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09-03-2023, 08:38 PM (This post was last modified: 09-03-2023, 08:39 PM by brianbear.)
Mild Sleep Apnea on CPAP--Still Tired
Hi everyone!
I got an at-home sleep test done, with a diagnosis of mild OSA. The test gave an AHI of 5.3 and RDI of 14.4:
I've been on CPAP since early-June. In the first month, I titrated my minimum pressure to 7 mmH2O with EPR of 1, and have been on that setting since then. Here's the OSCAR overview from the past month:
Despite sleeping on average nine hours every night, I still struggle to wake up in the morning and have low energy/alertness throughout the day. However, this is still an improvement from before CPAP use, where I had to be resting in bed for around 16 hours a day.
Here's the OSCAR data for what a typical night looks like for me:
I've read is that I should use the "For Her" setting on the Resmed, and increase the EPR to 3, because my low AHI and relatively higher RDI suggests I have UARS. Is there any truth to that?
Any suggestions would be greatly appreciated--thank you!
-Brian
In case they are of any use, I've also attached zoomed in figures of when the events occurred in the OSCAR data above. Thank you again!
optimizing comfort for UARS patients is often suggested, so there is some truth to that. Data shows that those with primarily UAR achieve greater rates of compliance when they switch to ASV (bipap with backup rate).
The for-her algorithm is designed to respond to every flow limitation, it has slower pressure decays, it responds less aggressively to events so as to minimize arousal, and it has a few other features, like responding to frequency of events. There are some downsides, however. The for-her algo was created for the many women who have SDB but present differently than the standard, stereotyped, middle-aged, overweight man. The general principle surrounding the philosophy of softening the delivery of treatment hangs on the idea that "the machine could be doing more harm than good". It should come as no surprise that some people are very sensitive, and having mask on your face, air blowing around, abrupt pressure changes, high pressures, etc can be disturbing for some.
I hope this helps. Feel free to ask any additional questions you may have.
PS your data looks pretty good. Nothing overly alarming. What stands out most to me is the volatility in your flowrate.
Thank you for the thorough response. The for her algorithm might be a good option for me to try then. I'm in my 20s and have a BMI of ~22, so I don't fit the stereotype for OSA patients anyway.
Although I don't have any compliance issues, I wonder if increasing the comfort will also improve the quality of rest. However, since I purchased the Resmed 11 Autoset, I don't think I would be able to get another machine at this time. Are there any settings I can change on my current machine to more closely resemble ASV? Perhaps increasing the EPR?
Also, what could the volatility in flowrate mean in the context of the data that I uploaded?
Yeah, there is a possibility that the change in algorithm could help, and I suppose you will never know unless you try. Maybe a good first step is just increasing the EPR, which is Resmed's brand-specific comfort feature that mirrors the value of pressure support that you'de find with a bipap machine. ASV might be a bit overkill, and I'm not entirely sure if my recommendation is correct now that I thought it over, but I'm very confident I read that in the literature. It's typically indicated for central apnea, complex apnea, and CSR.
The flowrate is just the waveforms of your respiration, so if it's all over the place, then that's indicating you're breathing is inconsistent, which could be for various reasons. There is variation between individuals, between sleep stages (REM versus NREM), etc. Maybe add a zoomed-in picture from 415-430AM so that I can see it a little more closely. It could be nothing.
Got it. I've been using the other algorithm and higher EPR for the past two days. I can't say that I feel a noticeable difference, but I'll keep monitoring how I feel over time.
Here's a photo of the zoomed in section you requested. Let me know if anything stands out to you. Thanks again!
You have flow limitations throughout the entire month, although they are low. Your 95% amount is 0.05, and we worry about them really until they're at least 0.1 at 95%. Just as experimentation, and only if you're willing and you don't find it too uncomfortable, I'de be interested to see how your flow limits react if you put yourself at a fixed pressure around 10-11cm, and if you have EPR enabled, put it how ever many EPR you have on higher than that, so if EPR is 2cm, then fix it at 12. The downslopes from your max pressure decays are flow limits are essentially being eliminated. Maybe before doing this share the new data just so that there isn't anything else that we should be taking into account.
The data from the for her algorithm + 3 EPR setting doesn't seem too different to me:
I tried to use the 13 mm pressure as per your recommendation, but could not fall asleep on it. I lowered it to 11 mm, and here's the data from that night:
Do any of these offer any new insight? Thanks again.
Minus the leaks, it looks to me like you did best on 11cm fixed, but you also turned EPR off. I also believe you did better when you turned both auto for her on and EPR to 3cm, but you did both at the same time, so it's hard to discern where the responsibility lies.
Summarized:
EPR 3 + auto for her > EPR 1
Fixed 11cm > EPR 3 + auto for her + 7/15 (maybe)
Keep in mind that we're splitting hairs here, and your comfort/subjective quality of life is the desired outcome. In the context of therapy, it's considered very successful.
Thanks for the summary. I agree that we're splitting hairs here--the fluctuations from night to night renders the difference between each setting even less significant. I think I'll stick with the "for her" and EPR = 3 setting that you suggested, since it's significantly more comfortable than the constant pressure.
In terms of my QoL, I'm certainly one of the unlucky ones with low AHI and significant symptoms. Hopefully I don't have additional undiscovered pathology accounting for these issues. For now, I'll just have to keep at it with the settings and hope things keep improving.
For what it's worth, sleep-disordered breathing is a spectrum, and all UAR/flow limit IS suffocation/suboptimal breathing. On one side, I don't want to induce you into a state of becoming overly consumed by reaching some state of absent flow limit, but I think it's also reasonable to keep alive the idea that the remaining flow limitation could be disturbing you. There do seem to be some differences in the literature regarding treating patients just for apneas/hypopneas/snores versus patients for apnea/hypopneas/snores AND flow limitation. For example, one study found no difference in sleep quality and daytime vigilance tests between those two groups, but there was a difference in sleep latency in favour of the flow-limit-treated group. That is, they didn't fall asleep as fast in a test that measured how long it took people to fall asleep in a comfortable position with the light off. Attached pic related. Keep in mind, this study was n=18, which is very small.
