[Symptoms] Transitional CSA - oximetry freaking me out. How low is too low?

[Apprenticepragmatist]

Hi everyone. I'm new here.
(scroll down to the questions if this is too long)


I seem to have sleep transitional central apnea and significant dips of me O2 % are freaking me out.    They are not obstructions - as when I look at my flow rate in OSCAR it just shows a gradual loss of flow to flat line, and then a gradual increase back to normal breathing ( if I don't wake up during the event).  

I honestly don't know how long I've had this, but now I am VERY aware of it due to my new Wellue O2Ring.   The desaturations are associated with rises in pulse rate and drop in flow rate so I'm inclined to think these are not sensor glitches.  I'm not really sure how low the SPo2 will go during these CA's (my alarm is waking me up at 90%) but for sure into the 80's sometimes.    These dips absolutely are acute in that they rebound to normal levels once breathing smooths out.   Average spo2 is 97 during sleep and 98-99 during the day.

Basically what's going on is I have my O2 alarm set to go off at 90% with the idea that if it goes off, it will wake me up so I can take some deep breaths to bring my Sp02 back up - which it does nearly immediately.   

It does NOT happen every night, but maybe 60% of the time it does to some degree. When I do get desats during transition that AREN'T low enough to trip the alarm, it repeats usually 2-4 times and then my breathing and o2 levels smooth out.  

from Medscape:  

"Up to 40% of healthy individuals may exhibit

 central apneas during sleep-wake transition.

 The central apneas occur during the period that

 chemoreceptors are resetting and instability

 of ventilation control occurs. They are usually brief

 and not associated with significant oxygen desaturation

. The clinical significance of this entity is unknown.

 Once stable sleep is reached, normal individuals

 should not have more than 5 central apneas per hour of sleep."

But no definition of what a significant desaturation is so that's a rather subjective statement in the context of the article.

note: This is currently happening with AND without the cpap in play for me.


Question:  How bad is it really to get a periodic desat into the 80's that maybe lasts 10-20 seconds below 90%, but the rest of the night I'm generally above 95% with my cpap and/or dental appliance working?   
Everybody says below 90 is worrisome.   Well, mission accomplished - you got the guy with health-anxiety worried.    


Question: Does anybody else here monitor their O2 desats during wake/sleep junk?   What are your lows like?


Question: Am I letting my anxiety get the better of me?  Should I turn off the alarm all together and just ignore the sleep/wake junk regardless of how low my O2 levels get? - Because right now this is interfering with me actually getting to sleep due to the alarm going off at 90%.


About me:

I am right at the beginning of my OSA therapy journey.   Within the last month I have gotten a dental device that works really well, combined with nasal strips and flonase, I probably wouldn't even need CPAP for my OSA with these,  but I have also just received a cpap and am about two weeks into that therapy.

Longterm goal is surgical solutions for nose and throat ( I have HUGE tonsils so lookin at getting those and adenoids out along with some sort of nasal surgery to open my nasal airway) but I'm also considering going the extreme route and doing Double Jaw surgery. 

I get health anxiety (which is why I'm making this post)
Male - 44 - BMI 20 - don't exercise.
recent good EKG 
recent good cardiac exercise stress test
recent CT scan of lungs - normal
I have had a history of mild OSA for last 10 years - untreated as the sleep doctor wasnt worried about my numbers during lab sleep study 10 years ago.
Last year or so OSA had gotten worse - new sleep study in lab show mild-moderate OSA and warrants treatment. No mentions of CSA in the labs.
Currently starting CPAP therapy (2 weeks on Airsense 11). Prescribed pressure is 6.  Trying to NOT use EPR.   Nasal mask.
BUT also have a new Mandibular Advancement Device for sleeping at night which also works well.  Using breath-right nasal strips which seem to help with nasal airway resistance.

[staceyburke]

I have been on Oxygen at night for over 30 years. My Dr. said 88% is the threshold. Less than 88% for an extended length of time (several minutes) is what I was told. Spikes are not a problem and if the % comes back within a minute or two no big deal.

[Apprenticepragmatist]

Actually that helps a bit, thanks for replying.


Ya, I guess you can have abnormal O2 readings but not be within the threshold of supplemental oxygen and therefore it's not immediately   concerning.

I figured that random dips in O2 wouldn't be as detrimental as sustained low readings.

Based off your reply, a little google-fu on criteria for prescribed nocturnal supplemental oxygen therapy were kind of surprising to me.  


I think I'm going to reduce my alarm trigger to 85.   86 seems to be the lowest I've ever seen it when I was having obstructive events before my dental appliance and cpap entered the equation.

[Gideon]

Not enough info to even think about commenting on your specific situation

In general.

Spikes to "lows" ann be ignored except a a flag to look deeper. The common cause, not the only one, is a sensor glitch, a momentary loss of contact not being unusual.

88% for extended time, medicare uses 88% for 5 or more cumulative minutes to qualify for overnight oxygen.

Nurses will respond and initiate oxygen at 88% unless special circumstances ( testing ) say something else.

You are right in that it is extended time at low O2 that is bad.

[punkrockcholo]

Any follow-up on this, Apprenticepragmatist?

I've recently started seeing CAs appear (Feb 15) and Dormeo recommended I watch my 02 levels to be safe.

[Apprenticepragmatist]

Okay,   So as for an update.

I have a new cpap mask, I have a MAD, and I've stopped taking lemborexant - which seems to exacerbate the issue.   

I feel a lot better at 6.6 or even 7 but as I push in the high 6's I start to get bad - almost painful air aphasia at night.

staying on the cpap and stopping the lemorexant seems to have the best effect on reducing the sleep wake CAs

[punkrockcholo]

I get tons of sleep wake CAs and then they disappear assuming after I'm asleep.

But my sleep is cut in half now. Unable to go back to sleep. Dormeo asked if I had any medication or stress. No medication to relate it to, but my health-anxiety sure isn't helping.

[stevew168]

I suggest lowering the SPO2 alarm to 88%. There is no reason to have it wake you up at 90%, especially if it is not lasting very long. Partial pressure of O2 starts dropping rapidly below 88%.

[Gideon]

Post your daily charts as that will give us some data to discuss.