Obstructive apneas persist despite high pressure (20/16 cm)

[Mr Bill]

Welcome to the forum NapsZ. I remember when I was 5' 11.5" and 155# back in high school (74 rules! ). Its possible to have obstructive sleep apnea even without a big neck if you have too small of an airway. I agree with other posters that perhaps what you are seeing are central events induced by the pressure although I suppose it could be OSA events followed by sudden breathing. I am not so familiar with the Resmed units. However, most of the data units will bump the pressure briefly to test for obstruction or clear airway apnea and the unit will flag the apnea. If these are CA then it may be you are experiencing complex sleep apnea in which the pressure needed to open the airway induces central apneas. If this is the case then you may end up needing an ASV. Only a sleep study can definitively tell if CA flags on your machine are actually CA events. Because only sleep studies actually measure breathing effort.

[NapsZ]

Wow, thanks ozij. That comparison plot is helpful. It's reassuring to know that the flow patterns do not look like CS respiration. That does leave anatomical issues as a strong possibility then ...

I went to see my primary care doctor and he peeked down my throat and up my nose. He said my tonsils looked nice and small, nothing unusual up or down there he could see. But he quickly added that he was no expert and gave me a referral to an ENT doctor

Thanks for the links to the people who did surgery. That's formidable. But if I need to do it, I'll do it.

[NapsZ]

Hi Mr. Bill, yeah that seems to be the big question, whether these are pure obstructive events punctuated by gasps, or complex events requiring ASV treatment. I'm not a big fan of the sleep studies -- so many variables they try to change in such a short period of time, and then so much treatment gets extrapolated out of what's measured over such a brief (and artificial) setting. But yeah they have that chest strap which measures respiratory effort, and I don't.

More data: I took another look at what happened when I tried to use a nasal mask last night. Most of the time the data is useless due to crazy mouth leaks. But there is a 15 minute interval where I am falling asleep and the mask is sealed, and the pressure is 14/10 cm. Then I see one central after another. So under some conditions maybe centrals get induced ...



I read a paper today on diagnosing central sleep apnea (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2276128/). There were some interesting sentences, one suggesting that periodic breathing could induce airway collapses and obstructive apneas (so they don't need to just be centrals):

Reduced and oscillating motor tone to the upper airway can result in intermittent upper airway collapse in those with hypoxia-induced periodic breathing, and direct visualization of the upper airway reveals collapse at the nadir of the respiratory cycle to be common in central sleep apnea.

and another suggesting that a key pattern is the appearance of periodic breathing at higher pressures:

This syndrome is thus a mixture of obstructive sleep apnea and hypopnea with a periodic breathing pattern frequently made more overt, often with the induction of central apneas, by the pneumatic stabilization of the upper airway with positive airway pressure.

So I am thinking the key experiment to try will be to put myself on different CPAP pressures (say 6, 10, 14 cm) over the next few nights, and see what patterns of apneas and breathing flows emerge. Pretty much what john_dozer mentioned previously. This should help distinguish between complex apnea vs stubborn anatomy. I'll let you folks know the results after I finish the sequence! Thanks.

[jamiswolf]

Hi Napz,
Getting masks to seal at those high pressures is difficult. Especially FF masks.

The handful of people on this forum who use ASV have to deal with even higher pressure spikes when a timed breath kicks in. You might get some good advice from them. There is an ongoing ASV thread where they hang out. Interesting reading in the thread too.

viewtopic/t65791/ASV-users-join-the-eve ... hread.html

I'm using a Comfortgel Blue nasal mask at mid-range pressures (10-16) and it seals nicely. If I want to sleep on my side which keeps my pressures lower, I have to cinch it a bit tighter then normal but again...a good seal and no leaks.

I appreciate the struggles you're going through. I'm dealing with a few of my own.
Take care,
Jamis

PS Looking forward to the results of your pressure change experiments. Knowledge is power.

[NapsZ]

Thanks Jamis. Yeah, that's been an ongoing project, controlling mask leaks at high pressure. Right now I'm using a Quattro FF cinched on super-tightly. It leaves red marks, but I can definitely get it to a state where it is stable at 20/16 cm. The problem is right after apneas kick in, I start to gasp and snore inside the mask, and that does shift it around enough to cause leaks. I can tell on the data trace when this happens because you can see a bunch of leaks appear, following by me quickly waking up and turning off the machine

I'll check out the ASV forum. Yeah, their pressure changes would even more dynamic! It's like a brave new world of mask engineering that is required ..

