Finally! A Leak Rate Recorded.

jules · Post by **jules** » Fri Nov 16, 2007 1:01 pm

I agree with Dream Stalker that you are getting a leak rate in the upper 40's and should be in the lower 30's. The leak rate is higher than it should be but why? How many large leaks? With the LED display you can't answer much more.

You said your husband heard leaks that night. A graph of the actual leak rate would give you much more information.

As an example suppose your leak rate was 150 for one hour and 30 for 7 hours, your average leak rate for the 8 hour period would be 45.
(7 * 30 + 1*150) / 8

The person would have had a great leak rate for 7 hours but had an hour where the machine was just blowing out of control. ( I see LL on my remstar that high).

Flying_Norseman · Post by **Flying_Norseman** » Fri Nov 16, 2007 1:04 pm

That would show up in the Large Leak reading. Manufacturers don't even want to hear about it if the leak is under 80.

gasp · Post by **gasp** » Fri Nov 16, 2007 3:17 pm

[quote="Flying_Norseman"]Gasp,

Some people would tell you that you can't trust your AHI numbers if your leak rate looks like that. I am not sure if they are right or not.

gasp · Post by **gasp** » Fri Nov 16, 2007 3:20 pm

DreamStalker wrote:Interpolating from the chart posted by Bob a while back the Standard setting at 11 cm should be about 34 to 35 liters per minute.

That means that adding the 14.4 liters per minute makes your leak equal to about 48.4 to 49.4 (or about 49 LPM) for your reading of 0.24 LPS from the LED/software using the Optilife at 11 cm of pressure.

So your leak rate should be 30 LPM and you are getting 49 LPM … your leak rate is about 163% of what it should be. You should probably work on trying to get it down a bit IMO.

Thanks for posting this! Not only may it potentially help Treesap, it certainly is good information for me. I see that for my consistent average pressure of 8, my leak rate is actually lower than the acceptable amount.

Flying_Norseman · Post by **Flying_Norseman** » Fri Nov 16, 2007 3:53 pm

I am still at the stage where I check every morning when I get up. Oddly enough there are times when I feel great and my AHI is still pretty high (10 or so).

[quote="gasp"][quote="Flying_Norseman"]Gasp,

Some people would tell you that you can't trust your AHI numbers if your leak rate looks like that. I am not sure if they are right or not.

Treesap · Post by **Treesap** » Fri Nov 16, 2007 10:23 pm

Oh gawd! Now I am more confused. How did you come up with that leak rate Dream Stalker? I understand L/s should be multiplied by 60 to get a L/m rate. My machine registered a .24 L/s rate. That's how I came up with the 14.4 L/m. How did you get what you got?

I'm actually not bad at math, but this leak rate is getting me really confused.

ozij · Post by **ozij** » Fri Nov 16, 2007 11:41 pm

CPAP masks have vents, necessary to blow out the CO2.
The higher the pressure, the higher the intentional leak rate of the mask.
When you leak more than the intentional vent rate, the you're leaking from somwhere in the circuit - your mouth, your mask to fact fitting, any hose connection etc.
Resmed machines give you that leak information, in a sophisticated way:
1. The machines keep a database of Resmed masks intentional leak rates.
2. You tell the machine what your mask is.
3. The resemed will show you a 0 leak rate as long as you're within the mask's intentinal leak rate.
- There is a group of masks that belong to the "Standard" definition on resmed machines
.

You're using the Optilife, on a setting of Standard. So Dreamstalker did the following:
- 1. Looked at the intentional leak rate for one of those masks at the pressure you reported.
  2. Added the leak rate you had
  3. Compared the result to the expected leak rate for you own mask at that pressure

O.

OT : Hey, can you all tell I'v just learned how to use the "list" button on the reply? Here's the link on how to do it - and more besides: http://www.phpbb.com/community/faq.php?mode=bbcode

DreamStalker · Post by **DreamStalker** » Sat Nov 17, 2007 7:34 am

Yep ... ozij has it correct.

