Leaks and AHI Readings

6PtStar · Post by **6PtStar** » Tue Dec 25, 2007 12:10 pm

I know this was discussed recently but I did a search and could not find it. I don't seem to be very good at defining search names.

Is there a point at which leaks are so large that the machine quits recording AI & Hi's. I have a friend who I have trying to help and his leaks are horrable. I have been trying to get him to work on lowering his leak factor. He won't listen because his AHI is around 2+ so he says it does not matter that he has leaks if his AHI is low. I thought I read that at a certain leak rate the machine quits recording or at least does not record properly.

Any one help me out so I can counter his argument that since his AHI is low that leaks do not matter.

Jerry

cflame1 · Post by **cflame1** » Tue Dec 25, 2007 12:23 pm

With a Respironics machine when you get large leaks, then it stops recording anything.

Wulfman · Post by **Wulfman** » Tue Dec 25, 2007 12:38 pm

Everything except SNORES......

If it's a sporadic large leak for a few minutes and the rest of the night is "reasonable", then it may not be a big deal, but if they're as bad as I'm interpreting from your post, that's something that needs to be addressed.
The data comparing the mask, the pressure and the typical "vent flow rate" all need to be taken into consideration.
For example, if you use a UMFF at 12 cm and your leak rate is supposed to be around 40 and your average for the night is like 60.....you got a problem.

Den

RipVW · Post by **RipVW** » Tue Dec 25, 2007 2:02 pm

Is a leak rate of around 40 about right for a Ultra Mirage FF mask?

Gerald · Post by **Gerald** » Tue Dec 25, 2007 3:05 pm

While trying to help my lady (she's a hose-head, too), I noticed something very interesting.

She had, what I consider, mild leaks during the night.....and her AHI score was 1.8......what many would consider "not too bad".

What fascinated me was.....that her O2 levels were below minimums for 1/3 of the night......she got down to 87% saturation part of the time......and she didn't feel too hot during the day....sort of "draggy".

So.......what I'm seeing here is that we can have AHI scores under 5.0 (considered "normal" by the medical profession) and still have sub-par O2 levels.

We've learned that if we don't get the leaks under control, the O2 levels become unacceptable.

Your friend needs to slap a recording oximeter on his wrist for a few nights to see what he's REALLY doing.

I think he might be shocked by what he sees when he puts a gauge on himself....instead of guessing.

Gerald

Goofproof · Post by **Goofproof** » Tue Dec 25, 2007 4:19 pm

Your treatment doesn't start unitl you get the leaks under control. It's all about air pressure holding your airway open. You can't get there by ignoring the Laws of Physics. Jim

Take a balloon and blow it up, then let the air out and cut the end off the balloon, then try to blow in up. Won't fly.

RipVW · Post by **RipVW** » Tue Dec 25, 2007 4:43 pm

Found this leak rate chart that has stats provided by many of you CPAP "old timers."

http://www.internetage.com/cpapinfo/leak-rates-1.html

6PtStar · Post by **6PtStar** » Tue Dec 25, 2007 4:44 pm

He is wearing a Swift and has a very heavy beard. His leak rate is running around 60 L/Sec. Huge black line on his leak page. Had one night his Average Leak rate was 80 L/Sec. Said he had a cold that night. He has been on a cpap for about 6 years but never seem to be getting much benefit (in my opinion). I recently talked him into going for sleep study. He never had one, an ENT sent him home with a auto and gave him some kind of basic machine. After his sleep study he went from 6 cm/h2o to 12. He got a "M" auto with A-flex and now I can read his card. I have a feeling he is mouth breathing and with his beard he won't seal with a full face mask. I talked to him about taping and might have been talking to the wall. Won't even consider it.

I was thinking there was a specific number that would kick out the recording. I will keep after him but as long as he keeps pointing to the low AHI I am not sure I will get through to him.

Thanks for the information.

Jerry

Wulfman · Post by **Wulfman** » Tue Dec 25, 2007 5:39 pm

RipVW wrote:Found this leak rate chart that has stats provided by many of you CPAP "old timers."

http://www.internetage.com/cpapinfo/leak-rates-1.html

Did that answer your questions, Rip?

