Leak = no events???

[Pugsy]

Here's my data, both ways, for the last two weeks. The last two days have been at 15/12 and the prior days were all at 13/10.
Date ---total leak rate--unintentional leak---difference

Hmmm, interesting. Obviously not one set "unintentional leak" numbers. Close but not exact. Goes to show us that there is actually another variable there to try to factor in. Small variable but there nonetheless.

My overall average pressure runs about 11 cm with a set range of 10 to 18. When I have time this evening I will go look at my differences when I toggle the values. See if they vary any at all or pretty much stick to one number.
Probably all I will prove is that I can't use a magnifying glass on these numbers.

[Pugsy]

Okay, I checked mine.
I use the Swift FX also, per the chart with the mask
12 cm pressure vent is 37 L/min at 8 cm vent is 29 so at 10 cm halfway in between 33. Of course there is always a slight variable with these numbers.
My overall average for each night (last 7 nights) was pretty much at 10.8 cm. No large spikes in pressure to mess with the average. So I will think of vent at my average being maybe 35 L/min.

Chart does mention Resistance at 50 L/min (I am assuming total leak) that this would result is 0.5 cm drop in pressure
at 100 L/min the result is 1.8 cm drop in pressure.

I had one rather leaky night where I came close to the 50 L/min line but only stayed there maybe 30 minutes.
Total leak average for that night was 38.0 and Unintentional Leak average was 10.10, difference of 29.90

I had one night with Total Leak average being 32.0 and Unintentional Leak average being 4.90 difference of 27.10.

I had 2 nights with Total leak being 34.0 and Unintentional leak being 6.40 difference of 27.60
I had 3 nights with Total leak being 36.0 and Unintentional leak being 8.00 difference of 28.00

Visually looking at the lines I can see where there were times, zero leaks (easy to spot on the Unintentional Leak graph) along with some ups and downs that we all get.
The nights with more ups and downs scored a bit higher Total leak average which is to be expected.

So from this experiment the machine seems to "allow" roughly 28 as my "vent/unintentional leak" which is well below what the chart says I should have at my pressure.
I think that what this tells me is that best I can get is a WAG as far as the numbers go and it is more important to look at the overall line's ups and downs should I have questions about how the night went.
Sort of proves what someone told me a long time ago that the leak averages on Respironics machines are notoriously inconclusive.

I have no experience at all with ResMed machines to see just how close their "averages" might be and since we can't get a Total Leak number from ResMed software we really have no idea what number they subtract before giving us their leak average or baseline.

[DreamDiver]

I highly doubt that I was mouth breathing for an hour. I suppose anything is possible, but it's unlikely. My hubby knows he is to wake me up if he notices any leaking or mouth breathing.

Mouth breathing and mouth leaking are different animals. Mouth leaking can be silent or comparable to normal vent noise. Your mouth might look closed to the casual observer. Hubby may not have even noticed, or might have been deep asleep himself. Since your vent leak rate averages about 30 and your leak rate for that one hour was 50, either it was leaking through your mouth or there was enough mask torque for the air column to leak out from around one or both of the nasal pillows just a little. Either way, I see about 50L/min for that hour - 20L/min over your normal leak rate. If 25L/min over your normal leak rate would inhibit therapy (55L/min) and you were 20L/min over the normal leak rate, it stands to reason that you could be getting passable therapy but enough overleak to hamper the machine's ability to detect actual events.

If your normal night is peppered with events during any given random hour, and only leak rate is significantly different during the one period where no events are detected, would it not stand to reason that the two things are related?

[jbn3boys]

If your normal night is peppered with events during any given random hour, and only leak rate is significantly different during the one period where no events are detected, would it not stand to reason that the two things are related?

It would, except that this is not always the case. I have noted that there are times of little/no episodes with "large" leaks. But as I look closer, there are also times with little/no episodes with no leaks, and also times with many leaks with a similar "large" leak. My nights seem totally random, and that just makes this all so much more frustrating. There seems to be nothing that will improve (and nothing that will worsen) my data, and, correspondingly, how I feel.

NOTE: I also looked at my chart wrong when I was quoting my intended leak rate. I looked at the Swift LT, instead of the Swift FX. For the Swift FX, which I use, at a pressure of 14 the intended leak rate is 40. (I am set at 15/12 straight bi-level)

As for the eternal question ("how do I feel"), most days I feel like crap. I am exhausted most of the day. I seem to be having more headaches recently, and most days I just want to crawl back into bed. So, I don't think I'm at optimal therapy yet. Sigh.