Look at Bob's chart and note that the leak rate for the standard is 33 l/m at 10cm and 36 l/m at 12 cm ... so by interpolation 11 cm is somewhere between 33 and 36 l/m. Since you said you had a pressure of 11.6 cm , then the ResMed machine automatically subtracts about 35 l/m from whatever actual leak you had and then lists the remainder (0.24 l/s or 14.4 l/m) on your LED.

So to get your real leak rate you have to add the remanider to what was subtracted by the ResMed machine (14.4 + 35) using same units of l/m so that your true total leak rate is around 49 l/m ... yet it should be around 30 l/m.

So find out if you are leaking from your mouth or the nasal pillows and take action to correct the leaks.

Best of luck.

Treesap · Post by **Treesap** » Sat Nov 17, 2007 3:12 pm

I don't believe I leak from my mouth. I don't wake up with dry mouth, and I usually see my teeth indentions in my tongue in the morning which would indicate that my mouth is closed and my tongue has been pressing up against the back of my teeth. Right?

The night hubby woke me up, I could tell I had leaks from the nasal pillow. I tightened my head straptraps, and I think it took care of it.

I've been doing really well for a while, but these last 3 weeks or so have been a challenge for me.

I got a Comfort Curve mask on it's way from someone who is going to le tme try it. I hope it does, or I might have to try some other masks.

GumbyCT · Post by **GumbyCT** » Sat Nov 17, 2007 4:12 pm

::I don't know why I get into these things::

Could it be that everyone is saying the same thing? Just in different ways? Or ways that they are familiar with?

The way that is familiar to me is (1st I dont have a ResMed) but if they automatically subtract the "known leak rate" (the mask) from the 'detected leak rate' (an unknown) doesn't THAT give you the real leak rate? NO Math required - NO confusion.

What IS displayed (IF you choose the correct mask) is the amount of leak above what the mask has leaked. NO Math required - NO confusion- NO Voodoo - the leak rate appears.

NOTE: IF the correct mask (or known leak rate) is NOT entered "ALL Bets are OFF".

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Treesap · Post by **Treesap** » Sat Nov 17, 2007 7:06 pm

I can't choose the correct mask because I have a Respironics mask, and there is not a true setting for that mask on the Resmed machine.

My question now is: Should I be trusting the machine when it shows 0 leaks?

DreamStalker · Post by **DreamStalker** » Sat Nov 17, 2007 7:15 pm

If your ResMed machine shows zero leak ... all you can know is that your leak rate for your Optilife is somewhere between 30 and 35 l/m at 11 cm of pressure.

GumbyCT · Post by **GumbyCT** » Sat Nov 17, 2007 8:40 pm

Treesap wrote:It's set to "standard". I tried the Swift setting a few weeks back, but that's when I started waking up feeling terrible, so I changed it back.

Guess that really depends on what "Back" is/means?

ps. I think you may be over analyzing this. How do you feel?

Treesap · Post by **Treesap** » Sun Nov 18, 2007 10:32 am

Well, let's see. If I now have it on "standard" as that is the only setting for an Optilife. Then I tried the "Swift" setting which didn't work, so I set it back. I think that means I am back to "standard".

I haven't been feeling that great, so that's why I started questioning my data. I'm probably going to have to buy the software.

jules · Post by **jules** » Sun Nov 18, 2007 11:20 am

The mask setting should only be affect how the leak rate is determined inside the machine then posted on the LED. I don't have a Resmed machine but that is how I would expect the software on the machine to post it. I suspect that switching from Swift to Standard just changes the numbers on display but it doesn't affect the machine's performance.

When your leak rate is greatly in excess of the manufacturer's allowed rate, and you can't get a graph of the actual leaks, you really don't know where the leaks are coming from. Since your husband heard leaks that other night, you can assume there was a mask leak but you don't know how much and for how long and how much then of your excessive leak rate can be attributed to that.

How long have you been on CPAP and how much of a sleep debt do you have to repay? Some people take months to feel better.

But there might be other reasons why you aren't feeling good such as AHI, medications, supplements, number of hours of sleep, stress in your life, toxic exposures (even what you might think are benign chemicals you use as personal care products). toxic relationships.

I am sure others can add more things that complicate this whole picture.

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