CPAP Problems for People with Large Lung Capacity?

[AquaMan]

Hi All:

Fellow Meditators, Divers, Martial Artists... or just large/barrel chested folk who have beyond normal lung capacity, what are some problems you have with your CPAP machine you think are linked directly to your 95th-99th percentile, perfectly natural and normal ... 

abnormality?


I for one am encountering at least these issues:

1.  Registration of CSA or CA events, when I am awake, because my breathing is slower than "expected" from a normal little lung person, the algorithm was written for.  Yes, my waking life is a meditation.     This happens prior to falling asleep. whenever I have wakeful periods during the night, and in the morning while I lay there trying to decide whether to try to go back to sleep or get up.  The problem is these add to my AHI score... (it's another matter whether this umbrella AHI should be the focus when my CPAP machine cannot technically treat, prevent, or reduce CSA events).

Just to put things into perspective, things for me are moderate... average AHI is 5.62 but CSA is 3.6 (artificially high)

2.  Registration of false positive leak rate, again while awake, because my breathing is slower than "expected" from a normal little lung person, the algorithm was written for.  At the end of my long expirations the machine is registering a leak... when in fact there is no change in my position or mouth breathing or anything of the sort...  the machine is likely calculating a leak because it is confused about the resistance it is encountering.. "what? this small lunged person cant still be breathing out...error error"

3.  The biggest issue for me is ... drum roll... the machine actively fighting me to take smaller breaths.  There is an undeniably strong change in pressure and or flow functionality prior to the end of each exhale and each inhale.  The machine changes from operating in a way I would characterize as in synch with me or assistive with me (as it is when I choose to abnormally breathe with shallow little lung breaths) to fighting me ... and sometimes "pulsing" at me, near the end of my inhale or exhale and sometimes as early as halfway through my current in or out breathing process.

As a test, once awake, I held my breath to set a marker in the data for my own inspection later... after which I took nice long breaths natural to me ... and the machine fought me tooth and nail...

"error error....you are a little lung person... you cannot breathe like that... you will take shallow breaths like the others...  resistance is futile...."

Thoughts? Stories? Solutions? Complaints?  Rants?

Any feedback would be appreciated!

(PS: No offense to you little lung people... you are the majority.. and you are "normal" even if freakishly small winded...    )

[AquaMan]

OK I'm from a generation which pretends to be tough and laugh a little bit at adversity.... so didn't let on how desperate I am to figure this out, and how much this is really bothering me.  

Can anyone help me?  ANY speculation or bits of knowledge about this large lung capacity problem!


PLEASE ANYONE HELP ME!



BTW Here is the trace of my test:  breathing then held my breath (OSA events ...) , then took nice long breaths... (false CSA events, false leakage... weird pressure and flow caused by the machine).

     

[Sleeprider]

I have an above normal lung capacity but normal respiration rate. In recent years my tidal volume has dropped out of the 700s to upper 500 to mid 600 range. But it seems as I get older I’m taking shallower more frequent breaths. I’m able to satisfy my tidal volume needs faster using bilevel pressure support and a high trigger sensitivity. This shortens inspiration time and results in a more normal breath rate. I can’t promise that is a solution for you, but my CA event rate has become very low.

It’s worth repeating that events recorded by your machine while you’re awake are not SDB events. It might help to see an Oscar chart including flow rate, events, tidal volume, insp time, minute vent.

[AquaMan]

Thank you Sleeprider!

BTW1:  I have an AirSense 10 Autoset... (I should update my profile...) so not just a straight CPAP, and I have EPR on.

BTW2: I don't think I have a breathing problem, I love swimming underwater, and my ability to hold my breath etc. I like my lungs and how I breathe nice and deep, I just wish the machine would tolerate and comply more .... with me, and how I breathe!  Shallow breathing feels unnatural for me.

Just to clarify, I did my test upon waking up in the morning, but before taking off the mask or touching the machine. Notice in the details, the machine is using all 22 CA events (including the 4 when I was awake) to calculate the clear airway index (22 events / 7 hours =  3.14) and the OSA index also included all 12 OA events (including the 2 when I held my breath) to calculate the OA index (12 events / 7 hours = 1.71)


Here is a second screen shot of of my Oscar chart with: events, flow rate, tidal volume, insp time, minute vent:

   

Here is a screen shot of the details info:

   


After thinking about it I wonder if this has something to do with mask pressures hitting the inhale and exhale "therapy pressure" limits. I have the EPR setting ON to make exhaling easier.  In the original screen show (previous post) it looks like the mask pressure is allowed to vary until I hit the upper and lower therapy pressures (red and green), but once I hit those pressures the machine kicks in to maintain that pressure, not allowing any further pressure variation which is felt as extra work.  If I could extend the distance between the lower and upper therapy pressures I might avoid hitting those walls, but my EPR is already set to 3 mm Hg ...can it get any higher or am I simply out of luck?

[Sleeprider]

A Vauto gives you a lot more flexibility in the respiratory timing an other therapy options. Your tidal volume and respiratory rate are not at all unusual. You can compare to an older chart of mine below. My Vt and Vm are both nearly twice yours. My impression of your therapy is that your EPAP pressure is very low starting at 7.0/4.0 and maximum at 13/10, and may account for the relatively high OAI and there may even be a positional aspect at work (chin tuck).

[Grandpapa-G]

I don't really understand the point of your post. At no point do you indicate if the use of CPAP is a benefit. Almost everyone will register high numbers "apparent" apneas while awake or during periods of partial wakefulness (often referred to as sleep / wake junk) but these are not sleep apneas and are not considered to be a problem. Like you I have a much larger than normal lung capacity and when I was young both my twin (identical) brother and I would routinely  hold our breath under water much longer than any of our friends. As a teenager I learned to use deep breathing to aid relaxation. when I was 70 I was diagnosed with sleep apnea and I felt it the use of an Airsense 10 greatly reduced my daytime fatigue. At the beginning I felt the 10 second definition of a sleep apnea event was highly arbitrary and made it almost impossible for me to obtain AHI numbers under 5-8 / hr on even my best days with EPR of 3. It was clear that all my events were occurring during SWJ or while I was awake. Six months ago I was able to purchase a lightly used Aircurve 10 VAUTO which is a much more capable machine than the Airsense 10 and has many degrees of freedom that need to be optimised. I have found I can now obtain an AHI of about 1/hr with pressure support (EPR) of 4.5.

[AquaMan]

Thank you Grandpapa-G, you are right that the machine is for treating my sleep apnea and not really about wakefulness. You note I have not stated whether there is any benefit to my using the CPAP machine, and at this point, honestly, I cannot tell. I know that my sleep test required that I sleep on my back and I had a score of about 38 (severe apnea). At home, with or without that machine, I always sleep on my side.

Personally, I have nights when sleep does not come easy to me and when I do wake, fighting the machine to breathe naturally distresses me, and makes falling asleep again more difficult.

My intention is to look for help and share stories with anyone else having the same issues that I am having.

Thank you for mentioning the Aircurve 10 Vauto... I will look into that.

[quiescence at last]

I hope that silence so far is because you found something to help your situation. Why not drop a line so we know.

Also, trying to fake out the sleep genie and acting asleep is generally not successful. The idiot portion of the algorithm will still count the fake apneas, but waveforms are really hard to fake. I have not found anyone yet that matches sleep breaths while awake. Also, generally technicians have to consult the patient's EEG to be certain about the characterization of the wake and sleep states.

really look carefully at your air flow chart and you can probably tell the difference, but it isn't always accurate.

QAL
good luck.