AHI still erratic, time to wingding?

Sludge wrote:

robysue wrote:Increasing the min EPAP from 13 to 17 is a huge increase, particularly if it's done all at once.

But how did we even get to 13?

My understanding of the tale is this: After the home sleep study showed an AHI of 40+, mom was given an APAP set wide open (4-20) and the doc didn't really pay attention to proper follow up. Nine months later (with the APAP set to 4-20 the whole time), after getting her own PAP problems straightened out, College3girls noticed that the data gathered by Mom's APAP was indicating that therapy was not working as intended because the treated AHI was still way, way too high. In Mom needs more help prior to DME and Sleep DR app't College3girls wrote:

I'm trying to help my mom, who is registered as theresem on the forum. She has been on APAP since June of 2013, with a resmed s9 auto (left at a range of pressure from 4-20 until I intervened.) She never received any follow-up or titration. The DME never supplied any new masks. Needless to say nothing is working, and at the moment she is wasting her time on APAP, despite using it faithfully all night every night.

Thanks to input from all the good folks of this forum, I changed her ramp to 5 min and her pressure range is now 8 for the ramp, and 12-20 for the pressure range. Depspite this, her AHI is still high, over 12 most nights, and sometimes as high as 20.

Throughout April and early May, the suggestions from posters tended to focus on increasing the min pressure setting a bit. Much of that advice was based on information from College3girls that indicated the 95% levels on the APAP were really high and that the data was showing few or no centrals and that mom's snoring continued while on APAP with the APAP running near its max of 20cm most of the night.

At the beginning of suggestions for bipap settings? College3girls wrote:

My mom is going to be switched from APAP to BIBAP. After being on APAP for a year, her AHI is still in the mid teens to over 20 on most nights with APAP.
...
My question is, what pressure should she start out with? Her APAP pressure with a Resmed s9 autset never goes below 13 on a very rare, good night. Most of the time it is at the max of 20. Her ramp is set at 10 for a length of 10 min, then the min is 12.5. and the max is 20. Her 95% pressure is 19.5. She does not use the EPR

Later in the same thread, she wrote:

I have no idea yet what her prescribed pressures will be. To date, she does not have any central apnea, even with the high pressure of 20 all night, so I'm thinking central apnea should not be an issue.

With the responses from that thread, and the continuing belief that centrals were not the problem, I believe that College3girls set the VPAP Auto with min EPAP = 10 and max IPAP = 25.

In weeks worth of data, no consistency-what next? College3girls was finally able to post the first of the screen shots of her mom's SleepyHead data from the VPAP (those screen shots are no longer available, however.) College3girls was still very concerned about the direction the data was going and the doc's seeming lack of interest in looking at anything beyond compliance. She wrote:

he just started BIPAP. Am I not waiting long enough for her to settle in, or should I be adjusting settings? She had a couple of great nights when first starting, but now her AHI runs about 11, and sometimes more. I don't want to wait too long to make changes since it has taken a year to convince the sleep Dr her therapy hasn't been effective. The Sleep doc and insurance just look at compliance.

Pugsy's initial reaction to the posted data was that supine sleep and/or REM might explain the really bad clusters of machine-scored OAs on the bad nights and that the min EPAP was probably too low. In this thread I raised concerns about whether the nasty clusters might contain (a lot) of mis-scored events and that mom's breathing seemed to become more unstable rather than less once the IPAP > 21.

