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Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Fri Jan 12, 2024 6:37 pm
by lazarus
Rubicon wrote: ↑Fri Jan 12, 2024 4:39 am
IF we're going to be big about this...
Is this some kind of a new forum policy? Because I don't think I ever got that memo.
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Fri Jan 12, 2024 8:33 pm
by breathturn
Rubicon wrote: ↑Fri Jan 12, 2024 4:39 am
OK but get electrolytes too as if valid, that result could suggest metabolic alkalosis (the compensation for is reduced breathing).
Sorry, for electrolytes, do you mean the electrolyte testing you get in a metabolic panel? I've had a few comprehensive metabolic panels over the years, results are generally within norms except AG ratio which is a bit on the high side. Here's one from Feb 2023:
Rubicon wrote: ↑Fri Jan 12, 2024 4:39 am
Since the NPSG guys are idiots, they probably don't know (or care) that DC devices need to be calibrated to the NPSG program. An
xCO2 machine doesn't actually send the CO2 value to the program, it sends a DC signal (0.0 - 1.0 DCV). Calibration is accomplished by alternately sending 0.0 and 1.0 DCV signals from the CO2 device to the NPSG software before monitoring starts and adjusting the scale in the software. That calibration should be part of the graph but in your case it isn't.
In addition,
xCO2 themselves need to be calibrated periodically with a known value of lab grade gas (usually 5.0% CO2) about every 6 months. Otherwise they may drift high (yeah aha moment).
Use above points to show you either got an underlying something or you're twice as knowledgeable than those "techs".
Makes sense, I can ask the sleep clinic folks about what's going on with this next time I see them (sadly, in 2 months, but I also have the ASV sleep study coming up before that).
Rubicon wrote: ↑Fri Jan 12, 2024 4:39 am
This a crude comparison of diagnostic and therapeutic NPSG. Looking specifically at sleep architecture and heart rate activity, IMO it doesn't make a difference whether you are treated or not:
...
Oh wait-- you already know that.
Yes, but doing the side-by-side was a great idea -- now I feel silly for not having thought of doing this sooner. It's good to have this as hard evidence to back up my subjective experience. I can maybe use this as ammo to drive home that they're missing something.
So, two things:
- With my PCP, we've tried Gabapentin, Clonazepam, Levetiracetam. We also tried more "general" sleep meds like Remeron/Lunesta/Ambien. Ambien was the one where I felt like there was most noticeable change (remembering more/longer dreams, so potentially helping with sleep maintenance), but no change in my bottom-line symptoms of headaches/fatigue.
- The sleep clinic had me do a nap test (not sure what the official name is) to rule out Narcolepsy and IIH. Basically they have you do a normal night's sleep, and the next day you try to nap 5 times for ~30 minutes over the course of a few hours. That test was negative: they told me I "dozed off" (stage 1 sleep) in each nap, but not nearly to the point where there's a chance of narcolepsy/IIH. I think the test was fluky in a lot of ways that made it harder for me to fall asleep than I usually would (the nervousness of "trying" to fall asleep in the 30 minutes was tough for me, and there were various lab conditions that didn't help either) but I agree with the bottom line of ruling out narcolepsy/IIH -- my symptoms don't seem consistent with those.
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Sat Jan 13, 2024 4:56 am
by Rubicon
Your CO2 is theoretically perfect so IMO your
pCO2 is normal and they have NFI how their equipment works.
Nap test is called Multiple Sleep Latency Test (MSLT). I have a passing familiarity with them.
In re: sleep meds, since narcolepsy has been ruled out, I'd take a look at suvorexant (Belsomra is contraindicated for patients with narcolepsy). IMO you need a long-acting something (ambien is short-acting).
From the kids:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5263087/
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Sat Jan 13, 2024 4:58 am
by Rubicon
lazarus wrote: ↑Fri Jan 12, 2024 6:37 pm
Rubicon wrote: ↑Fri Jan 12, 2024 4:39 am
IF we're going to be big about this...
Is this some kind of a new forum policy? Because I don't think I ever got that memo.
Note: that was a big (literally and figuratively)
if.
