New CPAP user, a few questions

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Pugsy
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Re: New CPAP user, a few questions

Post by Pugsy » Fri Aug 04, 2023 2:19 pm

Can you use the free version of SleepHQ online thing so that the forum members can actually zoom in on the flow rate for those flagged centrals to see if any of them happen to be flagged while asleep?

Anything while awake in terms of flagged events don't really count in terms of therapy but of course point to less than adequate sleep quality itself.

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Re: New CPAP user, a few questions

Post by Steerpike58 » Sat Aug 05, 2023 12:50 pm

Pugsy wrote:
Fri Aug 04, 2023 2:19 pm
Can you use the free version of SleepHQ online thing so that the forum members can actually zoom in on the flow rate for those flagged centrals to see if any of them happen to be flagged while asleep?

Anything while awake in terms of flagged events don't really count in terms of therapy but of course point to less than adequate sleep quality itself.
I'm new to all this so bear with me - in reading around, I see that there's an alternative to OSCAR from SleepHQ. This SleepHQ alternative may provide some insight into my situation that OSCAR is not providing? I see that SleepHQ is not free, but - there's a free version? Or perhaps just a free limited-time trial? What should I be looking for at SleepHQ exactly - a free trial download or something else?

Regarding 'flagged centrals'; I see at the top of the charts there's a section for 'event flags', but I don't see any reference to 'centrals'. I see lots of 'Clear Airway' events (and others). I got a new report for last night's activity, which I'll post separately with some context.

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Re: New CPAP user, a few questions

Post by Steerpike58 » Sat Aug 05, 2023 1:10 pm

Night 3 with my new friend OSCAR. Based on the advice of one user here, I increased the min-pressure to 8, and left all else the same. I started out at 2am and used a raised pillow to try to stay on my back, since a lot of the 'leak' issues seem related to the physical issues associated with lying on my side (pressure on the mask from my pillow causing it to leak).
Image
There are two distinct 'sessions' here; the first, using the nasal mask I've been using most of the time and am most comfortable with. This session ran from about 2am to 4:15am. I feel like I didn't get too much actual sleep during that time, but I did try to pay close attention to the 'experience'. At around 4am, though, I noticed a horrible dry mouth again, and I see there was a large leak close to that time so my gut feeling is, I dropped off to sleep, and during that time the pressure from inside started blowing out through my mouth, drying it out. When I started out at 2am I noticed how 'pleasant' the experience was - gentle air being forced into my nose (which is much improved since I started using the humidifier), easy breathing. All good. But by 4am, I notice from Oscar that the pressure had risen to close to maximum (13, for me). My hunch is, that higher pressure is 'too much' for my system and air is being forced out through my mouth. But I also imagine, I "NEED" that higher pressure to solve the Apnea problem? If not, can I just reduce the max pressure to something like 10, or is that just going to render the whole thing useless?

So around 4:15am, with the terribly dry mouth, I had a drink of water and got up to pee. I decided to try the full face mask once again, to see if it addressed the 'air being blown through the mouth' issue. It seemed to start out OK, although I did notice minor leakage around the mask; nothing I did with the straps seemed to stop this, but it wasn't too bad. I probably drifted off to sleep for a while. But then I woke around 5:30 to the feeling of air really hissing out around the mask, going into my eyes, making a noise, etc. At 5:30 I gave up and slept without any CPAP from then on.

This is not going well :)

Edit To Add: Now that I've turned off the 'ramp' feature, the machine basically has two pressure settings - min and max. The machine seems to start out at the min setting, and then gradually rises to Max. What 'rules' or 'algorithms' is the machine following when doing this? Does it always try to hit max? Are there circumstances when it will stay below max? All my problems seem to occur (dry mouth, leaks, etc) at the higher pressure settings (which seems obvious) so I'm inclined to simply reduce the maximum, but then - I guess there's a minimum-required pressure to do the core job of the machine - to stop me from having 'apnea events'. So what's the basic design goal of the machine with regards to pressure?

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Re: New CPAP user, a few questions

Post by Respirator99 » Sat Aug 05, 2023 8:59 pm

Steerpike58 wrote:
Sat Aug 05, 2023 12:50 pm
Pugsy wrote:
Fri Aug 04, 2023 2:19 pm
Can you use the free version of SleepHQ online thing so that the forum members can actually zoom in on the flow rate for those flagged centrals to see if any of them happen to be flagged while asleep?

