Huge SpO2 dips at sleep onset (with and without bi-level)
Images say more than words.
I already was planning to post this question as I typically see this huge SpO2 dip at sleep onset with therapy. But last night I tried sleeping without (upcoming sleep test, wanted to convince myself I need therapy. Guess what...the answer is a big yes, terrible night, so switched to bi-level) and to my surprise I see this SpO2 dip again! So it is not related to the therapy but me.
Does this indicate something beyond sleep apnea/UARS?
RE: Huge SpO2 dips at sleep onset (with and without bi-level)
Most people are going to tell you its normal just adapt and it goes away. I didn't accept that.
I switched from APAP to CPAP, EPR off, and added vcom. The issue stopped immediately.
No more CSA transitioning to sleep, no more hyperventilating during sleep.
Airsense 11
F&P Solo Cushion
Before Therapy AHI 11.4
Before Therapy RDI 21.4
RE: Huge SpO2 dips at sleep onset (with and without bi-level)
Thanks. For me having no PS is not an option unfortunately. I did experiment yesterday night with the trigger setting (from my baseline very high to high) and then this event becomes, as you state, a few central events.
RE: Huge SpO2 dips at sleep onset (with and without bi-level)
Please post the OSCAR chart for that night. Other than the one dip your SpO2 does not look bad, but OSCAR may show something else.
Yesterday, 01:05 AM
(This post was last modified: Yesterday, 01:05 AM by THEVGE.)
RE: Huge SpO2 dips at sleep onset (with and without bi-level)
Well, this issue is even there without therapy. And my Oscar charts have been pretty good for a long time already (in other threads you verified this for yourself). But here it is.
RE: Huge SpO2 dips at sleep onset (with and without bi-level)
Now could you do a 2-3 minute zoom over the time period just before and after the SpO2 drop? If there is anything there it should show it.
Yesterday, 11:20 AM
(This post was last modified: Yesterday, 11:20 AM by THEVGE.)
RE: Huge SpO2 dips at sleep onset (with and without bi-level)
Sure, here they are:
Before the drop very slow and shallow breathing:
After the drop quickly to my "normal":
RE: Huge SpO2 dips at sleep onset (with and without bi-level)
I think you figured it out on your own. You have flow limitations driving you to the SpO2 drop, then a quick recovery to normal breathing. The flow limitations are not enough to trigger the counter,. but they are there as you can see in the flattened tops. You can also see the drop in respiration rate during that time. When you look at the first chart you posted you can see the same pattern. As you said it is there without using the CPAP, but at least you now know why.
Why is it happening? No idea. Is it a problem? Same. If it concerns you there are a number of things you can probably try, but I expect you have likely already done them.
RE: Huge SpO2 dips at sleep onset (with and without bi-level)
I tried a few things but nothing of the basis stuff seems to have a real impact (EPAP, PS, trigger). I normally have my Ti max at 4 seconds, not sure if that will help by reducing a bit?
Theoretically, as breathing is CO2 driven, it could maybe signal me that I have too high CO2 in my blood? I do have an over-stimulated nerve system so I probably breath faster at day time then I should.
Also no idea if it is an issue, but as my sleep sucks anything deviating is of interest for me to dive into.
RE: Huge SpO2 dips at sleep onset (with and without bi-level)
High co2 would tell your body to breathe. Low co2 tells your body to stop breathing.
Breathing toi fast drops co2 too low.
This is why mouth breathing leads to sleep apnea and why people get treatment emergent central apnea.
Airsense 11
F&P Solo Cushion
Before Therapy AHI 11.4
Before Therapy RDI 21.4
