BiPAP - Good AHI but feeling tired

[Jason S.]

Hi, just wondering why you went from CPAP to BiPap. I am currently on CPAP and not getting good treatment. My sleep doctor mentioned a while ago about the possibility of me moving up to BiPap. I’m sure I would have to have another sleep study, which would be my third, to see if BiPAP would be effective for me.

[palerider]

Happy to try that, would doing so not negate the benefit of using a BIPAP machine though? I thought the purpose of BIPAP was all about having a pressure differential. As I understand it the pressure differential would help with my CO2 being on the high side.

Yes, but if that ps is causing centrals... Then you're blowing off too much co2

[jonron]

Happy to try that, would doing so not negate the benefit of using a BIPAP machine though? I thought the purpose of BIPAP was all about having a pressure differential. As I understand it the pressure differential would help with my CO2 being on the high side.

Yes, but if that ps is causing centrals... Then you're blowing off too much co2

One thought on this, would taping over some of the vents on the mask allow me to run higher PS? Or is this counter-productive?

Presumably taping some of the vents would keep more CO2 inside the mask? I use a Dreamware FFM with vents on the front of the mouthpiece and also vents at the top of the headgear.

[palerider]

Happy to try that, would doing so not negate the benefit of using a BIPAP machine though? I thought the purpose of BIPAP was all about having a pressure differential. As I understand it the pressure differential would help with my CO2 being on the high side.

Yes, but if that ps is causing centrals... Then you're blowing off too much co2

One thought on this, would taping over some of the vents on the mask allow me to run higher PS? Or is this counter-productive?

Presumably taping some of the vents would keep more CO2 inside the mask? I use a Dreamware FFM with vents on the front of the mouthpiece and also vents at the top of the headgear.

There was one person I helped a while back who had horrible centrals on his prescribed machine and settings, and even with *zero* PS he was having significant centrals. I suggested that he might try blocking the lower hole on his dreamwear, to create more deadspace, and increase CO2.

The number of centrals he had went way down... and he slept better, and was better rested.

So, theoretically, what you say is possible, but not something I'd want to play around with 'just because'.

[jonron]

Very interesting. Agreed, I'd not do it "just because", but in testing I get exclusively centrals with any PS above 2.. Doctor recommends trying to get PS to around 4, which gives me an AHI of around 5 normally - all central.

I am thinking I might try taping over a small portion of the vents as a trial..

[palerider]

Doctor recommends trying to get PS to around 4,

Why?

[jonron]

Said my CO2 levels were slightly high on my in-lab study and that more PS would help me take deeper breaths which should help this.

But now it seems that the higher PS may be making me blow off too much CO2 and trigger centrals?! So trying to find a happy balance with a view to not feeling so tired all the time.


I wonder if there are any at-home CO2 monitors that would be worth getting. Similar to the pulse oximeters. That way I could actually measure this and know for sure..

[jonron]

So I tried this last night. I taped over 6 out of 13 holes on front of the Dreamwear FFM. I got an AHI of 1.5 last night! Normally get between 5-6. Also, I slept through the whole night where I normally get up at least once.

Very interesting. I wouldn't say I feel any different though.. I think I will try taping more/less and see what happens. I'll start with less and see if I can discover what the minimum amount of holes I need to cover to get similar results.

What this is telling me is that all masks are not created equal. I chose this one (after trying 10+), because it was the only one I found that was comfortable and fit well. I might end up having to try other masks, or find the "correct" number of holes to cover up to get the correct amount of O2/CO2 in the mix. This is just a theory of course but somethings definitely going on here with this mask..

[jonron]

Last night I tried with just 3 holes taped over. AHI of 0.3! Wow! I have never seen numbers that low before.

I need to try and understand whats going on here!

[Pugsy]

To make understanding anything more difficult there remains the fact that we don't sleep the same each night so we can have rather wide variances in data and make no changes in anything.