First Mo Findings - High Central, Volatile AHI, low pressure

[urbanscribe]

was diagnosed a while back with severe OSA (2 sleep studies, 39 and 34) in the last 4 months. one showed more Obstructive one showed more Hypopneas, NONE showed Centrals/Clear Airway apneas. 48yrs old, 25 BMI index, 6:1, 200 pounds, generally good health.

Have been on APAP ResMed S9 for about 20 days now. See attached findings.
First started with prescribed 8-12 pressure range (without titration study, just GP not sleep doctor eyeball) then changed to 6-20 broader range due to aerophagia and desire to see unrestricted results.

Few questions:

1) Biggest numbers reported (both at 8-12 and also 6-20) across all S9 therapy stats are CLEAR AIRWAY apneas (purple), that's consistently the largest number. I understand that having too high a pressure will cause aerophasiga and central/clear airway apnea, BUT these centrals/clear airways are also present at low pressures like 6-7-8 see july 3,4(see graphs)
-> how come i still get centrals/clear airway apneas at such low pressures?

2) Although my AHI numbers untreated in the sleep studies were very high (39 and 34), it seems that the best results i have gotten are at low pressure. When on 8-12, best results at the 8 bottom, on 6-20 best results around 6.5 pressure.
-> is it possible to have large AHI untreated which are properly rectified with such low pressure? everything else being equal, i would have expected such high AHIs to require HIGH pressure to cure/solve

3) Any insights into the high variability of the AHI results?
Obviously i recognize that these results have clearly shown therapy is helping reduce AHIs. I've tried a few masks (Swift FX nasal pillows, Airfit F10 FFM) with no discernible patterns. Best results on the nasal pillows so not mouth breathing but there is really no logic as i also got my worse results with the pillows as well.



first study


second study (in french)

[Pugsy]

Severity of OSA has nothing at all to do with the pressure(s) needed to effectively prevent the airway from collapsing.
A person can have rather "mild" OSA with AHI of say 12 and maybe need 20 cm of pressure to hold the airway open and another person might have a really "severe" OSA with an AHI of say maybe 80 and only need a pressure of 6 to hold the airway open.
It's all about how floppy the airway tissues are and not the pre cpap AHI number.

I can't see your images...might be my internet connection...exceeded my allowance and now have to suffer with really slow download speed for a few days.

[urbanscribe]

thanks pugsy

let me know if you can't see the images again soon. they are on dropbox and properly show up in preview and post view.

i understand there is no causality but wondering about correlation and wether there is meaning in achieving best results at low pressures, particularly since these graphs show a high incidence of centrals which were not there pre-therapy if you believe the sleep studies.

also confused why one at-home study would report of 39 AHI, 33 coming from OBSTRUCTIVE when a second at-home sleep study reports a 33AHI, 32 of which comes from HYPOPNEAS. can these test be that variable in reported results. 0 centrals on both.
seems high standard error of the estimate going on

[Pugsy]

The image issue is on my end for sure. It's my internet speed (which is a crawl) the images try to load but taking forever....I get a tiny snippet and that's it and the little spinning thing telling me that things are trying to load just keeps trying.

So I can't see how many centrals you are having but remember.....the machine doesn't know if you are awake or asleep and it will/can often flag awake/semi awake breathing irregularities as some sort of apnea event and most often it will flag them as a central. The machine is easily fooled.
Higher pressures causing centrals??? About 10 to 15 % of the cpap population might see centrals materialize with the introduction of any cpap pressure. People think that higher pressures are the cause but actually they can happen with as little as 5 cm of pressure so not always the higher pressure being the sole cause. It can sometimes be "any" pressure.

Not all centrals are related to pressure anyway. Having some central events is normal and expected...like sleep onset centrals when we transition in sleep stages.
Since I can't see your images I will have to defer to others who can see them...and I would only want to see the detailed report images showing when they happened. For myself I wouldn't dwell on the home study reports...be it apnea or hyponea.....the diagnosis is there and I would just move on.


I also wouldn't dwell on the differences in the home study results. Hyponea vs apnea distinction sometimes is just a matter of small difference in criteria. Often just a slight difference in the amount of flow reduction.
Also we simply don't sleep the same way each night.

[robysue]

urbanscribe,

The images are not showing up.

This is what I see where the images are supposed to be:

Image

first study
Image

second study (in french)
Image

When I open up the your post by quoting it, I do see the full links, but when I paste them into my browser I get a

• Not Found
  The resource could not be found

error.

I suspect the problem may either be that the drop box folder is not "public" or "shared" and that's why the rest of us can't get to it. That would explain why you see the images (it's your dropbox folder) and we don't.

Or the problem could be with the start of the urls:

• https://photos-3.dropbox.com ....
  https://photos-4.dropbox.com ....
  https://photos-2.dropbox.com ....

My browser can't find the machine(s) specified by these URLs and hence can't find the image files.

[robysue]

also confused why one at-home study would report of 39 AHI, 33 coming from OBSTRUCTIVE when a second at-home sleep study reports a 33AHI, 32 of which comes from HYPOPNEAS. can these test be that variable in reported results.

The line between an OA and an H is arbitrary: A typical home study will score an OA when the flow rate drops by 90% or more (and other conditions are met), but if the drop is only 88%, it gets scored as an H. The sensitivity of the equipment may have been an issue if a lot of your events have a drop that is right around that 90% are cut off line to distinguish OAs from Hs.

But the thing is that it doesn't really matter very much if the events are 33 OAs or 32 Hs. They're both bad for you and they both get treated the same way.

[Pugsy]

Hey, wouldn't you know it.....I finally have one image in front of me.....the home study in French.


Question....just what is the AHI that we are concerned with? And what is thought to be "high central" are we talking 10 centrals over the entire 7 hour night or 10 centrals per hour which would mean 70 over that 7 hours?

