Large Leaks

I get short and long lasting large leaks often. An example is:

Pressure rose to maximum 14 cm with no apnea event or large leak indicated. A large leak event on OSCAR showed 4 minutes after the pressure went to 14 cm. A one RERA appeared 2.5 minutes after that. Large leaks continued for 55 minutes with pressure moving up and down from about 11 cm to 13.5 cm (min is , no more RERAs nor apneas. It seems like the high pressure caused the leak or did a leak(s) cause the high pressure? Could have I bumped the mask loose causing a leak that caused a pressure increase, but the large leak event did not register on OSCAR until four minutes after the pressure hit the max at 14 cm?

Screen shot not present due to lack of data space.

ejbpesca wrote: ↑

Sun Feb 12, 2023 1:54 pm

Screen shot not present due to lack of data space.

Then post it on imgur as people have been repeatedly told.

ejbpesca wrote: ↑

Sun Feb 12, 2023 1:54 pm

It seems like the high pressure caused the leak or did a leak(s) cause the high pressure?

APAP machines do not increase the pressure setting because they detect a leak. They increase the airflow through the mask in an attempt to maintain the current pressure setting. Many machines, including the Resmed ones, as I recall, will even decrease the pressure setting slightly in the presence of a very large leak in an effort to get the mask to reseal.

Since you said there was no apnea event associated with the rise in pressure, the most likely reason your AirSense 10 increased the pressure was some combination of detected snoring or flow limitations: Resmed machines respond aggressively to both snoring and flow limitations since these can indicate the airway is in danger of collapsing; increasing the pressure because of flow limitations and/or snoring allows the machine to do a better job of keeping the airway open and thus preventing apneas and hypopneas from happening.

A sudden increase in pressure can cause a mask to spring a leak, however. Particularly if the person fit the mask at relatively low pressure and particularly if the person over tightened the headgear.

Could have I bumped the mask loose causing a leak that caused a pressure increase, but the large leak event did not register on OSCAR until four minutes after the pressure hit the max at 14 cm?

The more likely scenario is that your AirSense 14 increased the pressure because of snoring or flow limitations and after the machine reached its max at 14cm, you bumped the mask loose causing the leak.

Once again: Machines do not increase the pressure setting because of large leaks. Your machine was reacting to something in your breathing; most likely it was reacting to some subtle flow limitations or snoring. Once the pressure was increased to 14cm, something caused the leak, and in my opinion the most likely culprit was that you moved around in some fashion that bumped the mask enough to trigger the leak.

Screen shot not present due to lack of data space.

Post the Oscar screen shot at imgur.com and then link to the image in your post over here. You just need to put the image's url inside the image tags and it will show up.

I think I have been fretting over high AHI scores needlessly for years due to my often Large Leak cluster of events. It has always been a wonder as to why many times I may feel better with a 7.30 AHI than a 2.75 AHI and a frustration that for 18 years I could never get an AHI below 1.75 yet I see other's OSCAR reports showing frequent < 1.00 and even 0.00 scores. I am concluding that if you Large Leak for more than a few seconds your AHI is not accurate. Take out the OAs, CAs, and UAs of a Large Leak cluster then calculate the AHI for a more accurate score especially if the events are within a tight cluster of an event every minute (AHI 60.00) which seems like more suffocation, not apneas. Why average in a short time period of AHI 60.00 with hours of AHI < 2.00? Does this not skew the AHI?

The possibility that my AirSense 10 is false flagging of events during a Large Leak gray area is part of my issue with a possibly skewed AHI. I can have 20 events within a 20-minute cluster within a gray area. The large amount of compacted events raises the AHI giving a false indication of the quality of therapy over a total sleep session. In other words, pull out the Large Leak time and its cluster of events from X hours of sleep and the AHI score will drop dramatically. Why be concerned over a 7.00+ AHI when it was a 20-30 minute cluster of events within a Large Leak gray area that caused the score? The AHI would be < 1.00 with the cluster excluded. Even if the events are accurate, they skew AHI's meaning toward the overall sleep session with over 90% of the sleep time in an AHI of <.50.

If a cluster of events is seen on a report even though over a gray Large Leak area the interpretation includes, "positional," and "chin tucking." The advice will be to use a low pillow and a soft cervical collar and may give suggestions on how not to roll to the back during sleep. Some CPAP users strap their chins, tape their mouths, collar their necks, and put nostril-opening spring strips to their noses when another mask could be all that is needed to get AHI down by reducing Large Leaks.

