Do mask leaks affect flow limitation?

[tiredman]

My sleepyhead data shows a lot of flow limitation but also a lot of mask leaks.

I'm wondering if the mask leaks are affecting the flow limitation readings?

[palerider]

My sleepyhead data shows a lot of flow limitation but also a lot of mask leaks.

I'm wondering if the mask leaks are affecting the flow limitation readings?

no.

leaks are excess flow.

flow limitations are flattening of the inhalation curves during the first half of a breath.

you can zoom in on the flow trace in sleepyhead and look at the shape of the flows, when they're nice and round, then your flow limitation reading will be low, when they're flattened, you'll see that the flow limitation will be higher.

flow limitation is all about how smoothly you inhale.

[Pugsy]

Depending on just how bad the leaks are....if the leaks are really bad then the machine may not be able to sense and record and report whatever it thinks is going on. So in that sense it could maybe affect flow limitation reporting/recording/sensing.

Also if the leaks are really bad then it's possible that the airway is maybe collapsing just a little bit because the pressure isn't able to stay where it needs to in order to prevent the airway collapsing and flow limitations could maybe increase for that reason. Pressure is insufficient to keep the air moving optimally.

Leaks would have to be really bad for the above scenarios to take place though. Minor leaks wouldn't/shouldn't affect flow limitations one way or the other.

[thecpapguy!]

My sleepyhead data shows a lot of flow limitation but also a lot of mask leaks.

I'm wondering if the mask leaks are affecting the flow limitation readings?

no.

leaks are excess flow.

flow limitations are flattening of the inhalation curves during the first half of a breath.

you can zoom in on the flow trace in sleepyhead and look at the shape of the flows, when they're nice and round, then your flow limitation reading will be low, when they're flattened, you'll see that the flow limitation will be higher.

flow limitation is all about how smoothly you inhale.

This graph is awesome!

I know that flow limitation won't be affected by a leak percentage, but what would your recommendation be if a high leak percentage is shown and the patient's pressure is maxing on an Auto CPAP unit with an elevated AHI? I've seen countless downloads that look this way and the general consensus is to fix the leak and you fix the problem. After the mask leak has resolved I've noticed that the pressures likely no longer max and the patient's AHI decreases. This is definitely not every patient, but it is high number of users. I just am hoping for your knowledge on the matter.

[palerider]

I know that flow limitation won't be affected by a leak percentage, but what would your recommendation be if a high leak percentage is shown and the patient's pressure is maxing on an Auto CPAP unit with an elevated AHI? I've seen countless downloads that look this way and the general consensus is to fix the leak and you fix the problem. After the mask leak has resolved I've noticed that the pressures likely no longer max and the patient's AHI decreases. This is definitely not every patient, but it is high number of users. I just am hoping for your knowledge on the matter.

I'm not sure what you mean by "leak percentage" that's not appropriate terminology. if you mean 'high percentage of excessive leak during the night"...

coincidentally, oksleepdoc and I had a rather in depth discussion on leaks vs pressure rise vs flow limitations a couple days ago on the irc channel. I'm waiting on him to find any data from modern machines that appear to show pressure increasing as a result of leaks, and nothing else. my stand is that no modern machine will increase pressure due to leaks. they do increase the FLOW rate to compensate for the leak, in order to maintain pressure, but they don't increase pressure.

if there are a lot of leaks, then all sorts of things can be happening, leaks are often very disturbing to sleep, and may cause extra movement, tossing, turning, and such that could lead to other artifacts that could end up being scored as something to cause pressure to increase. without seeing detailed data, it's just a guessing game. with raw data, you can zoom in and see what the waveforms look like, and perhaps get an idea why pressure is so high.

the machines can maintain therapy pressure in the face of huge leaks, (there's a chart in the back of each clinician manual from resmed that shows how many liters/minute of leak the machine can sustain and still maintain pressure, it varies with hose type/length and presence or absence of a humidifier, but it's often 130lpm+. however, the machine can't really detect what's going on with that amount of leak.

minimizing leaks is almost always a good thing, or at least, getting them to an acceptable level, and taming them so they don't disturb the sleeper. mask liners help tremendously in many cases, they won't *seal* better, and may increase the leak amount a bit over a perfect seal, however, instead of loud squeals and farting noises, and jets of air in the eyes, they will usually turn all those disturbing things in gentle, non awakening sighs of air.... they were a huge game changer for me when I used a FFM.

my guess is that if the sleeper is less disturbed by the mask, they'll sleep better, possibly deeper, and that may help the ahi go down, which will result in lower pressures.

[tiredman]

Thanks, very helpful. What do you make of these? A couple short segments from one night. Please not that each are a different scale in terms of time period.

My AHI for the night was 1.95 however as usual I am very tired/fatigued/unrested the next day.







And the whole night's flow limitations:

[palerider]

Thanks, very helpful. What do you make of these? A couple short segments from one night. Please not that each are a different scale in terms of time period.

My AHI for the night was 1.95 however as usual I am very tired/fatigued/unrested the next day.

you have a fair number of flow limitations, but they're generally not too bad.. but they likely add up.

you mention leaks, but don't show what they are.

a full screen shot with flags, flow, pressure, leak, snore, flow limitation, charts would be better than little snippets.

[tiredman]

(deleted)

[palerider]

Ok here's all the data for that night.

that's not what was asked for.

this will explain it better:https://sleep.tnet.com/resources/sleepyhead/shorganize

[tiredman]

Ok here's all the data for that night.

that's not what was asked for.

this will explain it better:https://sleep.tnet.com/resources/sleepyhead/shorganize

Sorry, thanks for the link--I've updated the post.

[OkyDoky]

We really need to see a screenshot like you are seeing on your computer.

The pie chart doesn't give us very much info so you can turn it off by going to File - Preferences -Appearance - Uncheck Show event break down pie chart
That allows us to see the details on the left.

Take a screen shot after you organize your graphs. You can push F11 ( or click file - view - fullscreen toggle) on your keyboard before you take your screenshot and it makes it full screen with no ID info.

If you need more help. https://sleep.tnet.com/resources/sleepy ... screenshot
I know you are using Imgur but I can't enlarge the image. Not a big problem with the size it is but here is a link with more info.

[tiredman]

(deleted)

[palerider]

Ok sorry, and thanks for the advice. Here's a full screenshot:

this is what she's looking for, from the page I linked you earlier:


that has all the desired information on one page.

[OkyDoky]

If you do a screenshot like I described above it should give you the left side and the graphs together. This is one where I uploaded to imgur after signing in to my free account and following the instructions in the TNET link.

If you notice you can click on it and it will open in another window that you can click on and enlarge.

I'm not trying to make this difficult. Just trying to get all the information together where someone might be able to help you.

[tiredman]

If you do a screenshot like I described above it should give you the left side and the graphs together. This is one where I uploaded to imgur after signing in to my free account and following the instructions in the TNET link.

If you notice you can click on it and it will open in another window that you can click on and enlarge.

I'm not trying to make this difficult. Just trying to get all the information together where someone might be able to help you.

I'm really sorry, I'm very tired, and right now me following directions is like a monkey doing algebra. I got it though... (was;t able to make a thumbnail size but it is clickable now)