[CPAP] What is wrong?

[williwaw]

Hi,

I've been using CPAP for about 5 yrs. My sleep has deteriorated over the last few months, waking up multiple times and struggling to fall back to sleep. 
If I take the mask off,  I can sleep deeply. 
If I need to take a deep breath, I feel that the machine doesn't give me the air that I need, but in general terms, I don't feel suffocated, and I'm OK using the device.

AHI is not bad (1.0x), but it seems that it has increased in the last year or so. It is not about the numbers; I'm more tired during the day than I used to be. 

Looking at my OSCAR data, do you suggest any setting changes?

 Device Settings (for about two years)
  Mode: APAP (Resmed Airsense 10 Autoset)
  Pressure Min 4.00 cmH2O
  Pressure Max 7.00 cmH2O
  EPR Full Time
  EPR Level 1 cm H2O
  Mask Nasal (DreamWhisper)
+ Chinstrap

Thanks in advance!

    .      .      .

[Gideon]

Welcome to the forum.

While your numbers all look good your description does not. Your description describes pretty classic feeling of air starvation. The pressures you are using specifically the min of 4 is considered by many to be a pediatric pressure.

Try a min of 6 and set EPR =2. And see how that goes. Set your max to 10, I doubt your pressure will go there.

I suspect you may need a min of 7 and possibly a EPR of 3. But we will see.

[Sleepster]

You are hitting your max pressure of 7 quite a bit, so it may simply be that now, being five years older, you need a higher pressure. You also have a lot of flow limitations that might be addressed with a higher EPR. Maybe raise EPR to 2, set min pressure to 6, max pressure to 10, and see what happens.

Your leak rate is low enough (below 24) that it's not supposed to affect your therapy. But you have a lot of leaking. That alone could be disrupting your sleep, even though it's not compromising your therapy. So I would try a chin strap or better yet a full face mask. Even if you weren't able to tolerate a full face mask a couple of years ago, you probably can do so now with ease.

Quick edit. I see Gideon answered while I was typing. Interesting that his pressure recommendation matches mine.

[ICEMAN]

Deleted, to not duplicate and overcomplicate, as other more  experienced already answered your question.

[williwaw]

@Gideon, @Slepster,

Thank you for your prompt reply.
As a first step, I adjusted the pressure to 5 and 9 and EPR to 2.

I had a better night with fewer wake-ups, and the feeling of "air starvation" improved a great deal.  I will try these settings for a while and report back.

Thanks again!
   

[staceyburke]

Min5 epr2 does not work well. 4 is the absolute lowest the machine can go. Your exhale is min minus EPR (5-2) the min cannot be 3. So min 6-2 =4. Or min 7 - 3 exhale =4.

[williwaw]

@stacyburke

I thought that the while I exhale, the pressure would be reduced by the EPR setting, but it would at all times ensure it is at least the "Min pressure".
So, even with  "Min Pressure set to 5 and EPR to 2, the pressure would be 4 if I exhale while the inspiration pressure is 5; if the inspiration pressure at the time is, let say, 8 (Max setting=9), the expiration pressure would be 8-EPR=6.

The " relief" would not be much, at pressures below 4+EPR, since EPR setting won't be "honored" by the machine that can't handle anything below 4 cm H2O.

Could you clarify if my understanding is correct?

[Sleepster]

I thought that the while I exhale, the pressure would be reduced by the EPR setting, but it would at all times ensure it is at least the "Min pressure".
So, even with  "Min Pressure set to 5 and EPR to 2, the pressure would be 4 if I exhale while the inspiration pressure is 5; if the inspiration pressure at the time is, let say, 8 (Max setting=9), the expiration pressure would be 8-EPR=6.

The " relief" would not be much, at pressures below 4+EPR, since EPR setting won't be "honored" by the machine that can't handle anything below 4 cm H2O.

Could you clarify if my understanding is correct?

You have it correct.

Which is why I recommended a minimum pressure of 6. The idea was to boost the EPR to 2 to address the flow limitations; but with a minimum pressure of 5 you're not getting a difference of 2 are you? And the reason for the upper pressure recommendation of 10 is because you likely need at least that much to address the obstructive apneas.

[Gideon]

You could set your max = 20 and not impact your therapy because your pressure will never go that high. 10 is just a "safe" value because you had very low settings.

Please Note in detail how you feel at Min = 6 and EPR=2, this is your new baseline, your new "safe" spot.

you stated "feeling of "air starvation" improved a great deal" which implies there may be room for improvement.

Try Min = 7 and EPR = 3

Now which settings feel better and why?

[williwaw]

Thanks, Gideon.
I've changed the preassure settings to 10 and 6, EPR: 2.
Let's see how it works. The first night was OK; AHI incremented to 1.8 with multiple CA, but it's just one night.

Thank you all for taking the time to help me.