Central sleep apnea periodic breathing

[vsheline]

But does pressure support affect exhale pressure or also inhale pressure? One sets an IPAP and an EPAP, correct? The difference is the PS, am I right?

But does the PS increase the inhale pressure because I had another exchange with vsheline or someone else about it and did not quite understand. I want to understand it first with non-variable pressure support in contrast to Auto bilevel for the time being.

If a bilevel therapy mode has settings for EPAP and IPAP it will not also have a separate setting for Pressure Support, but one can speak of the difference between EPAP and IPAP as being the amount of Pressure Support being used.

If a bilevel therapy mode has settings for EPAP and PS it will not also have a separate setting for IPAP, because IPAP will be a function of EPAP and PS. Changes in PS will change the pressure used during inhalation (the IPAP in the formula IPAP = EPAP + PS). Changes in PS will not change the pressure used during exhalation, EPAP in the formula. Changes in EPAP will change both EPAP and IPAP, so as not to change PS.

In the AirCurve 10 VAuto, the self-adjusting VAuto mode has settings for Min EPAP and Max IPAP and PS and it is the EPAP which self-adjusts. PS stays the same all night, meaning as EPAP self-adjusts higher or lower the IPAP will change higher or lower in step with EPAP, so that the difference between EPAP and IPAP remains unchanged.

[tedburnsIII]

vsheline-

Okay, thanks, but I am getting a bit 'dizzy'

I've noticed that you list your CPAP pressure with no reference to IPAP, only one to EPAP. So, it appears to me that EPAP is more important setting for you with your particular machine's mode, and that you have it fixed at 15cm, and that IPAP is variable, dependent upon what machine chooses at a given moment as its PS, if in Auto mode, and it's somewhere between 4-10cm PS?

And because EPAP is always less than IPAP, the IPAP pressure will vary at any moment, but not the EPAP? Sorry if I may have made the same or similar inquiry before.



Cheers,

Later: Every time I read your post directly above mine it is starting to make more sense. You are clearly distinguishing modes and settings on various bilevel machines- seems there's a lot to 'play with', dependent upon machine.

Thank you.

[Sleeprider]

Ted, glad to see you getting good help on understanding these more complicated machines and their functions. This is why I took exception to your simplistic understanding of titration and suggested that in time you'd come to a fuller understanding.

I also use an auto BiPAP which uses a minimum EPAP and variable pressure support. I have a maximum IPAP of 18, but it really does not ever come into play. Something Vsheline touched on earlier is that there is a difference in how Resmed and Respironics deals with auto bilevel. The Resmed uses a constant PS, while the Respironics unit can use both a variable EPAP and variable PS.

In the AirCurve 10 VAuto, the self-adjusting VAuto mode has settings for Min EPAP and Max IPAP and PS and it is the EPAP which self-adjusts. PS stays the same all night, meaning as EPAP self-adjusts higher or lower the IPAP will change higher or lower in step with EPAP, so that the difference between EPAP and IPAP remains unchanged.

So the Respironics can have the EPAP adjust upwards within a range, so in auto BiPAP mode, the Minimum EPAP, Min PS, Max PS and Max IPAP are all able to be set. The pressure support is variable, so it can vary from the minimum to the maximum as needed. With this machine EPAP and IPAP can both move at different rates.

Someone once explained the difference with an analogy to dancers. With Resmed the dancers are always the same distance apart, while with Respironics the dancers can move closer and farther away all within the bounds set by EPAP and IPAP.

There is also fixed BiPAP which is the CPAP of bilevel. It has a single EPAP and IPAP which do not change. Most Auto Bilevels can do CPAP and fixed Bilevel modes.

[vsheline]

I've noticed that you list your CPAP pressure with no reference to IPAP, only one to EPAP.

Well, saying EPAP=15 and PS is 4 to 10 is just a different way of saying EPAP=15 and IPAP is 19 to 25. They mean the same thing. Like 6 or half a dozen mean the same thing.

So, it appears to me that EPAP is more important setting for you with your particular machine's mode, and that you have it fixed at 15cm, and that IPAP is variable, dependent upon what machine chooses at a given moment as its PS, if in Auto mode, and it's somewhere between 4-10cm PS?

And because EPAP is always less than IPAP, the IPAP pressure will vary at any moment, but not the EPAP?