In the initial post on this thread, College3girls said:

I'm posting Jun 1-4 data for Mom (theresmp). When her AHI is good, it's great. When it's bad, it's bad. No middle ground. No consistency.
She can't tell is she is sleeping on her back. She's been using a blanket roll behind her thinking that would keep her from rolling supine, but the bed is so big (King), I'm not sure that is working.
Pugsy and Robysue, you have been commenting on this whole mess. Should I make changes to her settings, and if so, what should they be? I have my APAP all figured out for me, but I don't know enough about BIPAP to know where to start making changes. Pugsy had mentioned increasing the EPAP, I think

and posted several days of detailed data that indicated the median EPAP was running between 11.50 and 14.44. In my response I made a suggestion to cap the max IPAP at 21 since it seemed clear things got worse, not better once the IPAP was that high. On the min EPAP, I hemmed and hawed and was torn between saying: Don't increase EPAP at all and increase EPAP a bit. When I looked at that median EPAP data, and figured that a min EPAP = 13 might be a reasonable starting place for the EPAP since College3girls was reporting that snoring was still going on and the fact that anecdotally things seem to get worse when mom is back sleeping.

But in light of the things you've been contributing to this thread, it seems prudent to think that min EPAP = 13 may be too high.

Sludge wrote:Note to self:

• F&P Simplus full face mask promotes CO2 washout when mouth breathing because of design;
• Consider nasal restriction/obstruction responsible for obstructive apnea identification if nasal breathing; and
• Sure seems like people forgot what the A10 Rule was all about.

And what is the A10 Rule?

And how is it relevant?

robysue wrote:

Sludge wrote:Note to self:

• F&P Simplus full face mask promotes CO2 washout when mouth breathing because of design;
• Consider nasal restriction/obstruction responsible for obstructive apnea identification if nasal breathing; and
• Sure seems like people forgot what the A10 Rule was all about.

And what is the A10 Rule?

And how is it relevant?

A10 simply presumed all apneas that occurred at CPAP pressure > 10 cmH2O to be central and left them alone.

The A10 algorithm increases the APAP pressure, once the apnea is cleared, by an amount proportional to the apnea duration. The increment is limited such that the APAP pressure cannot exceed 10 cmH2O in response to apneas. However, it will be appreciated that the APAP pressure may exceed 10 cmH20 in response to other physiological events (for example, snore).

Sludge wrote: A10 simply presumed all apneas that occurred at CPAP pressure > 10 cmH2O to be central and left them alone.

The A10 algorithm increases the APAP pressure, once the apnea is cleared, by an amount proportional to the apnea duration. The increment is limited such that the APAP pressure cannot exceed 10 cmH2O in response to apneas. However, it will be appreciated that the APAP pressure may exceed 10 cmH20 in response to other physiological events (for example, snore).

That's a major part of the Resmed S8 AutoSet's auto algorithm as I recall. And presumably it (or something like it) was also a major part of the Respirionics M-Series auto algorithm?

Now for a different question entirely: How much science was there behind this assumption? I understand that a line had to be drawn somewhere to keep the machine from running off to its max setting if someone was experiencing huge clusters of what were real centrals.

Relatively speaking, just how common is it for (some) centrals to occur in a manual titration sleep study once the pressure gets to be on the high side of 10cm?

The RT reviewed Mom's sleepyhead data and agreed with Robysue and Sludge. CA's were being misread as OA's, and her pressures were way to high. He immediately called the sleep Dr and asked for a change in prescription. Both the IPAP and EPAP were lowered, to 17/10, the ps was left at 4, and the EPR(?) was lowered from Med to Low. He said this would allow the machine to be more responsive to Mom's breathing. He said her tidal volumes were more representative of a 6ft 250 lb guy, not a petite little lady of 5' 2".

To clarify, the original settings on the BIPAP of 25/10 were prescribed by the sleep Dr., basically wide open and the same failed philosophy that had been used with APAP. I didn't pick those numbers.

I did raise the EPAP to 13 based on earlier forum advice, and Mom's AHI did improve for some nights with the change, but problems were still obvious even with a good AHI, as analyzed by Robysue and Sludge.

I didn't waste time this round, and contacted the RT. Initially I was asking for his assistance in getting Mom's over-night sleep study report, but when I told him how high and how fast her pressures were shooting up, and how long they they stayed so high, he determined he needed to come out. Great Guy!

Mom is to report in to him Monday morning with how things go over the weekend at these lower settings. I'm much more confident that he will keep on top of things.

