BiLevel to ASV

[ChonkyTonks]

Hey all.  Not unlike a number of people out there with sleep apnea, I have spent the last near three years trying to find the right solution for me.  I started with a CPAP and fought with that for two years.  The only thing that kept me from going office space on that device was...well, I am not sure how I didn't break it into little bits.  I went back in for a sleep study knowing that CPAP wasn't working and figured BiLevel would be of benefit.  Given the way they performed the test, they said BiLevel wasn't right.  I advocated for myself and said I wanted to try it anyway (paying out of pocket instead of fighting with insurance). That definitely worked better than my CPAP, but I will still not feeling rested even after getting great participation aware numbers on MyAir.  I then started looking at what else I could do since it looked like the BiLevel was working for my obstructives, but not my centrals.  I, again, purchased a new unit (ResMed AirCurve 11 ASV) out of pocket and have used it for the last six nights.  So far, I see no clear airway events unlike the BiLevel and CPAP.  My AHI numbers are down to at most 2.  It feels like I am getting deeper sleep and am tossing/turning less.  To tune it I simply went with the settings I had on my BiLevel and then guestimated the PS Min/Max.  Settings and data from last night are shown in the attachments.  If you need more data or have insights as to how I can better share the data, let me know.  Please ask me any questions you want.  I am here to learn.

[Sleeprider]

You have setup the ASV at EPAP min 8.0, EPAP max 12.0 and PS 3.0-8.0 and getting good results. That tells us you don't need a lot of pressure support to stimulate spontaneous respiration to complete the breath. With the Resmed ASV there is no detection of the type of apnea (FOT on the CPAP and VPAP), but we can safely assume that any flagged UA events are obstructive. ASV requires at least 5 cm of difference between PS max and PS min, so at 3 to 8 cm you found that . Your respiration rate is much lower when pressure support is at or near 8.0 cm, so I presume the device is pacing breaths due to centrals at those times, and the result is slower, deeper breathing during periods of higher pressure support. The tidal volume and minute vent are maintained in spite of a slower respiration rate, so the ASV is working correctly and adequately.

Since you are sleeping better, there may not be much else you need to do with pressure settings. You can experiment with some slightly higher PS max and decide if that feels better or is more disruptive. In spite of all the "science" the doctors try to throw at this, therapy is often a matter of pragmatic trial and error. It might be interesting to see a chart from your bilevel effort. If you were using a Resmed, setting trigger sensitivity to very-high often works to trigger a breath when centrals occur. It seems you have gotten the therapy you need in spite of little help from your medical team...typical.

[SarcasticDave94]

Agreed with Sleeprider. Good job.

[ChonkyTonks]

Sleeprider, I cannot thank you enough for your reply.  I ultimately took the EPAP max/min from my BiLevel and then fudged the PS until I had good numbers.  Originally, it was 3-18 and my mask was blowing off my face.  I just wanted to make sure I was headed in the right direction (which it sounds like I am).  Oh, and, my sleep nurse let’s me do whatever I want to do since I have been pretty spot on with my sciencing.  That is why I came here, though.  My sleep nurse is very nice, but doesn’t give the best advice.  Anyhow, I am glad this board is here. 


-Chonks

[Sleeprider]

Welcome to Apnea Board. Your good instincts with ASV and experience with CPAP and VPAP may help others with their therapy. Don't hesitate to ask any questions if you have any.