I just got done with the control experiment (4 cm CPAP). That was a tough night! (actually 2 nights, since I forgot to stick in my memory card the first night). I made some comparisons to the 20/16 cm case, which I'll post below.
I'm off to see the doctor this morning so I'll see what he thinks about the data, and what he recommends.

May I ask what problems you are working on solving Jamis? I'd be curious .. have you posted on another thread?

[NapsZ]

Some comparisons between control conditions (4 cm CPAP) and bilevel conditions (20/16 cm). These are the slides I will bring in to the doctor today for discussion.








I'll let you guys know what he thinks!

[jamiswolf]

NapZ wrote: May I ask what problems you are working on solving Jamis? I'd be curious .. have you posted on another thread?

Thanks for asking. No, I haven't posted any of my issues on a thread of my own. Just lurking on related threads to get as much info as possible. I had a computer crash recently and I'm struggling with a little laptop. I'm not a whizz with computers and can't even get my recording oximeter to work. If I post, first thing that will be asked is...where's the data?

I'm just over two months into CPAP with an auto machine. My Doc is either busy or disinterested so I'm rather on my own, and since it's a small town...choices are limited. My issues are related to AHIs still being very high despite treatment. On my sleep study it was AHI-21 with some sentrals and periodic breathing. With my auto treatment (I've settled on 10-16 pressures after much experimentation) AHI I'm still running 20 to 30's and 25% periodic breathing... worse then my sleep study.

There seems to be a significant positional element to my apnea and when I was running my subscribed pressures of 4-14, if I stayed on my side, it seemed like whenever I woke and peeked at pressure...it was 4. But if I lay flat on my back I need close to 16cmH20 and sometimes higher.

I've been experimenting with different masks and have found that most of my problems were because of mal-adjustment on my part. Now I can go back and use masks that initially didn't work. Mostly I was overtightening them.

I've been occasionally skipping treatment and sleeping on my side or stomach and I wake up feeling better then I do with cpap. Truthfully I have no idea what's going on. Once I get a new computer and scrape together some spare cash, I suppose I'll get the software to read my chip.

Good luck resolving your issues and I hope your MD visit goes well. I've found your thread educational and interesting.
Cheers,
Jamis

[NapsZ]

Hi Jamis, yeah I can certainly sympathize. I've only been two and a half weeks into my treatment, and frustrated that it's not improved -- 2 months seems like a long time to be experimenting with masks and sleeping positions! My initial elation following my diagnosis is giving rise to a realization that it's going to take some time to optimize all relevant variables ..

Is your machine data capable? what kind of recording oximeter do you have? if any of it is similar to mine I can share information, since I've gotten those two components at least to work.

"Knowledge is power" -- I do enjoy looking at my sleep data every morning, though I'm starting to think there's a Garden of Eden "picking the apple" aspect to all of this. It's very useful to have all this information, but I'm starting to miss just being able to go to sleep and not have to think so much about it. Hopefully we'll get to that stage soon! I'm jealous of the forum members who are down to optimizing their AHI's less than 5.

Hmm I wish I could contribute help to your problem! Maybe once you get the data set up working some parts of it will jump out.

Good luck with your continuing treatment, and let me know how it goes, please.

p.s. my MD said the issues I described just sounded like my mask not fitting right at high pressure. So I'll be trying a nasal mask + chinstrap tonight. I'm also going to try out some more full face masks this week (Innomed Hybrid via the mask exchange program @ http://www.cpaplibrary.com/mask-trials.html; and Fisher & Paykel 432 via DirectHomeMedical.com with 30-day return. These got good reviews on the forum!) So it looks like I'm going down a similar road of just trying to get a mask that fits right ..

[jamiswolf]

Hi Napz,
Well the first month was my compliance month. In order for insurance to cover machine and supplies. I actually thought things were going good. But when I took my chip in to get the data read before MD appointment I was surprised by how bad the numbers were. My Doc, like many, puts no stock in machine numbers. He express the opinion that it could be neurological...but then took no action (go figure).

I bought a new computer that's Windows 7 64 bit which is messing me up a bit on software.

My oximeter is CMS50D and my computer can't install a proper driver. Won't recognise it. And the software doesn't work on my computer even if I could install a driver.

