(07-11-2012, 08:38 PM)Sleepster Wrote: Averages:
First 3 days on CPAP therapy: AHI=9.43, CA=0.19, OA=6.73, H=2.63.
Next 13 days on CPAP therapy: AHI=3.05, CA=0.13, OA=1.73, H=1.29.
Next 19 days on BiPAP therapy: AHI=9.96, CA=9.21, OA=0.42, H=0.33.
After this they lowered my BiPAP pressures and now my AHI averages 2.0.
But you can see a dramatic jump in the CA index with the onset of BiPAP therapy. This study is the first verification I've seen that this thing can happen to other people, too.
The question is, what's the cause. The conventional thinking is that when the CPAP pressure is too high your brain tells your lungs to stop breathing because there's too much oxygen in the blood. This is called CPAP-induced central apnea. Lowering the pressure fixes the problem.
But when we have bilevel (BiPAP or BLPAP) therapy there's an increase in pressure between the exhale and the inhale, and a drop in pressure between the inhale and the exhale. For some reason, this changing of the pressure also causes this effect to appear.
I have the exact problem you are discussing. I have been using bipap for 3 weeks and now almost all my apneas are central apneas and only 1 or 2 are obstructive. My AHI is 15 with only 2 being OA and 13 central apneas.
I see my sleep doctor on Friday. I wonder what he will suggest.
I am using an Oximeter every night too. Most events are between 90 to 94 percent oxygen saturation but some are between 84 to 89 and one event was 79 percent.
It seems like a lot for using the bipap therapy.
I hope something can be done like lowing the pressure support or I might have to use the ASV machine (if my health insurance would pay. I priced,those machines. Very expensive.)
Thank you for the research.