Central Apnea: Detecting CSA Events Using Desat Signature

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
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GearChange
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Location: California, USA

Central Apnea: Detecting CSA Events Using Desat Signature

Post by GearChange » Thu Jul 21, 2022 3:16 pm

In the follow-up to my last post which attracted way more than the usual numbers of off-topic responses(!), I ran an experiment last night, in order to see if my recent drop in AHI and "machine initiated breaths" are an indication that my ASV therapy of the past year has in fact been remedial and not just therapeutic.
So I simply took off my mask at 4 am and kept my SpO2 Ring on and then got up at 8 am and put the mask back on.
The results are interesting in that there's an obvious and immediate drop in my Oxygen Saturation level (Please note that my ring registers about 3% below the actual value. I know this because I have tested it ), so 100% saturation shows at 97%.
Anyway as you can see in my sleep chart, desaturation happens right away after taking the mask off. This much is expected, however as we go along, you can see two occasions when my SpO2 takes a big dive and then comes back up to its previous level. This signature is left by the sudden desaturation of blood, when I experience those long periods of total breathing cessation, except that without my Respironics ASV, these events lead to very short arousals to gasp for air, followed by an immediate fall back into sleep, when the cycle will keep repeating itself until I eventually start to breath normally and then it continues until the next event.
In conclusion therefore, it appears that I can save myself a new sleep study, due to the fact that my ASV therapy has NOT been remedial, but rather therapeutic which means that I am stuck with the machine for now, but in about 6 months from now, I will start checking again. Also interesting to note that it has taken me nearly an entire year of therapy to get to this point, where I can breath normally throughout the night, "almost" every night.

BUT a question still remains:
Is 86% (+3% error) which is the lowest that my SpO2 drops to, too low? I don't think 89% for short bursts of time, is too bad and besides, there are studies that suggest this desaturation through cessation of ventilation, is normal as the body is simply trying to maintain its CO2 balance. (waking up to gasp for air still sucks though).
What do you think? Is this much desaturation bad enough to warrant continued PAP therapy?
Thanks for reviewing my post and I trust that you will resist the temptation to go off the rail and off-topic in response.

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Even though I have had extensive experience with the use and functionality of several types of different PAP machines,no information in my posts should be put in practice unless cleared by your own medical practitioner first.