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[Equipment] Mask adaptation or oxygen bleed in causing readout errors?
#1
Mask adaptation or oxygen bleed in causing readout errors?
Greetings! Hope experienced users can help me figure this out.
I have been treated for central/mixed sleep apnea for a decade. I breathe through my mouth and am using the Amara View mask, with an oval cotton pad covering the nose opening. The mask appears to seal just fine this way and I have been using this arrangement for over a year. I have a supplemental oxygen bleed-in line connected between the hose and the mask connector. My oxygen level is 3 liters per min.

After completing a new sleep study in February, I was upgraded to a ResMed Aircurve 10 ASV, which I began using two nights ago with the same mask and oxygen setup. The machine has a mask fit feature to check your mask for leaks, which shows that my mask does not leak. However the sleep report data for the last two nights shows high leakage. My sleep study showed high leakage with this mask also, though the therapists could not see or hear any leakage when they checked it. My doctors comment was just to ignore it (?!).

Is there something about adding the cotton pad that would produce this mask fit error even though it feels and sounds sealed? I do not know how the machine calculates the error.

Also, I see that the clinician's manual states "Adding oxygen may affect the delivered pressure and the accuracy of the displayed leak and minute ventilation." Is it more likely the added oxygen is producing the error?  How so?

Not sure how to test either possibility. My AHI index shows 5.5, way down from 32 in the sleep study, so it seems to be working. Sure would like to see a smiley face instead of a frown on that sleep report though!

Experience and wisdom appreciated!
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#2
RE: Mask adaptation or oxygen bleed in causing readout errors?
Update and info for others with new machines and frowning faces

After the third day of treatment on the new machine, it shows a smiley face for mask fit. I did not change anything, so why the change in status?
As near as we (my DME provider and myself) can tell, this is what happened...

My machine is showing 4 nights usage, but I have only used it three nights, so the first day the frown face is not for a night I used it, but for the demo day when my provider opened the hose full blast and demonstrated that I would get a frown with a leak. The data cut off is noon for each day and she did this demo just before noon. So the machine showed this as leaking a significant portion of the time the machine was on (the "sleep time.")

The day after I used the machine and saw the mask fit frown on the report, I used the "mask fit" option, checking to see if the machine was working right .. i.e. was my mask leaking or not. No leak. I then opened the hose and put my hand over it, off of it, over it, off of it, to see if it would change the frown face on the sleep report like she did, not knowing how it was calculated or that this action would artificially increase the "leakage" level on the report (which encompassed the 24 hours after the first daily report). This averaged into my sleep time and was enough to keep it in the "bad" status the next morning.

The next day the frown changed to a smile as I had a 24 hour period without any interference (and no mask leak).

The takeaway here is not to worry about the frown face on a new machine as your DME provider has probably caused it. And also to know that if you are doing this, it will affect your readout!

Machine is working fine....sigh of relief!
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#3
RE: Mask adaptation or oxygen bleed in causing readout errors?
I'd get an OSCAR chart up
I'd remove the cotton pad, there may be defusing under it at higher pressure. It's like a man with face stubble.
I would buy a CMS50 spo2 meter that will record your o2 overnight. To check while you are setting up your machine.
mask fit http://www.apneaboard.com/wiki/index.php...ask_Primer
For auto-cpap, from machine data or software. You can set the min pressure 1 or 2cm below 95%. Or clinicians commonly use the maximum or 95% pressure for fixed pressure CPAP, this can also be used for min pressure.
https://aasm.org/resources/practiceparam...rating.pdf
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#4
RE: Mask adaptation or oxygen bleed in causing readout errors?
Thank you so much for your reply, Ajack. I downloaded OSCAR but then saw the info about ResScan software. Can I use either one? Is there a reason to use one vs the other with a ResMed Aircurve 10 ASV?

I found my mask was actually leaking when I woke up last night around 2am. I have noticed lying down (on a wedge) with the headgear on, the mask will shift down slightly if I tilt my chin up and the other way if I tilt chin down. My jaw drops further open during sleep, which causes the lower part of mask to slide upward on my chin even though it stays sealed. The wedge probably makes jaw drop worse with gravity working against me. It usually doesn't pull up enough to leak, but last night it did and the leak was major. Anyway, I replaced old headgear and mask with new ones last night. It seemed to stay put for the rest of the night, but of course I had the frown face on my machine in the morning.

Today I read about using a cervical collar to help prevent chin tucking and improve AHI levels. I believe my chin is more tucked sleeping on the wedge than if I were lying flat. I got a collar to try this evening. Maybe the airway improvement will stop my ASV from going to those extreme pressures, which would help with mask leak.

I do have the equipment to do the oximetry as my doctor always wants the data at our appointments. If I don't see an improvement soon, I will run it for a few nights. Good idea.

