Mask Vent Rate Problem?

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
gerhardps
Posts: 3
Joined: Wed Apr 18, 2012 8:43 am

Mask Vent Rate Problem?

Post by gerhardps » Wed Apr 18, 2012 9:35 am

Hi. I have found this forum to be an incredible source of information since I got my CPAP machine 3 months ago. Hopefully you can help me with the issue I am having. First off, I have a PR System One Remstar Auto Cpap Machine with heated humidifier. I started out with a Philips Comforgel full face mask. This would cause sores on my nose, even with the use of gecko strip and Remzz liners. This mask was given to me by my DME (covered by insurance). Since I knew switching masks with this DME was going to be a hassle, I purchased a swift FX nasal pillow from cpap.com. This has been working very well for me, with AHI lower than 3 most nights. With allergy season here, my nose is stuffed felt I needed to switch to a full face mask. I was able to have my Dr. get me a Mirage Quattro full face mask. I find it much better than the philips in terms of comfort. Now here's where the issue comes in. I have tried the mask 2 nights and have gotten some weird results. My vent rate seems to be off the charts, the pressure remains steady at 10 (no increase) and my AHI spiked. I can feel no leaks from the mask, or hear no sound, but the vent seems to be blowing very hard relative to the other 2 masks. Here is a link to my report (sleepyhead) from last night
https://docs.google.com/open?id=1YrzsIN ... PG6oYZ4WLL

and

from a few days ago with the swift

https://docs.google.com/document/d/1BLH ... 0rJNU/edit


Is there something wrong with the new mask that I would be getting results like this? Could it be venting at too high a rate? I wore the mask while awake and detected no leaks and the rate was still that high.

thanks in advance for any help.

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JohnBFisher
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Joined: Wed Oct 14, 2009 6:33 am

Re: Mask Vent Rate Problem?

Post by JohnBFisher » Wed Apr 18, 2012 4:06 pm

Check page 7 of the Resmed Quattro Mirage Full Face Mask User's Guide:

http://www.resmed.com/us/assets/documen ... er_eng.pdf

To read it, find your pressure on the Y axis and then read across to the intersecting line on the X axis for the estimated flow rate in Liters per minute. For example, if your pressure is 12cm H2O then the estimated flow rate should be 41L/min (plus or minus 6L/min).

If it maps up with that flow rate you are getting the expected flow rate. If not, you might have some leak somewhere.

Hope that helps.

_________________
Mask: Quattro™ FX Full Face CPAP Mask with Headgear
Additional Comments: User of xPAP therapy for over 20 yrs. Resmed & Respironics ASV units with EEP=9cm-14cm H2O; PSmin=4cm H2O; PSmax=15cm H2O; Max=25cm H2O
"I get up. I walk. I fall down. Meanwhile, I keep dancing” from Rabbi Hillel
"I wish to paint in such a manner as if I were photographing dreams." from Zdzisław Beksiński

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Pugsy
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Location: Missouri, USA

Re: Mask Vent Rate Problem?

Post by Pugsy » Wed Apr 18, 2012 4:38 pm

The total leak (vent plus excess) is appropriate for each mask. The full face mask has a higher vent rate than the nasal mask. This is common. Full face masks have more vent rate than an over the nose mask and the nasal pillow mask has the least vent rate of all masks.

If you continue to have such a higher AHI (looks like mostly hyponeas) with the full face mask when compared to the nasal mask, I suspect that you are one of the few people who may need a wee bit more pressure with a full face mask. While not hugely common...some people seem to need less pressure with nasal pillow masks. I know one person who needed near 18 cm with full face mask and was able to use 14 or 15cm (don't remember exactly) and get just as good of an AHI or better with nasal pillow mask.

_________________
Machine: AirCurve™ 10 VAuto BiLevel Machine with HumidAir™ Heated Humidifier
Additional Comments: Mask Bleep Eclipse https://bleepsleep.com/the-eclipse/
I may have to RISE but I refuse to SHINE.

If you want to try the Eclipse mask and want a special promo code to get a little off the price...send me a private message.

gerhardps
Posts: 3
Joined: Wed Apr 18, 2012 8:43 am

Re: Mask Vent Rate Problem?

Post by gerhardps » Wed Apr 18, 2012 4:44 pm

Thanks for the response. One question I have is why my auto machine varies the pressure with the nasal pillow, but stays at the lowest setting with the full face mask? I am set at 10-20. Also the vent rate at 10 should be approx 40, from the graph my total leak rate is over 120. Thats not too high?

