Mirage Quattro acceptable leak rate - resolved (I think)

Pugsy wrote:

Otter wrote:I'm pretty sure they use a chart like the one I linked above, and that it's based on testing sealed masks at different pressures. Is there doubt about this? How else would they do it?

S9 Mask choice simply says "full face mask" is that true?

Yes. And Resmed claims the same expected flow rates for all their FFMs. I don't imagine they all really are exactly the same, but they should be somewhat close.

I'm sure there's a fair amount of fudge in all these numbers, including the 24 l/m maximum unintentional leak rate, but that's how it's designed to work. When you start saying, "yes but..." and doing your own calculations, you're eating into the fudge factor the engineers came up with. That's what you're saying, eh? It's likely that none of the numbers they give us are exact enough that we can use them to calculate alternative leak limits. The guesstimating has already been done, and second guesstimating could take you into the realm of fiction.

Thanks all for all of the great feedback!!

I'm posting the data here. As suspected, I had some prolonged leaks I'm guessing due to movement and the mask getting slightly dislodged... I keep it pretty snug, so I'm not sure what more I can do. Just got the mask liner + anti-leak strap from Padacheek but still got these leaks. Will continue trying w/this mask but am going to consider trying a nasal mask again.

Here is the leak line etc from last night:







Thanks again!!

Does your leak rate usually trend upward through the night?

Otter wrote:It's likely that none of the numbers they give us are exact enough that we can use them to calculate alternative leak limits.

For people obsessed with the numbers having to be exact all this is a recipe for a huge headache. As it is, we just have to accept that there are no absolutes and deal with it however suits our own minds so as to avoid that headache. We have to start somewhere and ResMed has given their line in the sand. Stay away from it and you will be fine. Get close too often, it might mess with therapy and warrants work.

I have never been one to put too much stock in any % number anyway. If someone else wants to put a lot of stock in them, that is certainly within their right to do so. It is just a number, no more no less and sometimes it tells the whole story and sometimes it doesn't.

Randy, refresh my memory. What was the deal with the nasal mask? Was it mouth breathing?

Otter wrote:Does your leak rate usually trend upward through the night?

Yes it does. I often have a very good low leak period (2-3 hours) at beginning of night, then higher leaks especially w/higher pressure.

Pugsy wrote:Randy, refresh my memory. What was the deal with the nasal mask? Was it mouth breathing?

Pugsy - I tried a nasal mask (I don't know which one) during my sleep study but I was a little bit congested that night and therefore couldn't breathe well through my nose and my mouth kept opening, so they switched me to the Mirage Quattro and sent me home with that.

I have been taking steps to improve nasal breathing (irrigation etc) so I might be in a better place to try a nasal mask again.

Also, I am not so concerned with what my leak rate % number is, but want to be able to trust the other data (AHI, AI etc) and I have been told that if leak rate is too high the other data will not be vaild. I just want to be able to look at my AHI etc for the night and be able to trust it & know whether I am getting good therapy or not.

Thanks.

RandyJ wrote:

Otter wrote:Does your leak rate usually trend upward through the night?

Yes it does. I often have a very good low leak period (2-3 hours) at beginning of night, then higher leaks especially w/higher pressure.

That makes it difficult to adjust, eh? I don't move around too much when I sleep, so I'm not much here, but what sort of pillow are you using? And what how are you routing the hose?

Otter wrote:

RandyJ wrote:

Otter wrote:Does your leak rate usually trend upward through the night?

Yes it does. I often have a very good low leak period (2-3 hours) at beginning of night, then higher leaks especially w/higher pressure.

That makes it difficult to adjust, eh? I don't move around too much when I sleep, so I'm not much here, but what sort of pillow are you using? And what how are you routing the hose?

otter - I use a regular pillow but sleep on the edge of it so mask hangs off, hose is routed around headboard of bed. I think it's a good setup but was thinking about splurging for one of those fancy papillows.

Btw last night's reported leak rate on S9 was "0.0L/min" so something must have improved!! (Will look at detailed graphs later). AHI was 2.1, AI = 0.9, CI = 0.2, avg pressure = 18.4 and usage = 7.6 hrs.

It was very late and I was super-tired when I went to bed, maybe that helped and I didn't move around a lot.

With the Padacheek liner I can not hear or feel any leak going on - that was true both last night and the previous night when I had a high leak rate.

Thanks for your input.

RandyJ wrote: Btw last night's reported leak rate on S9 was "0.0L/min" so something must have improved!! (Will look at detailed graphs later). AHI was 2.1, AI = 0.9, CI = 0.2, avg pressure = 18.4 and usage = 7.6 hrs.

Well done. This also gives some validity to your data shown when you had higher leak and wasn't sure if it messed with the numbers or not since it is about the same. It may have been better than we thought.

RandyJ wrote:Btw last night's reported leak rate on S9 was "0.0L/min" so something must have improved!! (Will look at detailed graphs later). AHI was 2.1, AI = 0.9, CI = 0.2, avg pressure = 18.4 and usage = 7.6 hrs.

0.0L/min was your 95th percentile leak rate?! That's awesome. At the very least, it indicates that solution is possible with the mask you have now.

Otter wrote:

RandyJ wrote:Btw last night's reported leak rate on S9 was "0.0L/min" so something must have improved!! (Will look at detailed graphs later). AHI was 2.1, AI = 0.9, CI = 0.2, avg pressure = 18.4 and usage = 7.6 hrs.

0.0L/min was your 95th percentile leak rate?! That's awesome. At the very least, it indicates that solution is possible with the mask you have now.

Yes the 0.0 is what displayed on the S9 screen this morning so I believe that is the 95th percentile number. I am encouraged. Hopefully it wasn't just a fortunate combination of circumstances. I think it's possible that when I am very tired I may move around less during sleep and therefore am less likely to dislodge mask.

Also maybe I had the Padacheek liner tighter than the night before. Anyway, happy day!

Pugsy wrote:
Well done. This also gives some validity to your data shown when you had higher leak and wasn't sure if it messed with the numbers or not since it is about the same. It may have been better than we thought.

Thank you

I've had two good low leak nights now - 1st (Sat) was 0.0 L/min and 2nd (Sun) was 4.0 L/min (95th percentile numbers).

I think the Padacheek mask liner is the key; I'm very happy with it. The first night I used it I had large leak rate but it must have been an anomaly.