Low spO2 levels even with low AHI

[Sleeprider]

This is pretty elementary.  You need a higher minimum pressure to improve oxygenation.  Your machine is setup at the default 4-20 and with the minimum pressure set that low, you are constantly triggering flow limitations and have a remarkably low minute vent.  The tidal volumes are not visible with that pie chart in there.  

Your pressure is swinging up from 4 and averaging 8 and your 95% pressure is 12.  You need to set that minimum pressure to 7 or 8 to get your therapy out of the hole and improve oxygenation.  I have posted it before, but this is an excellent presentation of what can be accomplished with CPAP and Bilevel pressure machines. The part you need to hear is EPAP pressure, or in your case minimum pressure, establishes a patent airway and promotes oxygenation.  Increase the minimum perssure, you'll be amazed.

[Tigerman67]

Thanks for the info.

I switched to the auto titrating CPAP setting to try to get a feel for whether my older prescription (11 in standard CPAP) was still in the ball park. My 90% number has been averaging 11, my 95% was averaging 12-12.5

So is it usually preferable to run it in the auto titrating CPAP setting, but with higher starting pressure you mention, or go back to the fixed pressure?

[Sleeprider]

If you are accustomed to higher pressure, my recommendation would actually be a minimum pressure of about 9.5 on auto mode. You are able to get good treatment with lower pressures, so there really is not need to use fixed pressures. The machine is clearly responding to your needs by raising pressures. By being within 2 cm of your therapy pressure, you should get the best of both worlds. Even for titration purposes, a higher starting pressure would have been in order. My suggestion for 7 to 8 would have been a good auto-titration starting point, but you can get good therapy with auto mode as long as it starts in the right range.

Finally, your machine must be in auto mode to record flow limitation, and this is something we want to evaluate for your SpO2 concerns. Go to a higher minimum pressure in auto mode, and you may never need to be in fixed CPAP mode. The machine pressure will follow sleep stages, body position and your changing needs to provide effective treatment.

[trish6hundred]

Hi Tigerman67,
WELCOME! to the forum.!
Better luck to you this time around with your CPAP therapy, hang in there for more responses to your post.
You have come to the right place for guidance.