Low daytime SPO2 and fatigue

[vpsdub]

Hello

Since March 2022 I have fatigue, frequent shortness of breath, chest tightness, low SPO2. My heart rate is 110-115 bpm even with light housework or slow walk, getting tired and sleepy after hour or two awake. 

My daytime finger oxymeter readings are around 90-92% especially in the evenings. At night SPO2 drops to 85-88, despite APAP use since 2017 every night for 5-6 hours. Usual AHI is between 6 and 14, should be below 5, but it seems that's the best I can do. I had an appointment with Respiratory Consultant last year, not much advice, just continue with CPAP. 

Machine is Airsence 10 Auto, FFM mask Airfit F20  is 3 month old, pressure min 9.2 max 13. Sleep very disrupted, frequent awakenings. 
CPAP data shows mainly Unclassified/Central apnea,  there very few obstructive apnea events. Respiratory rate is high, around 34-36 breath per minute. My leaks are a bit high, probably due to beard. 
Cardiac stress perfusion MRI done in July 2022 detected low oxygen saturation in the heart muscle. Cardiac CT angiogram done in October detected the plaque in coronary vessels, but level is not sufficient to be deemed a critical condition. Cardiologist reckons my issues not coronary, but caused by apnea and obesity.

Can apnea cause low SPO2 during the day? My main concern is fatigue but it is probably caused by low SPO2? My respiratory appointment coming soon, any point to ask about different treatment like supplemental oxygen and/or ASV machine? 
Thanks

[Jay51]

Thank you for the post.  If you could post a few OSCAR charts that would help.  I only have one comment based on what you wrote.  You seem to know which numbers are abnormal.   If your respiratory rate at night averages 34 - 36 that is abnormal.  Very abnormal IMO.  This is hyperventilation.  Severe hyperventilation it seems to me.  You hyperventilate to take in more oxygen (and raise spo2).  It is no wonder you wake up so frequently during the night.  I think you definitely could benefit from supplemental oxygen (both during the day and at night).  I will leave that up to your Doctors.

[vpsdub]

Thank you for the post.  If you could post a few OSCAR charts that would help.  I only have one comment based on what you wrote.  You seem to know which numbers are abnormal.   If your respiratory rate at night averages 34 - 36 that is abnormal.  Very abnormal IMO.  This is hyperventilation.  Severe hyperventilation it seems to me.  You hyperventilate to take in more oxygen (and raise spo2).  It is no wonder you wake up so frequently during the night.  I think you definitely could benefit from supplemental oxygen (both during the day and at night).  I will leave that up to your Doctors.

Thanks for your reply. Will ask doctor about oxygen.
Here are Oscar charts
   
   

[Jay51]

Just a few brief comments.  Your respiration rate based on your median is not too bad.  Average is around 12 to 20 or so at night.  20 or so median for you is not bad.  You do hyperventilate at times up to 35 or the 30's or so.  Clusters of the obstructive apneas are probably positional.  You could benefit from a soft cervical collar during sleep to help combat this.  Tidal volume looks fairly normal to me (mid 400's or so median).  You have a CA cluster just as you start to sleep.  I am not sure what that is about.   
That is what jumps out at me.  Someone else may notice something in your OSCAR also.  AHI is still a bit high and some tweaks could possibly bring it down some.  Keeping spo2 around 95 or so average at night is important, too.

[Jay51]

Minute vent around 10 for your median is pretty high also.  Sorry I forgot to post that in previous post.  Around 6 or so (even a little higher or lower) is normal.

[vpsdub]

Minute vent around 10 for your median is pretty high also.  Sorry I forgot to post that in previous post.  Around 6 or so (even a little higher or lower) is normal.

Thanks for your comment. Night SPO2 unfortunately lower than 95 - basal SPO2 (is it median?) is 92, min 79, time below 95 is 85 percent. Have oxymetry report as pdf, can't attach pdf. Tomorrow will convert to image and attach.

[pholynyk]

In my opinion, a waking SpO2 below 95% is abnormal, 90% to 92% is worrisome. I would suggest getting a complete cardiopulmonary workup to find the cause of these low numbers.

[B1Sailor]

With your numbers, you should invest in a oximeter that you can import into OSCAR.

My spO2 average is 95. My sleep study showed same with brief drops to 88 but not long enough or frequent to require O2. But it did cause me to buy a CMS 50 so I could track with my therapy data.

[vpsdub]

With your numbers, you should invest in a oximeter that you can import into OSCAR.

My spO2 average is 95. My sleep study showed same with brief drops to 88 but not long enough or frequent to require O2. But it did cause me to buy a CMS 50 so I could track with my therapy data.

Thanks for your comments. I have Contec finger oxymeter, here are reports
https://i.imgur.com/gOTcNg5.jpg
https://i.imgur.com/oZNAmaT.jpg

[vpsdub]

Any views whether ASV/Bilevel machine would be beneficial for me - see my Oscar charts and oxymetry reports in earlier posts.
Are those more difficult to tolerate comparing to APAP?
Since my CPAP therapy started in 2018 my main issue with machine is feeling that exhaled air stays in my mask and in the next breathe I inhale warm and humid exhaled air. To handle this I loosen mask a bit, this results in leaks.

How low SPO2 during daytime can be explained?
Thanks