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AHI vs Leak Rate
I am not sure if vs is the right comparative.

I have been on CPAP for about 1 week and my AHI is 0.50 which is down from the 19 in my study so I feel that the machine is set right.  However, my mask is showing an average leak rate of 16L/min.  (per resmed myair).

My questions is do I need to be concerned with the leak rate if I am having such good results in AHI?  Should I consider a different mask?

I don't feel any leaks around my mask (Aifit f10 FFM) but I do have a beard.
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Your leak rate is fine.  A reading over 24L/min on a ResMed machine would be considered high.

Your AHI is very good, and you seem comfortable with your mask, so I wouldn't worry too much.

Just curious, does your SleepyHead Leak Rate Reading compare with the myair reading?
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Organize your SleepyHead Charts
Using Attachments to Post ScreenShots and Images.

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Thank you Opal Rose.  I will let you know what Sleepyhead says tonight after I get home.

I felt that the numbers looked good and was looking for opinions from others who know better.
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The problem is, that your AVERAGE leak rate is 16 L/min, which is 2/3 of the large leak. So how much of the night is actually large leak? Is the leak rate steady, or are there long periods of large leak?

The leak rate is not acceptable if it is disruptive to sleep and comfort, or results in a lot of large leak, and may be resulting in an under-estimate of events that can't be detected during large leak. I think if you feel better and more rested, this is not so urgent, but an average leak rate of 16 suggests a badly fitting mask. You need a different style or size and should be in touch with your DME to get this done.

I think your work with Bonjour is likely to help as he has some of the best insights on mask fit with beards. You have a ways to go to get this to about half your current leak rate.
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Here is last nights chart.  Large Leak for 6% I will keep adjusting.

[Image: tuqR60Kl.png]
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The AHI is really good.
Most importantly, how do you feel?
Please organize your SleeyHead screenshots like this.
I'm an epidemiologist, not a medical provider. 
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That leak rate is workable, and I think the machine is giving you a realistic feedback of events. Sleeping well? The respiratory and event stats are outstanding. Nice to see a guy with a normal 600 mL tidal volume.
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Yes I am sleeping well and the wife is not complaining about snoring anymore either.

I will keep working to improve mask, or try another. But I thank you for your insights to confirm my belief that even though there are leaks they are not severely detrimental to my sleep.
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(03-10-2017, 09:32 AM)Sleeprider Wrote: Nice to see a guy with a normal 600 mL tidal volume.

At the risk of hijacking this thread I have to ask, what is the significance of a lower than normal tidal volume? My average tidal volume runs between 420 and 510. What is considered normal? I'm sure it's related to lung capacity and, therefore, body size. I'm not a little guy; 6'2", 200lbs, 72 yrs old. I think you mentioned in a response to my initial postings that my tidal volume was low for a male. Is this indicative of a problem?

Hope I'm not putting you too much on the spot but your expertise is impressive.
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The only real way to measure respiratory capacity and health is the simple FEV (forced expiatory volume) test. I had one recently at the doctor's office. Basically blow in a tube until you think you're going to pass out, and the machine records the volume, flow and time and even charts it. The CPAP records minute vent and those stats are in the charts, and are not diagnostic.

Normal tidal volume is based on ideal body mass, and there is a lot of variation. In a healthy, young human adult, tidal volume is approximately 500 mL per inspiration or 7 mL/kg of body mass.tidal volume and averages it out. For seniors, and people with respiratory issues, "normal' can be quite a bit less.

If your ideal body mass is 200 lbs 90.7 kg), then 90.7*7= 634 mL. Most people's ideal body mass is well below that so at 150 lbs, (68 kg) you're looking at 476. So that tends to be the range for healthy males, and if you fall below those number based on what your CPAP says, I wouldn't worry too much about it. If it is really low, like under 250-300 mL, you might want to look for reasons why. There are a ton of reasons people have lower tidal volume. My comment above was simply because in this CPAP cohort that posts their graphs, relatively few have volumes above 600. When I see tidal volumes above 400, I generally assume good pulmonary health, and if it seems unusually low, I might ask a question.
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