My first night on ASV

[-SWS]

...they also wrote:

4.2.1.2 The recommended minimum starting CPAP should be 4
cm H2O in pediatric and adult patients (Consensus).

I don;t think 4cm H2O is expected to be a prescribing pressure. My take is that 4 cm H2O is the minimum starting pressure for a CPAP titration.

My understanding is that a titration will typically start low to help establish a baseline regarding the physiologic response to CPAP. Given that baseline, homeostatic disturbance clues across the various PSG data channels can then be monitored as the pressure is gradually increased. So I think the basis of the 4 cm H2O minimum recommendation lies in starting titration no lower for the sake of ensuring adequate CO2 clearance.

I think it's difficult for the various committees and organizations to come up with consensus recommendations for CSDB/CompSA. They're still trying to determine exactly what it is, how the various presentations can vary, possible confounding factors, etc.

[georgepds]

your sleep seems to go into the tank once you get into REM....

How did you determine REM sleep from the posted chart?

[Snoredog]

your sleep seems to go into the tank once you get into REM....

How did you determine REM sleep from the posted chart?

Periods of events are more clustered around 90 minute intervals with relatively quiet periods seen in between. You should have
3 to 5 of those periods per night. REM is also were most obstructive events would be likely to be seen most severe.

[Banned]

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

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

"The "recommended minimum IPAP-EPAP is 4 cmH20 and the maximum IPAP-EPAP differential is 10 cmH2O (Consensus)", refers to a recommended 4-10 cm gap between EPAP and IPAP or IPAP Min.

That recommended EPAP/IPAP/IPAP Min 4-10 cm gap has nothing to do with properly setting IPAP MAx.

Banned

[-SWS]

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

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

"The "recommended minimum IPAP-EPAP is 4 cmH20 and the maximum IPAP-EPAP differential is 10 cmH2O (Consensus)", refers to a recommended 4-10 cm gap between EPAP and IPAP or IPAP Min.

That recommended EPAP/IPAP/IPAP Min 4-10 cm gap has nothing to do with properly setting IPAP MAx.

Banned

A maximum EPAP/IPAP gap of 10cm means that IPAP minus EPAP should be 10cm at the maximum. Okay. So let's take these examples: EPAP=10, IPAPmin=14, and IPAPmax=24

So what happens with EPAP? It always stays at 10 cm. So what happens with IPAP? On some breaths it automatically goes as low as 14cm. On other breaths it automatically goes as high as 24 cm. So what is the EPAP/IPAP gap on all those breaths when IPAP automatically goes up to 24cm? The EPAP/IPAP gap for all those breaths would be an IPAP-of-24cm minus an EPAP-of-10cm.

That's an EPAP/IPAP differential of 14cm for all those breaths when IPAP automatically goes as high as 24. But the maximum recommended EPAP/IPAP differential was recommended at 10cm. And here you have a patient conceivably spending significant amounts of time with an EPAP/IPAP gap of 14cm instead. Admittedly if a patient hits that IPAPmax ceiling again and again, a clinician will have to weigh the pro's and con's of exceeding that 10cm recommended max EPAP/IPAP gap.

So what's the point of exceeding the 10cm max recommendation if a patient seldom hits that upper limit anyway?

[-SWS]

refers to a recommended 4-10 cm gap between EPAP and IPAP or IPAP Min.

Okay, Banned. Let's run yet another example using a 10cm gap between EPAP and IPAPmin exactly as you suggest above: EPAP=6, IPAPmin=16, IPAPmax=26

So let's assume a patient is unusually unstable and manifests significant night-to-night variability. Let's assume they somehow manage to max out IPAPpeak roughly half the time during an unusually bad night. That means they spend roughly half the night with an EPAP/IPAP differential of 26cm minus 6cm.

That amounts to spending half the night at a whopping 20cm EPAP/IPAP differential. Not even close to consensus medicine's maximum EPAP/IPAP differential recommendation of 10cm.

[Banned]

SWS,

I going to assume you are putting me on.

But in the unlikely case you are serious, take another look>

Results: http://james.istop.com/apnea/reports/AsvNov30.pdf

Do you really believe it would be the 'consensus' of the people writing these 'recommendations' that James clip IPAP Max with his SV? Then please explain to the board the benefit James gained from clipping IPAP Max?