Anything while awake in terms of flagged events don't really count in terms of therapy but of course point to less than adequate sleep quality itself.
I'm new to all this so bear with me - in reading around, I see that there's an alternative to OSCAR from SleepHQ. This SleepHQ alternative may provide some insight into my situation that OSCAR is not providing? I see that SleepHQ is not free, but - there's a free version? Or perhaps just a free limited-time trial? What should I be looking for at SleepHQ exactly - a free trial download or something else?

SleepHQ is a web-based program which displays your data in a manner similar to Oscar, but it's not quite as comprehensive. Being web-based, SleepHQ requires you to upload your data to their server and you can then access it from any device with a web browser (eg a phone or iPad). The great advantage of SleepHQ is that you can send a link to your data to anybody else (eg this forum) and people can look closely at the data, and zoom in on areas of interest. With Oscar, you might have something happening at (say) 2:00am, 3:15 and 5:45 - you would then need to supply screenshots of each of these. But with SleepHQ you just need to provide a single link.

There is a free version which has some limitations but is useful for all practical purposes. The paid version gives increased functionality and access to the SleepHQ community.
Regarding 'flagged centrals'; I see at the top of the charts there's a section for 'event flags', but I don't see any reference to 'centrals'. I see lots of 'Clear Airway' events (and others). I got a new report for last night's activity, which I'll post separately with some context.
It's the same thing - clear airway event is just a more generic term to cover "false alarm" flags. Sometimes you'll have a pause in breathing due to a disturbance in your sleep, and sometimes it will be because your brain has failed to send a "breathe now" signal. As far as your machine is concerned it's the same thing. In both cases your airway is open - ie not obstructed. By zooming in close on the flow chart you can often see disturbances which indicate a false apnea - SleepHQ is good for this.
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Re: New CPAP user, a few questions

Post by ozij » Sun Aug 06, 2023 4:30 am

Lying on your back is an almost failsafe way to ensure your airway collapses and you need more pressure to keep it open.
You can see how much more pressure you needed during the first session compared to the beginning of the second in which you had some stable breathing (probably sleep) at lower pressure.

Handling mouthleaks:
Full Face Mask or taping your lips shuts. Yes, I'm serious - it terrified me 18 years ago - I've been doing it since.
Search the forum - too busy now to go into further details.

Handling leaks caused by dropped jaw and open mouth:
For some, a chin strap
For others (search zonker's posts) a cervical collar + +

Handling mask leaks:
Search for videos with fitting instructions and troubleshooting.
Consider different head pillow - even one made for CPAP users.

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dataq1
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Re: New CPAP user, a few questions

Post by dataq1 » Sun Aug 06, 2023 9:20 pm

Steerpike58 wrote:
Sat Aug 05, 2023 1:10 pm
So what's the basic design goal of the machine with regards to pressure?
That's a very valid question and if you understand the design goal, and the limitations of the machine it may help to clarify.

Broadly speaking, the goal is to splint (hold them in place) tissues that may become obstructions (full or partial).
The parameter settings (last posted night 8min 13 max) simply is the range of pressure that the machine has to work with to accomplish the goal.
During the night the pressure being applied will never drop below 8cm, and will never exceed 13cm, regardless of the number or types of events that the machine detects.

Despite central or clear airway index being one of the elements that make up the AHI (last posted 12.7), the CAI was 7.39, meaning that the remainder (5.31) are the obstructive or near obstructive events.
This has impact on how the machine reacts to these central or clear airway events, because your APAP machine does NOT react, that is it does NOT alter the pressure to splint or support the airway.
What your APAP machine will react to are the full obstructions and partial obstructions, and generally it does it in this fashion: Within seconds after an obstruction is detected, the machine will incrementally increase pressure (in an attempt to ward off subsequent obstructions.

If there are no further or continued obstructions, the machine will gradually reduce pressure (but never below the commanded minimum). [The assumption has been made, by yourself or your medical professional that you would require at all times this amount of pressure support]

Now, there is one additional factor that contributes significantly to modulating the pressure, "Flow Limitations". In it's most simple description, the term "flow limitations" relates to the observed shape of the inspired breaths. Ideally, the inspired breath shape ought to be a bell shape (that is a nicely increasing flow into the lungs to an apex flow, followed by a nicely decreasing flow as the lungs are nearing being filled. However, IF that bell shaped inspiration curve is distorted (say it has a flat top , or looks like the outline of a molar tooth (divot at the apex)), that is suggestive of something that is preventing that nice smooth bell. It may well be that what is causing that distortion is something in the airway that is impeding the airflow.