Again, thanks for your interest and comments.
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#5
RE: Mask adaptation or oxygen bleed in causing readout errors?
As far as software goes you can use both OSCAR and Resscan with the Aircurve ASV but OSCAR is faster and easier to produce graphs for which we can provide advice on changes if needed
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#6
RE: Mask adaptation or oxygen bleed in causing readout errors?
Oscar has a better chart layout. ASV doesn't really matter, I used oscar/sleepyhead when I used the ASV. My iVAPS needs resScan for stats and alveolar vent. I use Oscar[old sleepyhead really] for the charts. It's just easier. It will really help when you get a chart up Smile

You would turn the wedge the other way, so that the mass in under your neck. But a better pillow would be better. The collar is diagnostic, I have 2 sizes from when I did it. To sleep forever in one isn't for me, unless I had to. I would get use to it, as I did with a mask. Working to get a pillow right is my first choice.
mask fit http://www.apneaboard.com/wiki/index.php...ask_Primer
For auto-cpap, from machine data or software. You can set the min pressure 1 or 2cm below 95%. Or clinicians commonly use the maximum or 95% pressure for fixed pressure CPAP, this can also be used for min pressure.
https://aasm.org/resources/practiceparam...rating.pdf
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#7
RE: Mask adaptation or oxygen bleed in causing readout errors?
Again, thanks to all who have taken me on. There is so much more to share, but trying to keep it simple, which of course it's not. I downloaded OSCAR and am unable to make sense yet of the data, but at least I have data! The myAIR account is a joke! 

But to address the last reply. My wedge runs from waist to top of head -- about 5" elevation and I use it for GERD. I don't use a pillow with it, but usually scrunch up a bit of blanket to make a "neck roll" and then scrunch that in on the sides to make a "nest." So at least I start out the night with my chin up and head turning . I sleep on my back 100% of the time due to other physical issues. The cervical collar did not work well last night as I didn't have it on tight enough and woke to find my chin under the mask. After readjusting, went back to sleep and it was in the right position in the morning. I did not scrunch up a blanket with it for neck support as the cushioning in back provided plenty! In fact it felt a bit like I was in traction! But I think I could get used to it if it really helps. You will see there are two gaps in the data during the night where I took off my mask. The first time, I loosened the collar. The second time is when I found my chin under the collar and tightened it up. I did not awaken to air blowing out the bottom or sides of the mask at any time.

I am posting one OSCAR screen, but there would be many if I send all data. Please let me know the easiest way to capture and the screens you need to see. Maybe the rows of data can be rearranged.

My history with masks is probably typical, but with a few twists. I tried at least thirty different masks since 2007. Anything blowing air up my nose was immediately ruled out as it caused cracking, bleeding and infection, probably due to deviated septum and year round allergies. Hence the nose pad with my current mask. The last mask I used was a hybrid with the nose prongs (which I filled with moldable silicone swimmer's earplugs). That mask is no longer manufactured. Before that I used an oracle, but it caused a lot of stretched out skin around my mouth, and it had some leak problems as well. Any other full face mask would not seal across the bridge of my nose and ended up abrading the skin or blew air across my eyes (which my eye doctor said was coming in from the tear ducts and under my closed eyelids!). My current mask, Amara view, is a dream compared to everything else I have tried, in terms of solving all these problems and I would be reluctant to give it up. It fits under the nose and seems to seal very well all the way around .... at least that's how it feels and what the mask fit indicator says, but of course we always test that at lower pressures, so now I don't know. For one of my sleep studies the doctor had me use nose plugs because he was afraid air might be leaking into my mouth (why that should matter I don't know since the mask also covered my mouth.) Anyway there was no difference with nose plugs vs cotton pad. I'd be ok with another option to block my nose, or blocking the nose opening on the mask, if it turns out the cotton pad is diffusing air. I don't feel any air coming out though, with my hands above the cotton pad.  Even if there were a little, it doesn't seem like it should matter because the vent just above it blows a ton of air on purpose. During my sleep study, the attendants noted they could not find a leak either, but the data kept showing leakage. I was using their machine then, so of course they wanted to blame my mask. The put me on another mask temporarily, but also with the nose pad, and got the same result. So maybe the machine just can't deal with how the air moves around the cotton pad somehow ???

I am on medications for adrenal dysfunction and hypothyroidism. I have had two heart ablations. My sleep apnea is classified as complex. I tried out a CPAP, BiPAP, and an oral appliance in the past..none of which worked. I feel long term untreated sleep apnea contributed to the heart and adrenal issues. My doctor think the centrals may be related to traumatic brain injury caused by a head on car accident years ago (although I don't seem to have any other "residuals" from it). I am 100% compliant on use of my machine and am committed to finding a solution. Although the data is not bad (AHI just 5+ last night), how can you trust that if you really do have a major leak going on?

I read the Mask Primer page, which was so well written, and which I agree with completely. Been there, done that, and you can tell the writer really understands the problems. Neither my sleep doctor, nor my DME rep knows any answers to this stuff. They immediately want me to try on another thirty masks ... which would be my last choice! Thanks to all of you who are willing to share your expertise to help others. Any further ideas on my situation would be appreciated!


