Higher AHI but feel better?

Hi all,

My sleep study AHI was 38. I was prescribed with bipap: min EPAP = 5.5, max IPAP = 16, PS 3 to 8. With this setting I am getting AHI <5 but I am not feeling particularly more rested. Majority of my events are CA, followed by Hypopnea then obstructive.

Four nights ago I started changing the settings. First, I changed min EPAP to 7 and the rest remain unchanged. The next morning I had AHI = 8, PB=7% and record high Hypopnea and CA events. I felt like crap that day.

The following night, I changed min EPAP to 4.5, min PS = 4. The next morning I had AHI=6.42, PB=0% and I didn't really feel sleepy but a little heavy headed. Generally I felt more rested than min EPAP 5.5 and min PS 3.

Because I felt more rested, I continued with this setting for another night and AHI was 10.8, PB=1%. Yawned a few times in the day but again, feel more rested, not so sleepy.

Last night was the 3rd night on this setting and this morning my AHI was 7.7, PB=0%. So far, I am feeling OK too.

In all cases, the majority of the events are CA, followed by Hypopnea then Obstructive.


I am now puzzled as to why higher AHI left me more rested and feeling better. Should I change the settings again to bring down the AHI? if so, what should I change?

Lastly, would it make sense if i just open up the ranges (e.g. min epap 2, max ipap 20; PS 2-16) and let the machine decide the required pressures?

Help anyone?

I read in other thread that deep sleep and REM sleep relaxes the tongue causing more events. And high AHI could mean deeper sleep and more REM sleep thus feeling better. Is it true?

Welcome to the forum.

What model machine do you use?

Hopefully a machine that will work with SleepyHead but we need to know the model name and who the manufacturer is.

I am using the PR System One. And yes! I have the sleepyhead data but do not have access to it right now.

Which model System One? It's one of the bilevel/bipap models but your pressure settings sound like one of the ASV models used to treat central apnea as well as obstructive apnea.

Do you have a copy of your original sleep study? If not...get it. Did you have a large number of centrals during either the diagnostic sleep study or the titration sleep study (where you wore the mask and machine was on)?

Did you have a sleep study where they put you on the machine to determine pressure needs?

I need to see a detailed report from SleepyHead for a good night at your original settings and then one from now since you have changed things to be able to offer any ideas.

If the majority of your events are clear airway/central then you probably can't blame it on REM because we don't do much central apneas in REM. Obstructive yes but central not so much.

Off hand I think it sounds like you need to go back to the original settings and the only change be to change PS...from 3 to 8 to 3 to 15 but I really need to see the detailed reports to know for sure if that is what I would suggest.
Plus I need to know what your diagnosis was...was it obstructive apnea, central apnea or complex apnea.

There is a model number on the bottom of the blower that will tell use which model.
A 3 digit number that usually begins with DS or REF

Also how long have you had or been using this machine?

I'll let you and Pugs work out the settings thang, but a lower AHI doesn't always mean you'll feel better. Everyone is different and responds to therapy different. My average AHI is a .3 or .4. If I get a zero, I know I'm gonna feel crappier that day than I would with a higher AHI. I'll get a zero may once or twice a month. Not real bad, but slightly worse. In fact, if my AHI edges up toward a one, I do feel better! This is just me though, and might not be the same for everyone else. Be sensitive to how you feel during the day. The bottom line is for us to feel better and well rested and.... protect our health.

Food for thought....


Sheriff

Pugsy wrote: ↑

Mon Aug 13, 2018 4:16 am

Which model System One? It's one of the bilevel/bipap models but your pressure settings sound like one of the ASV models used to treat central apnea as well as obstructive apnea.

Do you have a copy of your original sleep study? If not...get it. Did you have a large number of centrals during either the diagnostic sleep study or the titration sleep study (where you wore the mask and machine was on)?

Did you have a sleep study where they put you on the machine to determine pressure needs?

I need to see a detailed report from SleepyHead for a good night at your original settings and then one from now since you have changed things to be able to offer any ideas.

If the majority of your events are clear airway/central then you probably can't blame it on REM because we don't do much central apneas in REM. Obstructive yes but central not so much.

Off hand I think it sounds like you need to go back to the original settings and the only change be to change PS...from 3 to 8 to 3 to 15 but I really need to see the detailed reports to know for sure if that is what I would suggest.
Plus I need to know what your diagnosis was...was it obstructive apnea, central apnea or complex apnea.

Pugsy , thank you for your response and being so careful about giving your recommendation

My model is REF-761P. Been using this machine since 28-Jul, so about 2 weeks. Prior to this machine i was on CPAP (4 weeks) and BiPAP (1 week) trial. Decided to get BiPAP because I could sleep for a longer stretch with it. All other factors (e.g. AHI, feel rested or not) are similar on both machines.

During the home-based sleep study I had 97 OA, 24 mixed apneas, 0 central apnea, 176 hypopnea and 0 RERA. These resulted in total apnea index of 14.5/hr, with an OA index of 11.6/hr, CA index of 0/hr, mixed apnea index of 2.9/hr, hypopnea 21.1/hr and RERA index 0/hr. AHI was 35.5/hr. RDI 35.5/hr. REM AHI 62.5/hr. REM RDI 62.5/hr. Respiratory arousal index 6.6/hr. O2 lowest desaturation was 81%. My sleep coach did a titration during my first visit but I did not really fall asleep so I am not sure how accurate the resultant pressure is.