Hope this is helpful
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Re: New CPAP user, a few questions

Post by Steerpike58 » Mon Aug 07, 2023 6:41 pm

dataq1 wrote:
Sun Aug 06, 2023 9:20 pm
Steerpike58 wrote:
Sat Aug 05, 2023 1:10 pm
So what's the basic design goal of the machine with regards to pressure?
That's a very valid question and if you understand the design goal, and the limitations of the machine it may help to clarify.
Certainly helpful! Thanks. I have a 'physics/engineering' background so it does help to have this type of explanation.
dataq1 wrote:
Sun Aug 06, 2023 9:20 pm

Broadly speaking, the goal is to splint (hold them in place) tissues that may become obstructions (full or partial).
The parameter settings (last posted night 8min 13 max) simply is the range of pressure that the machine has to work with to accomplish the goal.
During the night the pressure being applied will never drop below 8cm, and will never exceed 13cm, regardless of the number or types of events that the machine detects.

Despite central or clear airway index being one of the elements that make up the AHI (last posted 12.7), the CAI was 7.39, meaning that the remainder (5.31) are the obstructive or near obstructive events.
This has impact on how the machine reacts to these central or clear airway events, because your APAP machine does NOT react, that is it does NOT alter the pressure to splint or support the airway.
What your APAP machine will react to are the full obstructions and partial obstructions, and generally it does it in this fashion: Within seconds after an obstruction is detected, the machine will incrementally increase pressure (in an attempt to ward off subsequent obstructions.

If there are no further or continued obstructions, the machine will gradually reduce pressure (but never below the commanded minimum). [The assumption has been made, by yourself or your medical professional that you would require at all times this amount of pressure support]
OK, looking at my last posted chart above, to which you refer, I see a correlation between OA and H events (obstructive apnea and Hypopnea events) and pressure increases. For each OA and H 'tick' on the chart at the top, the pressure steps up. It steps up more for OA events than for H events, which I guess makes sense as H events are only partial. So that correlation I can see, and understand.
dataq1 wrote:
Sun Aug 06, 2023 9:20 pm

Now, there is one additional factor that contributes significantly to modulating the pressure, "Flow Limitations". In it's most simple description, the term "flow limitations" relates to the observed shape of the inspired breaths. Ideally, the inspired breath shape ought to be a bell shape (that is a nicely increasing flow into the lungs to an apex flow, followed by a nicely decreasing flow as the lungs are nearing being filled. However, IF that bell shaped inspiration curve is distorted (say it has a flat top , or looks like the outline of a molar tooth (divot at the apex)), that is suggestive of something that is preventing that nice smooth bell. It may well be that what is causing that distortion is something in the airway that is impeding the airflow.

...
I'm comfortable with the ideas of bell shapes and such. To observe these curves (bell shaped or 'molar' shaped, or whatever), should I be looking at the 'Flow limit' chart in close-up? or are these details beyond the resolution of these charts? I do see some correlation with peaks on the 'Flow Limit' chart and pressure increases. I see a peak in 'flow limit' at 2:40, and a corresponding step up in pressure. Same for 3:26, and especially around 4:00am and beyond. Same goes for 4:52, and then around 5:10, 5:15.

This is my chart for Sat/Sun, Aug 5,6:
Image
Only 1:30 total duration; I tried going with the full-face mask from the get-go, did OK with it but woke up with lots of 'leak' noise issues; could not stop the leaks and gave up.

And this is my chart for Sun/Mon, Aug 6,7:
Image
Another short-ish session, again just with the full mask for 'as long as I could stand it' (3:20).

So what exactly do I make of the preponderance of 'Clear Airway' events?

Thanks!

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Re: New CPAP user, a few questions

Post by dataq1 » Mon Aug 07, 2023 9:58 pm

Tackling the last question first:
As I said, the clear airway events are comprised of two possible components neurologic causation or spontanous (non-respiratory) breath-holding.
The best way to explain the neurologic caused apnea is to understand how the brain controls respiration. Here is a short, but well done, video that describes the complexity of the brain centers and how it regulates breathing.
[url][/https://www.youtube.com/watch?v=9j6BpanhpKY]
Be aware that, while not "rare", central (or neurologic rooted) apneas tend to be the exception rather than the rule. Diagnosis of a true centrally initiated apnea is best done with an EEG.

