Rapid Breathing-Fractured Sleep-Out of Breath

[Fixit50]

SingleH- 
Thanks for all of this information!  It was good of you to take the time to provide these details.

I can see that I’ll need to do some learning to get the most out of the VAuto.  Sleeprider has given me a starting point on the settings, and I’ve told the DME that I plan to self-titrate. 
 
One thing I’m a little confused about is you mentioned that a high EPAP is sometimes needed to clear apneas.  I had always thought that apneas only occurred on inspiration and never on expiration.  Therefore, I reasoned it was IPAP that cleared apneas and that EPAP or expiratory pressure, was just something the machines made you deal with owing to constraints in their design.  Ideally, I figured that you would exhale into atmospheric pressure and have pressure to overcome apneas on inspiration.  I can imagine that high pressure support may involve pressure changes that users may find unnerving, but apneas are a separate issue from that.  Anyway, it’s a little confusing to think higher EPAP may be better in preventing apneas, but perhaps I have a fundamental misunderstanding on the origin of apneas. 
 
You wrote:  “Interesting comments about your recoveries. I dont know too much about this, but I notice that before the event you have a more linear graph and after, it looks a more erratic with higher peaks and lower lows. Does your waveform eventually return to looking like it did before, as per the red box on the left or does it just continue on in a slightly more erratic fashion.”  That one was taken with the chin strap on and it’s different than what normally happens without the chin strap.  Without the chin strap, these recoveries happen at the end of the rapid (tachypnea) and irregular breathing, a good example being the first screen shot in post #1. I don’t normally see them at other times without the chinstrap.  In the example you refer to, the chin strap was on, and its more often that the left side appears more erratic or variable than the right side rather than the opposite which is seen in that example.  About 20-minutes after the recovery in that example, I woke up and for that time to the right of the recovery the breathing did not change appreciably. 
 
You wrote:  “I have seen these "events" in my Dads data, with a corresponding peak in tidal volume and minute vent.”  If you have the opportunity to capture a screen shot of one of these recovery “events” I would like to see that to compare against my own. 
 
You wrote:  “The other aspect in relation to CO2 that might be worth checking is your I:E ratio. Does your machine report I:E ratio? Im not sure about the specifics of your model, but as its similar to the Aircurve I believe this should be displayed in the sleep report icon. If not you may need to enable the essentials plus setting to get the i:e ratio. If it is available what is your ratio typically?”  My machine doesn’t report the ratio directly.  It does report “Insp. Time” and “Exp. Time.”  Using these numbers, I:E lands in the range of 1:0.9 to 1:1.1.  I gather this is quite low compared to the 1:2 considered normal in the article you referenced.  I wonder if the VAuto might correct this? 
 

[SingleH]

Many thanks for the kind word Sleeprider,

Much of the progress I have made, has been down to your guidance on this forum!

Happy new year to you!

[SingleH]

Happy New year Fixit50.

You are not alone in your misunderstanding of how apneas work as I had exactly the same understanding until spending time on this forum. I dont think manufacturers or general CPAP literature actually makes this point clear. When initially setting up the Bilevel I was spending most of my time focused on IPAP, and getting poor AHI results, only to more recently realise its the EPAP I need to get control of to get those figures down. i'm not in a position to give you word perfect description of how it works, but I beleive the basic premise is that apneas happen due to an insufficient pressure during expiratiion and you will need a certain level of pressure to clear them.
In my Dads case he is fine with a minimum EPAP of 5 and sleeps fine with that, but when apneas start the machine adjusts itself and typically climbs to an EPAP of 13-15 at which point the apneas clear. The Aircurve steps up 1 level of pressure with each apnea until they go away, and then it drops the EPAP back down to your minimum setting for comfort and optimum ventilation. In Oscar you will see the machine responding as appropriate. Initially when I had not grasped the EPAP importance I had a low max IPAP pressure of 17 and a Pressure support of 6 or higher to clear flow limitations, 17 minus 6 meant the highest EPAP it could reach was 11, which was not high enough to clear his Apneas so he would get load of events, but I didnt know why as I thought IPAP cleared events and PS treated flow limitation.

I'm still learning about I:E but yes 1:2 is normal, but I believe normal ranges on here are around 1:1 to 1:3. The Aircurve will definitely give you the tools to adjust this. Timin, Timax, Trigger sensitivity and Cycle sensitivity will all impact this value and PS somehow seems to also affect this.