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Sat Jan 13, 2024 5:19 am
by Rubicon
breathturn wrote: ↑Fri Jan 12, 2024 8:33 pm
Makes sense, I can ask the sleep clinic folks about what's going on with this next time I see them (sadly, in 2 months, but I also have the ASV sleep study coming up before that).
Ah yes, ASV. AKA The Big Lie.
This is where they'll take your evidence-based AHI of 0.0
and they'll...
So why are we doing this again?
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Sun Jan 14, 2024 5:02 am
by breathturn
Rubicon wrote: ↑Sat Jan 13, 2024 4:56 am
Your CO2 is theoretically perfect so IMO your
pCO2 is normal and they have NFI how their equipment works.
Yes, sadly I think this is the most likely...
Belsomra was mentioned by my primary care once or twice. I'm not positive, but we may have done a short trial of it a few years ago -- I'll check on this.
As for the ASV, they only suggested it after I mentioned it in the context of having noticed the central apneas reported by the machine (naturally, this was before the discovery in this thread of the PS causing at least some, if not most of the central apneas). While our discussion has lessened my faith in their lab/data, I think at least the subjective experience of how I feel on ASV might tell me something.
What makes ASV "The Big Lie"?
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Sun Jan 14, 2024 6:48 am
by Pugsy
breathturn wrote: ↑Sun Jan 14, 2024 5:02 am
What makes ASV "The Big Lie"?

That it fixes all your breathing problems and all your sleeping problems and is the greatest thing since sliced bread...and it might also take care of the world peace problem.
Don't get me wrong...there's a time and place and need for ASV but there are a lot of unrealistic expectations about ASV floating around out there.
BTW....The Belsomra thing....I have it on hand myself. In fact I took one last night. I don't take it every night though.
I save if for what I perceive as a much needed aid usually when I have had crappy sleep several nights in a row kind of thing.
It does help to some extent and worth having it in my arsenal but it isn't a total miracle drug either.
It is probably cost prohibitive though for most people unless it is covered by insurance in some fashion. I am lucky in that my insurance covers it at a level 3 tier which is the most expensive copay at 47 bucks for 30 day supply.
It does help to some extent but the biggest plus for me with taking it is that I don't have the next day hangover stuff that I got with Ambien plus Ambien really is more of a sleep onset fixing drug and not a staying asleep type of drug.
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Sun Jan 14, 2024 7:08 am
by Rubicon
breathturn wrote: ↑Sun Jan 14, 2024 5:02 am
What makes ASV "The Big Lie"?
Breathing is controlled (mostly) by CO2 levels. As CO2 increases one breathes deeper and faster, as CO2 decreases one breathes shallower and slower.
An arousal from sleep may cause one to take a deep breath or two. Consequently the body may wait a few extra seconds before it takes its next breath in order to allow things to equilibrate.
However, your machine, about as smart as your aforementioned sleep team, views this as a "central apnea" and the world is about to end. Enter ASV, who not only thinks the world is about to end, but it's going to prevent this ELE by sending in some breaths. The ASV now says "Oh boy! There's no central apnea to report!" This is of course misleading as the reason there's no central apnea to report is the ASV put a couple of waveforms in there. Did it have to (in this scenario)? No. Should it have had to? No. Did it hurt anything? Not really as breathing will (should) slow, it will just take a little while longer.
Anyway, in the morning when people do their downloads and see their CAI is reduced from
xx.x to 0.0 they go go "Wow! This is magic! We are really doing God's work here!"
Are they really? Well this actually might be a grey area. If the increased CAI was due to bad sleep; and if ASV improved bad sleep because it's a more comfortable mode; or if as a placebo ASV improved bad sleep; then you might say yes ASV has value.
Is it worth getting a visit from the CPAP Police for Improper Utilization of Mode? Or dropping 4K$?
Not my call.
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Sun Jan 14, 2024 9:06 pm
by lazarus
Hey, I know, let's treat all common phenomena and possibly meaningless "symptoms" and then call it a miracle cure for everything! After all, "evidence-based medicine" means that the recorded metrics of any chosen arbitrary index always mean much more than the reality of true medical significance.
Progress!!
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Thu Jan 18, 2024 12:00 am
by breathturn
Thanks, good to know re: Belsomra and ASV.
