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Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
#21
RE: Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
It depends on the variable. Specifically with PS if 9 is going to be good then 6 should be better then 3. PS is differential pressure, think of it like water pressure in your house. If your water pressure is 40 psi it is going to flow more than if it is 30 psi, you might not consider the flow ideal until pressure is 60 psi but you should notice a difference and it should appear that you are getting closer to satisfactory results.

There are two main variables important in CPAP treatment. EPAP holds your airway open to stop obstructive apnea from occurring and PS increases flow if you still have a partial restriction. First step you want to find the EPAP required to stop obstructive apnea, you can then try higher EPAP to see if it also helps hypopnea, flow limitation or anything else like that but if it doesn't help then you should step back to a lower EPAP. Then you can try PS to treat any remaining hypopneas, flow limitations etc. Too high of PS can cause issues (central apnea, hypocapnia etc) so again you want to watch as you increase and if there is improvement you are on the right track if not then it probably isn't helping and less may be better.

If you try higher pressure and higher PS and none make changes then the question becomes what are you actually trying to treat and why is it not responsive to CPAP treatment? Maybe it isn't a breathing issue after all or if it is breathing perhaps it is something that pressure/PS can't treat and therefore you need something other than CPAP treatment since that is all it is capable of providing. The examples you posted if breathing related look like they would best be treated by a higher PS and if PS helps you should see fewer instances like that (you would have to look manually since those cases are not flagged).
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#22
RE: Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
I can actually see reducing min EPAP, but let's wait.
Increase PS by no more than 0.5 and try that and see.

Always show your full night chart, that's your canary, warning that settings are getting out of hand and the context for any close-ups. And continue to post the close-ups, multiple flow segments on one attachment are fine.

And report the number of events you count as you did above and also convert that to a FEI, Flow Limit Event Index (number per hour)
I'm in my car so no detailed read.
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#23
RE: Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
(07-27-2021, 02:40 PM)Geer1 Wrote: It depends on the variable. Specifically with PS if 9 is going to be good then 6 should be better then 3. PS is differential pressure, think of it like water pressure in your house. If your water pressure is 40 psi it is going to flow more than if it is 30 psi, you might not consider the flow ideal until pressure is 60 psi but you should notice a difference and it should appear that you are getting closer to satisfactory results.

There are two main variables important in CPAP treatment. EPAP holds your airway open to stop obstructive apnea from occurring and PS increases flow if you still have a partial restriction. First step you want to find the EPAP required to stop obstructive apnea, you can then try higher EPAP to see if it also helps hypopnea, flow limitation or anything else like that but if it doesn't help then you should step back to a lower EPAP. Then you can try PS to treat any remaining hypopneas, flow limitations etc. Too high of PS can cause issues (central apnea, hypocapnia etc) so again you want to watch as you increase and if there is improvement you are on the right track if not then it probably isn't helping and less may be better.

If you try higher pressure and higher PS and none make changes then the question becomes what are you actually trying to treat and why is it not responsive to CPAP treatment? Maybe it isn't a breathing issue after all or if it is breathing perhaps it is something that pressure/PS can't treat and therefore you need something other than CPAP treatment since that is all it is capable of providing. The examples you posted if breathing related look like they would best be treated by a higher PS and if PS helps you should see fewer instances like that (you would have to look manually since those cases are not flagged).

That makes a lot of sense, thanks for taking the time to type it all out. Last time I tried it this way, my CA shot up after small PS increases. It's been a while so fingers crossed! Anyway, thanks again for being so thorough and patient with me.

(07-27-2021, 03:02 PM)Gideon Wrote: I can actually see reducing min EPAP, but let's wait.
Increase PS by no more than 0.5 and try that and see.

Always show your full night chart, that's your canary, warning that settings are getting out of hand and the context for any close-ups.  And continue to post the close-ups, multiple flow segments on one attachment are fine.

And report the number of events you count as you did above and also convert that to a FEI, Flow Limit Event Index (number per hour)
I'm in my car so no detailed read.

If it's not too much to be annoying to type out, how come you think we could reduce min EPAP?

Sleeping at 1:15, I started my count at 2:00 AM. By 2:40 AM, every single minute had at least one part with small amounts of flattening, cliffs, or jagged tops. A rough glance over 5 AM to 6 AM shows that's even worse. There's an attached image showing what I believe to be these flat/jagged top occurrences. Are they an issue?

Is that what you want me to look for, or just the "big stuff"? If I do the former, I'll do it tomorrow as it's almost midnight here. 

I've attached some more flow rate issues if it helps at all. I appreciate you taking the time, Gideon. I'll up PS by 0.5, which should be fine.


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#24
RE: Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
At the worst those are flow limitations causing RERA's, potentially they are related to rem sleep (see if they occur in patterns that would correlate to rem sleep) which often has worse quality breathing due to the paralysis that occurs. If flow limitations then pressure sometimes helps but PS is usually more effective so often it makes the most sense to reduce EPAP because it isn't doing much then increase PS. If increasing PS causes centrals then you breathing may be sufficient as it is, unfortunately it is really tough to determine if flow limitations and RERA's are actually an issue and worth trying to treat.
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#25
RE: Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
Your AHI at EPAP med of 6 is extremely good. The fact that your setting is 6 AND your med is 6 with your OA is zero puts an exclamation point on it. Therapeutically you can lower your EPAP pressure. It may be that at lower EPAP we see a significant increase in OA and if so that would be too low. It could be you are like me and feel air starved at lower pressures in which case we increase pressure purely for comfort but you have issued no complaints about that. Therefore your EPAP min can potentially be lowered. Only trying it will show us.

