Low Oxygen causes?

[PressuresOn]

I'm hoping someone can suggest if any of the measurements from my cpap can shed light on my low O2 readings. I've imported the Wellue oxy data into Oscar and attached all the graphs. The weird thing to me is that the lowest O2 reading (84) precedes a Clear Airway event by about 40 seconds (I would have expected the opposite order). I have synched and double-checked the clocks between cpap and oxymeter, they are only two seconds apart.

Earlier in the night, the o2 readings were around 92, but trended lower until the low of 84 triggered an audio alarm and woke me up.

I woke up sweating.

Thanks for looking at this.

[Jay51]

I see a few things.  Your therapy looks pretty good.  Good low AHI.  Not too many CA's IMO.  Everything else looks relatively normal to me also.  

This is how I would proceed:  max out your therapy on this machine (get it the best you possibly can).  If you are still having significant problems in SPO2 drops with therapy going very well (it looks like you may have therapy maxed out right now) then you may have another underlying health issue that is causing your lower SPO2.  Normal SPO2 averages about 95 or 96 all night.  Yours is a bit lower than normal (92 and 90).  You could work on leaks some to reduce them and that could help.  A visit to PCP might be the next step.  Go equipped with lot of data (SPO2 charts, OSCAR) in order to convince PCP (and/or Sleep Dr.) there is a problem that needs to be addressed.

[gainerfull]

How long are you spending below 90% sp02 per night on average? Have you tried fixing your leak rate? Very very high and will impact your therapy immensely.

[PressuresOn]

I'll work on those leaks. The o2 median overnight was 90, so guess under 90 half the time. Typical range was about 88-92. My daytime O2 is usually about 95, but was 93 at my doctor's office today.

My GP was helpful and drew TSH, iron ferrite, folate, among others, this afternoon. So, maybe some answers coming from these tests.

Thanks for the suggestions!

[PressuresOn]

I have a small update/theory about that CA event following my low O2 alarm, which seemed like a backwards pairing of events. The same thing happened last night. I have a nasal mask, but when the low-O2 alarm went off, I sat up in bed and took several hurried deep breaths - through my mouth. I wear a nasal mask, so the cpap must think I quit breathing for a bit and marked me up for a CA. I'll try to do deep nasal breathing on the next alarm so as to improve my AHI :-)

[gainerfull]

Are you mouth taping at night?

[PressuresOn]

No taping, my sleep doc considers it too dangerous. I used a chin-strap for a couple of years, but finally mastered nasal breathing (although, not perfectly).

[DevinJones]

Make sure your pulse oximeter is calibrated correctly and records accurate data. The non-professional pulse oximeter I was using recorded oxygen saturation levels significantly lower than the correct levels. 

I then started using a professional pulse oximeter that is FDA approved for use in hospitals and confirmed that my previous pulse oximeter is not accurate or reliable.

For me, a non-professional pulse oximeter is okay for spot checking but is not accurate enough for pulse oximetry overnight. 

Wellue makes the professional Handheld Pulse Oximeter SP-20, which is medically accurate for use in medical facilities and can be purchased for just $169.

[PressuresOn]

That's a good idea. I recently purchased the Wellue Checkme O2 Max, but just put blind trust in it. I'll take it with me to my cardiology appt next week for comparison.
Thanks!

[DevinJones]

A quick check in the doctor's office will be a comparison of the devices for spot checking, but the best comparison is for many hours overnight. My professional device rapidly responds to fluctuations in oxygen saturation levels and is far more accurate, especially over a period of many hours.