Mask fit & sleepyhead data & how good can it get?

[bpb21]

I've been using my BiPAP for 83 days now, and I thought I was having good results. My AHI is under 3.0 pretty consistently and the Philips App (that you can sync your data via bluetooth to your phone) has been saying lately that mask fit is 100%, or in the 90% range. I now know that's not really the way to go...so I installed SleepyHead and imported my data from the SD card.

My summary data for Most Recent shows an AHI of 1.88, use of 8:30 hours, compliance of 100%, but Average Leak Rate of 17.89, 90% Leak Rate of 30.00 and % of time above leak rate threshold: 30.73. (Last night the app showed mask fit of 100%. I guess that's not accurate?)

That's better than my stats from last week, which have AHI of 2.04, avg. leak rate of 19.35, 90% leak rate of 36.00, and % of time above leak rate threshold of 32.99%.

All of that is still better than the 6 month summary data showing avg. leak rate 38.77, 90% rate of 66 and % time above leak rate threshold of 71.91%.

I should mention here that my BiPAP pressure is set at 17/21. I should also mention that I don't have facial hair getting in the way, my head is normally shaped, I use the Amari View mask with mask liners to help the seal, and I've tried multiple masks and sizes from the provider and from eBay (new stuff, just cheaper than a co-payment), I sleep on my back and/or side most all of the time, no caffeine, all that good stuff.

So...does my mask fit? I'm learning about all of this data, as far as what it all means. SleepyHead tells me my mask is leaking way too much and to talk to my CPAP provider.

Questions: is it possible to get a good fit with pressure as high as 21? I hear that's a rather high pressure and some leakage is normal.

Another question: I've read what those terms for leakage "mean" but, in all honesty, I don't understand it. I've also read on here I think, that if the average leak [whatever] is 30 or below then the BiPAP machine can still detect rather accurately your AHI and sleep events and...stuff. Mine is, I think here lately, on average just under 30 so...my AHI is ok?

Should I tape my mouth? Does that do anything in re this? I don't know if I open my mouth or mouth breathe at night - I'm usually asleep during it! (Ha, ha.)

I'm still kinda sleepy in the mornings; I go to sleep and wake up about the same time, although I could easily doze for another hour or so.

What does the community think? This forum has been extremely helpful, especially in my despondent first few weeks trying to get the mask on my head correctly! One day I hope to be able to help others like myself on this forum!

[Pugsy]

We need to make a change in the default settings in SH so that your % of time above red line is correct.

% of time above leak rate threshold: 30.73. (Last night the app showed mask fit of 100%. I guess that's not accurate?)

Go to File/Preferences/CPAP tab
Look on the right side for "flag leaks over threshold" an change the setting from 24 to something around 80 to 90 L/min. The 24 L/min is for ResMed machines and they report excess leak differently.
You could also simply remove the check mark and turn it off and just go by the Large Leak (LL on the events graph) to eyeball large leaks. The machine is accurate but the % of time in large leak calculation in SleepyHead is incorrect due to the calculations being based on the wrong number.

I've also read on here I think, that if the average leak [whatever] is 30 or below then the BiPAP machine can still detect rather accurately your AHI and sleep events and...stuff. Mine is, I think here lately, on average just under 30 so...my AHI is ok?

Your machine reports total leak and you won't ever see 0.0 leak because total leak includes the mask's expected vent/intentional leak rate plus any excess leak.
ResMed machines only report excess leak so the 24/30 comments relate to ResMed machines and not yours.
If your machine isn't flagging very much Large Leak...you don't have any major mask leak problems.
For your machine to be missing flagging apnea events your total leak number would need to be over 100 L/min and maybe a little further given your higher pressure needs.
Intentional vent rate increases with pressure increases...so the vent rate for someone using a pressure of 7 is going to be lower than your vent rate. In the mask paperwork there should be a graph showing the vent rate at your pressure. Then you add any excess leak on top of that to get total leak.

Sounds like you are having minimal to none time spent in large leak and that means the AHI is accurate.

SleepyHead will attempt to calculate excess leak only but it's not necessarily as accurate as we would like (on the Respironics machines) so for that reason we usually tell people to understand total leaks and where large leak territory begins in term of total leak and not excess leak.

[bpb21]

Ok, I went and did that and this seems more in line now. For my most recent I had AHI of 1.88, Obs.Index of 0.71, Hypopnea Index of 0.71, Clear Airway index of 0.47, and 0 for flow limitation index and RERA index. That also puts the % time above leak threshold to 0.00%.

I was going to also ask, what happens when you detach the mask (Amari View has that quick release) if you have to get up to use the bathroom or go let the cat out or something? Is that when a gap in the graphs might show up? That wouldn't be considered a "leak", per se, I take it?

Anyway, thank you very much for the tip! That change makes the overall stats seem more in line with my expectations; at that high of a pressure I didn't think any mask was going to be leak-proof.

As always, this is a great forum and community!

[Pugsy]

I would always turn the machine off if I get up during the night for some reason. Even with the Auto Off feature turned on (so that after a little bit of time the machine will turn off if it doesn't sense breathing on your end) there is going to be a brief spike in the leak and it messes with the numbers a little bit. While not a huge deal and it's easily seen on the graphs (big leak spike before there's a gap in therapy seen) I just preferred to just turn the machine off and not have that spike.

So if you turn it off...obviously there's going to be a gap in the therapy line.
If you let the machine continue to blow it will first show up as a spike in the leak and then if it isn't set to turn itself off (I think around a minute) and it continues to blow then that's when you get the BND flag...Breathing Not Detected which means the machine is on and blowing but no human breathing on the other end.

So if you remove the mask and the machine is still blowing...it's flagged as a large leak and the time in the large leak gets thrown in with all your other leak data. It's easily seen and mentally removed from the evaluation though so not that huge of a deal.

I just turn it off before I take the mask off. It only takes a split second and it's just a habit I have developed.
I also just remove my mask at the same time. Since I use a nasal pillow mask that requires essentially no fine tuning to get it to seal easily and quickly putting it back on in the middle of the night doesn't require much effort. Now if I was using a full face mask where the fine tuning was more involved then I might just continue to wear it and make use of just detaching it from the long hose. Whatever works for you to make it easier is okay to do. No hard fast rules. I rarely have to get up in the middle of the night though. Once my OSA was treated the nocturia (and I was having to get up and pee about every hour on the hour) totally went away so it's rare that I get up in the middle of the night.

I do have my machine set to turn off if it senses I am not on the other end but it is extremely rare that I utilize that feature...even in the mornings when I get up...I always turn the machine off and then remove my mask..usually at about the same time.