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#8
RE: Mask adaptation or oxygen bleed in causing readout errors?
As you know, the first thing is the mask leak. I really would work on that. Masks are very individual, if you can get the Amara to seal, you should be more comfortable. I haven't used one, so I can't tell how hard it would be to fit the nose on top on the mask and tight enough. So it doesn't make the soft tissue hurt, it could apply pressure to the cartilage. I can't see nose plugs doing anything, either it seals on your nose or it doesn't. The leak may not even be at the nose and be around the mouth. Do you use the mask fit function on your machine that blows high pressure? As you know the ASV uses high pressure and then further adjusts. So it is more important for mask fit than some other machines.

Have you seen this Amara video? There are a few on youtube.
https://www.youtube.com/watch?v=Mp02l4r6Je8

With the [big and now I understand] wedge. As you know, as well as chin to chest, you can get chin to shoulder, forward and/or side movement. You may be better feeling like you are in traction for a while and use the collar. When you are sorted, you can stop or you may find you like it. I use mine for sleeping upright in a plane as well. There are some other travel or snore types, that may be more comfortable long term.

Do you still have the f20 around? That was the one I managed to fit after going through many. It might be worth dragging that out for a night, if all else fails.
mask fit http://www.apneaboard.com/wiki/index.php...ask_Primer
For auto-cpap, from machine data or software. You can set the min pressure 1 or 2cm below 95%. Or clinicians commonly use the maximum or 95% pressure for fixed pressure CPAP, this can also be used for min pressure.
https://aasm.org/resources/practiceparam...rating.pdf
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#9
RE: Mask adaptation or oxygen bleed in causing readout errors?
Thank you for your response, Ajack. I certainly agree that the mask leak is the most important thing to focus on. I watched the video you linked, which pretty much approximates my method. I used the mask fit function on my last machine and on this new one. It always tells me my mask fit is fine, but if it were truly fine, I would have a happy face on my reports in the morning. I have experimented a bit since my last post and done quite a lot of reading as well. I'm attaching two screen clips for Monday and two for Tuesday night experiences, which should be useful.

The data for Monday night shows the AHI was 6.37. This was the second night I tried using the cervical collar. It seemed to stay in place all night, but you can see there are a lot of large leaks after I took it off and replaced it during the night. There must be an optimal tightness for the collar. I did have a smiley face on the sleep report in the morning, but I had strap marks on my face and felt very bloated. Back to the drawing board.

The data for Tuesday night shows the AHI was 0.37. I started the night with the cervical collar and the usual cotton pad over the nose opening of the mask. When I woke up the first time during the night and saw the frowny face for leaks, I took the cotton pad off, cut a strip out of it, rolled both ends toward the middle and stuck the rolled ends in my nostrils. I put the mask back on with no cotton pad across the nose opening of the mask, hoping for a better seal. I put some tacky gel around my mouth and nose and continued using the cervical collar as well to keep my chin up, hoping it would prevent mask slippage. There are no large leaks from that point on...finally!  The last half hour I was awake and observing possible leakage. There was nothing major, but I could feel very minimal leaks on occasion along the side depending on lip position (smiling or pursed lips) and on occasion at the nose and chin. These registered on the graph as minimal leaks. I felt very bloated when I woke up each time and of course the frowny face remains on my report for leaks during the night.

Your comments on the charts would be helpful to me. I am only now learning about how to read them. I have cheyne-stokes breathing pattern at times, which I can see when I expand the graphs. I am curious why there is such a difference in the AHI between these two days. There is quite a large period of time without high leakage but with lots of events on the first night, whereas hardly any events on the next night even when there was high leakage. Is the data still untrustworthy?

Thanks ahead for your time Ajack and to anyone else who cares to comment.


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#10
RE: Mask adaptation or oxygen bleed in causing readout errors?
Update ... next night minimal large leaks!
I consider the leakage problem solved for the time being. For those who have read this far, here is the end of the story and graphs:

       

What I did:
No cotton pad over the amara view mask nose opening
Rolled cotton in nostrils to prevent air in nose (and taped to keep it on)
Cervical collar to prevent chin drop and facial slacking from unsealing the mask
Tacky gel to prevent mask shifting


The AHI was around 18 when I woke up in the night but there was still a smiley face for mask fit. I added more tacky gel, but then had trouble getting the mask to seal at the nose as I could not slide it around due to tackiness and had to take it on and off a few times and try again. Finally it sealed and mask leak was minimal (and out of the large leak zone) the rest of the night. I noticed the Cheyne-Stokes pattern of the previous nights has largely changed to a standard obstructive apnea pattern for this night, which seems to indicate a more vigorous response to the treatment when the leaks are stopped.

Take away: Oxygen bleed-in line can't be blamed for large leak problem
Take away: For the Amara View mask, you need to seal it to your skin ...cotton pad interface isn't good enough even if your mask fit feature says it is.
Take away: Cervical collar really does work to reduce chin drop/mask leakage
Take away: Tacky gel does keep the mask from shifting as much
Take away: Less leakage = better treatment response

Thank you for your input Ajack and I hope this experience helps others with leakage problems
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