Home Sleep Study - Low AHI but significant desat

[SarcasticDave94]

Yes, EPR edits would be the thing to try in order to affect CA. Keep us updated on the progress via a hour you feel and an OSCAR. If they're going to respond it's going to be seen right away after an edit typically.

[Gideon]

Looking at the desats be aware of this.
Pressure Support, EPR on your machine, is increased to increase volume to your breathing. This increase in volume is what improves your sats, but it also decreases your drive to breathe by flushing additional CO2 from your system.

In other words, decreasing EPR will decrease your CAI but will also likely decrease your oxygen sats at the same time.

What are your expected tidal volume and minute vent. These require your size, height, weight, and sex to calculate.

[SarcasticDave94]

Yep another teeter-totter, to address one symptom for the good, another symptom goes down to the worse.

Best case scenario is find a happy medium for this.

[ArcherNeedsSleep]

Looking at the desats be aware of this.
Pressure Support, EPR on your machine, is increased to increase volume to your breathing.  This increase in volume is what improves your sats, but it also decreases your drive to breathe by flushing additional CO2 from your system.

In other words, decreasing EPR will decrease your CAI but will also likely decrease your oxygen sats at the same time.

What are your expected tidal volume and minute vent.  These require your size, height, weight, and sex to calculate.

Oh boy, you nailed this.  I decreased the EPR to 2 and had such a bad night that I ended up taking the mask off in the middle of the night - something that I told myself I wasn't going to do.  My CAs went up and my O2 went down.  Everything went the wrong direction.

After reading your post with the questions about tidal volume and minute vent, I just spent way too long going down that rabbit hole.  But I am learning a lot!  

Using an online calculator that takes into account my current weight rather than the "ideal body weight" (something I've never been, even when playing intercollegiate sports and on active duty in the Air Force), my expected minute vent (female values) at 6-8 mL/kg would be in the range of 462-616 mL.  What I can't figure out is how that translates to a setting on my machine.  Do you know of any links or references that might help me understand that last link in the chain?

I've attached the ugly Oscar data from last night, that includes the SpO2 data even after I took the mask off.  I mostly held my own after removing the mask, but could see it deteriorate over the final hour or so.  I also zoomed into one set of CAs and attached it.

Ugh - tonight I'll go back to the settings that previously worked best and learn and think a bit more before I go winging the dials again.    

          

[SarcasticDave94]

Well that went a bit ugly. Have we talked about consideration for the ResMed VAuto since it has the full range PS? PS may be helpful to keep things going correctly IMO.

[ArcherNeedsSleep]

Well that went a bit ugly. Have we talked about consideration for the ResMed VAuto since it has the full range PS? PS may be helpful to keep things going correctly IMO.

We haven't talked about that specifically, but I've picked up on the possibility from multiple other posts.  

I bought the current machine out of pocket because insurance wasn't covering it with the super-low AHI.  However, if I can ever get the referral appointment scheduled with the pulmonologist (I still don't have a callback from him...grr), I plan to push him to help me get coverage based on the additional complication of low oxygen saturation.  If, at that point, it appears that the VAuto is the right answer, I'll be able to use insurance to get it.  It's a pretty big expenditure otherwise.

[SarcasticDave94]

OK I copy that. In 2017 when I was waiting on approval and delivery of my ASV, I made a call to the doc or DME's office every day. I figured it might quicken the delivery by way of them getting tired out from hearing from me.

[ArcherNeedsSleep]

At the risk of jinxing myself, I think the current settings (the ones I returned to, not the reduced EPR) are going to work very well. Great night last night.  Very few O2 drops, and only down to 89% for a total of one minute.

I'm posting the chart, but it will probably be my last one for a bit if the current results hold.

Thanks for everyone's help.



   

[MrSpeed]

Thank you for posting your journey. It is relatively uncommon here so really appreciate reading about it. I have similar problems. Low AHI so doctors tell me there is no problem and insurance has no standard coverage. My AHI is 5-10 during PSG and 0.1 according to my resmed device. But I do have ODI 4% of 17 per hour and 3% 35 per hour.  With Airsense Autoset  CPAP I did not see  much improvements. It did not recognise the mainly central hypopneas. I then opted for ASV (out of pocket) which did detect them and reduced the depth, duration and broke some of the cycles. Average saturation has gone up slightly. Your chart looks very similar to mine with varying average saturation levels during the night. I still have periods of 1 hour with saturation of 90. Average over the whole night is 93-94.  I still have almost daily light headaches in the morning. What I noticed is that with higher pressure settings the brain fog and heart problems are less though then begin to feel my lungs after a while. That worries me a bit. If the settings are too low the low saturations (90-92) cause my heart to start beating heavily. I have this not only during sleep but also when I am awake and lying down. I have the same reservations when it comes to oxygen though getting closer to the point that I want to give that a try. At a low setting maybe 1 liter per minute. Currently I cannot sleep or lie down for more than 4.5 to 6 hours. The moment I sit up straight all heart and low saturation problems are gone. The headaches remain though. I live at sea level but at 7000feet altitude my saturation without ASV dropped to below 80 for a short while while sleeping. When not lying down saturation is fine. Like you I am not obese but I am overweight. Sometimes think it is simply my belly that keeps me from breathing normally. Though not diagnosed there is a possibility I have occasional mitral valve prolapses. When this happens my heartbeat is audible outside of my chest up to 1-3 feet away. I have that occasionally after intense exercise. All cardiology tests came back normal. Thanks again for sharing your story. Let us know how your progress.

[ArcherNeedsSleep]

Thank you for posting your journey. It is relatively uncommon here so really appreciate reading about it. I have similar problems. Low AHI so doctors tell me there is no problem and insurance has no standard coverage. 

MrSpeed - My husband always tells me being "uncommon" with regard to healthcare is a bad thing.  I agree, but unfortunately, I've managed to fall into that category for most of my health issues throughout my life.  It sounds like you're suffering from the same challenge - I feel for you!

I did jump on here to post a new screenshot and just say that I'm still working my way through the newbie challenges, but it gets better every day.  I moved my min up to 9 based on comfort.  Once I got over the air swallowing thing, I found that setting provides the best amount of air.

I am consistently staying above 90% saturation for most of the nights now.  I still drop occasionally, but my maximum time below 90% is hovering around 15 minutes, which is still way better than without the PAP.  And I'm feeling pretty good.  Still have some fuzzy head and light morning headache, but not every day, and not as bad as it was.

We had a round of stomach flu roll through the family last week and there was no way I could put the mask on my face for two nights.  But I did track SpO2 those nights and was back to my old status of ~60 minutes below 90% saturation.  So I am pretty certain that the PAP is the difference.

I am also seeing that I mouth breath for short periods of time when I'm really tired.  My husband complains of the "hoover" sound when my mouth opens, so it's happening often enough to wake him up.  He's been very supportive through this process, and I don't want to jeopardize that by waking him up from sleep.  So, I'm going to try the F30 full-face mask and see if it reduces the impact (or at least the sound) of my open mouth.  Mouth taping is an option if I stay with the P10, but I'm not quite ready to try it yet.  

Overall, though, I’m still happy with the progress.