He also personally requested a copy of the over-night titration study, and will be sure we get a copy as soon as he gets a copy.

When I get the study, I will send it to you, Robysue.

robysue wrote:And presumably it (or something like it) was also a major part of the Respirionics M-Series auto algorithm?

Right, the ol' NRAH Algorithm:

http://www.healthcare.philips.com/main/ ... hlogic.wpd

robysue wrote:How much science was there behind this assumption?

I guess if I said "Everybody knew that!" , that would not qualify as "science".

I suppose the issue back then was that everybody didn't know that, and the numbers didn't start to come out until CompSAS started to become quantified.

robysue wrote:Relatively speaking, just how common is it for (some) centrals to occur in a manual titration sleep study once the pressure gets to be on the high side of 10cm?

"IMHO" it would be more practical to look at CompSAS tendencies rather than pick a CPAP number, and that's in the neighborhood of 15% (depending on who you talk to).

College3girls wrote:The RT reviewed Mom's sleepyhead data and agreed with Robysue and Sludge. CA's were being misread as OA's, and her pressures were way to high. He immediately called the sleep Dr and asked for a change in prescription. Both the IPAP and EPAP were lowered, to 17/10, the ps was left at 4, and the EPR(?) was lowered from Med to Low. He said this would allow the machine to be more responsive to Mom's breathing. He said her tidal volumes were more representative of a 6ft 250 lb guy, not a petite little lady of 5' 2".

In the Spirit of Hope and Crosby, we are now on The Road To Recovery.

College3girls wrote:Both the IPAP and EPAP were lowered, to 17/10...

BTW, is that a locked EPAP @ 10 cmH20?

Sludge wrote:

College3girls wrote:Both the IPAP and EPAP were lowered, to 17/10...

BTW, is that a locked EPAP @ 10 cmH20?

The full quote from College3girls is:

Both the IPAP and EPAP were lowered, to 17/10, the ps was left at 4, and the EPR(?) was lowered from Med to Low.

So it sounds like C3g's mom is still in auto mode with

• min EPAP = 10
  max IPAP = 17
  PS = 4

which should mean that the max EPAP is 13 since mom is using a VPAP Auto.

And a note to College3girls:
It's not an EPR setting that was lowered from Med to Low since the VPAP Auto doesn't have EPR. My guess is that the RT changed either the TRIGGER setting or the CYCLE setting from Medium to Low. Or perhaps the RT changed both the TRIGGER and CYCLE settings.

TRIGGER controls when the machine will transition from IPAP to EPAP. My understanding is that changing TRIGGER to Low should keep the machine from dropping to EPAP before your mom has finished inhaling.

CYCLE controls when the machine will transition from EPAP to IPAP. My understanding is that changing CYCLE to Low makes the machine more sensitive to the beginning of the inhalation---i.e. a smaller amount of air going into the lungs will trigger the change from EPAP to IPAP.

Overall, it sounds as if things may finally have a chance to turn around for your mom. Here's wishing her the best with the new lower settings.

Sludge wrote:

robysue wrote:And presumably it (or something like it) was also a major part of the Respirionics M-Series auto algorithm?

Right, the ol' NRAH Algorithm:

http://www.healthcare.philips.com/ma

Sounds like on the M-Series, Resprionics was trying to be a bit more flexible in its approach to cluster of apneas occurring at high(er) pressures. From the line you provide:

Philips wrote:Other algorithms limit the treatment of apnea events above a fixed pressure level, resulting in under-treated patients. The REMstar Auto actually identifies when patients do not respond to pressure increases triggered by apneas or hypopneas.

If a persistent string of these events is detected, the device activates the Non-Responsive Apnea/Hypopnea (NRAH) logic, which limits pressure increases to 3 cm H2O. If at this time the patient continues to have events, the REMstar Auto will lower the pressure by 2 cm H2O and hold pressure for an extended period to stabilize the airway. This pattern of increasing pressure, followed by subsequently decreasing pressure, allows the REMstar Auto to appropriately manage events that are non-responsive to increases in pressure.

