I'm trying to learn how to read OSCAR data - can you add insights?

[Pugsy]

I know Pugsy knows a lot more than me and I’ve read her posts where she does mention she doesn’t see any relation to respiration rate to REM. I have also read posts stating the opposite. At the end of the day I’m going to have to decide what maps to me.

I personally have never been able to spot any sort of correlation with respiration rate and REM....and I have looked.
I just can't see it in my data.
Doesn't mean it doesn't/can't happen but I just haven't seen it myself.
And I have an advantage that my OSA is 5 times worse in REM so in the past 10 plus years I have got pretty good at spotting probable REM just from past experience watching the pressure graphs go up because I usually need a lot more pressure during REM.
Despite all this I have never been able to spot any sort of respiration rate change during what is probably REM stage sleep. I just don't see it in my own personal reports....at least anything consistently.

Now others say they can spot it and I see their reports and it sure looks like it....but I personally haven't been able to document it on my reports.

So just because I don't/can't see it...doesn't mean it doesn't happen. All it means is I don't see it myself. There probably is an ever so slight change but it's so slight I can't spot it reliably or consistently in my situation.

I am NOT saying that the area in question on that one report isn't REM related....all I am saying is that the machine doesn't respond to respiration rate as part of its auto adjusting algorithm. The auto algorithm only responds to airway related flow reductions of some sort that meet the criteria for it to do it's auto adjusting. Respiration rate isn't included anywhere in that criteria.
That was your question..."why didn't the machine do anything"...the answer is nothing happened besides the increase in RR to meet criteria for the machine to do anything.

[DustyDoozeer]

I am NOT saying that the area in question on that one report isn't REM related....all I am saying is that the machine doesn't respond to respiration rate as part of its auto adjusting algorithm. The auto algorithm only responds to airway related flow reductions of some sort that meet the criteria for it to do it's auto adjusting. Respiration rate isn't included anywhere in that criteria.
That was your question..."why didn't the machine do anything"...the answer is nothing happened besides the increase in RR to meet criteria for the machine to do anything.

Yup, so there are two parts:

1. You haven't seen RR related to REM in your charts. I completely understand that. I'm going to keep looking at my trend data as I collect more. If I see repeatable correlation, I'll dive into it more.

2. "The auto algorithm only responds to airway related flow reductions of some sort that meet the criteria for it to do it's auto adjusting. Respiration rate isn't included anywhere in that criteria." --> Good point and that does answer my question -> the flow rate graph is its input, not RR. If I look at the flow rate graph, in the earlier events, they mapped to flow rate dips which is part of the algorithm and why it adjusted pressure. Interestingly, the associated RRs on the first event where pressure was adjusted had a much larger exhale spike as well, but more importantly the flow rate charts changed quite a bit that was the trigger that changed the pressure.

[DustyDoozeer]

I am NOT saying that the area in question on that one report isn't REM related....all I am saying is that the machine doesn't respond to respiration rate as part of its auto adjusting algorithm. The auto algorithm only responds to airway related flow reductions of some sort that meet the criteria for it to do it's auto adjusting. Respiration rate isn't included anywhere in that criteria.
That was your question..."why didn't the machine do anything"...the answer is nothing happened besides the increase in RR to meet criteria for the machine to do anything.

Yup, so there are two parts:

1. You haven't seen RR related to REM in your charts. I completely understand that. I'm going to keep looking at my trend data as I collect more. If I see repeatable correlation, I'll dive into it more.

2. "The auto algorithm only responds to airway related flow reductions of some sort that meet the criteria for it to do it's auto adjusting. Respiration rate isn't included anywhere in that criteria." --> Good point and that does answer my question -> the flow rate graph is its input, not RR. If I look at the flow rate graph, in the earlier events, they mapped to flow rate dips which is part of the algorithm and why it adjusted pressure. Interestingly, the associated RRs on the first event where pressure was adjusted had a much larger exhale spike as well, but more importantly the flow rate charts changed quite a bit that was the trigger that changed the pressure.

Also:

And I have an advantage that my OSA is 5 times worse in REM so in the past 10 plus years I have got pretty good at spotting probable REM just from past experience watching the pressure graphs go up because I usually need a lot more pressure during REM.

Out of curiosity, how did you map OSA to REM in the first place in your charts? Did you use any external devices to track REM?

[Dog Slobber]

Ice cream sales do not cause forest fires.

[DustyDoozeer]

Ice cream sales do not cause forest fires.

You are baiting at this point, and/or assuming you know more about basic statistics than me. I'l let that pass. Understandably, internet forums are an essential part of self-importance for many.

[zonker]

Ice cream sales do not cause forest fires.

of course not. forest fires obviously drive ice cream sales.

duh!

