ASV, leakage and flow limit

[garyseven]

I am grateful to have found this community. Suffering with dizziness, fatigue and high BP, I was diagnosed with Mild OSA (AHI 6) in home and overnight lab studies last August. I was prescribed CPAP with pressure 10cmH20 a few months later but couldn’t stay compliant. I tried Excite OSA and also lost 25 pound so my snoring stopped, but not sure which helped me there! I was able to cut back on BP meds and I tried a WatchPAT One last month to see if apnea had resolved, but result showed pAHI of 10.6 and . I was titrated for and failed BiPAP (12/8) a couple months ago as well and, in viewing the Oscar and BiPAP titration data, it seemed centrals were presenting themselves. My sleep therapist loaned me a ResMed AirCurve 10 ASV a little over a week ago. I don’t know of any CPAP/BiPAP to ASV conversion and so have been experimenting with the titration for comfort and AHI reduction. Unfortunately, the BiPAP titration was performed before my LVEF results (>45%) became available, so testing on ASV wasn’t an option.

While I’m better at tolerating the ASV (6+ hours per night), and the machine’s LCD sleep report shows AHI at a seven day average of 0.34 and average daily leaks less than 24, I’m not feeling any better (slightly worse, if anything) and the Oscar report looks peculiar to me with respect to flow limitation and leaks. Also wondering if the ASV can catch OSA’s as well as a CPAP/BiPAP can? Mask is ResMed N30i with pillows (I’m told this is correct for UTN cushion) mask-type setting Any suggestions or input, including suggestions for OSCAR fields to include here, are very much appreciated!  

Gary

[SarcasticDave94]

The ASV when properly set up will treat all Apnea. Flow limits not very well though. In fact I'd ignore the FL chart on ASV.

It might be helpful to take screenshots of OSCAR via the F12 button and attach like you have. The formatting is a bit different than what I expect.

OSCAR charts in pretty normal order, Events, Flow Rate, Mask Pressure (standard Pressure OK somewhat interchangeable), Leaks were the ones I paid attention to while on ASV.

[garyseven]

Thanks so much for your reply, SarcasticDave. I'm attaching an updated screenshot of my Oscar data per your suggested layout. Hoping to find out if these leaks seem excessive and/or if the self-titrated ASV pressure settings seem appropriate and ideal given my previous lab-titrated results (CPAP 10cm in late 2023, BIPAP 12/8 last month). Haven't tried Auto ASV much, just regular ASV. 

Thanks!
Gary

[attachment=71531]

[SarcasticDave94]

OK thanks, better view of OSCAR here.

ASV mode as you have now equals fixed EPAP. You'll probably be wanting more than 4. In this mode, it has no auto adjusting to EPAP.

ASV Auto mode makes EPAP a range, where it will Auto adjust between Min and Max settings. You might want to try this mode with a small range, maybe 6-10 or so.

Leaks? The experience when I used ASV, you'll get better results minimizing this leak rate. There's a small amount of large leaks. ResMed leak redline is 24 L/Min. Just below that and you'll have probably sleep disturbance from it. Over 24 and the machine will struggle to compensate.

[garyseven]

I have been using an Aircurve 10 ASV consistently for over a month, self-titrating on a loaner unit from sleep doc (failed CPAP and had trouble titrating VAUTO settings for comfort). Using in regular (not auto) ASV mode, EPAP 5.4, PS 3.0-8.0. I wondered if the attached OSCAR or sleep, or o2 saturation data points to anything: the machine keeps waking me up around 3:30am and then again at 6am. Overall o2 saturation seems very good, but I feel like I start hyperventilating and the machine is blowing me up like a balloon, interfering with deep and REM sleep. I try turning off and on, but not sure that resets the algorithm? I keep hearing about backup rate with ASV?...N30i with airtouch UTN cushion and MYPAP CAP/nightguard.
MACHINE SLEEP REPORT STATS:
Days 4+ Hrs: 30/30
Avg. Usage: 7.6 Hrs.
Pressure: 13.8
Exp. Pressure 5.4
Leak 22L/min

I am 50, 180 pounds, and just diagnosed with low free-Testosterone (Free = 4.7 pg/mL, Total = 330 ng/dL) too, so wonder if that’s part of the issue. Going for TRT eval soon. Thank you so much, in advance, for any ideas/suggestions.[/font][/size]

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[Sleeprider]

Your ASV results look good. These kinds of low pressure settings are normally used for bilevel therapy without central apnea. You are nearly at the minimum pressure your machine offers, although you could move to EPAP 4. I think you might have had better luck with the Vauto using fixed pressure. What was the problem? What the therapists don't know is that we can usually resolve centrals with a high or very-high trigger settings.

[Sleeprider]

Your ASV results look good. These kinds of low pressure settings are normally used for bilevel therapy without central apnea. You are nearly at the minimum pressure your machine offers, although you could move to EPAP 4. I think you might have had better luck with the Vauto using fixed pressure. What was the problem?

I have merged your two threads. Please keep your therapy question in a single thread or we end up chasing related issues in different threads. When copying and pasting, only post text, not formatting tags.

[SarcasticDave94]

The higher leak rates might be of concern in my opinion. Looks to me like a constant mouth leak combined with a pillows mask.

[garyseven]

Thank you both, and thanks for the ASV-related thread merge. I understand and appreciate that. Perhaps I can re-introduce my question about low-T in another thread down the line...

Sleeprider, the problem with VAUTO was that I just couldn't dial in a comfortable EZ-Breathe setting given the 12/8 Rx, even after watching Lanky Lefty's detailed settings video. I still own that machine and may try again, with input from the helpful folks here. 

Regarding the constant mouth leak, Dave, I've got my my PAP CAP chinstrap pretty tight and the mouthguard has always seemed to help me tolerate PAP therapy. Will try tightening up the strap with airtouch N30i/UTN a bit more, maybe switch to P30i pillow. Trying to save the airtouch F20 for colds. 

Thank you both again for your input!
-GS

[SarcasticDave94]

A tighter strap on a mask might just be what you don't need. Tighter will probably distort and crush the cushion. It will also not fix mouth leaks, if the pattern is in fact a mouth leak pattern.

The chin strap might be pulling your chin back, causing its own problem.