Different Pressures for Different Masks?

jrfoster · Post by **jrfoster** » Mon Jun 30, 2008 8:40 pm

Is it possible that even though one is tritrated, say at 10cm using a profile light nasal mask, that a pressure of 10cm will not provide the same results using a comfort gel nasal mask?

All things being equal, I can't get the comfort gel to give me the same AHI numbers that the profile lite mask does. I like the comfort gel and would rather wear it each night but need better numbers. Could it be that different masks require different pressures to yield the same results?

Jeff

ww · Post by ww » Mon Jun 30, 2008 10:00 pm

Although it takes a little trouble to post your results on a free account on photobucket.com and then reference them here in a post, it lets many people see your numbers and how the pressure line looks to them. You will probably get a lot more help this way by posting a typical day or two for each mask, but keep in mind that data varies from day to day and it takes about a week for it to stabilize on any change in masks. Just as an example, here is one post I made when I was starting out:

viewtopic.php?t=29565&highlight=

khvn · Post by **khvn** » Mon Jun 30, 2008 10:58 pm

It seems to make sense that different masks would require different blow rates to take account for each mask's specific vent rates.

But I would guess that you won't need to take on this job and adjust the pressure setting manually yourself since the machine automatically up the pressure until the final stabilized pressure to be where you set it to be. But then again, I can be totally off the mark here. Somebody may shed some light on this.

Snoredog · Post by **Snoredog** » Mon Jun 30, 2008 11:44 pm

probably NOT with those two masks, but if you went from say a nasal mask to a full face mask then you may need a higher pressure.

while everyone's anatomy is different, having the splint pressure of CPAP enter the mouth vs the nasal passage makes the job harder trying to push your tongue out of the back of the throat, that would be the reason for the higher pressure being needed.

Now I'll argue this point until the sky turns blue but the medical establishment seems to have this "mystical" thing for saying your "airway collapses" vs the simple fact your tongue gets lodged into the back of the throat. Patients start thinking they have neurological disorder or something when it s a simple part of our anatomy we cannot control when we are asleep. You are inhaling when it happens and your tongue gets sucked into the back of the throat, that is an apnea.

So if you study cervical MRI's, X-rays and other image techniques you can only come to one conclusion its the tongue stupid, now expand on that and observe where the air pressure of CPAP enters to push it out of the way, a whole lot harder coming in from the mouth, there ain't no leverage there!

This is the very reason WHY when you sleep on your side or stomach you have fewer apnea events, if they did positional testing during your titration you should see it in black and white.

DreamStalker · Post by **DreamStalker** » Tue Jul 01, 2008 8:17 am

Snoredog wrote:...

its the tongue stupid, ...

Great conclusion!

bap40 · Post by **bap40** » Tue Jul 01, 2008 8:57 am

I rotate between the CG and profile-lite and FP406. Of the first 2 my numbers are almost always better with the Profile mask. Don't know why but it is.

Bearded_One · Post by **Bearded_One** » Tue Jul 01, 2008 9:02 am

There is a difference between pressure and flow rate. With a CPAP, the prescribed pressure is a fixed value, the CPAP machine increases the flow to try to maintain the prescribed pressure. The bigger the leak the greater the flow, until the machine cannot produce enough flow to compensate for the leak.

Needsdecaf · Post by **Needsdecaf** » Tue Jul 01, 2008 9:07 am

[quote="Bearded_One"]There is a difference between pressure and flow rate. With a CPAP, the prescribed pressure is a fixed value, the CPAP machine increases the flow to try to maintain the prescribed pressure. The bigger the leak the greater the flow, until the machine cannot produce enough flow to compensate for the leak.

Wulfman · Post by **Wulfman** » Tue Jul 01, 2008 9:35 am

Needsdecaf wrote:
Bearded_One wrote:There is a difference between pressure and flow rate. With a CPAP, the prescribed pressure is a fixed value, the CPAP machine increases the flow to try to maintain the prescribed pressure. The bigger the leak the greater the flow, until the machine cannot produce enough flow to compensate for the leak.
True, but the original poster has an APAP, which theoretically should adjust to make the difference.

Except that I believe Jeff is using his in CPAP mode at a pressure of 10. (according to his first post)

But, even so......in CPAP mode, the machine should be able to "measure" the 10 cm it's delivering. Even with leakage, it should still adjust for that and deliver 10 cm. The higher end machines have "Leak Compensation".

Den

jrfoster · Post by **jrfoster** » Tue Jul 01, 2008 4:56 pm

Wulfman wrote:
Needsdecaf wrote:
Bearded_One wrote:There is a difference between pressure and flow rate. With a CPAP, the prescribed pressure is a fixed value, the CPAP machine increases the flow to try to maintain the prescribed pressure. The bigger the leak the greater the flow, until the machine cannot produce enough flow to compensate for the leak.
True, but the original poster has an APAP, which theoretically should adjust to make the difference.
Except that I believe Jeff is using his in CPAP mode at a pressure of 10. (according to his first post)

But, even so......in CPAP mode, the machine should be able to "measure" the 10 cm it's delivering. Even with leakage, it should still adjust for that and deliver 10 cm. The higher end machines have "Leak Compensation".

Den