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Joined Oct 2020
Joined Oct 2020

Sierra Thank yo so much for your feedback. It is a mine of info that I’ll keep in mind while trying to sort it out with my respirologist

To put thing into perspective, though, overall these CSR episodes don’t affect me as much. I usually sleep well and feel well at wake-up.

If I wrote this post it is because I am a bit concerned that these CSR’s, albeit rare, may be a precursor of something more serious to come, given the fact that I am 81 ( still running and windsurfing, though)

My betablocker is metoprolol. It was prescribed after two occasional tachycardia episodes at rest, two years ago, which led to an atrial fibrillation diagnosis.

My GP increased the dose to 2X50 mg/day after the 2nd tachycardia/ Afb episode 2 years ago. I am also on Metformin for borderline A1C and I read that metformin can be a factor in sleep disturbances.

By reading extensively about CSR and CA, I have come to realize that perhaps the CO2 dynamics may be involved. I asked myself whether there was some degree of CO2 retention( hypercapnia, as they call it) and I wondered whether the EPAP setting needed to be adjusted . Perhaps it was too high and impeded the full CO2 evacuation

. Currently, my pressure setting was 12.4-15.8. I thought that lowering the EPAP to 10.5 , with 15.8 IPAP could facilitate the CO2 evacuation. I’ll see how it works. If I still have CSR’s I’ll try the EPR adjustment you suggested , as a 2nd venue.

Another association I made is about the Tidal Volume. I noticed that when the AHI ‘s are on the rise ( above 1, which is rather rare) , particularly when I have CSR events, the minimum tidal volume drops to 0. AS I understand it, perhaps wrongly, if the TV is 0, there is no air exchange in the lungs and the blood CO2 then may increase.

Last night, with the new adjustment, I had an almost perfect AHI score of 0.59 ( 0.23 OA’s, 0.35 H). What is interesting is that the TV reached a peak of 1500 ( 99.5), which happened only once before with an even lower AHI score of 0.25. Usually, the TV is 1200-1300 at 99.5. Perhaps the lower EPAP setting has contributed to a higher TV.

Thanks again


I’m 81, I’ve been on CPAP for almost 3 years. My nightly AHI count is fine, at around 1. I rarely, if ever, had CSR events, but lately the OSCAR read-outs report CSR events more than usually Last night I had two of them, with a duration of 506 and 1067 ( seconds, I suppose)., respectively almost 18 minutes. It seems to me a hell of a lot, even though, I feel well, as usual.

I spoke to my respirologist. I had my annual apnea check-up about two months ago and everything was normal. He finds it strange that I should have CSR’s all of a sudden. I have requested an appointment, but the system is overloaded and it will take some time. I’m in very good health, generally. I’m on betablocker for occasional atrial fibrillation in the past, but I am exercising ( running) regularly.

I’m a bit intrigued, ( to say the least !) because medical literature associates CSR’s with congestive heart failure( of which I have no sign) and dying events.

Awaiting to hear from my doctor, I’d like to understand a little better about CSR.

There seems to be a connection with CO2 levels . If there is too much CO2, the system reacts with hyperventilation in order to remove the excess CO2, which depresses or slows s down breathing and this goes in a loop, sort of vicious circle. . Beyond this, if CO2 retention is the cause, I cannot understand what causes it, to the point of triggering the stop-and-go breathing pattern underlying the CSR. Perhaps the mask pressure ( too much or two little IPAP-EPAP ) needs to be adjusted?

I wonder if somebody is familiar with this issue.