Den

Wulfman · Post by **Wulfman** » Tue Dec 25, 2007 5:43 pm

6PtStar wrote:He is wearing a Swift and has a very heavy beard. His leak rate is running around 60 L/Sec. Huge black line on his leak page. Had one night his Average Leak rate was 80 L/Sec. Said he had a cold that night. He has been on a cpap for about 6 years but never seem to be getting much benefit (in my opinion). I recently talked him into going for sleep study. He never had one, an ENT sent him home with a auto and gave him some kind of basic machine. After his sleep study he went from 6 cm/h2o to 12. He got a "M" auto with A-flex and now I can read his card. I have a feeling he is mouth breathing and with his beard he won't seal with a full face mask. I talked to him about taping and might have been talking to the wall. Won't even consider it.

I was thinking there was a specific number that would kick out the recording. I will keep after him but as long as he keeps pointing to the low AHI I am not sure I will get through to him.

Thanks for the information.

Jerry

Did you discuss him using Polident adhesive denture strips? That might not sound as severe as "taping".

Don't know what else to suggest, Jerry.....other than appealing to his sense of self-preservation by improving his therapy.

Good luck.

Den

Snoredog · Post by **Snoredog** » Tue Dec 25, 2007 9:30 pm

On the Remstars (classic and M series) it is 75L/m, a higher leak is classified as "Large" leak and machine will stop responding to events, it shows up as a solid black mark on the Encore reports, machine will also drop pressure by 2 cm (if an auto).

glfredrick · Post by **glfredrick** » Tue Dec 25, 2007 9:32 pm

RipVW wrote:Is a leak rate of around 40 about right for a Ultra Mirage FF mask?

I'm using the same mask, and my leak rate is in the low 30 range -- typically around 32. I think the mask leaks around 30 by itself from the vent holes. Anything more is leakage around the face.

FWIW, I can't imagine getting any mask to seal with a full beard. Might want to try the nose pillow option with some sort of device to hold the mouth closed.

Wulfman · Post by **Wulfman** » Tue Dec 25, 2007 9:43 pm

glfredrick wrote:
RipVW wrote:Is a leak rate of around 40 about right for a Ultra Mirage FF mask?
I'm using the same mask, and my leak rate is in the low 30 range -- typically around 32. I think the mask leaks around 30 by itself from the vent holes. Anything more is leakage around the face.

FWIW, I can't imagine getting any mask to seal with a full beard. Might want to try the nose pillow option with some sort of device to hold the mouth closed.

According to your profile, you're using the Quattro.....and, depending on your pressure and whether you have taped the elbow in the front of the mask, that can make a difference.
With my Quattro, I can get a low 30's leak rate at 12 cm. whereas with my UMFF masks, about 38 - 40 on a good night.

Den

sharon1965 · Post by **sharon1965** » Tue Dec 25, 2007 10:07 pm

i know, i know, i've asked this question before...but every time the concern that leaks are skewing our results comes up, i start to worry, since i never really get this concept down

i used the headrest/aura and at my pressure of 8.5, the leak rate is 22
i always register zero large leak on my reports, and for the last couple of weeks, my ahi has been 1.0, 1.2 around there, every night

my leaks look like this:

large leak 0

max leak 79, 90% leak 29, avg leak 26.07
max leak 51, 90% leak 26 avg leak 25.53
max leak 64 90% leak 32 avg leak 26.84
max leak 94 90% leak 30 avg leak 26.56
max leak 48 90% leak 31 avg leak 26.78
max leak 105 90% leak 31 avg leak 26.19

sooooo, once again i just want to check that these numbers actually are good, and what the heck does the 90% leak refer to anyway!? do i just need to pay attention to the avg. leak number? and is it close enough to the intentional leak rate of 22?
thanking you all AGAIN, in advance (den, don't give up on me even though you've already tried to explain this to me )

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CPAPopedia Keywords Contained In This Post (Click For Definition): AHI

6PtStar · Post by **6PtStar** » Tue Dec 25, 2007 10:40 pm

Thanks Snoredog I think the 75L/M was what I was remembering.

Sharon I think your leaks look good. No need to worry about those numbers. The Max leak could be a bit lower but it must be a very small duration because it is not effecting your avg or 90% very much

Jerry

Mask

Additional Comments: Pressure = 16!!!