[CPAP] OSCAR confusing me with leaks/apneas

[cathyf]

sorry, got sloppy trying to cut corners. I meant my screenshot in post #36. even if you were awake, rls might show up. IF it's present, it could explain a lot. continuing to try to pin down whether sbd/apnea events occur before movement or vice versa using video and oscar would be informative.

I don't have much of anything to tell you about unflagged events. we all have them and intuitively I wouldn't think they'd cause significant desats although it makes sense to me that cumulatively they'd wear us down. I'd think you'd treat them same as other obstructive issues, which, with your machine means raising pressure, particularly epap. I've no experience with PR machines but try flex if you haven't. otherwise, you may in fact fare better with a bilevel.

I have it set to C-Flex One, I'll see if I can tweak it around. I'm aware that the Wiki says that C-Flex is nothing like ResMed's EPR, but I guess it would be better than nothing. The Sats aren't really a concern for me, its rather the unflagged events being responsible for disturbing my sleep.

Comparing the unflagged events, they appear to be unflagged hypopnea's rather than flow limitations and PR seemingly flags hypopnea's at random, but the flow limitation flags are appearing in areas with those Class 2 and 6 Flow shapes as I mentioned above.


Seems to me that the culprit is just unflagged events and flow limitations that PR isn't paying attention to?

When you read things like the patents on the machine algorithms, and what I can see when I look at my data, and also what I know from being a computer programmer, there's a lot of "slop" in the scoring.

The point is that the machine can only do one thing -- blow air down the hose -- and all of the analysis that the machine is doing is focused on a single decision, which is how hard to blow the air.

So if flow limitations mean "blow air harder" and central apneas mean "don't blow so hard" and apneas and hypopneas mean "blow air harder" (which is a rough summary of what's going on) then when you are in the middle of apneas and hypopneas then the machine is going to ignore what's going on with flow limits.

Also, I'm pretty sure that there is a main logic loop which is examining time slices of your breathing, calculating stuff, building a picture of what's going on. Depending upon what it's looking at and what it's looking for, it might be looking back a few seconds into the past or might be minutes into the past. There are rules about it not reacting the first time it sees something, and then reacting on the second or third time -- but that means that there are a whole series of timers in the code looking for that second occurrence and if enough time passes the timer resets.

So the answer is "it's complicated." And whether my flow limitation should be scored as 0.11 or 0.12 -- it doesn't matter the machine is going to make the same decision about pressure. (And your machine just scores "yes" and "no" so that's yet different.)

Hey, when I go into a complete train wreck of events, my machine will score multiple events during the same time interval, and so my AHI gets a little inflated. But you know 75 vs 80 -- a train wreck is a train wreck!

[godletmesleep]

Thanks for the input cathyf and sheepless, I'm aware that the C-Flex option on Philips Respironics machines is nothing like a Bilevel or the EPR setting available on a ResMed and I believe some studies have noticed this as well as being notated on the Wiki.

It's honestly just a bit confusing, unsure if switching to a ResMed would be a good idea or just asking my physician for a full blown Bilevel. There's also the frustration factor as whenever I was picking out an initial machine, it was insisted that I buy the Philips rather than the ResMed simply because the ResMed was more expensive. I guess I got what I paid for there

The flow limitations do not seem to be caused by any movement, most movement follows whenever these hypopnea's and flow limitations start. It surprises me how many hypopnea's the PR scores and how many it misses despite their flow rates looking almost completely similar. This issue has truly been hiding under my nose the entire time, as whenever I factor all verified User Flags into my AHI, my AHI is always at 6 at the lowest and 8 at the average.

Wonder if in the mean time, I could just raise the pressure to resolve flow limitations, does there need to be a pressure support factor for it to limit flow limitations? I figure that a higher IPAP without an appropriate EPAP just means you'll be facing more obstructionals?

Troubleshooting times in CPAP-land.

Wish we could get staceyburke, Sleeprider, or Gideon to give some input here as well. I believe they're also knowledgeable about the flow shapes and whatnot, haven't seen them in awhile.

[DaveL]

godletmesleep my environment is different than yours. I am Canadian.

When I bought a cpap/humidifier mask I was offered 3 choices. Expensive. More Expensive. Most Expensive. The Most Expensive was always Respironics. The Mask was always some cheap brand/no substitutions. And the Machine offered was a brick. It monitored hours on...nothing else.

Turns out the DME was 1/2 owned by the hospital. The sleep doc worked at the hospital. Just those 2 things...I smell a rat.

So some purchasing agent bought the machines--least cost? someone on the take?

Of course I need a prescription in Ontario to buy a machine.

I got around that--first time--buying a slightly used machine from a co-worker who gave up on cpap therapy. She had a diffferent sleep doc....ResMed S9E with card; ResMed full face mask.

Point is--my 30+ years of OSA experience is that sleep docs know squat about equipment; they don't know how to set them up. And 4 hours use a night with score below 5 means I'm compliant.