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Pugsy
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Re: Mask Vent Rate Problem?

Post by Pugsy » Wed Apr 18, 2012 4:53 pm

By gosh it does stay the same doesn't it. I saw the straight line and assumed cpap at 10.
I was looking at leak line and just glanced at pressure line.

Oh crap..I looked at wrong line on the full face mask report...disregard my previous comment about that total leak being appropriate. It is not. It is huge and it is so huge that the machine doesn't know what to do and that is why no movement in the pressure line. It can't sense anything with that amount of leak.
It is well over 90 L/min which is large leak territory. The machine threw up its little hands and said "what the heck do I do now" It isn't responding because it can't sense a darn thing.

Something bad going on with the full face mask leak....vent rate is probably around 40 (give or take a little) at your pressure....you shouldn't see more than 60 L/min on that top leak line.
It was so high I didn't see it.

Check all the full face mask connections...that amount of leak is HUGE and desperately needs to be sorted out.

_________________
Machine: AirCurve™ 10 VAuto BiLevel Machine with HumidAir™ Heated Humidifier
Additional Comments: Mask Bleep Eclipse https://bleepsleep.com/the-eclipse/
I may have to RISE but I refuse to SHINE.

If you want to try the Eclipse mask and want a special promo code to get a little off the price...send me a private message.

gerhardps
Posts: 3
Joined: Wed Apr 18, 2012 8:43 am

Re: Mask Vent Rate Problem?

Post by gerhardps » Wed Apr 18, 2012 5:02 pm

Thanks for the help. I have solved the problem, and thought I'd post for future reference. My mask came misassembled. There is a little rubber part that is supposed to be blown upwards and seal the large hole at the bottom of the mask. My mask came with that part in the wrong position, so that those 2 bottom holes were completely open. I had assumed that was the vent. After doing some digging on line i realized that the vent was at the top of the mask, took it apart and put it back together the right way. Seems to work now.

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JohnBFisher
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Re: Mask Vent Rate Problem?

Post by JohnBFisher » Wed Apr 18, 2012 5:04 pm

I agree with Pugsy ... your leak rate is HUGE .. sounds as if the mask is not fitting well.

_________________
Mask: Quattro™ FX Full Face CPAP Mask with Headgear
Additional Comments: User of xPAP therapy for over 20 yrs. Resmed & Respironics ASV units with EEP=9cm-14cm H2O; PSmin=4cm H2O; PSmax=15cm H2O; Max=25cm H2O
"I get up. I walk. I fall down. Meanwhile, I keep dancing” from Rabbi Hillel
"I wish to paint in such a manner as if I were photographing dreams." from Zdzisław Beksiński

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RandyJ
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Re: Mask Vent Rate Problem?

Post by RandyJ » Wed Apr 18, 2012 5:14 pm

gerhardps wrote:Thanks for the help. I have solved the problem, and thought I'd post for future reference. My mask came misassembled. There is a little rubber part that is supposed to be blown upwards and seal the large hole at the bottom of the mask. My mask came with that part in the wrong position, so that those 2 bottom holes were completely open. I had assumed that was the vent. After doing some digging on line i realized that the vent was at the top of the mask, took it apart and put it back together the right way. Seems to work now.

That is the anti-asphyxiation valve. You should see it close when you start the machine and open again when you turn machine off.

_________________
Mask: AirFit™ P10 Nasal Pillow CPAP Mask with Headgear
Additional Comments: Backup & Travel Machines: PR System One Bipap Auto, S9 VPAP Auto, S9 Autoset, Oximeter CMS-50E
Diagnosed March 2011, using APAP 14 - 16.5 cm, AFlex+ 2
Alt masks Swift FX pillows, Mirage FX nasal mask, Mirage Quattro full face mask

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avi123
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Location: NC

Re: Mask Vent Rate Problem?