Have downloaded Sleepyhead and hopefully I'll be able to check my machine data. I'm diagnosed as having mild to (low)moderate apnea and I feel there's a significant positional component to it. So by side sleeping I can mostly remove the obstructive component. Or that's my theory awaiting proving. I actually feel pretty good. No headaches and good energy (for a fat old guy) I'm exercising, dieting and playing the didgeridoo all in an effort at improving my breathing and health status.
Cheers
Jamis

[Cuda]

Hey Nap, my charts look like this when not using a full face mask because of mouth breathing. I had to give up nasal masks and pillows or tape with a chin strap. Your other charts where leaks are controlled I feel for you. I am only at 15cm now but I am having obstructive events as well and still do at 20cm. I guess I need to see an ENT as well but my charts are not as wicked as yours are but I have the same breathing patterns. It seems I keep going more shallow in my breathing until the event. I figured the airway was slowly relaxing until an event wakes me up and the process repeats itself. I will finally have insurance coverage next month so I can actually ask doctors for help! I can't wait.

[NapsZ]

Hi Jamis,

My operating system is also Windows 7 64 bit. I have a CMS50H though, which may be better at interfacing with the newer OSes. I downloaded SPO2 assistant v2.1 from this page:

http://www.pulseoxstore.com/Manuals-Downloads.html

and as for drivers, the oximeter automatically installed something called "Silicon Labs CP210x USB to UART Bridge (COM5)". It works fine, I can download the full data from the oximeter.

It's great that your sleeping position can remove a lot of the obstruction. Yeah hopefully when you are able to get more data you can get rid of the rest. I think my doctor trusts the original sleep studies a lot more than any data I've brought him. And to be fair I may end up reading too much into certain day-to-day data traces. But overall I think it's let me figure out a lot more quickly what's working and what's not ..

Best of luck with your treatment ..! and good to hear you are feeling well these days.

[NapsZ]

Hi Cuda, it looks like we're in a similar situation indeed! It's interesting that we have the same breathing pattern, and obstructive apneas that persist to high pressure. I've got an appointment to see an ENT this coming Friday. I'd like him to do some in-depth probing of my airway anatomy to see if there's any unusual features. Hopefully he'll be the type to do that, and not the type to blindly recommend surgery. I'll let you know if he finds anything, in case it lends any insight into your condition as well.

The insurance situation -- I certainly sympathize. I was uninsured when I did my sleep study (which is why I put off getting it for so long!) And after the diagnosis, I was like, well, there's no way I'm going to be able to get individual insurance now. Sure enough, Anthem deemed me uninsurable. But ironically, this made me eligible for California's high risk pool, and at my age, the premiums (for PCIP) are quite reasonable, $218/month for excellent benefits ($1500 deductible, 15% coinsurance for in-network up to $2500 max-out-of-pocket). I never imagined when I voted for Obama that his policies would have such a direct impact on my life; I am so happy that this program is available to me. It helps a lot.

I wish the best for your treatment and hope you feel better soon!

[deltadave]

I've got an appointment to see an ENT this coming Friday. I'd like him to do some in-depth probing of my airway anatomy to see if there's any unusual features. Hopefully he'll be the type to do that, and not the type to blindly recommend surgery.

During the exam, he should pass a video/fiberscope through your nose and then have you attempt to inhale against a closed airway following an exhalation (Müller's maneuver). OSA surgery is based on the site of obstruction (UP3, usually in combination with something else if the obstruction is retropalatal; GA and/or hyoid suspension, MMA, if its retroglossal). His system should be able to take images, make sure you check them out.

UP3 only works if the problem is with a "P". A complication of UP3 is VPI (if you sneeze with a mouthful of food, it all comes flying out your nose).

Reminder: Once you take something out, you can't put it back.

In

http://postimage.org/image/2cfaeu3t0/

if your point is that all the events are central, that could be a distinct possibility. While these algorithms are quite accurate when they call centrals, there are frequent instances when centrals may be mislabelled as obstructive.

[robysue]

While these algorithms are quite accurate when they call centrals, there are frequent instances when centrals may be mislabelled as obstructive.

Deltadave, can you elaborate on this a bit?

And am I understanding what you say correctly if I think you are saying:

When one of the algorithms labels an apnea as a central (clear airway) apnea, there's a high probability that the apnea is indeed a central one.

But ....

Many (how many?) central apneas wind up being scored as OAs by the machine algorithms.

And hence for a person with significant numbers of centrals on their sleep studies, the machine computed CAI should be considered a lower bound for the true CAI under treatment.

Thanks,
robysue

[Cuda]

I did just discover that side sleeping really helps. With leaks controlled I was able to have ZERO obstructive events over 6 hours at 16cm EPR 1. On my back the events are numerous and long.