[DreamDiver]

It would, except that this is not always the case. I have noted that there are times of little/no episodes with "large" leaks. But as I look closer, there are also times with little/no episodes with no leaks, and also times with many leaks with a similar "large" leak. My nights seem totally random, and that just makes this all so much more frustrating. There seems to be nothing that will improve (and nothing that will worsen) my data, and, correspondingly, how I feel.

...

As for the eternal question ("how do I feel"), most days I feel like crap. I am exhausted most of the day. I seem to be having more headaches recently, and most days I just want to crawl back into bed. So, I don't think I'm at optimal therapy yet. Sigh.

I hear you. So if you have increasing random episodes of times where there are no apneas and it cannot always be related to large leak, I have to say - your body is likely re-learning how to sleep without apnea, if only for small portions of your sleep. Instead of looking at as a challenge, we may need to look at this as a blessing. You're having longer periods of sleep without events! Good for you! As for feeling not so hot, this is the case with many of us. It's only since I got my S9 that I have had decent experience with therapy.

For the most part throughout the night your leak line is fairly straight even during the period with 50L/min. That's a good sign. I confess I was a little leary of suggesting that a 50ml leak rate could be impeding event recording for that mask, but it's been a long time since I used a nasal mask and wasn't sure if it was that much different from a full face with regards to air column and leak. Because you suggest that leak rate and lack of events for some durations are not linked, I can only suggest that you are actually having periods without events.

That's good, right?

If the crumminess continues, it might be time to buy or borrow an oximeter. If you had an AHI of .2 at one point, was that before you went to bipap, and did you feel better or worse then?

[robysue]

As a math person, I'm concerned that the Large Leak flag in the Resprionics machine is NOT a close estimate at all. I'm also concerned that there seems to be NO documentation in (a) the user manual for the machine itself, (b) the documentation for EncoreViewer, and (c) the documentation for EncorePro that lets a person determine just what the PR engineers think a Large Leak is and when the PR engineers believe the quality of the therapy and the reliability of the data starts to get compromised. Resmed is acting much more responsible here---even if their choice of Mr. Green Smiley Face and Mr. Red Frowny Face are insultingly stupid ways to tell the user there is a serious problem with leaks

I hear you and I agree but not much we can do about it. Frustrating? Yes.

To quote someone whom I never thought I'd quote: You betcha!

Personally it's not a big issue for me since I so seldom have any leaking big enough to worry about. And I've learned to interpret the "raw" data of the total leak graph: As long as it's flat and at or below the Swift FX intentional leak for my pressure(s), I know I don't have any leaks to worry about. Heck, I wouldn't even get worried if I had a flat leak line just above the published Swift FX intentional leak rate. And the fact that my flat leak rate graph has a tendency to bounce around from nights with a near constant leak rate of 17 L/min to nights with a near constant leak rate of 20 L/min? I don't let it bother me: The leak rate is an approximate rate anyway and there is a margin of error in both the mask's expected leak rate and the machine's ability to measure it.

But as a mathematician, I believe the total lack of a description of what constitutes a Large Leak is an issue in general for the users of PR machines: I can't help but wonder how many PR System One users are out there (and not on the board) who look at the machine's on-board Large Leak rate averages and see 0.0% time spent in Large Leak average night after night who assume all is well, but are also having problems typical of mouth breathing or who know they have problems with leaks because of air blowing in the eyes, but assume that nothing can or should be done because the Large Leak average reports 0.0% of the time in large leaks .... And then because the dry mouth becomes unbearable or they just can't stand the air blowing in their eyes one more night, just give up. And never tell their sleep doctor why---most likely because they never see the sleep doctor again.

I just have to tell myself that Respironics doesn't really cater to me (the end user) and the DME's and doctors that they do cater to, don't/won't look at individual items. They just look for general "trends" if they look at all. Does it make it right? Of course not ...

But the issue is more than Respironics catering to the DMEs and doctors who just looking at trends (if anything): The PR machines simply do not provide any meaningful TREND data about the leak rates because the raw data itself appears to be meaningless. So even if you've got a doc or DME who cares enough to give a cursory glance at the trend data because you are complaining constantly about a dry mouth, he or she can easily be persuaded to tell you there's no problem because the long term trend graph for Time Spent in Large Leaks is a nice, flat horizontal line at 0.0% night after night.