Out of curiosity: How did this NRAH algorithm determine whether the patient was or was not responding? Was a "persistent string of these events" just a long cluster of As and Hs that didn't clear up with a pressure increase?

And if someone had clusters of events like College3girls's mom has been having, the M-Series Auto CPAP would not have zoomed up to the 19-20 cm?

Out of curiosity, was any of this NRAH algorithm incorporated into the newer Auto algorithm for the System Ones?

Sludge wrote:

robysue wrote:How much science was there behind this assumption?

I guess if I said "Everybody knew that!" , that would not qualify as "science".

I suppose the issue back then was that everybody didn't know that, and the numbers didn't start to come out until CompSAS started to become quantified.

So there was this gut instinct that it wasn't a good idea to just keep on raising the pressure higher and higher in response to apneas because some folks' AHIs never seemed to go down???

Why was 10cm chosen as the cutoff for the A10 rule?

robysue wrote:Relatively speaking, just how common is it for (some) centrals to occur in a manual titration sleep study once the pressure gets to be on the high side of 10cm?

"IMHO" it would be more practical to look at CompSAS tendencies rather than pick a CPAP number, and that's in the neighborhood of 15% (depending on who you talk to).

So the new conventional wisdom is that about 15% of PAPers will have CompSAS tendencies, and these tendencies are worse at high pressures?

But unfortunately, the FOT algorithm may also be less accurate at high pressures. And I assume that the PR Pressure Pulse algorithm for deciding whether a particular apnea is an OA or a CA has its own issues with accuracy, particularly at high pressures?

And so if you are in that unlucky 15% of PAPers with CompSAS tendencies, then it's a probably a bad idea to run your machine in Auto mode with the max pressure up at 20 (or above with a bi-level)?

robysue wrote:And a note to College3girls:
It's not an EPR setting that was lowered from Med to Low since the VPAP Auto doesn't have EPR. My guess is that the RT changed either the TRIGGER setting or the CYCLE setting from Medium to Low. Or perhaps the RT changed both the TRIGGER and CYCLE settings.

TRIGGER controls when the machine will transition from IPAP to EPAP. My understanding is that changing TRIGGER to Low should keep the machine from dropping to EPAP before your mom has finished inhaling.

I believe that is backwards:

Trigger (Very Low / Low / Med / High / Very High)

Sets the level of inspiratory flow above which the device changes from EPAP to IPAP.

IOWs, how easy it is to "trigger" the machine to give a breath.

And indeed, this alone should make a significant difference in the AHI number, because, upon closer review, many "obstuctive apneas" may have been scored because the machine was insensitive to inspiratory effort (note presence of flow without reaction of machine):

Sludge wrote:

robysue wrote:And a note to College3girls:
It's not an EPR setting that was lowered from Med to Low since the VPAP Auto doesn't have EPR. My guess is that the RT changed either the TRIGGER setting or the CYCLE setting from Medium to Low. Or perhaps the RT changed both the TRIGGER and CYCLE settings.

TRIGGER controls when the machine will transition from IPAP to EPAP. My understanding is that changing TRIGGER to Low should keep the machine from dropping to EPAP before your mom has finished inhaling.

I believe that is backwards:

Trigger (Very Low / Low / Med / High / Very High)

Sets the level of inspiratory flow above which the device changes from EPAP to IPAP.

IOWs, how easy it is to "trigger" the machine to give a breath.

in pictures:
http://www.resmed.com/ap/products/s9_vp ... nc=dealers

Sludge wrote:

robysue wrote:And a note to College3girls:
It's not an EPR setting that was lowered from Med to Low since the VPAP Auto doesn't have EPR. My guess is that the RT changed either the TRIGGER setting or the CYCLE setting from Medium to Low. Or perhaps the RT changed both the TRIGGER and CYCLE settings.