Banned

[Banned]

And while you are at it, can you please explain to the board the benefit of James clipping IPAP Max just after hour 3 when he concurrently scored a hypopnea?

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

Thanks,
Banned

[-SWS]

Banned, I'm going to assume you are putting all of us on.

As you can see, for the first 3 hours I was wide awake.

Okay, so what's the point in even looking at all that wide-awake data, Banned? Fast forward to about hour 3, when James finally gets to sleep. Forget all about the fact that James couldn't sleep because of that manual backup rate via trial-and-error that is bugging him so much.

So just how much "clipping" of IPAPpeak do you think you see there, Banned? I only see one minuscule blip right before hour 9.

[Snoredog]

"The "recommended minimum IPAP-EPAP is 4 cmH20 and the maximum IPAP-EPAP differential is 10 cmH2O (Consensus)", refers to a recommended 4-10 cm gap between EPAP and IPAP or IPAP Min.

That recommended EPAP/IPAP/IPAP Min 4-10 cm gap has nothing to do with properly setting IPAP MAx.

Banned

Actually is does. The recommendation is for fixed bi-level but the same guidelines should apply. This is Pressure Support we are talking about here. That is the difference between EPAP and IPAP pressure.

-On the Minimum side for Bi-level they suggest a Minimum EPAP-to-IPAP of 4 cm.
-On the Maximum side for Bi-level they suggest a Maximum EPAP-to-IPAP separation of 10 cm.

This has NOTHING to do with any IPAP Min, it is NOT a 10 cm working pressure range from IPAP Min to IPAP Max. Respironics
says Set EPAP then set IPAP Max 10 cm higher. Doing so keeps the Maximum pressure suppport allowed to 10 cm and within
task force guide lines.

But the bottom line is, if you already have 10 cm allowable pressure support and you are bumping into any IPAP max consistently then EPAP needs to be increased by 1 cm so you do stay within that 10 cm pressure support maximum.

But when you look at Adapt SV therapy the only difference is IPAP is responding much faster or rapidly then what you would see on even a Bipap Auto, but it is still Bipap therapy. On this machine, that IPAP working pressure can increase much more rapidly to meet peak target values.

Hard to tell from 1 night's settings, but I'm surprised to hear that breathing against BPM=12 seemed fast for him but I suspect the avg. BPM we have been looking at in the reports has been weighted by some rapid breathing leading to the PB seen. That did drop ever so slightly from 1% to .8% which is what I was wanting to see, certainly didn't increase, so we are going the right direction if that one night is an indicator. He probably is going to need 10 before its over. But when using fixed lowering by only 1 BPM can have a big impact on respiration as it changes the duration of the breath, my new calculations for BPM=11 are:

Pressure Settings:
===========================================================
EPAP=10.0 (he seems to like that setting)
IPAP Min=12 (I would move this to 13 cm, that is where it has been averaging anyway)
IPAP Max=20 (I'd still follow protocol and general guidelines, no sense in over inflating his lungs when it is not needed).

New BPM=Fixed settings I would try:
=============================================================
BPM=11 (60 / 11 = 5.45 secs per breath, for IT; 5.45/2=IT=2.72 seconds)
IT=2.7 (if you can dial that in, should be able to dial in 2.5)
Rise Time=3 or 4 (I would set this while awake for most comfort).

While I'm concerned about the increase seen in Machine Triggered Breaths, the rest looks pretty good and we did see
-Periodic Breathing reduced slightly
-No real change in HI seen
-Peak and Tidal volumes are up
-He reports he feels better

We have to toss out the first 2.5 hours of therapy as those settings didn't work, then you have to toss out the first 1/2 hour of concurrent sleep seen because peak and tidals seen are up with any settings used. I would try sticking to fine tuning the backup BPM mode instead of making any drastic pressure changes.

When you look at what are we trying to fix, it is the residual PB and central H's seen, both of those kind of go together in either case. We have no AP's so there are no obstructive apnea showing up, I consider that taken care of. Now we are trying to correct the PB and hopefully land at settings which produce more stable sleep across the night. I don't consider those rapid pressure swings of IPAP to be an indicator of that, allowing more of that to be seen with a higher IPAP max is the opposite of what you want to see.