My idea of "high" may not be the same as your idea of "high". I know of one guy who says his centrals go "through the roof high" when they go from 0.5 per hour to 1.5 per hour. Not my idea of "through the roof high" at all.

[robysue]

Hey, wouldn't you know it.....I finally have one image in front of me.....the home study in French.

Well, it's not showing up for me yet.

Question....just what is the AHI that we are concerned with? And what is thought to be "high central" are we talking 10 centrals over the entire 7 hour night or 10 centrals per hour which would mean 70 over that 7 hours?

My idea of "high" may not be the same as your idea of "high". I know of one guy who says his centrals go "through the roof high" when they go from 0.5 per hour to 1.5 per hour. Not my idea of "through the roof high" at all.

Good and relevant questions.

[palerider]

I understand that having too high a pressure will cause aerophasiga and central/clear airway apnea,

correction, *may* cause. only a small percentage (15 or so) of people develop pressure caused centrals. and not everybody has issues with aerophagia, (I don't).

[palerider]

I can't see your images...might be my internet connection...exceeded my allowance and now have to suffer with really slow download speed for a few days.

it's not you.

[urbanscribe]

thanks all

moved the images from dropbox. they show up on browserstack but inconsistently for phpbb inclusion i guess. won't use public dropbox share for this. must be some incompatibility of some sort.

Question....just what is the AHI that we are concerned with? And what is thought to be "high central" are we talking 10 centrals over the entire 7 hour night or 10 centrals per hour which would mean 70 over that 7 hours?

forgetting the sleep studies which both show 30+ events index (PER HOUR).
the current S9 autoset results show 2/3 (two thirds) of events being CA, not H or O.
for example

june 3 indexes (again PER HOUR)
H 0.13
OA 1.87
unclassified 0
CA 4.82

again no Centrals ever in both in-home sleep studies PRIOR to treatment.
this remains the question here.
worry/not worry about these centrals which average 2-5 PER HOUR every night which did not exist if you believe two at-home studies.

My idea of "high" may not be the same as your idea of "high". I know of one guy who says his centrals go "through the roof high" when they go from 0.5 per hour to 1.5 per hour. Not my idea of "through the roof high" at all.

what is YOUR idea of high for CAs, absolute or relative?

correction, *may* cause. only a small percentage (15 or so) of people develop pressure caused centrals. and not everybody has issues with aerophagia, (I don't).

my understanding is that significantly too high pressure/volume in the lungs causes a natural reflex in the respiratory system to stop breathing, which while not CAs are REPORTED as CAs.

finally the issue here
IS NOT should i worry if i have Central Apnea/Clear Airway Events which i know how to answer
but
IS should i worry if the Autoset REPORTS Central Apnea/Clear Airway Events
and if the Autoset REPORTS Central Apnea/Clear Airway Events then how much more pressure adjustment/mask trial should i undergo before considering i now have an actual CA problem

peace out.

[urbanscribe]

reposting the original unanswered questions now that the images should show up

1) Biggest numbers reported (both at 8-12 and also 6-20) across all S9 therapy stats are CLEAR AIRWAY apneas (purple), that's consistently the largest number. I understand that having too high a pressure will cause aerophasiga and central/clear airway apnea, BUT these centrals/clear airways are also present at low pressures like 6-7-8 see july 3,4(see graphs)
-> how come i still get centrals/clear airway apneas at such low pressures?

3) Any insights into the high variability of the AHI results?
Obviously i recognize that these results have clearly shown therapy is helping reduce AHIs. I've tried a few masks (Swift FX nasal pillows, Airfit F10 FFM) with no discernible patterns. Best results on the nasal pillows so not mouth breathing but there is really no logic as i also got my worse results with the pillows as well.

[Pugsy]

what is YOUR idea of high for CAs, absolute or relative?

Greater than 5 per hour ...every night...that I cannot explain away as being awake/semi awake centrals being flagged by mistake because the machine is misinterpreting my awake breathing irregularities.
Greater than 5 per hour every hour and not a cluster of 20 in one hour that makes the hourly average elevated and I go for hours with no centrals.

Seeing the trend graphs for AHI breakdown don't tell us when those centrals are occurring...
Are they clustered around known awake times? That's a real important question that needs to be answered.
We need to see the detailed nightly graphs to get a feel for when these centrals are happening....
Like this image below... I had a truckload of centrals starting around 1AM and lasting approx 45 minutes...I was awake the entire time. Woke up with really bad nausea and I lay there trying to decide if I needed to get up and go find the throne but I didn't....but the machine misinterpreted my awake breathing irregularities as centrals and while it looks ugly....it isn't/wasn't anything to be concerned about.

When newbies get into a panic over centrals (when there were none during the initial diagnostic sleep studies) they don't realize that sometimes these "centrals" aren't anything to get into a panic over. I don't know what is going on in your situation but we need to see when your centrals are actually occurring before we hit the panic button.
For all we know right now your nights with a higher than we would want to see central average might be explained away by awake/semi awake breathing getting flagged by mistake.
Can you provide an example of a "bad" night and a "good" night in detail like this image of mine?

[urbanscribe]

thanks very helpful.

here are examples

good night





bad night

[Pugsy]

Well those bad nights are really ugly. On the bad nights I can't really see the pressure line except on the July 3 image as the others show only the zoomed in on the clusters pressure....so hard to say if they are pressure related or not with any certainty.

Your good nights are really good though.

On the bad nights did you have a lot of awakenings or sleep soundly pretty much through the night?

Can you think of anything that changed from the good nights to the bad nights? Anything that might affect your sleep? Meds? Pain? Anything?

If you are thinking maybe related to pressure...maybe limit the maximum to 10 and see what happens.????