[CPAP] Adjusting for flow limitations

[jane2911]

Follow SleepRider’s recommendation for pressure changes. It likely will not reduce the flow limitations, but should help with sleep quality.

Flow limitations, as well as arousals and UARS, are interesting beasties to chase. There is a trade-off on managing them vs going after quality sleep. Just because you can reduce flow limitations does not mean you will sleep better, it just means you have managed flow limitations. Same for arousals. 

Feeling rested, regardless what your machine or OSCAR reports, is our goal. We all get caught up chasing numbers, but it does not mean we had quality sleep. Quite a conundrum at times.

That makes sense. Numbers are fun but not the end goal. Feeling rested is hard bc of how subjective it is. I also take stimulants, which I think lead to fatigue at the end of the day regardless of my therapy. To be honest, my best indicator of therapy right now has been how bad my headache is in the morning (ranging from hit with a club to none at all). When my therapy goes well, I wake up without a headache, and I actually often forget to take my medication. Prior to CPAP, I needed it to even get out of bed, much less stay awake throughout the day. 

I changed my settings but need a few more days before posting results as I have to temporarily be on a med that disrupts sleep

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The Apple Watch really has been useless for helping with breathing issues at night. You really need a device that measures oxygen and heart rate continuously.

Yes, this is why I gave up wearing it, honestly. It wasn't giving me super useful information, and is an older model without the ability to do 02. Would love any suggestions you have for something else that would work better, I haven't looked into it much yet.

[jane2911]

Hi all! I know it has been a long time since I came on here, but I wanted to come back with results since I changed my settings. I played with a lot of different things that were recommended. I like data so I actually have just been running the analyses to see what works best. I also got an Oura ring for my birthday in March, so I've been able to see how using my CPAP/breathing metrics impact my sleep. Although Oura measures Sp02, it has only detected irregular breathing for me once (despite many nights of CPAP noncompliance), so I stopped looking at it.  


- Increasing EPR significantly improved my RERA index (average= .41 to .03), R^2= .207, b= -0.226, p = 0.003 
 
- Increasing EPR significantly improved my 95% flow limitation (average = .131 vs. .09),  R^2= 0.223, b= -.051, p= 0.001

- Increasing EPR significantly improved my hypopnea index (average= .176 vs. .08), R^2= 0.345, b= -0.207, p < 0.001 

- Increased EPR was unrelated to central apneas. 

- Increasing my pressure min did not significantly affect any of my metrics, though there was a trend towards improvement. I recently lowered it because I felt it impacted how long I kept my CPAP on, but this actually was not born out in the data, so I may increase it again. 

- Increasing my pressure max did not significantly change any metrics, except oddly, my REM sleep percentage, which it improved. 

Basically, just wanted to thank everyone, especially SleepRider for the advice! It was clearly very helpful for me

Below are just more datapoints I found interesting. 

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- On nights I wear my CPAP for more than 6 hours, my physiological "stress time" the next day is 21% less, t= -.182, p= .079 
- Higher AHI values were associated with lower total sleep time, b= 8014.4337, p= 0.051
- Higher AHI significantly reduced my REM sleep percentage, R2=0.166, b=−0.0158, p=0.002.
- One of the weirdest findings has been that the higher my 95% flow limitation the night before, the fewer my phone notifications the next day (CA and OA were trending this way as well). The best way I can explain this is the better I breathe during my sleep, the less socially withdrawn/more productive I become the next day. This finding was one of the most significant for my daily notifications, which is what really struck me, especially since other sleep quality predictors did not predict it in the same way (e.g., REM sleep). It's my sleep disordered breathing that appears to be the direct impact on it.
- One unfortunate finding is that my HRV is significantly decreases with CPAP usage. I don't know a ton about HRV, so its possible that this is just measuring how much I stop breathing (therefore more variable? somebody please correct me haha). But it could also indicate my body is slightly more stressed with it on.
- Use of a "garden gummy" the night before was trending toward significance in increasing 95% flow limitation, which makes sense given that it would increase sedation, p= 0.069
 

[40plus]

As someone who tried both apple watch and galaxy watch i can inform that the galaxy watch is way more helpful with its continous heart rate and blood oxygen sensors.

Actually blood oxygen is less importnat than lowest heart rate at sleep for me. When i have a good night with the right pressure my lowest heart rate every given hour is around 47 bpm. And bad nights with wrong pressure can have it at 65 bpm as lowest. And not always does the O2 follow this, you can sleep fine with a bit dodgy o2 as long is its not spiking up and down too much or way below 90 %.

[alwyns42]

Jane out of curiosity, what is your current nightly stats for pressure, epap, etc.  since you mentioned you lowered some values.  I'm currently in the boat where I'm trying to find the sweet spot for myself.

As for HRV, it differs a lot between people, but as I understand it people on CPAP have lower values.  When I'm sleeping bad and feeling bad mine is in the 15-19 range, when I sleep better and feel better its 21-25.  Those are from my Garmin Fenix 7, an Oura might be more accurate, but since I have an O2ring I can't really justify an Oura.

[Sleeprider]

Thanks for the stats on the use of EPR. Those are the results we typically expect to see with the use of EPR, or essentially bilevel pressure. As long as CA is not increased, it works great, but everyone seems to have an individual response. Glad it's working well for you.

[jane2911]

Happy to share current stats.  It's good to know about HRV being impacted by CPAP for others as well. Mine is typically from 40-55 on my Oura (at night; during the day much lower). 


I added a screenshot from last Oscar upload. I'm going to increase my pressure min to my pressure med and decrease my pressure max tonight as both are really correlated with deep sleep for me it turns out, even if not impacting my breathing stats (aka what I was told to do in the first place by Sleeprider earlier in this thread, but of course played around with it too much)

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Yes, really grateful for the advice about EPR!! And happy to have found this forum

[Sleeprider]

Your flow limits are high in spite of EPR 3. You probably have some form of upper airway obstruction in your nose or throat. Increases in pressure are going to stabilize pressure changes, but will not likely make substantial changes to flow limits. Your AHI is excellent and short of using bilevel, there is not much more I can recommend.

[jane2911]

Interesting, I was wondering what normal flow limitations were vs. mine. I have no doubt I have an obstruction-- my nasal airway is so small and collapsing that I cannot use it even during the day. I'm considering surgery but have been scared. I might consider a bilevel once I'm out of training and have a real job next year, appreciate it I'm already happy with the improvements in my RERA and just sleep metrics in general. (I can't believe nobody prescribing my CPAP mentioned to even switch to autoset for her, much less EPR changes!!)