Every time you make a change to EPAP you have to start over with IPAP settings, that is why that value is so critical once you find it you set it and forget it.

If IPAP Min feels more comfortable at 12 cm then 11 then that is where I would set it. IF IPAP Min feels better at 13 or 14 that is where I would set it. Machine is going to 13 to 16 cm range when EPAP=10 anyway. But it appears BPM=Fixed has a big impact on what is seen so we don't want to limit where IPAP working pressure (SV) is thinking it should land.

[-SWS]

Banned, I'm going to assume you are putting all of us on.

As you can see, for the first 3 hours I was wide awake.

Okay, so what's the point in even looking at all that wide-awake data, Banned? Fast forward to about hour 3, when James finally gets to sleep. Forget all about the fact that James couldn't sleep because of that manual backup rate via trial-and-error that is bugging him so much.

So just how much "clipping" of IPAPpeak do you think you see there, Banned? I only see one minuscule blip right before hour 9.

Banned, you threw me off with that second link.

Okay, we have the 28th and the 30th there. Regardless, there is one pattern on both charts: the vertical-downward events that match up with those few "IPAPmax ceiling bumps" collectively don't account for much residual PB or residual AHI by any clinical standards.

So why even violate consensus medicine's maximum recommendation by hiking IPAPpeak's ceiling when you're really not going to improve either the PB index or AHI index very much?

[Snoredog]

And while you are at it, can you please explain to the board the benefit of James clipping IPAP Max just after hour 3 when he concurrently scored a hypopnea?

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

Thanks,
Banned

I'd say he was recovering from a DEEP Breath as Peak and Tidal volumes seen are off the chart, good thing the IPAP Max WAS where it was at or it would have only gone higher.

He only bumped into IPAP Max 1 time the whole night? I'd say that is a pretty good setting to use.

[Snoredog]

Fast forward to about hour 3, when James finally gets to sleep. Forget all about the fact that James couldn't sleep because of that manual backup rate via trial-and-error that is bugging him so much.

So just how much "clipping" of IPAP peak do you think you see there, Banned? I only see one minuscule blip right before hour 9.

If the SV side of things was doing its job he wouldn't be going to the BPM mode. But in prior nights where it was Auto all you are doing is bouncing him from SV mode to Auto with no real correction seen.

Was the 11/28 the best we can expect to see? you don't know until you try and know your limitations on either side, just like tuning in a station on an old stereo you wing them dials in either direction until you land in the center.

Is it really he is spending more time in machine triggered breathing because he doesn't like it or is it he is spending more time there because those settings are working better?

What are you basing your assumption on?

If you spend all your time in Auto mode you will never know if you do any better with fixed. They don't have that luxury in the lab, they get about 240 minutes and show's over. So far all I've seen come from that is basic protocol settings.

I think the biggest gain seen from last night's data is he feels better. Getting the machine comfortable where he is comfortable in using it is where its at.

So what is the machine doing with the settings to make it more comfortable if BPM=auto? Why can't you duplicate those Auto settings. While he is still on the SV side of the machine it should be still doing its thing.

I would expect this machine on the SV side and BPM=Auto to correct his breathing and if a central shows up switch him over to the backup side, correct breathing of that event and send him back to SV side and now correct breathing a little bit so he doesn't land back on that side and each time it does it he ends up in the BPM mode less and less.

But it doesn't seem to be doing that. We have seen him use EPAP=9.0 to EPAP=10 with no change in HI's seen. Obviously with IPAP not bumping into IPAP Max the machine is free to eliminate any obstructive hypopnea seen. So you have to determine those HI's seen are central. That would also make sense as to why machine is spending so much time in BPM mode.

So lets see why he is going to BPM=Fixed settings so much? SV side should be operating just as it did before with BPM=Auto. Backup settings are nothing more than fixed Bilevel. He should NOT be going to that mode for PB, only Centrals.

I understand in BPM mode we will no longer be targeting Peak with IPAP working pressure, so that would drop to IPAP Min set (another reason to increase it to at least 13 cm pressure). So now if he is in BPM mode he should be using EPAP=10 cm and IPAP=13 cm, fixed Bi-level with IT=2.05, and respective Rise Time. So in BPM mode he would be:

EPAP=10
IPAP =13 (IPAP Min setting)
BPM=11
IT=2.7 sec
Rise Time=3

So in Backup mode he should be experiencing the above settings. I would think if his body disliked those settings so much it would be in a hurry to get back to spontaneous breathing.