[Pugsy]

Out of curiosity, how did you map OSA to REM in the first place in your charts? Did you use any external devices to track REM?

My in lab diagnostic sleep study confirm the REM dependent OSA.
In non REM sleep...measly 10 to 12 per hour AHI
In REM sleep....well over 50 per hour AHI.
Oxygen levels in the low 70%....that's bad.....real bad.

When I first was put on cpap I was prescribed a fix pressure of 8 cm....works great for non REM sleep but not so great for REM.
I simply saw a lot of dense clusters happening at roughly the normal time frames where we usually have REM sleep happen.
90 minutes after sleep onset for the first REM and it's usually fairly brief but as the night goes on REM comes on more frequently and lasts longer with the greatest amount of REM occurring in those wee hours of the morning.

Google "sleep stages" and look at normal hypnograms to get an idea how the cycles run.

No...I didn't use any external devices because there really weren't any back in 2009 that could reliably tell us sleep stages.
Even now there's nothing (cheap anyway) that can reliably tell us sleep stages. We get educated guesses from various devices.

So I actually just put 2 and 2 together with some common sense deductions...and I can pretty much spot probable REM just from what the pressure does. I don't get as much REM as I need...I know I don't because I wake up often during the night. Other health problems cause the wake ups though and I just do the best I can. Multiple awakenings, no matter what the cause, will mess with those sleep cycles so we end up not getting the needed percent in each stage.

I used to have a posted report that showed a lot of clustering when I was trying out a fixed pressure bilevel machine.
Not sure it is still available but let me go see if I can find it.

And DS has a point....correlation doesn't always mean causation. People tend to want to put all their eggs in the sleep apnea basket and sometimes those eggs have nothing to do with sleep apnea. I think that is probably why so many people give up and say "cpap didn't help" because they had unrealistic expectations as to what symptoms they put in that sleep apnea basket and expected the machine to work miracles and fix a problem totally unrelated to sleep apnea.

Let me go see if I can find that report. I will post it here in this thread with an edit if I find it.

Edit...
Image attached from when I did a little experiment on a fixed bilevel machine. I think we can see when REM probably happened for the most part. This is why I am such a firm believer in auto adjusting pressures. Now I can use fixed pressures but I have to use a lot higher pressures all night just to deal with the REM events. I can do it but it's not much fun using 18 inhale and 14 exhale just to deal with the 20% of the night I might be in REM needing more pressures.

bipap pro with REM.JPG

[DustyDoozeer]

And DS has a point....correlation doesn't always mean causation. People tend to want to put all their eggs in the sleep apnea basket and sometimes those eggs have nothing to do with sleep apnea. I think that is probably why so many people give up and say "cpap didn't help" because they had unrealistic expectations as to what symptoms they put in that sleep apnea basket and expected the machine to work miracles and fix a problem totally unrelated to sleep apnea.

Let me go see if I can find that report. I will post it here in this thread with an edit if I find it.

Excellent info Pugsy. Thanks.

Yes, I do get the difference between correlation and causation. So far, I haven't stated its causative. I'm investigating at the moment and nothing is off the table for me. People always make assumptions about others, knowing very little of their background and motivation.

[DustyDoozeer]

Could someone help me understand why this particular event was marked a RERA? From the graphs, if at all, the chart right after the RERA segment seems more like RERA.

Screen Shot 2020-03-04 at 4.24.11 PM.png (457.53 KiB) Viewed 726 times

[Pugsy]

Now you know why I take RERA flagging with a grain of salt along with the absence of RERA flagging. It doesn't always make much sense.

The section of respiration right after the RE flag...that actually points to probably just arousal breathing and most likely the machine didn't think that something in the airway caused the arousal so not breathing or respiratory related.
We have arousals from stuff not related to the airway....pain, bad dream, neighbors fighting, cat fighting, cat jumping on us, dog and cat fighting on us, kids crying, etc.....all sorts of potential causes for arousals and we don't know the cause but we do know the machine doesn't think it was related to anything in the airway.

There is certain criteria that needs to be met to earn any event flag and if that criteria isn't met then no flag no matter how it might look to us. RERA flagging...the machine is making an educated guess at best since it really doesn't know if someone is asleep or not and for it to be a real for sure RERA there must be sleep preceding it.

And not every arousal breathing segment we see was caused by some sort of airway collapsing issue...no matter how much we might want to put the blame on sleep apnea stuff.

[palerider]

And it's also possible that the flag is in the wrong spot.

There were quite a few of them that showed up in the wrong places in older versions of SH, and were only spotted through VERY tedious comparisons between Encore and SH.

