS wrote:Here's the other 4cmH2O to 10cmH2O recommended gap Doug mentioned in his post above:

2008 AASM PAP titration clinical guideline wrote: 4.3.1.6 The recommended minimum IPAP-EPAP differential is 4 cm H2O and the maximum IPAP-EPAP differential is 10 cm H2O (Consensus).

http://www.aasmnet.org/Resources/Clinic ... 040210.pdf

http://www.pubmedcentral.nih.gov/articl ... id=2335396

Yeah, but if we read and believe this stuff than we have to capitulate that Snoredog was right, and who wants that?

E.g. "4.3.2.8 A decrease in IPAP or setting BPAP in spontaneous-timed (ST) mode with backup rate may be helpful if treatment-emergent central apneas (CSA) are observed. (Consensus)"

These look like clinical guidelines written by Snoredog!

Banned

Banned wrote:

-SWS wrote:Here's the other 4cmH2O to 10cmH2O recommended gap Doug mentioned in his post above:

2008 AASM PAP titration clinical guideline wrote: 4.3.1.6 The recommended minimum IPAP-EPAP differential is 4 cm H2O and the maximum IPAP-EPAP differential is 10 cm H2O (Consensus).

http://www.aasmnet.org/Resources/Clinic ... 040210.pdf
http://www.pubmedcentral.nih.gov/articl ... id=2335396

Yeah, but if we read and believe this stuff than we have to capitulate that Snoredog was right, and who wants that?
E.g. "4.3.2.8 A decrease in IPAP or setting BPAP in spontaneous-timed (ST) mode with backup rate may be helpful if treatment-emergent central apneas (CSA) are observed. (Consensus)"
These look like clinical guidelines written by Snoredog!
Banned

I think what is more important than numbers is the logic behind how they go about correcting the event seen.

1. They start you off with 10 cm delta between EPAP and IPAP max. then you observe for partial obstruction such as Hypopnea
and Periodic Breathing (James's case seen on last report).
2. IF Hi or PB are seen AND IPAP working pressure is bumping into IPAP Max then they say to increase IPAP Max by 2 cm. You are now 12 cm above EPAP with IPAP Max, or a 12 cm spread, THEN they say if this does NOT eliminate the events,
3. Set Fixed BPM to 2 less than Spontaneous (meaning change BPM=Auto to BPM=Fixed), set Start I Time to "minimum" of 1.2. They don't tell you what to set IT=xx because they don't know what BPM you are getting in Spontaneous mode, so you do the math and figure it out as I did above.

It is my opinion:

1. You first try and eliminate the PB because PB can lead to Central Apnea.
2. Once you eliminate PB then you go about to eliminate residual Centrals.

So I see PB a more critical modality to eliminate then Centrals seen, because many of those may drop off once you correct the PB.
So in James's case he has about a weeks worth of data, PB is persisting in every report, it is time to move away from the BPM=Auto mode and try the BPM=Fixed mode according to the titration guide. They wouldn't tell you to go to that mode if it didn't fix it.

In the above calculations, I took his avg BPM rate seen on the report, subtracted 2 from it, think it left 12.5, next I figured out the duration of the breath from that same BPM/RR by dividing within 60 seconds, I then halved that and came to the 2.05 sec Inspiration Time. I think you can be a little shorter on BPM (i.e. 12 vs 12.5) and/or 1.7, 1.8 or 1.9 on IT time and it won't do any harm.

As mentioned before, I suspect the machine is not correcting his PB because the 4-minute sample the machine uses probably also contained a marginal amount of Periodic Breathing, that will throw off the BPM=Auto settings so it doesn't fully correct things when he lands there, by going to fixed settings you are assured those fail-safe settings will be set slower than spontaneous. Let's say he enters a cluster of PB and things become a train wreck with PB, that might last several minutes, now half your sample to be used for BPM=Auto mode is tainted. Ideally I would think you want that 4-minute moving sample data avg. to represent concurrent breathing.

IF IPAP Max ceiling is not being hit and PB continues to exist and the machine is not correcting it, then I read the logic behind the titration guide as wanting to slow overall breathing down. If this is done it will mean fewer BPM avg. seen on the report. Lower
BPM should also equate to greater peak and tidal volumes seen. A faster BPM/RR would make that go the other direction.

There is no need to move the IPAP Max ceiling up if the working pressure is not continually bumping into it. If you follow conventional Bi-level consensus if that would happen on a Bi-level you would bump up EPAP by 1 cm, then IPAP should fall to the bottom. While there is no written rule in the titration guide for a 10 cm delta from EPAP to IPAP max, it is where they start you off. There is nothing in the guide to indicate that there is a 10 cm delta from IPAP Min to IPAP Max or that it needs a greater working range.