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Flow Rate / Leak Rate / Flow Limit Data Questions - Printable Version

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Flow Rate / Leak Rate / Flow Limit Data Questions - temperance - 04-10-2022

Good afternoon,

I've been on cpap therapy for about 8ish months now - my AHI is about as good as anyone with sleep apnea could ask it to be, however, I still have frequent awakenings at night.

The data on my charts is fairly consistent. I have patterned leaks that I've been chasing for a while now without any success. I've tried roughly 8 different full face masks that all leak horribly. The best sleep/data I'm able to achieve is with a resmed p10 and somnifix mouth tape, however, after using this combination of mask/mouth tape I still have leaks and wake up 3-5 times a night, sometimes more. It's been my thought that these are mouth leaks and I've hoped that over time I'd learn to keep my mouth/throat shut but that doesn't seem to be the case.

At this point, I'm wondering if the leaks are even mouth leaks. I've been scouring the forums to trying to understand flow rate, leak rate, and flow limit but I'm still at a loss at what I'm looking at. I'm hoping someone adept at understanding this information can take a look at some of the data from my chart last night to hopefully provide insight on what I'm looking at, and perhaps what direction to take my therapy to try to improve my results. I'm still tired all the time due to frequent awakenings, despite my low AHI, and I'm hoping this data may shed some light on as to why.

If anyone could assist, that would be great.

I'll reply below with more screenshots from my data as it's more than 3 attachments

More screenshots.

Final two


RE: Flow Rate / Leak Rate / Flow Limit Data Questions - Rubicon - 04-10-2022

(04-10-2022, 01:53 PM)temperance Wrote:  I've tried roughly 8 different full face masks that all leak horribly. The best sleep/data I'm able to achieve is with a resmed p10 and somnifix mouth tape, however, after using this combination of mask/mouth tape I still have leaks and wake up 3-5 times a night, sometimes more. 
Specifically, what is your criteria for "leak horribly"?

Are these awakenings due to leaks?  Or when you wake up, you coincidently happen to notice leaks?  Do you ever wake up and the mask is not leaking?

A lot of your data show leaks lasting an hour.  Do you sleep for most of that (I'm kinda thinking you would, otherwise you'd adjust the mask and fix the leak)?


RE: Flow Rate / Leak Rate / Flow Limit Data Questions - temperance - 04-10-2022

(04-10-2022, 02:42 PM)Rubicon Wrote: Specifically, what is your criteria for "leak horribly"?

Are these awakenings due to leaks?  Or when you wake up, you coincidently happen to notice leaks?  Do you ever wake up and the mask is not leaking?

A lot of your data show leaks lasting an hour.  Do you sleep for most of that (I'm kinda thinking you would, otherwise you'd adjust the mask and fix the leak)?

I have not fallen asleep with a full face mask - none of the ones I've tried seal properly around my face for me to get to that point. By leaking horribly, any movement other than lying perfectly still creates leaks around the cheek/chin area of the mask.

There are times with the p10 setup that I will wake up and have air leaking from my mouth opening, but not always. It's hard to answer that question, because by the time I'm fully awake enough to remember waking up, it's likely I've adjusted my mouth/throat and closed it.

I'm going to guess I'm sleeping through these leaks, what I'm trying to figure out is if this data points to the leaks being mouth leaks/mouth breathing while I'm sleeping.


RE: Flow Rate / Leak Rate / Flow Limit Data Questions - 2SleepBetta - 04-10-2022

Your OP touched on a question that is off your topic, but I link to your OP and use your question in an illustration. My post did not seem to be appropriate here, but you may wish to read it here A question about calculation using OSCAR-reported "Med." values as variables | Apnea Board .


RE: Flow Rate / Leak Rate / Flow Limit Data Questions - Rubicon - 04-11-2022

Three points about leaks:

1. If they're below 24 L/M the company that built that machine says they're not a problem. If you're worried about your number, don't be.

2. If the leaks are what's disturbing your sleep, then yes that's a problem.

3. If you wake up because your sleep is poor, then a mask and a CPAP machine is probably making it worse.

Did you ever get another sleep study? WatchPAT is not accurate in mild cases of OSA. AAMOF it is easily fooled by such things as PLMs (their rationale on ruling out PLMs is "Well if the PAT events only happen in the beginning of the night then that could be PLMs" and "If the PAT events happen in REM then they can't be PLMs" but since WP guesses what REM is I wouldn't necessarily call that scientific.


RE: Flow Rate / Leak Rate / Flow Limit Data Questions - Rubicon - 04-11-2022

Taking a little bit (OK a lot) of artistic license:

[Image: Ob8hixX.jpg]

[Image: hhLqfkq.jpg]

If body movement can generate PAT events, and central apneas can generate PAT events, can central apneas from train wreck sleep architecture generate PAT events?


RE: Flow Rate / Leak Rate / Flow Limit Data Questions - temperance - 04-11-2022

I'm not sure how you ended up on the subject of my watchpat test, I am here looking for clarification regarding the leak patterns and the flow rate/limit on my data and what it points to.

Yes, I understand the leaks may be what's waking me up. From what I've read, there are certain patterns that point to the leaks specifically being mouth breathing/mouth leaks, and I was hoping someone could answer if that's what these leaks look like. On occasion, I have woken up with leaks coming from my mouth, but that's rare. Most of the time, I do not know what's waking me up.


RE: Flow Rate / Leak Rate / Flow Limit Data Questions - Expat31 - 04-11-2022

I have had really terrible mouth leaks and couldn't for the life of me stop them. I tried  1" tape, no good not wide enough, then 2" tape, still no good!!  I was totally lost as all seemed totally incomprehensible.

Then.... during one night, I was in between sleep and being awake, and heard, and felt the air passing UNDER the tape. The tape was well fixed, but still didn't understand. I pressed a finger on top of the tape and the leak stopped. Curiouser and curiouser...
I found the problem then, I have a very small crease on each side of my mouth (advanced years). The pressure of the air found its way in this ready-made "channel" to escape.

In deep sleep, the jaw muscles relax, jaw drops a bit and the trouble starts. I was lucky and caught the moment.

The solution for me is to reinforce just this area with an extra layer of 1" tape. My leaks were on average really high 30-40 L/min, now down to 15-20. I still have to be really careful in preparation each night, as otherwise, leakes go crazy again.


Hope this my help somebody


RE: Flow Rate / Leak Rate / Flow Limit Data Questions - temperance - 04-11-2022

I'll try the tape you're using and see if it makes a difference sealing the entire mouth. The somnifix mouth tape has a vent in the front between the upper and lower lip.


RE: Flow Rate / Leak Rate / Flow Limit Data Questions - Rubicon - 04-11-2022

(04-11-2022, 09:54 AM)temperance Wrote: I'm not sure how you ended up on the subject of my watchpat test...

Oh sorry, I thought I made that clear when I said

"Did you ever get another sleep study? WatchPAT is not accurate in mild cases of OSA."

Because WatchPAT can easily be fooled into giving false positives in mild > no sleep apnea cases.

I would even question how WatchPAT is identifying REM:

[Image: 4UyTZRE.jpg]