Please help me understand this RESMED data

kennethryan · Post by **kennethryan** » Fri Jan 25, 2008 7:00 am

bigk wrote:Bill - are you saying 0.06l/sec are out of control leaks?

Personally I jump for joy if I get a leak rate anywhere near that low.

Typically I end up in the 0.3-0.4 L/s range.

I had two nights recently where the reported leak rate (as reported in the "Efficacy Data" page on the machine) was in the neighborhood of 2.0+ L/s (yes, over 120 L/min). I had to recheck my mask to be sure it hadn't fallen on the floor while I was sleeping! I think my problem was the mask was too small (a Quattro). Curiously, the same exact mask also has given me some of my lowest leak rates ever. I evidently do not understand this mask thing at all...

mindy · Post by **mindy** » Fri Jan 25, 2008 7:05 am

kennethryan wrote: I evidently do not understand this mask thing at all...

Join the club Every time I think I have it nailed, there's another twist ... a game of whack-a-mole!

Mindy

Slinky · Post by **Slinky** » Fri Jan 25, 2008 7:52 am

bigk wrote:Actually every morning, my previous nights mask fit is shown as excellent *****

In addition to what BillBolton said about the Mask Fit:

You really cannot do a Mask Fit according to the LED screen yourself because you can't SEE the LED screen in various sleep positions. You need someone to view the screen whilst you lay in your various sleep positions. You can always adjust the mask for a good fit sitting up so you can see the LED screen - but the law of gravity takes over on our facial skin and tissue as we lay down on our back and roll to one side or the other and that sitting up mask adjustment is all outta whack w/the reality of our facial tissues and skin when we lay down.

And THAT is one of the reasons so many of us get such a LOUSY mask fitting by the DME supplier's RT. Either they don't have the facilities for us to lay down, the CPAP to provide our set pressure during the fitting or they just plain don't know HOW to do a PROPER fitting. Or don't really give a darn.

kennethryan · Post by **kennethryan** » Fri Jan 25, 2008 9:34 am

Slinky wrote: - but the law of gravity takes over on our facial skin and tissue as we lay down on our back and roll to one side or the other and that sitting up mask adjustment is all outta whack w/the reality of our facial tissues and skin when we lay down.

And THAT is one of the reasons so many of us get such a LOUSY mask fitting by the DME supplier's RT.

One of my big problems is an extension of that - as I start to drift off to sleep my facial muscles relax and evidently the shape of my face changes drastically.

I'll have great fit sitting up (obviously) and lying in my various positions while I'm trying to fall asleep, but even without moving 15-20 minutes later big leaks start to develop.

I need someone to watch my LCD and be really really patient...

bigk · Post by **bigk** » Fri Jan 25, 2008 3:25 pm

Hmm Bill - that is not what the manual says at all. I have never done a mask leak test ever.

The other day I was mucking around re-fitting the mask (not using the mask fit function) and ran the S8 for a few minutes and I ended up with a Poor mask fit showing on the LCD at the end of it.

The mask fit thing is for the previous session. The clinicians manual says it relates to the 70th percentile and the star rating comes from the leak shown in that table I posted above.

I'm pretty comfortable that there is no problem with my mask fit now.

I have the S8 configured for the Activa which is what I am using.

Last Nights leak was 0.06L/s and the AHI was 4.1 Median pressure 11.8
The Median Pressure (and max pressure) has been lower ever since I increased the minimum to 9.

billbolton · Post by **billbolton** » Fri Jan 25, 2008 4:26 pm

kennethryan wrote:One of my big problems is an extension of that - as I start to drift off to sleep my facial muscles relax and evidently the shape of my face changes drastically.

My simplistic approach with a new mask (or renewed cushions etc) is that basically if I wake up and find my mask is leaking I adjust it right then so its not leaking anymore in that sleeping position.

After a few nights I generally have the mask dialled in to something that works for most of my common sleeping positions..... this may mean its a bit uncomfortable when I put first put it on at night, but I'm prepared to trade some level of discomfort off at that point in time in order to get truly restful sleep over the whole night!

YMMV

Cheers,

Bill

billbolton · Post by **billbolton** » Fri Jan 25, 2008 4:36 pm

bigk wrote:Hmm Bill - that is not what the manual says at all. I have never done a mask leak test ever.

Maybe its different on the S8 Spirit II model.

There are very few S8 II users here as its a very new model which is not yet on sale in the US, so you are pretty much on your own as far as nuances in S8 II features go.

Cheers,

Bill

bigk · Post by **bigk** » Fri Jan 25, 2008 4:36 pm

I agree Bill.

I guess the first week of my results is with a new machine and my own mask rather than the rental one from Resmed.

The last 2 nights have been really good stats so maybe it is fitting better. The headgear at least doesn't seem to be cutting into me as much anyway.

bigk · Post by **bigk** » Fri Jan 25, 2008 4:41 pm

billbolton wrote:There are very few S8 II users here as its a very new model which is not yet on sale in the US, so you are pretty much on your own as far as nuances in S8 II features go.

I'd be pretty surprised if they just changed it for the new model.

bigk · Post by **bigk** » Fri Jan 25, 2008 5:09 pm

OK from the clinicians manual page 32 (for the S8 AutoSet Spirit which I think is the same model called the Vantage in the USA)

Under Smart Data

The following Data can be made available showing for the most recent session:

* The star rating of the 70th centile mask fit
* 95th centile pressure
* total duration of session (usage)

The standard patients manual also says the start rating is for the latest session, not for the mask fit session.

track · Post by **track** » Fri Jan 25, 2008 10:08 pm

Your leak rate is excellent...just thought I would answer since you keep asking the question.

bigk · Post by **bigk** » Fri Jan 25, 2008 11:03 pm

Thanks - I thought it was too. Bill just threw me off with his first reply.

Slinky · Post by **Slinky** » Sat Jan 26, 2008 8:31 am

That quote from the Manual is interesting. Especially so since I've sat on the edge of my bed and used the Mask Fit to check the fit of my mask and as I move my mask or make an adjustment the reading on the LED changes to reflect the fit I am getting at the moment. Now that is with my Resmed S8 Elite. I haven't tried it w/my Resmed S8 AutoSet Vantage.

billbolton · Post by **billbolton** » Sat Jan 26, 2008 8:00 pm

Manuals oftens reflect the design intention of the manufacture, but may not reflect what a product actually does.

Just for grins, I ran a mask fit test before retiring last night, which I deliberated "rigged" to give a two star rating.

This morning the mask fit display on the LCD showed two stars, though the data in Autoscan showed.....

AHI = 2.9 (HI 2.0, AI 0)
Leak = 0.04 l/s (95th percentile), 0.18 l/s max

.... which is a 5 star leak level!

So, I have confirmed that what I previously reported is what my S8 "Vantage" labelled flow generator actually does.

Next time I use my S8 "Autoset Spirit" labelled flow generator (in my travel kit) I will perform the same test on it to see what it actually does.

Flow generators with different firmware may do different things.

As always YMMV.

Cheers,

Bill

bigk · Post by **bigk** » Sat Jan 26, 2008 8:37 pm

That's weird Bill. Clearly mine behaves differently. I have no idea why they would do this.

Mask	Humidifier

Additional Comments: S9 Autoset, H5i, Resmed Swift FX, Resscan 3.10

Machine	Mask

Additional Comments: Airmini, Medistrom Pilot 24, CMS 60C Pulse Oximeter, ResScan 6