ResMed Machines, "Standard" Mask Type & Flow Rates

I just posted in another thread regarding the frequent comment that ResMed machines deduct a flat 24L/min from total flow data for the "Standard" mask type. The topic will likely get lost in that thread, so I thought I'd start another thread and link to my post:

viewtopic/t44800/viewtopic.php?p=400274#p400274

This post shows flow curves that suggest a flat 24L/min reduction may not be accurate.

twokatmew wrote:I just posted in another thread regarding the frequent comment that ResMed machines deduct a flat 24L/min from total flow data for the "Standard" mask type. The topic will likely get lost in that thread, so I thought I'd start another thread and link to my post:

viewtopic/t44800/viewtopic.php?p=400274#p400274

This post shows flow curves that suggest a flat 24L/min reduction may not be accurate.

My assumption is that "Standard" is the choice for a middle-ground vent-rate curve.

The 24 L/min is the conversion of the 0.4 L/sec that is what I understand to be the "oops, over the line" mark for getting too far above normal vent rate with leak on any mask. So I think that is likely where that number came from. Or as the manual for my blower says:

"Leak is derived by analyzing inspiratory and expiratory airflows, and expected mask vent flows. A leak rate of more than 24 L/min (0.4 L/s) affects the accuracy of other measurements and is associated with patient discomfort, disturbed sleep, and reduced efficacy of treatment."

Here is a chart and graph on mask vent rate for ResMed masks, so whichever numbers and lines match up best to your mask might be the choice to make:

http://www.resmed.com/us/assets/documen ... sa_eng.pdf

Note that it is recommended that when using the Mirage Micro mask with an S8, "Standard" is the setting to use, just like the Mirage Vista, even though the vent rates for the two differ a few cm, according to the graph in the pdf I linked to above:

http://www.resmed.com/assets/documents/ ... sa_eng.pdf

Hope that helps.

jeff

The interesting thing, jnk, is that although ResMed says to use the "Standard" mask type for the Mirage Micro, the flow rates for the Micro are exactly the same as the Activa LT, for which they say use "Activa." I know the Micro has been re-designed (at least the vent port), so perhaps the vent curve has changed and ResMed hasn't updated their chart?

Further, the Kidsta mask is listed as "N/A" for mask type, so ResMed apparently thinks "Standard" isn't good for that one. I haven't looked at the Kidsta manual for the flow rates though.

Wow. Strange.

Even stranger is that "Swift" is the recommended setting for both the "Swift II" and the "LT," but their vent-rate lines seem to differ quite a bit with higher pressures, looks to me like.

OK. I admit it now. I am completely confused.

Maybe ResMed just likes playing with our minds to keep the forums exciting.

Maybe we all need to increase our rate of venting about vent rates?

jeff

jnk wrote:Maybe we all need to increase our rate of venting about vent rates?

jeff

Jeff!

I just checked the user guide for the Kidsta mask and see that the vent curve is identical to that of the Vista. (ResMed says use "Standard" for Vista and there is no setting for the Kidsta -- N/A.) IIRC, ResMed does warn that xPAP machines are for use by those over 66lbs. in weight, so perhaps they're saying the Kidsta must be used with no machine ... or a mythical machine just for those who weigh less than 66 lbs.?

Back in the original thread, jdm wished ResMed had a setting that displayed the full leak info. I think that's exactly what ResMed should do. But of course, they wouldn't want to make it too easy, cuz they want us to buy ResMed masks! But ... considering the differences in flow rate between masks which use the same setting -- as well as contradictions in ResMed's instructions for which setting to use -- it would seem likely that all the mask settings are indeed estimates. All the more reason for ResMed to provide an option for displaying full leak with no reduction for expected vent rate.

Perhaps we'll see this in the rumored new S9!

Is anyone monitoring this forum? I used to belong to Kaiser and got all my CPAP supplies from them. Now I need a replacement Activa Mask. It says Active Cell and Standard but I can't tell what size or type I should order. Anyone have any advice?

Yeah, well, obviously PR liked Resmed's confusing method as w/the PR S1s "they" have adopted mask settings as well. AND I find those mask settings even more confusing than Resmed's S8 method!!

From the PR S1 Provider Guide:
S1 Resistance - This setting allows you to adjust the level of air pressure relief based on the specific Respironics mask. Each Respironics mask may have a "System One" resistance control setting. System One resistance compensation can be turned off by choosing the setting "O". ...

From the PR S1 Users Manual:
S1 Resistance - This setting allows you to adjust the level of air pressure relief based on the specific Respironics mask. Each Respironics mask may have a "System One" resistance control setting. Contact your home care provider if you cannot find this resistance setting for your mask. ...

Has ANYONE found a list of Respironics masks AND their resistance settings???

At least Resmed DOES provide a chart of at least most of their masks and the Mask Selection to use.

Slinky wrote:Has ANYONE found a list of Respironics masks AND their resistance settings???

Thanks, Pugsy!!!

I take it my Simplicity is the "simple cushion" in the ComfortLite 2 table. The Simplicity is one of their oldest masks so it was easy to miss it the first time thru the table.