Original setting, felt rested, normal AHI (4.29):


After setting change, data from 2 nights ago, felt rested, highest AHI (10.77) so far:


data from last night, felt rested, higher AHI (7.64) compared to original:

seems like the images are not showing up as I would like.. please cross reference the AHI number. thanks!

Okay, not ASV and no centrals on the diagnostic sleep study to speak of.
The 761 is the PR System One 60 series BiPap Auto.

Let's step way back and just modify the original setting just a little.
Try this
Minimum EPAP 6.0 (it was 5.5 and did a decent job but could have maybe used a little minor tweaking to clean things up a bit more).

PS minimum...change it to 2 and PS max change it to 4.
Sometimes when people use too much PS it triggers centrals.

Maximum IPAP of your choosing but it probably isn't going to go anywhere near the max but you can use 20 max if you wish.

Probably will need further tweaks but right now lets start with this and rein in PS a bit just in case you are in that small minority where too much PS causes a problem.

Pugsy wrote: ↑

Mon Aug 13, 2018 6:53 am

Okay, not ASV and no centrals on the diagnostic sleep study to speak of.
The 761 is the PR System One 60 series BiPap Auto.

Let's step way back and just modify the original setting just a little.
Try this
Minimum EPAP 6.0 (it was 5.5 and did a decent job but could have maybe used a little minor tweaking to clean things up a bit more).

PS minimum...change it to 2 and PS max change it to 4.
Sometimes when people use too much PS it triggers centrals.

Maximum IPAP of your choosing but it probably isn't going to go anywhere near the max but you can use 20 max if you wish.

Probably will need further tweaks but right now lets start with this and rein in PS a bit just in case you are in that small minority where too much PS causes a problem.

Ok will change accordingly and report back. thanks!

Btw, which description in the profile page best describe my machine? can't seem to find any system one in the list

Pugsy wrote: ↑

Mon Aug 13, 2018 6:53 am

Okay, not ASV and no centrals on the diagnostic sleep study to speak of.
The 761 is the PR System One 60 series BiPap Auto.

Let's step way back and just modify the original setting just a little.
Try this
Minimum EPAP 6.0 (it was 5.5 and did a decent job but could have maybe used a little minor tweaking to clean things up a bit more).

PS minimum...change it to 2 and PS max change it to 4.
Sometimes when people use too much PS it triggers centrals.

Maximum IPAP of your choosing but it probably isn't going to go anywhere near the max but you can use 20 max if you wish.

Probably will need further tweaks but right now lets start with this and rein in PS a bit just in case you are in that small minority where too much PS causes a problem.

Pugsy, do you mind explaining:
1) why you decided to revert to original setting and tweak from there?
2) why increase min EPAP?
3) why reduce PS although higher PS seem to make me feel more rested?

I am trying to learn here. Thanks!

Your machine has been discontinued and is no longer a choice in the equipment menu.
Just manually add it to the comments section so we can see it there.
Typing PR S1 60 series BiPap Auto is sufficient.

bipap3800 wrote: ↑

Mon Aug 13, 2018 7:40 am

Pugsy, do you mind explaining:
1) why you decided to revert to original setting and tweak from there?
2) why increase min EPAP?
3) why reduce PS although higher PS seem to make me feel more rested?

Don't mind at all.

1....because your best apnea prevention settings were closer to the original and maybe with just a little tweaking with those settings you would have also felt more rested.

2...because the bulk of your AHI at the original settings was obstructive in nature and there wasn't a lot of them...and since we use EPAP to better prevent obstructive stuff then that is the logical first thing to change.

3...because of the clear airway/central apneas you are seeing....too many of them I don't care how well rested you are.
Let's try to get you more rested without triggering central apneas.

Sometimes in some people simply more pressure (as in more EPAP/IPAP because when you increase EPAP your are also increasing IPAP) will cause centrals to happen that weren't a problem before. About 10 % of cpap users might see this happen.
Another small majority of people will have centrals pop up with too much PS. Rare but can happen and you were sometimes going to 6 cm PS with your range and all I want to do right now is bring it down a little and let's see if the centrals reduce. We can add more later for comfort and well rested feeling but let's do it in small chunks (assuming that PS isn't the trigger) instead of big leaps.

Something caused you to have a whole bunch of centrals pop up and that's not good. You made multiple changes at one time so it's darn near impossible to know which change was the trigger. Sometimes it is PS that is the trigger...I know one woman who gets about 15 centrals per hour average with a PS of 4 but none to speak of with a PS of 3. Sometimes there is a very fine line we have to look for.

So...I prefer a more conservative approach...start back closer to what was originally prescribed and there was okay results and work from that starting point.
Make smaller changes and a more thought out experiment. Remember Science 101...keep your variables to a minimum so you can best evaluate your results.

Here's the data from last night - CA seem to increase.. what to do next?

How was your sleep quality? Did you wake very many times and/or spend much time awake with machine and mask on? I see one time where you turned the machine off...were there other awake times and you didn't turn it off?
How do you feel today?

Yes, slightly increased CA average when compared to what you got with initial settings but significantly reduced from the night where your AHI was 10 and 2/3 of it was central/CA.

Oh...where's the Events graph from last night? We need to see it also.
Always on the right there graphs
Events
Flow rate
Pressure
Leak.