The vast majority of the clear airway events are precipitated by some sort of arousal, what is euphemistically known as SWJ (Sleep-Wake-Junk). Those arousals may take many many forms, some that we are conscious of (like the urge to toilet), and those that we are barely aware of, if at all (like changing position while sleeping). There are literally dozens of benign arousals that are possible sleep disturbances - some that actually awaken us, some that don't necessarily awaken us. The key (I believe) to suppressing these arousals and micro arousals is to try to make our sleeping conditions as comfortable as possible, avoid stress and anxiety, use pain relievers (when needed) etc. In other words do everything one can to have a peaceful, restful sleep. Yea, I know, easier said than done

With regard to flow limitations, Take a look at the period from 01:40 to 0:215 (on Aug 6th), the pressure increases during that period (where there were no recorded events) are attributable to the changes in the flow limitations. That plot of flow limitations versus time has a y-axis scale of 0 to 1.0. The resmed algorithm examines the flows (shown in the flow rate curve) and assigns a numeric value ranging from 0 to 1 (perfect to terrible/awful). It is on the contemporaneous grading that the pressure is increased, decreased or remains the same.

The shape of the inspiration curve that I was alluding to previously can not be seen in your posted plot. You would need to expand the flow rate plot to be able to see individual breaths. If you don't know how to do that, I'll explain below.
Here is an example of my two breaths, with the inspiration phase highlighted in red:
Adjoining breaths fill.jpg
Adjoining breaths fill.jpg (7.17 KiB) Viewed 5824 times
this next picture shows some of the variations (where a class 1 is supposedly the ideal):
Classes of Flow limitations.jpg
Classes of Flow limitations.jpg (5.66 KiB) Viewed 5824 times
Hope this is helpful, pleasant sleep,

* to zoom in on any of your OSCAR plots: Click on the plot (at the time-of-day you want to examine. Use the left mouse button or the up arrow on your keyboard to zoom in. Use the right mouse button or the down arrow to zoom back out. Use the right and left arrow keyboard keys to move forward or backward in time.
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Re: New CPAP user, a few questions

Post by Tec5 » Tue Aug 08, 2023 6:54 am

dataq1 wrote:
Mon Aug 07, 2023 9:58 pm
In other words do everything one can to have a peaceful, restful sleep.
IOW …. Do whatever is reasonable to avoid stimulus that impedes sleep, including oral devices that might be irritating.
I am neither a physician nor a lawyer, so DO NOT rely on me for professional medical or legal advice.

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Re: New CPAP user, a few questions

Post by Steerpike58 » Tue Aug 08, 2023 11:37 am

dataq1 wrote:
Mon Aug 07, 2023 9:58 pm
Tackling the last question first:
...
I'll take a good look at all the info you provided here later on today. Meanwhile, last night I had a 'reasonable' session with the full-face mask; I made a strong effort to position myself on the pillow (on my side) such that the mask wasn't impacted, and did seem to get a fair amount of sleep. After 4 hours, I woke and gave up, but at least I felt like I made progress. The mask is now 'very tight', which is not too comfortable, but - it does seems to have helped with leaks and I do feel like I slept through most of this.

Image

There are two things of interest - a long spell of 'abnormal Cheyne Stokes Respiration' (3:50 to 4:15), with lots of CA events also, and then a significant drop-off of pressure from 4:10 onwards (which I presume is a good sign). I have no idea now what happened at 2:35am; I have a vague recollection of needing a drink of water. I also note a small but steady 'baseline' of 'leak rate'. I'm quite confident there is no leak at all, at least when I start off. I can both feel, and hear, leaks and I'm not sensing any at the start.

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Re: New CPAP user, a few questions

Post by Steerpike58 » Tue Aug 08, 2023 12:04 pm

dataq1 wrote:
Mon Aug 07, 2023 9:58 pm
...
With regard to flow limitations, Take a look at the period from 01:40 to 0:215 (on Aug 6th), the pressure increases during that period (where there were no recorded events) are attributable to the changes in the flow limitations. That plot of flow limitations versus time has a y-axis scale of 0 to 1.0. The resmed algorithm examines the flows (shown in the flow rate curve) and assigns a numeric value ranging from 0 to 1 (perfect to terrible/awful). It is on the contemporaneous grading that the pressure is increased, decreased or remains the same.