It's entirely possible that some of those bugs haven't been fixed for RERAs. *shrug*

[UglyBob]

I worked in the medical field for over 30 years but I retired some time ago. I am just an old biddy who likes to help people and I use the cpap myself and I have experimented just to ease the boredom...and I have read a lot.

"just an old biddy"?!?!?

no you are special and you need to know that. we are lucky to have you here.

not only have you read a lot, you've RETAINED it and make use of it in your help with people here.

Zonker is right! Pugsy is one of the most helpful people I've ever come across in life. She's helped me quite a bit and given me a lot of good advice. If something she says seems wrong, you probably just read it wrong.

Hi Zonker!

no getting up in the middle of the night to pee.

Zonker, this was the money quote. I've stopped waking up at 3am to pee! I'm surprised you said that - it matches exactly where I am now. I suppose I am on my way to a better life!

That was the first positive thing I noticed too. It's weird to think that it was caused by sleep apnea, isn't it? It was always around 3:40 for me.

But those graphs and OSCAR. I want to know what else I can do?

Why must you do anything?

Just because there is a lot of data and graphs, doesn't mean all of it is acted on.

I love numbers and graphs so I couldn't stop looking at all this stuff when I first learned about it. Usually numbers provide some real answers. After looking at this stuff enough I realized it was just making me crazy, there's too many variables.

Could someone help me understand why this particular event was marked a RERA? From the graphs, if at all, the chart right after the RERA segment seems more like RERA.

Screen Shot 2020-03-04 at 4.24.11 PM.png

I thought everything was getting better for me after the first few weeks on CPAP. The last month or so hasn't been going as well. Now I'm pissed, my pressure line has never looked that good. Seriously though, it looks like things are getting a lot better for you. I'm glad you found the right set up!

[palerider]

no getting up in the middle of the night to pee.

Zonker, this was the money quote. I've stopped waking up at 3am to pee! I'm surprised you said that - it matches exactly where I am now. I suppose I am on my way to a better life!

That was the first positive thing I noticed too. It's weird to think that it was caused by sleep apnea, isn't it? It was always around 3:40 for me.

Weird, but logical... Pugsy has a better link about the process, but in a very short summary: fighting to breathe raises your BP, the heart sends a signal to the kidneys to make more urine to lower the BP... and your bladder fills up.

Stop fighting to breathe, lower BP, kidneys do the urine concentration routine like they're supposed to do at night, and no more nighttime pee stops.

[DustyDoozeer]

Now you know why I take RERA flagging with a grain of salt along with the absence of RERA flagging. It doesn't always make much sense. The section of respiration right after the RE flag...that actually points to probably just arousal breathing and most likely the machine didn't think that something in the airway caused the arousal so not breathing or respiratory related.

And it's also possible that the flag is in the wrong spot.

Ok, good to know. Thanks.

I love numbers and graphs so I couldn't stop looking at all this stuff when I first learned about it. Usually numbers provide some real answers. After looking at this stuff enough I realized it was just making me crazy, there's too many variables.

Indeed. I hear you. I feel the conscious part of the average human brain is actually not a great tool for deep pattern analysis. My day job involves building AI/ML models and my hope is eventually to create a prediction model that maps my charts to how I feel that day. If my predictions match how I really feel, then parameter extraction becomes a relatively easier problem (the key components that affect this feeling). We'll see how that goes.

Seriously though, it looks like things are getting a lot better for you. I'm glad you found the right set up!

Yes, indeed. I'm just mildly ticked off at myself for walking into this without preparation (when I went to the sleep lab). I did not try and establish a real base line, and the reason that it important is because CPAP is a lifestyle changing habit and given the lab has the right equipment, I'd love to have started off at a more realistic level of my OA status. Oh well, can't change the past.

[palerider]

Yes, indeed. I'm just mildly ticked off at myself for walking into this without preparation (when I went to the sleep lab). I did not try and establish a real base line, and the reason that it important is because CPAP is a lifestyle changing habit and given the lab has the right equipment, I'd love to have started off at a more realistic level of my OA status. Oh well, can't change the past.

I don't understand what a "real base line" is good for, putting aside the fact that titration studies are very very often wrong...

My canned writeup:
As to sleep studies... they may be "The GOLD Standard", but they are, in many ways, woefully inadequate if you think about it.

You're in an artificial environment, all wired up and less comfortable than normal.
It's *one night* and likely only part of that night. reading any titration report, you'll see that "oh, your good pressure was 12cm, you slept for 45 minutes at that pressure!"

It's a simple fact that sleep varies from night to night and even hour to hour, you'll have better and worse days with the same exact settings. Yet the "gold standard" is a small number of minutes tested on one night.... a mere photograph taken during the marathon run that is your sleep.

It's not surprising that sleep studies are sometimes quite wrong, what's surprising is that they're ever right!