But obviously, our goal is to fine tune those a bit more where we keep him on the SV side of the machine. But while trying to do that we have people yelling from the peanut gallery "put him at 30!!" with no logic at all behind their decision and in fact they cannot even explain WHY those settings would help.

[-SWS]

Was the 11/28 the best we can expect to see?

That's entirely possible with CSDB. These are residual scores that some CSDB patients would just love to have---but will never manage to achieve using today's CSDB treatment methods. James is lucky to have these residual scores as a CSDB patient. But there just may be room for improvement.


http://james.istop.com/apnea/reports/AsvNov28.pdf
I honestly don't think the crux of the problem is that IPAPmax (the ceiling) is not set high enough. Here's another autoSV spin, looking at the above graph. Specifically I'm looking at hours 3.5 to 4.75. That could very well be James hitting heavier obstructions during REM---at least initially. If so, then a higher EPAP just may be what James needs. The H cluster occurs first--and that lead-in H cluster may be obstructive. The ensuing desats and machine-pressure hikes happen next. And those desats and pressure-hikes are what may have eventually triggered that typical CSDB sequence of PB, then A, then PB. Quite possibly we're seeing a CSDB domino effect starting with a cluster of obstructive H. We just might be seeing obstructive H occurring during REM, then James responsively stage-shifting into NREM---where CSDB tends to wreak its havoc.

Initially, we were hesitant to increase the EEP too rapidly; with experience, we have become more aggressive with our titrations... In another patient, undertitration occurred as the technologist adjusted the EEP for apneas and hypopneas, but did not adequately increase the pressure for residual RERAs. Our experience suggests that some of the early failures with ASV may be inadequate SDC/technologist experience, and not necessarily a problem with the device.

Above Dr. Brown comments that his clinic eventually learned to rely on higher EPAP/EEP pressures with some CSDB patients.

From the very little NPSG time James spent at autoSV EPAP=10cm, I'm not convinced anyone should assume those leading hypopopneas are either central or obstructive. They could be either. There's no great way to differentiate hypopneas on any Encore chart.

[Snoredog]

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

I honestly don't think the crux of the problem is that IPAPmax (the ceiling) is not set high enough.
Here's another autoSV spin, looking at the above graph. Specifically I'm looking at hours 3.5 to 4.75. That could very well be James hitting heavier obstructions during REM---at least initially. If so, then a higher EPAP just may be what James needs. The H cluster occurs first--and that lead-in H cluster may be obstructive. The ensuing desats and machine-pressure hikes happen next. And those desats and pressure-hikes are what may have eventually triggered that typical CSDB sequence of PB, then A, then PB. Possibly a CSDB domino effect starting with a cluster of obstructive H.

From the very little NPSG time spent at autoSV EPAP=10cm, I'm not convinced anyone should assume those leading hypopopneas are either central or obstructive. They could be either. There's no great way to differentiate hypopneas on any Encore chart.

I agree the IPAP Max is plenty high enough. I would also agree with trying a higher EPAP than 10 cm. We already tried 9.0 cm, so I'm for going with EPAP=11. I would let him set IPAP Min higher to what he thinks is comfortable. Once he changes EPAP you have to start over with IPAP but it appears that at least a 2 cm differential between EPAP and IPAP Min is what he prefers, I think he should put it where he feels comfortable.

But if those HI's were truly obstructive, then WHY wouldn't the SV go to IPAP Max to eliminate them? That can be seen throughout his reports, no apparent response by the machine to eliminate them.

IF we increase EPAP=11, I'd like to see us stick with past limits, that would mean

EPAP=11 (former settings were 9.0 and 10.0)
IPAP Min=13 (or where it is comfortable for him)
IPAP Max=21 (or +10 from EPAP)
BPM=Auto

I also recommend he set up a 30 minute Ramp time going from 8 cm to the 11. That may help him fall asleep faster.

If we use those setting we can compare to the prior nights where BPM=Auto. But I don't think we should totally rule out
using fixed settings if his goal is to feel better. I don't recall what his RERA's were from the last PSG. From what
I can tell they did nothing more in the lab then put him on the settings we put him on the first night and called it good.