When you post zoomed views always post the full night view too.

I see 2 different types of events in the zoomed views. Arousal which show as a section of larger slightly erratic breathing, and periods of shallower breathing. Are you monitoring your O2? If so I wouldn't be surprised to see some mild, not dangerous desats associated with this shallower breathing. If these are not caused by CO2 decreasing to near your apneic threshold, which is a possibility, the fix is more PS. Your FL stat was .73, the fix for this is more PS. Your study indicated mild to moderate (subjective interpretation) UARS, the fix - more PS.

After a few days another bump on PS. Don't rush it.
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#26
RE: Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
(07-28-2021, 01:10 AM)Geer1 Wrote: At the worst those are flow limitations causing RERA's, potentially they are related to rem sleep (see if they occur in patterns that would correlate to rem sleep) which often has worse quality breathing due to the paralysis that occurs. If flow limitations then pressure sometimes helps but PS is usually more effective so often it makes the most sense to reduce EPAP because it isn't doing much then increase PS. If increasing PS causes centrals then you breathing may be sufficient as it is, unfortunately it is really tough to determine if flow limitations and RERA's are actually an issue and worth trying to treat.

Is it possible to determine when I'd be in a certain stage, given arousals from RERA / events are likely changing what stage I'm in? 

(07-28-2021, 06:58 AM)Gideon Wrote: Your AHI at EPAP med of 6 is extremely good. The fact that your setting is 6 AND your med is 6 with your OA is zero puts an exclamation point on it.  Therapeutically you can lower your EPAP pressure.  It may be that at lower EPAP we see a significant increase in OA and if so that would be too low.  It could be you are like me and feel air starved at lower pressures in which case we increase pressure purely for comfort but you have issued no complaints about that.  Therefore your EPAP min can potentially be lowered.  Only trying it will show us.

When you post zoomed views always post the full night view too.

I see 2 different types of events in the zoomed views. Arousal which show as a section of larger slightly erratic breathing, and periods of shallower breathing.  Are you monitoring your O2?  If so I wouldn't be surprised to see some mild, not dangerous desats associated with this shallower breathing.  If these are not caused by CO2 decreasing to near your apneic threshold, which is a possibility, the fix is more PS.  Your FL stat was .73, the fix for this is more PS.  Your study indicated mild to moderate (subjective interpretation) UARS, the fix - more PS.

After a few days another bump on PS.  Don't rush it.

Thanks Gideon, I figured it'd be a waste to post the day again, my bad!

That makes sense with the EPAP, I appreciate the explanation! If worthwhile, do you have suggestions on what to buy to measure O2? 

I didn't see this until I slept, so I already upped PS by 0.5. Normally I'd wait 5-7 days before adjusting further. 

I've attached atypical flow rate activity which I assume means PS 4.0 should be tried? Minute to minute my flow was slightly better.

In the attached full-night graph, there's a huge gap of missing data in the centre. I woke to use the bathroom once in that time (never usually happens!), I only think it was for a few minutes. There's some pressure activity out of the screenshot that indicates the machine was on and adjusting pressure. Is there an issue or was it just a glitch?

I also attached an example of tiny gaps I've noticed both last night and the night before, missing data for less than a second at a time here and there. What's causing this?

CA was higher, so starting to see signs of the the problem that I had when SleepRider was helping me in February. I suppose I'll stay at 3.5 for a while and hope my body happens to adjust?


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#27
RE: Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
Ok, I want you to have some CA events. This qualifies as some. The concept is that by having some you have pushed the envelope as far as you can for now. We wait a week or so for the CA events to calm down. Then another small increase in PS. Increasing EPAP will not help.
This recurrence in CA was expected and why the small increase.
CA is consistently inconsistent meaning it will bounce all around.

The end goal is to get PS a bit higher without letting the CA get out of control. Your problem is on the UARS, not the CA.

Min EPAP of 6 is a safe spot for you. Now set min EPAP = 5 tomorrow, another night at 6. Determine which setting feels better to you, don't even look at the numbers untill after you determine this.

Your checking the detailed flow rate is just to make sure we are not chasing ghosts.

Remember the end goal is effective and good sleep. Not some arbitrary perfect CPAP numbers.
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#28
RE: Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
Beautifully explained. When I change EPAP min to 5 tomorrow, shall I keep EPAP max at 9? 

I found out I apparently woke at 8:30 turned my machine off and then fell asleep until I got woken up and put it back on, I just don't remember. So no glitch! Do you have any ideas around the tiny tiny gaps of missing data, is it just a glitch? 

I absolutely agree with the goal being good sleep. Sort out UARS symptoms, benefit from sleep, and being able to understand why people like sleeping so I can look forward to it when tired.. that's what I look out for. Maybe reduce or discontinue stimulant medication but I realise that might not be related to UARS. That said - is it worth buying something to measure O2? 

Looking forward to trying EPAP 5, I just realised I've always had it on 6 or higher, other than when I first got the machine and had it on 4. Skipped 5 completely!
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#29
RE: Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
No reason to change max IPAP. You are not going there now.
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#30
RE: Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]
(07-28-2021, 03:27 PM)Gideon Wrote: No reason to change max IPAP.  You are not going there now.

Makes sense!

Struggled to wake up, more brain fog, less motivation and concentration, overall just bleh. CAs have gone up a fair bit, and I think some aren't tagged as well.

Weirdly enough my first three hours didn't have any tagged CAs.

Am I still to change EPAP Min from 6 to 5 tonight and log how it feels relative to today, and then check the data afterwards?

Thanks.


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