The shape of the inspiration curve that I was alluding to previously can not be seen in your posted plot. You would need to expand the flow rate plot to be able to see individual breaths. If you don't know how to do that, I'll explain below.
Here is an example of my two breaths, with the inspiration phase highlighted in red:
Adjoining breaths fill.jpg

this next picture shows some of the variations (where a class 1 is supposedly the ideal):
Classes of Flow limitations.jpg
...
OK, here's a zoom in of a period where pressure was increasing, showing the details of the 'flow rate' curve. Does this reveal anything of interest?
Image

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Re: New CPAP user, a few questions

Post by dataq1 » Wed Aug 09, 2023 9:19 pm

For future reference,
1) on the Flow rate graph you can place a "zero" line (to distinguish between inspiration and exhalation) by:
right click on the word "flow rate" in the flow rate graph,
on the dropdown box left click "dotted lines" and
place a check in the "zero" box.

2) Change the scale of the flow rate graph, Again right click "flow rate" ,
move your cursor to Y-axis in scaling mode and select an appropriate scale to expand or contract the scale.

so, for example in your last post I'd have selected a Y-axis scaling of max +60 to min -60.

You can do similar Y-axis scale adjustments with other graphs, like the flow limitations graph.
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Re: New CPAP user, a few questions

Post by Steerpike58 » Wed Aug 09, 2023 11:25 pm

dataq1 wrote:
Wed Aug 09, 2023 9:19 pm
For future reference,
1) on the Flow rate graph you can place a "zero" line (to distinguish between inspiration and exhalation) by:
right click on the word "flow rate" in the flow rate graph,
on the dropdown box left click "dotted lines" and
place a check in the "zero" box.

2) Change the scale of the flow rate graph, Again right click "flow rate" ,
move your cursor to Y-axis in scaling mode and select an appropriate scale to expand or contract the scale.

so, for example in your last post I'd have selected a Y-axis scaling of max +60 to min -60.

You can do similar Y-axis scale adjustments with other graphs, like the flow limitations graph.
Great tips! What a powerful charting tool this is; I presume this must be based on some general purpose engine, and not developed by the authors of OSCAR ... but I digress ...

This is my chart from last night. I've pretty much resigned to using the full-face mask now (as I can't seem to control the escape of air through my mouth), and when the leaking and hissing wake me up, I just take a break and then restart. That's why there are three sessions here. By the time the third session is over, I sleep for a few more hours without the mask (which I much prefer, but - I'm determined to come to terms with this machine!). I also reduced max pressure down to 12 (from 13) as a way to see if reducing the pressure will reduce the leaking, while still providing some benefit.
Image
And here's a zoom in on a very short segment, showing individual breaths, and corresponding to a time when the pressure was being increased without any OA or H events shown.
Image
I adjusted the 'flow rate' as per your guidance to show more detail. I'm still not sure what to make of this, but maybe there's enough resolution there now for you to comment?

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Re: New CPAP user, a few questions

Post by Steerpike58 » Thu Aug 10, 2023 6:23 pm

I created an excel chart for the data so far, and a couple of things really stood out. Here's the data and chart, created in Excel:

Image

I noticed that, while my AHI has been consistently high (average 14.6), it's mostly made up of CA (clear airway) events (average 10.4). The OA (Obstructive Apneas) averaged at only 2.8, and the H (Hypopneas) averaged at only 1.4. Based on my limited understanding so far, the CPAP machine is designed to address OA's and H's primarily (that is, it's not designed to address CA events) - is that correct? Also - can I assume the CPAP machine is actually doing some good with the OA's and H's? If the reported OA and H values are 2.8 and 1.4, does that mean the CPAP machine is 'fixing' a lot more OA's and H's that are no longer occurring thanks to the pressure of the machine? Does that make any sense?

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Re: New CPAP user, a few questions

Post by dataq1 » Thu Aug 10, 2023 9:02 pm

Very nice !
And in case I didn't mention it before, a graphic representation of AHI components can also be seen by selecting the "Overview Tab" on your OSCAR report.

To your question: The home PAP machines do not react to Clear Airway events. In fact, for some people, the pressure applied in reaction to obstructive and hypopnic events may, for some people, increase the frequency of clear airway events. This is called treatment-emergent CSA and seems to occur in 10-15% of the population of folks who are being treated for obstructive apnea by positive pressure CPaP/APaP. You can Google "treatment emergent CSA".

Relative to the efficacy of C/Apap with respect to treating obstructive and near obstructive events, you have to compare against your untreated values (sleep study). That is why it is so important (IMO) that your sleep study results are reliable and representative of your "normal and usual" (untreated) sleep experience.

Hope this helps.
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