Yes, that is how the machine behaves. Actually, I consider the quickly self-adjusting Pressure Support the most important feature of my machine; it is what makes it an ASV machine. The EPAP setting should be high enough to eliminate obstructive hypopneas and apneas. The Min Pressure Support should be high enough to eliminate Flow Limitation, and Max Pressure Support should be high enough to allow the machine to do for me all the work of breathing when I can't. But that can add up to a lot of pressure (25 cmH2O in my machine, up to 30 in others), and sometimes high pressure can cause problems in addition to leaks. Problems like an excessive amount of central events, or aerophagia (excessive air swallowing), or pressure on inner ear causing tinnitus or vertigo or loss of hearing, or can worsen eye pressure, or if the lungs are damaged in an accident or are diseased and develop a hole pressure can dangerously worsen pneumothorax (air buildup inside the chest cavity). Sometimes best to use as little pressure as needed.

[swwalden1]

I hope to get some insights into this next week during my follow up Dr. visit.

Steve

Met with my sleep doc (Pulmonologist/Internist) yesterday. He said this breathing pattern is not Cheyne-Stokes. He said they see it all the time in the sleep lab when they "over titrate" a patient. He was very clear that he thinks the the VPAP machine is causing this breathing pattern.

He sent me home to try lower max pressures and less pressure support--which, as you know, is consistent with a lot of the advice given on this board.

I hesitate to even mention this because 1) it's only one night of data and 2) I have a lot of night-to-night variation.

Having said that, I switched to CPAP mode, 10 cmH2O with EPR of 1 and my reported events were 7 OAs, 12 CAs, 12Hs over almost 7 hours of usage. Not great, but OK, and only one episodes of two back-to-back CAs.

Steve

Please keep us updated -- your question about CA events is of high interest to me.

I've been on an APAP for 3 weeks, and my results are erratic, with occasional AHIs under 5 but most in the 7-9 range. Pressure 7-11 and recently 8-13. In every case the vast majority of my AHIs are CA events. I've tried nasal masks (which seem to work the best when lip leaks/mouth droops are relatively few), nasal pillows (not terrible, but also lip leak/mouth droop issues) and full face mask (no leaks, but poorest numbers, oddly). I've wondered about the relationship of CAs to pressure and mask type -- so far not enough samples to come to any conclusions.

Good luck to you,
Andy

I now have 5-nights of data and the periodic breathing central apneas seen to be abating. Here's the data from the last 5-nights.


Index
OA CA H OA+H AHI
2.01 3.01 0.14 2.15 5.17
1.03 1.77 1.77 1.58 4.58
0.14 1.71 1.56 1.50 3.41
1.38 3.59 3.32 1.57 8.29
0.90 3.17 1.51 1.58 5.58
0.47 1.09 0.47 1.62 2.02

While night 3 was not great about 1/3 of the centrals occurred during the last 15 minutes of sleep when I was dosing off and on. Other CA occur when I rollover or are the result of restless leg movements.

Steve

[Sleeprider]

It's not uncommon to experience CA during sleep transition, and along with your declining OA and H events suggests you are adapting to your current therapy. It beats the alternative! If you can regularly keep OA+H below 3, as you have done here, and keep CA to reasonable levels or mainly as sleep transition events, then you're doing fine.

[tedburnsIII]

I've noticed that you list your CPAP pressure with no reference to IPAP, only one to EPAP.

Well, saying EPAP=15 and PS is 4 to 10 is just a different way of saying EPAP=15 and IPAP is 19 to 25. They mean the same thing. Like 6 or half a dozen mean the same thing.

So, it appears to me that EPAP is more important setting for you with your particular machine's mode, and that you have it fixed at 15cm, and that IPAP is variable, dependent upon what machine chooses at a given moment as its PS, if in Auto mode, and it's somewhere between 4-10cm PS?

And because EPAP is always less than IPAP, the IPAP pressure will vary at any moment, but not the EPAP?

Yes, that is how the machine behaves. Actually, I consider the quickly self-adjusting Pressure Support the most important feature of my machine; it is what manes it an ASV machine. The EPAP setting should be high enough to eliminate obstructive hypopneas and apneas. The Min Pressure Support should be high enough to eliminate Flow Limitation, and Max Pressure Support should be high enough to allow the machine to do for me all the work of breathing when I can't. But that can add up to a lot of pressure (25 cmH2O in my machine, up to 30 in others), and sometimes high pressure can cause problems in addition to leaks. Problems like an excessive amount of central events, or aerophagia (excessive air swallowing), or pressure on inner ear causing tinnitus or vertigo or loss of hearing, or can worsen eye pressure, or if the lungs are damaged in an accident or are diseased and develop a hole pressure can dangerously worsen pneumothorax (air buildup inside the chest cavity). Sometimes best to use as little pressure as needed.