This is my basic interpretations of what settings address what problems.
PS - pressure support deals with flow limitations and seems to improve the waveforms as you increase it. (There also seems to be some relationship to respiration rate at least observed in my dad) - In some people increasing PS can result in a increase in central apneas, so you have to be vigilant if that happens to you.
EPAP is responsible for clearing Apneas - if you need to allow the machine a wide range of EPAP for clearing apneas, remember to set a high max IPAP.
IPAP is providing pressure to assist in breathing 
Timin sets a minimum inspiration period ( you can increase and decrease accordingly) will affect your I:E
Timax sets a maximum potential inspiration period (as above you can adjust) will affect your I:E. This does not enforce the inspiration duration, just the potential maximum duration.
Trigger and Cycle sensitivity, these define's how sensitive your machine is to you changing from inhalation to exhalation. Be aware if you have erratic breathing and you have sensitivity set to high, the machine may detect your breathing pattern erroneously. 
Essentials plus - enable this setting in the Aircurve to get the most data in the sleep report on the device. This will give you your i:E ratio, it also has some other interesting features, like you can see some of the above figures above in real time. You need to go into sleep report while the machine is in use and you can turn the dial to scroll through a few pages of the live values. I think its more for a clinician to observe when the machine is in use, so a bit difficult if you are doing this on your own. There is also an arrow symbol which I have not found literature on anywhere, but it seems to flag when your breathing is exceeding some of your values. Again not much use unless you have someone to watch it while you are sleeping.

This document is very helpful to understand some of the features in greater detail. i refer to it very often.


https://document.resmed.com/en-us/docume...er_eng.pdf


Here are some screenshorts, in most cases they have the same peak in resp rate, tidal volume and minute vent. My only theory was that they were either a "failed apnea" or a disturbance caused by the erratic breathing and the machine applying pressure incorrectly during a breath. This is there trigger and cycle settings come in. As you can see you have a mask pressure graph on the Aircurve and it shows you when it is applying EPAP and IPAP. 

           

[Sleeprider]

FixIt, do some reading in the Resmed Clinical Titration Guide https://document.resmed.com/en-us/docume...er_eng.pdf You will see how the settings are designed to work on all types of machines. In bilevel titration, obstructive events are addressed by increasing EPAP, while hypopnea, flow limits, snores and other restrictive inspiratory events are treated with increases in IPAP or PS. Note an IPAP increase without EPAP increase is the same as an increase in PS. Nearly all obstructive apnea initiate during transition from expiration to inspiration as negative pressure in the airway rapidly rises from inspiratory effort. This "vacuum" will collapse an airway with inadequate positive pressure stent. Observing mask pressure during an OA, the pressure never rises from EPAP unless the user is on ASV or ST-A. So, there is no way for rising pressure to break apnea. Auto machine respond to OA by raising pressure which raises EPAP where bilevel pressure is used. There is a lot of useful information on what the different devices intend to treat and how they work, so definitely worth your time.

[Fixit50]

Happy New Year SingleH and thanks for the explanation!  I looked at my Oscar data during an OA.  I can see based on the mask pressure, that the machine is clearly fixed at EPAP during the OA, so as you said, that is the pressure that must break the apnea.  This does place a limit on how much pressure support can be used before OAs become a problem, and I gather that is a limitation. 
 
Thanks also for attaching the screen shots.  I agree your dad’s breathing on the VAuto looks similar to mine using the chin strap.  The recoveries seen are also curiously similar, however mine are higher going as high as 30 L/min without the chins strap.  Ours are more comparable in magnitude when I’m using the chin strap which probably explains why I feel better using it.
 
Thanks for the link to the Sleep Lab Titration Guide.  I will read this over carefully. 
 
On the subject of I:E ratio I noticed another member DeborahK, experienced a marked increase in her I:E ratio from 1.27 to 1.82 after transitioning from APAP to BiPAP.  See post #86 here.  There is also another thread that deals with the subject of Rapid breathing on BiBaP.  I learned from that thread which you might also find helpful.  Unfortunately, it seems the BiPaP did not solve that member’s problem.

[Fixit50]

Happy New Year Sleeprider!  Thanks for these explanations and yes, I’ll read that document carefully. 
 
In looking at the mask pressure, I was able to see that the transition to IPAP from EPAP did not occur until just after the beginning of inspiration at the end of the apnea.  I gather the VAuto machine is designed to work that way also.  I wonder if I really need an ST-A owing to my rapid breathing situation?  Perhaps that would permit increased PS to tackle the flow limits that seem to be tied to the irregular breathing at least in my case.

[Sleeprider]

The ST-A is a ventilator and has many different modes that are not available on the Vauto. The titration guide discusses how iVAPS, PAC (Pressure Assist Control) and ST all work. I would not jump into the ST-A unless the Vauto really doesn't work. With the Vauto we have the ability to extend inspiration time and manipulate respiration in a number of ways, however the ST-A is really intended for individuals that cannot maintain spontaneous rate and volume. You're looking at a price 2 to 3 times a Vauto for ST-A and a significantly higher level of complexity. I have mentioned before, the random tachypenea issues you experience are not common, and I'm not sure any of the modes of either the Vauto or ST-A are designed to address spontaneous tachypenea. I think the use of pressure support with extended minimum time of inspiration (TiMin) as available on the Vauto, may provide some relief as described in this article. https://journal.chestnet.org/article/S00...X/fulltext

The ST-A PAC mode is capable of actually enforcing a minimum time of inspiration and not respond to spontaneous cycling, but this would be a very intrusive form of ventilation that does not allow for any spontaneous breathing, and would likely be very uncomfortable. I am aware on only one individual on Apnea Board using PCM and if you read her thread, you will see she had very complex and severe neurological and neuromuscular issues. https://www.apneaboard.com/forums/Thread...ntrol-Mode You will also see, most of us are pretty clueless on how to advise on the use of this level of ventilatory intervention. I don't think, and I hope you're not in need of such intrusive ventilation.