My story doesn't matter, except to say how remarkable the people are here that are helping us. And if you look at the number of posts and number of people asking questions I'm so grateful for the time they spend with us.

I'm absolutely sure that your treatment will improve. Mine did.

Be safe! (we had 2 cover-19 cases at work reported today. I'm working from home!

[SarcasticDave94]

If you believe there's flow limits to address then your Min pressure needs to increase. I don't believe Flex will do much to help. A higher Min pressure would also address Obstructive Apnea. Raising Max pressure would likely address very little.

[cathyf]

If you believe there's flow limits to address then your Min pressure needs to increase. I don't believe Flex will do much to help. A higher Min pressure would also address Obstructive Apnea. Raising Max pressure would likely address very little.

I'm not sure if PRs are different from ResMed in this aspect, but my experience on the ResMed side is that my level of flow limits mean that it's the minimum pressure that's irrelevant. In my case, "flow limited" is pretty much a synonym for "asleep". As long as I'm awake the machine stays at the minimum pressure. As soon as I'm asleep aka flow limited, pressure takes off. If I wake up, pressure comes back down. The maximum pressure is how high my flow limits will drive the pressure. The minimum pressure is where the pressure heads when I wake up. Minimum pressure only matters when I'm awake.

[kappa]

godletmesleep, I'm not convinced your inspiration flow pattern is class 2 or 6 most of the time. The small inhalation bit at the end of the exhale that you've labelled as '2' may just be due to machine pressure changes related to FLEX. And the '6' flows just look like a normal breath (class 1) with some of them plateauing (class 7) - you should only be considering the flow above the dotted red 'zero' line, not starting from the middle of the exhale.

I think you should look at the shapes after switching off flex completely - if that's sufficiently comfortable for you to be able to sleep.

[multicast]

Considering this shot

   

I hardly see any FL at all.  The flat passing through the zero line might be an indication of mouth leak: what was the leak rate at this time?  Keep in mind that the *inspiratory* FL are calssified and your inspiration looks quite well.

[godletmesleep]

godletmesleep, I'm not convinced your inspiration flow pattern is class 2 or 6 most of the time. The small inhalation bit at the end of the exhale that you've labelled as '2' may just be due to machine pressure changes related to FLEX. And the '6' flows just look like a normal breath (class 1) with some of them plateauing (class 7) - you should only be considering the flow above the dotted red 'zero' line, not starting from the middle of the exhale.

I think you should look at the shapes after switching off flex completely - if that's sufficiently comfortable for you to be able to sleep.

FLEX was not on for those screenshots, I should note.

The 6 Flows do not look like class 1's from what I can see, not to mention the machine started flagging those types of clusters. The Wiki provides some examples of class 1s and there is no plateau beforehand on such flows. Nor does that explain why they look different from prior breathes taken in the same night that are easily distinguished as class one.

I am starting at the zero line when evaluating those flows, not necessarily the the middle of the exhale. Doesn't seem to make much sense for someone to inhale slightly, exhale slowly, and then make a larger inhale? Or exhale and withhold their breath for a few moments before starting to inhale. That's what those 2's are appearing to be.

Then again, maybe I'm wrong, I'm just going off what literature I could find (which isn't much)

[godletmesleep]

Considering this shot

I hardly see any FL at all.  The flat passing through the zero line might be an indication of mouth leak: what was the leak rate at this time?  Keep in mind that the *inspiratory* FL are calssified and your inspiration looks quite well.

This begs the question of why all FL flags are surrounded by similar events




As for the leaks, it's hard to tell. OSCAR does not report good data on it since it insists that whatever leaks are above 13L are excessive. I would say the excess leak was around 10L, but I'm not sure. I'm unsure if mouth breathing would be an issue, I tape my mouth shut every night and I never wake up with it off. 

Here's a timeline of that night of flows, with leaks included

[godletmesleep]

If you believe there's flow limits to address then your Min pressure needs to increase. I don't believe Flex will do much to help. A higher Min pressure would also address Obstructive Apnea. Raising Max pressure would likely address very little.

Honestly every night I raise the pressure it just gets worse and worse.


Here's last night, complete and total trainwreck. I wish there was a way on OSCAR to exclude certain flags or times.

[rant]
Honestly just so close to giving up with PAP therapy. I'm so tired of trying to bother, doing all these changes and the machine not even picking up 90% of the events. My AHI is still practically above 10 in that image, even excluding Wake/Sleep/Junk at up to 23:10 and 2:34 to 3:10. I'm clueless and anytime I come up with a theory for the problem it just falls apart and I have no other alternatives.
[end rant]

I do seem to have alot of issues that line up with backsleeping, so thats something to target and address. Yet still a handful of incidents where I cannot see what is going on, but I'm on my side. I still am confused as to why some of my flows look completely different as the night progresses. Confusing stuff.

I do apologize to anyone if I have come off as needlessly hostile over the past few days, I am just getting very grumpy about all of this stuff.