I don't expect perfection from anyone or a machine, but I would like those concerned with CPAP therapy to take a closer look at apnea clusters within Large Leak gray areas and give more consideration to the possibility that these event clusters may not be caused only by sleeping positions that restrict airflow. They could be false flagged events due to a Large Leak. How can the machine flag events and measure airflow limitation if the air pressure is lost in the mask by air freely flowing out its perimeter? Does the rate of 75 events an hour make sense inside a Large Leak gray area? Could not the cluster of events be eliminated by fixing the leak problem as opposed to wearing a soft collar, mouth tape, or a chin strap? I do understand that it is jaw-dropping that may cause the Large Leak, but is it worth disturbing sleep with a collar if one or two event clusters in a gray Large Leak area are showing nonexistent events? Would not a mask that functions with a jaw drop be better advice than a collar or at least give it as an alternative try before a collar?

ejbpesca wrote: ↑

Sun Aug 04, 2024 1:14 pm

Would not a mask that functions with a jaw drop be better advice than a collar or at least give it as an alternative try before a collar?

Which mask model are you using? Your equipment profile needs to be updated.

ejbpesca wrote: ↑

Sun Aug 04, 2024 1:14 pm

I don't expect perfection from anyone or a machine, but I would like those concerned with CPAP therapy to take a closer look at apnea clusters within Large Leak gray areas and give more consideration to the possibility that these event clusters may not be caused only by sleeping positions that restrict airflow. They could be false flagged events due to a Large Leak.

So... fix the leaks. The machine is at a loss when leaks are over 25lpm... it tries still. If we had graphs to look at we could make a determination... but all I'm hearing is you a) not wanting to fix the leaks and b) wanting to discount events that happen during large leaks.

During large leaking the machine is not holding a good mask pressure... that means that you're no longer getting your prescribed therapy. This would tend to make more obstructive events happen. Do the flow limitation graphs rise? We don't know, we're not looking at your graphs.

For sharing here SleepHQ is superior to Oscar... either is preferable to a text description. Yes, of course, take a close look... if you let us.

Chicago Granny

I am using an Evora Full Face. Profile updated.

Vandownbytheriver

I have been attempting to fix LLs for 17 years. I can't control my movement during sleep which I am sure sometimes causes LL. I am awakened sometimes to find the mask blowing air out the sides, not into me. I have read everything about headgear adjustments and tried 7 masks (another is on the way).

Recently I have made a bit of progress, but I still get clusters that look like blowouts not just large leaks which may lead to bad OSCAR data due to malfunction of the mask.

I will look through my OSCAR Dailies to find an example of AHI, LL, and most data graphs shooting up.

How do I post a reply direct to a specific previous reply? Or, do all replies just stack up at the bottom of a Thread?

Thank you for your replies. ejb

Here's an example. An OA triggers a pressure increase. Then comes the gray area (LL) which is such a high level it looks more like a severe mask seal loss to me that I dub blow out. A string of hyponeas are flagged towards the end of the LL causing AHI rise. Mask pressure rises then falls I guess due to the LL, or blowout. 1st gray graph is FLimitations, next Snore, Tidal Volume, then Mask Pressure. Graphs below these shoot up also. I don't think therapy is occurring during the LL session.

Those screenshots are not what the forum needs. Get a free account at SleepHQ.com and upload your data there. Then post the link to this thread. The graphs will already be in the format needed. So easy.

Save OSCAR for when you have more experience with software.

Link to page:

https://sleephq.com/public/f6cd2586-904 ... 3aff927810

Thanks for taking a look. ejb

There are some big pressure swings. Do you perhaps sleep parts of the night on your sides and parts on your back?

ejbpesca wrote: ↑

Wed Aug 21, 2024 7:45 pm

Link to page:

https://sleephq.com/public/f6cd2586-904 ... 3aff927810

Thanks for taking a look. ejb

Wasn't that easy?

SleepHQ was easy but took an hour or so of upload due to my previous data being missing.

I move at night and cannot control that. Collars, chin straps, and mouth tape do not work for me.

I sleep with a very thin pillow starting on left side. When I move to my back I am not sealing off my airway. I do knock the mask off its seal sometimes and rushing air wakes me. I am not sure what happens as I roll to my left side but the move starts okay. Then it's back to the left side, repeat. I have permanent injuries that cause pain in any position so roll around I must.

My point is that when the mask is in big time loss of seal, as in high LL rate gray areas, I believe incorrect flagging is happening during the LLs session which in turn skews the AHI. Are Hs, etc. caused by LLs (loss of therapy), or are the LLs the cause of false Hs, OAs, CAs, and UAs? Looking at breath to breath wave forms I am finding where an H occurs in the gray area the VVVV shapes look the same as areas not marked with Hs.

If the machine is not functioning correctly during an LL, how can it accurately flag events?