Post by avi123 » Wed Apr 18, 2012 11:02 pm

gerhardps wrote:Hi. I have found this forum to be an incredible source of information since I got my CPAP machine 3 months ago. Hopefully you can help me with the issue I am having. First off, I have a PR System One Remstar Auto Cpap Machine with heated humidifier. I started out with a Philips Comforgel full face mask. This would cause sores on my nose, even with the use of gecko strip and Remzz liners. This mask was given to me by my DME (covered by insurance). Since I knew switching masks with this DME was going to be a hassle, I purchased a swift FX nasal pillow from cpap.com. This has been working very well for me, with AHI lower than 3 most nights. With allergy season here, my nose is stuffed felt I needed to switch to a full face mask. I was able to have my Dr. get me a Mirage Quattro full face mask. I find it much better than the philips in terms of comfort. Now here's where the issue comes in. I have tried the mask 2 nights and have gotten some weird results. My vent rate seems to be off the charts, the pressure remains steady at 10 (no increase) and my AHI spiked. I can feel no leaks from the mask, or hear no sound, but the vent seems to be blowing very hard relative to the other 2 masks. Here is a link to my report (sleepyhead) from last night
https://docs.google.com/open?id=1YrzsIN ... PG6oYZ4WLL

and

from a few days ago with the swift

https://docs.google.com/document/d/1BLH ... 0rJNU/edit


Is there something wrong with the new mask that I would be getting results like this? Could it be venting at too high a rate? I wore the mask while awake and detected no leaks and the rate was still that high.

thanks in advance for any help.
Reply,

I am not surprised that your AHIs were so different even if I don't believe in AHI (see the report on my signature line). I experienced the same when I switched from a F&P FF mask #431 to a Resmed Mirage Softgel Nasal mask, and also tried the Swift FX. The leaks dropped a lot and thus my APAP could suppress all the Obstructives, and thus the AHI dropped too. IMO, the leak rate is proportional to the length of the seal and in FF masks its the longest. The other reason is that nasal masks don't have anti rebreathing valves. Instead they rely on extra flow to carry the exhaled air fast out thru the small vent holes. It is called "passive venting" . On Resmed machines there are different settings for such nasal masks as NASAL, PILLOWS, and FF. With the SWIFT XF it is done to the extreme. The vent holes are tiny and the flow is so hi that I have found this mask to be uncomfortable b/c of the extra flow which is meant to carry the exhausted air out the the vent hols also exists during the inspiration stage and this extra air goes into my stomach as well and causes bloating. I don't get such ingested air when I use the Mirage SoftGel. So I decided to stay with the Mirage. IMO, a chinstrap is a must with any nasal mask, at least in my case. Otherwise, I would become a mouthbreather. The makers decisions of making those nasal masks with no anti asphyxia valves relies probably on the assumption that if the machine stops for any reason then the wearer would swich to mouth breathing. But what about if the person uses a chinstrap tightly on the head . The more cumbersome the nasal mask headgear and the chinstrap are the higher the chance of asphyxiation.

Another cause for the better results in the smaller masks is the Dead Space which is smaller in small nasal masks and this adds to the XPAP faster response to events.

My suggestion to you is if you can take the Swift FX and like it then use it b/c of the better data results that you e get.

_________________
Mask: Mirage™ SoftGel Nasal CPAP Mask with Headgear
Humidifier: S9™ Series H5i™ Heated Humidifier with Climate Control
Additional Comments:  S9 Autoset machine; Ruby chinstrap under the mask straps; ResScan 5.6
Last edited by avi123 on Thu Apr 19, 2012 7:43 am, edited 2 times in total.
see my recent set-up and Statistics:
http://i.imgur.com/TewT8G9.png
see my recent ResScan treatment results:
http://i.imgur.com/3oia0EY.png
http://i.imgur.com/QEjvlVY.png

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Goofproof
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Re: Mask Vent Rate Problem?

Post by Goofproof » Wed Apr 18, 2012 11:32 pm

When that mask first came out, I saw by the leak specs it wasn't allowed in my stash, I never allow anything that has a vent rate of 40 LPM or higher @ 15 CM, really I set my limit at 38 LPM leak rate for a mask. I don't care what the machine makes say, I set my standards, and they work well for me. Jim
Use data to optimize your xPAP treatment!

"The art of medicine consists in amusing the patient while nature cures the disease." Voltaire

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Gerryk
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Re: Mask Vent Rate Problem?

Post by Gerryk » Fri Apr 20, 2012 2:58 pm

I do not remember what the vent rate is for that mask, but I believe it is higher than other masks. Also remember that the higher the pressure the higher the vent rate will be. I use this mask and their are times that I had a leak and didn't really notice it.

Make sure the mask cushion is clean and wash your face before you put the mask on and see if that makes a difference. Also if you put the mask on and have your head tilted up or straight out and then fall asleep and your head tilts down, your mask will actually loosen up and leak.