SpO2 Drops Not Correlated with Apneas

[Crimson Nape]

I don't put a lot of faith in the hypopnea flags, other than the machine sensing a flow rate reduction. It is supposedly based on a breathing reduction of 50%, but I am not aware of the preceding time period it is using for comparison.
- Red

[SunMesa]

I still don't have a true explanation, but the folks on this board convinced me to request supplemental oxygen from my doc, and life is now 1000% better.

So do still use any form of PAP therapy? If so, do you alternate it with supplemental O2, or even combine it somehow with PAP? Thanks for any info, I'm very interested in the potential benefit of supplemental O2.

[ArcherNeedsSleep]

I'm very concerned about chronically low SpO2 causing permanent damage, including to the brain, ...

I definitely saw negative effects in my cognition.  I was stubborn and let mine go too long (years!) before I started pushing on my doc to get O2.  My mental processing bounced back pretty well after starting nighttime oxygen, but I still struggle with a few things that I shouldn't.  I'm hoping it's just a matter of time to recover mostly full functioning, but I suspect I had damage that won't heal.  Time will tell.

So do still use any form of PAP therapy? If so, do you alternate it with supplemental O2, or even combine it somehow with PAP? Thanks for any info, I'm very interested in the potential benefit of supplemental O2.

I mostly still use my BiLevel with the oxygen bled into the line.  I tried straight oxygen, and it works, but the air is so dry here in Colorado that I couldn't get enough moisture added, even with the bubbler attachment.  The PAP machine does a much better job of adding moisture, so I default to it.  Plus, the PAP gives me data, so if anything starts feeling "off", I can get insight to what's going on.

[SunMesa]

I also live in Colorado. We're starting with low O2 right off the bat!

I'm very glad and encouraged that you're getting cognitive recovery. You hear different opinions about whether this damage is reversible. Although it examines treatment of OSA with CPAP rather than supplemental O2, the following study indicates that dramatic reversal of OSA-induced brain changes does occur, but it takes a full 12 months of steady treatment:

Castronovo, V., et al, "White Matter Integrity in Obstructive Sleep Apnea before and after Treatment", Sleep, Vol.37, No.9, 2014
(see https://dx.doi.org/10.5665/sleep.3994)

If O2 depletion is driving these OSA-induced changes, it seems plausible that supplemental O2 might similarly reverse them, even (and perhaps particularly) in situations where mechanical airway blockage was not the principal cause of the O2 depletion.

I mostly still use my BiLevel with the oxygen bled into the line.

This is intriguing, but sounds tricky. Can you describe how it's done? I'm picturing a simple tee into the outlet tube from the PAP machine, but then there's the issue that you have to overcome a (potentially variable) positive pressure in that line.

[ArcherNeedsSleep]

That was a great article.  Thank you for the link.

To bleed O2 into your PAP, just add a connector like the one pictured here, or use the special climateline heated tube that has a port built into it.  

   

The calculation is explained in the apnea board wiki.  I built a quick spreadsheet to calculate my rate as 2.5L/min, using the flow rate of my P10 pillows (34.5L/min - found in the product documentation), the O2 concentration at my altitude of ~7500 ft (16%), and the concentration advertised by the concentrator I was buying (~90%).  I targeted a result of sea level O2 concentration (21%).  I just played with the O2 flow rate value until I hit an effective FiO2 of 21%.  It's working perfectly for me.