Mostly understood.

But portion in bold, italics, above- not sure that I understand it. I thought it would be IPAP that lessens events, unless you come to your EPAP pressure and use THAT as baseline to control events, knowing that that pressure + a minimum of 4 PS (which equals IPAP) will be therapeutic and also make machine breathe for you, if necessary.

Underlined area, above- a concern of mine. Most mornings if I am 'lucky' and all goes well, I sometimes feel the way I did after the titration following day- felt as if I were in my 20s/30s- remarkable (BMI presently ~31).

I do have a somewhat large bullae on my lung (unchanged according to second CT), but was told by pulmonologist not to worry about his suggested increase in pressure. He also was curious as why I had been prescribed auto, commenting that CPAP would have been prescribed by him.

I saw him because SOB while walking dog at cardio-prescribed pressure of 6-15cm. For once, emergency inhaler quickly remedied that, but was concerned.

My optimum titrated pressure had been 12cm, due to low sats, though RDI was <5.0 as low as 7cm.

So, 7cm would work to clear most events (and it did), but 12cm as titrated would not only result in 0.0 RDI but minimum Sa02 of 90% according to Guidelines.

In any event, he spent a couple of minutes with me, looked at titration table, recommended increase to 9-15cm, due to REM showing at 9 but did not comment nor was asked about the sats at 9, because at that time I did not know 'diddly' about it.

I prefer CPAP to APAP for various reasons.

But in light of your post I am a bit concerned about the effect on my lungs in light of the bullae there. One doctor said, without reference to any discussion of xPAP, that I may be subject to pneumothorax at some time and it would have to be addressed immediately and to call 911.

Titration chart to follow:





BOARD-CERTIFIED SLEEP SPECIALIST DOCTOR REPORT ON STUDY:

[Sleeprider]

Ted, this is where your chart is going to let your down. Please read the titration protocol guidelines for Respironics (same protocol applies for other brands) http://www.sleepdx.respironics.com/PDF/T...otocol.pdf. The CPAP protocol is on page 7 and starts titration at 4.0 cm and increases in 1.0 cm increments to eliminate, OA, partial OA and H. If a pressure of 15 cm is reached, the titration protocol switches to BiPAP. If excessive centrals are induced, pressure is decreased or titration proceeds with BiPAP AutoSV advanced (ASV).

The BiPAP S protocol is on page 10. For BiPAP, the EPAP is started at 4.0 and pressure support (4.0) is added to increased to make IPAP 8.0. EPAP is then increased to eliminate OA, while PS of +4 is maintained. For residual H and RERA, IPAP (PS) is increased.

The BiPAP Auto protocol is on Page 12 and specifically discusses PS rather than individual EPAP/IPAP settings. The real take-away here is that both BiPAP S and BiPAP auto are really for CPAP patients that do not have a significant central apnea component, and EPAP is used to control OA, while PS is added to control RERA and improve ventilation.

The BiPAP Auto SV is on page 14. This is similar to the BiPAP Auto for controlling OA, but CA is controlled by very high IPAP pressures and respiratory timing to induce adaptive ventilation when the patient does not initiate a breath.

The CPAP protocol you're posting is fine for CPAP, but does not proceed through the other potential sleep disordered breathing problems that are commonly encountered. Once respiratory events are resolved, the titration ends, and in the case of your protocol, it ended with CPAP. This is fine for a significant percentage of patients with sleep disordered breathing that do not require high pressure to resolve, or that have other complications. For those that cannot be titrated with CPAP alone, other protocols continue the process.

[richb]

I met with a sleep tech today to discuss modifications to my machine settings to reduce or eliminate my CAs which gave me an AHI of 38 last night. We are suggesting to the Doc that he allow 1 cm decreases in pressure per day or 2. The results would be checked daily to see the effect. Doc has suggested re-titration with a focus on CAs and periodic breathing but a date will not be available for a month.

[tedburnsIII]

... Doc has suggested re-titration with a focus on CAs and periodic breathing but a date will not be available for a month.

Is that all your doc said? If so, I am beginning to wonder if doc is a board-certified sleep doctor. You've never answered that question as I can recall.

Also, you may be able to do your titration earlier than a month, due to late cancellations. Perhaps you might inquire about it.

You are in a predicament, though, where a successful resolution is most likely. But it seems it's a PITA what you are going through...

Please continue to keep us posted as to developments in this interesting case.