TRIGGER controls when the machine will transition from IPAP to EPAP. My understanding is that changing TRIGGER to Low should keep the machine from dropping to EPAP before your mom has finished inhaling.

I believe that is backwards:

Trigger (Very Low / Low / Med / High / Very High)

Sets the level of inspiratory flow above which the device changes from EPAP to IPAP.

IOWs, how easy it is to "trigger" the machine to give a breath.

My bad.

And re-reading what I wrote, I'm not at all sure if I was wrong because I simply mistated what I meant to say---i.e. I meant to say these things affected how easy it is to "trigger" the machine to change from EPAP to IPAP (or vice versa)--OR if I simply misunderstood what I read.

In either case, however, I did write something that's way off base and thanks for correcting me.

And indeed, this alone should make a significant difference in the AHI number, because, upon closer review, many "obstuctive apneas" may have been scored because the machine was insensitive to inspiratory effort (note presence of flow without reaction of machine):

This is fascinating!

Unfortunately the new settings are not effective in controlling the AHI. All 3 nights at the lowered settings netted an AHI over 25. Mom will call the RT first thing in the morning as he instructed.

I haven't seen her data for these last 3 nights. I will try to be at her house when the RT next visits. He has been relying on what I'm able to show him, thanks to sleephead.

If VPAP doesn't work, what is the next step, if there is one?

I know not having the last 3 nights data with the AHI so high may mean no one can suggest what to do next, but Robysue, Sludge, Pugsy, let me know what you think we should do next.

I haven't forgotten about getting the sleep data from the titration study. I'm confident the RT will get that and it's just a matter of time.

College3girls wrote:Unfortunately the new settings are not effective in controlling the AHI. All 3 nights at the lowered settings netted an AHI over 25. Mom will call the RT first thing in the morning as he instructed.

I hope the RT wants to take a good hard look at some of the detailed data, including some close ups of the worst clusters of events for the last three nights.

I haven't seen her data for these last 3 nights. I will try to be at her house when the RT next visits. He has been relying on what I'm able to show him, thanks to sleephead.

If you need to be there to let him see just what the wave flow pattern looks like close up, I think you should be there.

If VPAP doesn't work, what is the next step, if there is one?

It really depends on what the detailed data shows. If the detailed data is continuing to show long clusters of things that look like they're miscored apneas, the next immediate step the RT may recommend is to lower the pressure some more.

It may not be financially possible, but it may be that what your mom needs is an in-lab diagnostic test to actually figure out whether she has OSA or CSA or a combination of both. Or neither. And presumably a follow up in lab titration study to determine the right ball park for the settings on the right kind of machine.

If your mom's problems really are with central events (mis-scored as OAs by the VPAP), then the next question has to be: Is there a strong central component to the untreated apnea? I know your mom had a home sleep study. Can you find out which company made the devices used in that study and what kinds of data were actually gathered on that study? In particular, an important relevant question is: How were the apneas determined to be obstructive in nature instead of central?

If the method for testing whether a particular event was an OA or a CA is questionable, then the whole home sleep study's data may be suspect.

If the original issue really is central sleep apnea OR if your mom's ongoing problems are CompSA, then machine of choice may be an ASV. But clearly whoever is doing the titrating needs to know how to do it. And a whole lot of attention will need to be paid to making sure the pressure settings on an ASV are helping rather than creating more problems.

I know not having the last 3 nights data with the AHI so high may mean no one can suggest what to do next, but Robysue, Sludge, Pugsy, let me know what you think we should do next.

As frustrating as it is, I think the first thing you have to do is talk to the RT. And maybe ask if the RT knows a better sleep doc than the one who let your mom keep using the APAP wide open for 9 months without really following up on the too high AHI numbers.

So see what the RT has to say. Consider it carefully before you do any more dial winging on your own. Personally, if it were me, I would not be willing to follow any advice to increase the pressure back up without a solid explanation of how the data indicates the problem is NOT caused by mis-scored centrals. But if the RT says lower the pressure some more, I'd follow that advice immediately.