I've been doing some analysis of my PAP data, in conjunction with the video recordings I use. Basically, what I'm looking for is an explanation for what's causing the sudden awakenings that I often see in the recordings. There's one pattern I see pretty consistently which seems interesting: some disturbed breathing (during likely sleep breathing, cross-validated with the camera where I appear asleep/not moving at all) which looks almost like a CA to me, but is not recorded as a CA event, followed a little while later by the actual awakening/movement on camera. Here are a few examples, all from this day:
https://sleephq.com/public/56f055cb-ef8 ... effa74edf6
I would really appreciate if anyone can help confirm if those look like CAs (or more generally, something notable), or if I'm seeing patterns where there aren't any
I'm also curious: is there any precedent for setting PAP pressures to some really low setting, such that the therapeutic effect is essentially zero, but you get the breathing data? I'd really love to see how my breathing looks without the effects of PAP, but naturally, the PAP machine is what I'm using to record the breathing...
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Thu Jan 25, 2024 2:26 am
by breathturn
Friendly bump on the last post
Rubicon wrote: ↑Sat Jan 13, 2024 4:56 am
Your CO2 is theoretically perfect so IMO your
pCO2 is normal and they have NFI how their equipment works.
So... interesting development here. I had my ASV sleep study (which was generally uneventful / didn't feel any different than usual after), and I mentioned the CO2 thing from the 2016 sleep study. When we were setting up all the equipment and doing testing to make sure everything was plugged in correctly, and the mask fit was good, the tech pointed out that my pCO2 level was already showing up as high, like low 50s. I couldn't get much info from them regarding calibration, but I have to imagine that they aren't seeing this level of pCO2 with all patients, unless we're talking extreme levels of incompetence... So it seems like there might be something here. Still planning to follow up on this with my primary care.
For what it's worth, I spotted that the device they're using to measure pCO2 is the Sentec Digital Monitor.
They also mentioned that the pCO2 levels went down during the night due thanks to the treatment, but I don't have any hard numbers on that (yet? hopefully I can get my hands on the full report when it's ready).
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Thu Jan 25, 2024 8:34 am
by ozij
"Weak breathing" is a hypopnea, not a central apnea.
The episodes are too short for the machine to count.
Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Fri Jan 26, 2024 1:14 am
by breathturn
ozij wrote: ↑Thu Jan 25, 2024 8:34 am
"Weak breathing" is a hypopnea, not a central apnea.
The episodes are too short for the machine to count.
Thanks! Does the length limitation also apply to hypopneas? I'm wondering why these aren't marked as hypopneas when I see other events that look more minor being marked as such.
My "real" question is whether these events are significant enough to cause (delayed) awakenings in themselves, but I'm guessing that's much harder to answer

Re: Understanding my long-running issues with CPAP and BiPAP
Posted: Tue Mar 26, 2024 12:43 am
by breathturn
Well, a lot of new things since last time.
I went through complete ABG/PFT/Chest XRay just to confirm nothing was wrong from a pulmonary point of view, everything checks out fine. Good news, I guess, though I almost wanted to find something wrong..
I got a cone CT scan of my airway, and as expected, it's just generally very small (20 mm2 in the worst spot). In addition, I have enlarged tonsils and adenoids which may be contributing to airway issues as well. It's seeming increasingly likely that surgery is going to end up being my only remaining option, but the question is which surgery is worth doing. MMA, palatal expansion, pharyngoplasty are all on the table.
In the meantime, I'm still trying BiPAP on and off. Based on a titration study done at the start of the year, they wanted to further increase my pressure, having once again observed issues controlling my apnea with lower pressures during the sleep study. The new recommended settings are IPAP max 15, EPAP min 11, PS 2 (argued down from 4 based on the CA findings in this thread). Unfortunately, I still haven't felt any benefit from treatment even with these settings. I'm continuing experimenting with pressures, and I've just started using the Bleep Eclipse mask. I like it a lot, except that I have a lot of issues with cheek puffing / air escaping through the mouth, even when using mouth taping / chin strap. If I'm not able to overcome that, I might have to back to full face mask.
Finally, I'm also still experimenting with myofunctional exercises, as well as sleep meds. I'm hoping to at least find something that helps a little, enough to give me confidence in proceeding with surgery...