How much is too much leakage

I have a mirage swift ii mask, the specification for leakage at 9cm pressure is about 33. My data is showing averages of 40 to 48 per night. Is this too much leakage?

Best regards

Are you getting the average leak from the LCD readout on the machine, or are you using Encore Viewer?

It is hard to evaluate from the average, but since it is higher than the mask rating, you must be having some episodes of fairly major leaking - however, if it is a fairly level leak line (from the software report) it MIGHT be ok.

It is from the Encore viewer software, it is not a flat line, more like a square wave, I can include the data later today, I didn't expect a reply to the post so fast.

I am trying to figure out if it is mouth leakage/breathing, movement of the mask while I am sleeping (rolling over, that type of thing), or improper fitting mask.

I have only started CPAP since October, and the results have been very poor until I found this forum


Thank you for the fast reply

Seeing the data itself from the reports will help - I'm sure the experts will chime in then.

I do know the reason it might look like a square wave is that the machine only reports flows in discrete steps of I think 7 lpm.

If it has a square wave pattern and you are not waking up with dry mouth or air blowing out your mouth ... you are probably doing fine.

Ideally you want a flat horizontal line but as sepool stated, that is not always possible because of the machine data resolution. If the nightly leak pattern showed valleys and hills (lots of variability) then that would indicate mouth and/or mask leaks.

Has anybody come up with a "True Pressure" formula that reduce the pressure increase when leak rate increases over baseline? If pressure goes up only to make up the volume lost through the leak, does the pressure increase into your lungs?

Obviously I had too much coffee this morning!

OldLincoln wrote:Has anybody come up with a "True Pressure" formula that reduce the pressure increase when leak rate increases over baseline? If pressure goes up only to make up the volume lost through the leak, does the pressure increase into your lungs?

Obviously I had too much coffee this morning!

Pressure is controlled by the PAP sensor. In other words, in CPAP mode the pressure is the same regardless of leak rate. So only the air flow increases when leak rate increases, pressure remains "constant" ... air flow and pressure are different measures and concepts.

In APAP mode the pressure is maintained within the min and max pressure settings according to airflow sensor ... so in APAP mode, leak rates can affect the air flow and thus the APAP algorithm ... but the pressure will be maintained within the min and max settings.

dorourke wrote:It is from the Encore viewer software, it is not a flat line, more like a square wave,

dorourke, welcome to the forum and cpap.
This is the place.
You want it to look like this.



Keep at it, ask questions, try stuff til it works, and it will.

All the best. It's a journey.

carbonman wrote:

dorourke wrote:It is from the Encore viewer software, it is not a flat line, more like a square wave,

dorourke, welcome to the forum and cpap.
This is the place.
You want it to look like this.


quote]

Oh for the love of god, there is no freaking way my leakage will ever look like that. Are you a machine??? Don't ever post things like that. But interestingly, my rate is never above what the system considers as a leak and the spikes are short in duration.

this is with my mouth taped - are you saying that my AHI numbers would be better if my leak rate was flat or is flatness simply sonething to strive for like 0 AHI??

Here is some data from last week



[img]ttp://picasaweb.google.com/lh/photo/75FAKSMUFZT_T32aCJ4jlg[/img]

Didn't work,

think you wanted this - your tag was wrong -

You have the software.

The Resmed software has a red line at the 24 cms mark and the Resmeds can compensate for leaks up to 24 cms - after that the accuracy of your data comes in to question is the way it was explained to me by the not so bright RT at my first local DME suppliers when I backed her into a corner about my leak rate.

Swift II at 9 is around 31 + / - 6.

Draw a horizontal line where 30 is approximately on your graph and look at how much time you are WELL above that line.

Look at when events occur. Once the machine gets to 75 I understand it will not record any apneas, snores, etc. just leaks.

Thanks Jules, I put the leakage @ 33 from the graph in an earlier post, I was being generous. The Large leakage came from readjusting and playing with the mask when I woke up in the middle of the night. I know that a certain amout is coming from the hose mouth piece joint and I am going to use teflon tape on that end and the end joint tonight and see what the results are.

What did you mean the tag was wrong, that you were able to get the graph to upload.

Thanks again