I tried a quick search to see how tachypenea is mitigated with positive air pressure, and this was probably the most useful article I found. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6175789/ As you can see, the subject has very little documentation and research associated with it, and even fewer solutions, but the approach was to use spontaneous timed (ST) pressure support to stabilize the phasic tachypenea patients, however results are not reported. Personally, I think ST with a square wave pressure deliver is too uncomfortable, and I would fall back to Vauto or VPAP S. I That's my best shot while watching football late on New Year's Day.

[Fixit50]

Thanks for the reply and continued interest.
Looks like I may actually receive my AirCurve 10 VAuto!  Not without some arguing on my part with the DME.  After making clear multiple times what machine was prescribed and what I wanted, I received two calls today from the DME advising me that they were all ready to send out my new AirSense 11 CPAP (oh boy).  I had to straighten that out and ask from where they determined that would fulfil my order.  Then I got a deer in the headlights gaze.  After some discussion where the agent pretty much sounded like they didn’t know anything about this, I got their agreement they would need to go back to insurance for the correct approval.  Okay, I guess mistakes can happen.  I went to another contact at the DME who is a little more on the ball, and she agreed to stay on top of this and make sure it gets done right.  About an hour later I got another call from a different agent saying they got the approval, and are ready to send out the machine.  Great!  She went through benefits, costs and other details when I asked her to confirm what machine she was to send out.  To my shock, awe, and consternation she said a brand new AirSense 11 series.  It was all I could do to maintain any composure.  Having done a pretty good job of taming my frustrations, I explained that this is the second time today they have gotten it all wrong and I was about to take my business elsewhere.  That had more of a positive effect that any past actions on my part to nurture this think along.  Immediately she corrected herself and said I’d be getting an AirCurve 10 VAuto.  I confirmed it was to be a factory fresh unit and that if I received anything else I would promptly return it.  Anyway, I think it might actually happen; we’ll see. 

Back to more fun stuff.  My home-made chin strap is loosening up so I tightened it two nights ago so as to keep my jaw more tightly closed.  This actually made even a further improvement in my waveform, although I’ve never seen any tachypnea using even a slightly loose chin strap.  The largest recovery was just under a peak of 15L/min on minute ventilation which a little less than half of what I see with no chin strap.  I haven’t woken up out of breath at all using the chinstrap for several weeks now.  I can post some additional screenshots if there is any interest.  I’ve been sleeping pretty well with the chin strap and feeling good also.  

The only thing that seems a little alarming is the I:E ratio is still close to 1.0 although when I calculate it, based on the breathing waveform, I get numbers in the range of 1.2 to 1.5 depending upon I think, how many flow limits there are.  Not sure how meaningful those numbers are or why the disparity between the ratio based on the waveform, and the ratio based on the times seen in the Oscar Statistics field.  

While nobody yet knows the root cause of my tachypnea with irregular breathing, it is certain that it is abated with the chin strap, or actually anything that keeps the mouth closed.  What I believe this does is keep the airway a little more patent thereby reducing flow limits.  Since a bipap is designed to decrease flow limits, I’m hoping this means it will also solve my tachypnea.  I guess I’ll have to wait and see on that. 

I know there aren’t many people here or anywhere that have what I have but,… has anyone who does share my tachypnea, achieved improvement by using a chinstrap or other device (mouth guard, cervical collar) to keep the jaw in place?  If so, I’d like to know more about their experience or if they tried it and it didn't help.

[Sleeprider]

FixIt, pretty good work keeping the DME on track. Amazing how hard it is for them to follow a prescription. I think most of your tachypenea will resolve with adequate pressure support to shorten inspiration time and improve inspiratory efficiency. No promises, but it may keep you from getting into the shallow, rapid and inefficient breathing pattern. We just don't know how sleep phase will affect things. One of the things I have learned about PAP therapy is that everyone is an individual, and predicting outcome without the trial is futile. All the best!

[Fixit50]

Thanks.  I wouldn’t disagree with any of that!  We can only hope for success with the VAuto.  Worst case, I may need to acclimate to the chin strap, though I’d rather let the machine do it for me!  I’ve got some reading and learning to do before the machine comes in.  
May need some help getting the settings optimized!  
Thanks for the help!