From a statistical point of view, meaningless data is worse than no data at all: With no data, you know you know nothing. With meaningless data, the temptation is to claim you know something when in reality you know nothing.

[robysue]

NOTE: I also looked at my chart wrong when I was quoting my intended leak rate. I looked at the Swift LT, instead of the Swift FX. For the Swift FX, which I use, at a pressure of 14 the intended leak rate is 40. (I am set at 15/12 straight bi-level)

So the "big" leak is much smaller than we originally thought. Although it is substantially greater than your normal leak that you typically see night after night.

As for the eternal question ("how do I feel"), most days I feel like crap. I am exhausted most of the day. I seem to be having more headaches recently, and most days I just want to crawl back into bed. So, I don't think I'm at optimal therapy yet. Sigh.

That's of course the kicker: You are doing so much to try to make this therapy work for you and you've seen so little payoff in terms of daytime functioning. Have you mentioned the headaches to the sleep doctor's office? If not, be the squeaky wheel and call to report them.

[jbn3boys]

I hear you. So if you have increasing random episodes of times where there are no apneas and it cannot always be related to large leak, I have to say - your body is likely re-learning how to sleep without apnea, if only for small portions of your sleep. Instead of looking at as a challenge, we may need to look at this as a blessing. You're having longer periods of sleep without events! Good for you! Because you suggest that leak rate and lack of events for some durations are not linked, I can only suggest that you are actually having periods without events.

That's good, right?

You are right. It was just the one time, but I do need to focus on the positives here.

If the crumminess continues, it might be time to buy or borrow an oximeter. If you had an AHI of .2 at one point, was that before you went to bipap, and did you feel better or worse then?

It might be worth doing, although during two sleep studies, they never recorded an O2 sat below 90%. I think I'm one of those "odd" ones who has apnea without the corresponding drops in O2 sats. The AHI of 0.2 that I did see was only in the sleep lab, during the second half (titration) of my first study. I really didn't feel any different that morning than most other mornings, aside from all the wires and such. I've never been anywhere close to that "in real life". On the very rare days that I have been between 2 & 3 for an AHI, I do feel better. But those days are very few and very far between.

That's of course the kicker: You are doing so much to try to make this therapy work for you and you've seen so little payoff in terms of daytime functioning. Have you mentioned the headaches to the sleep doctor's office? If not, be the squeaky wheel and call to report them.

I have not mentioned the headaches yet, since I'm not really sure if they are related. I'm going to give it a few more days and see what develops. It could just be stress related, as this has been a little more stressful week. I promise, I will try to remember to mention it to the nurse when she calls with my iron/ferretin levels. I'd like to hope that would be tomorrow, but the reality is it will probably be late next week before I hear anything.

Makes me think: "Slow and steady wins the race." But then again, is this "steady"?? I find that hard to believe when everything is so erratic.

[charliemack]

how does flow rate relate to the leak reading on a resmed s8?

if the flow rate is 44 liters/min (example) and I look at the readings and it says leakage .36 how do I relate the two?

[Pugsy]

how does flow rate relate to the leak reading on a resmed s8?

if the flow rate is 44 liters/min (example) and I look at the readings and it says leakage .36 how do I relate the two?

ResMed S8 machines report in L/second, to make it the same multiply the .36 L/sec X 60 sec to equal L/Minute or 21.60 L/min.

Bear in mind that the ResMed machines already subtract the intentional vent/flow rate before giving you the leak number and thus what is reported is all excess leak. ResMed says that it can't do a good job at 24 L/min. that 21.60 is awful close and probably is impacting therapy.

so for ResMed machines take the L/sec number multiply by 60 seconds to get L/min numbers.

Respironics users have a different math to do because our machines report the whole leak and we have to back out the intentional vent rate that might be the 44 you mentioned.

[me again.]

Yes. Leak = no events. If the air is going elsewhere than splinting open your throat the machine has no events to record, no resistance. Morning headache, yes, due to oxygen deprivation when sleeping. Yes, do borrow and use an oximeter if you can. It will verify the O2 deprivation. And you must find the leak whether it's in the equipment , the interface or your mouth/lips. Hoping you solve your problems quickly as you deserve a good sleep.