Optimal Pressure Question

[Dysautonomia_Fighter]

If a sleep study shows the Optimal CPAP pressure of 9cm.And i was to add supplemental oxygen on my own of 3 lpm too the cpap hose,Does that increase the overall cpap pressure to my face?.Do i leave the CPAP pressure alone or should i decrease it?.

[rested gal]

If a sleep study shows the Optimal CPAP pressure of 9cm.And i was to add supplemental oxygen on my own of 3 lpm too the cpap hose,Does that increase the overall cpap pressure to my face?.Do i leave the CPAP pressure alone or should i decrease it?.

I don't think using supplemental O2 will increase the CPAP pressure. Your prescribed CPAP pressure of 9 cm H20 will still be the pressure you'll be receiving.

In one of your previous posts, you mentioned that you're using a ResMed Autoset machine (an "S9", I assume.) What I'm going to write now doesn't have anything to do with your question about pressure and additional O2.

If you have EPR turned on "full time" and are using your ResMed Autoset in "CPAP" mode (one straight pressure of 9 ) you might want to consider raising your CPAP pressure the same number of cms that EPR is dropping it for exhalation. If you're using the Autoset in "autotitrating" mode, the minimum pressure in your range would be the pressure setting to raise...that is, if you decide to use a higher pressure to compensate for the drop EPR will give each time you breathe out.

Example of how I'd set it if it were me and had been prescribed a pressure of 9 cm H2O:

EPR off or EPR 1, 2, or 3 for ramp only
CPAP pressure 9

EPR "1" full time
I'd raise the CPAP pressure to 10

EPR "2" full time
I'd raise the CPAP pressure to 11

EPR "3" full time
I'd raise the CPAP pressure to 11 or 12

I'm not a doctor. That's just how I'd handle the pressure setting for myself if using ResMed's EPR comfort feature. I want to be sure my airway is being held well and truly open during breathing out -- especially during any pause after the exhalation is finished. I'd want enough pressure to be in place so I could get a new inhalation started smoothly and easily.

[Big Daddy RRT,RPSGT]

If a sleep study shows the Optimal CPAP pressure of 9cm.And i was to add supplemental oxygen on my own of 3 lpm too the cpap hose,Does that increase the overall cpap pressure to my face?.Do i leave the CPAP pressure alone or should i decrease it?.

Did you need oxygen during your cpap titration?

[sleepnationtv]

If you were not prescribed oxygen I would think twice about using it, your lungs will become Dependant on the oxygen and you may actually weaken your lung functions.

Be careful

[rested gal]

Had to Google "dysautonomia" -- not fun to deal with, I'm sure.
Good luck with your therapy and your battle, Dysautonomia_Fighter.

National Dysautonomia Research Foundation
http://www.ndrf.org/

Dysautonomia
A family of misunderstood disorders
By Richard N. Fogoros, M.D., About.com Guide
Updated May 06, 2010
http://heartdisease.about.com/cs/womens ... onomia.htm

AUTONOMIC NEUROLOGY SUBSPECIALTY GROUP
http://www.mayoclinic.org/neurology-rst ... group.html

Dys_Fighter, has a doctor prescribed supplemental O2 for you, or is it entirely your idea to add O2 to your CPAP therapy?

[Dysautonomia_Fighter]

Thanks Rested gal.

I have been sleeping with a oxygen concentrator 0n 2 lpm for 4 years now.I told my doctor in 2006 "I think i stop breathing with i sleep".I bought a pulse oxymeter that records my levels to prove it to her.So see prescribed oxygen to me for sleep.

I had a sleep study done in 2006.And unfortunately for me i had i good night during the study.I sleep on my side and my AHI was only 5.

So my doctor said that my ahi was not high enough for cpap,And told me to stick with the oxygen.

By the end of 2010 i had my doctor prescribe me a cpap that i bought out of my own pocket.Read the clinical manual and off i went.I started the unit in apap mode and found out that i have mostly central apneas.
So i changed to cpap mode with a setting of 8 because i read apaps arent that good for central sleep apnea.Since then i convinced my doctor to order another sleep test.

In feb 2011 I was off to another sleep study.This time my AHI was 18.And i was titrated at 9 without supplement oxygen.

So while a am awaiting my new cpap that insurance with pay for my lifetime.I am adjusting my current resmed S9 in cpap mode level 9cm.With ramp on for 10 mins start pressure 6 with epr on 1 just for ramp.

But i was wondering if i should add oxygen to my cpap therapy that i was already sleeping with for 4 years.Or will the cpap take the place of my oxygen concentrator.Sleepnationtv posted above that supplemental oxygen could weaken my lung function.

Thxs for all your help..

[Big Daddy RRT,RPSGT]

In our sleep lab many people come in using oxygen from an overnight oximeter report. However after titration they often no longer require oxygen. I would ask if oxygen was used during your titration. If oxygen was not used and your oxygen levels were acceptable without it, it was the sleep apnea causing your desats and you may no longer require oxygen at night. That would be goodnews.

[BigNortherner]

Technically, the answer depends on where the pressure is sensed.

A Remstar Auto classic, for example, senses pressure just inside the machine so can’t adjust for anything downstream (in the hose etc.) If a machine had a small tube running with/in the air hose to sense pressure in the mask at your face then it could control the pressure at your face.

I’m not familiar with use of oxygen, I presume it is introduced through fittings on the mask, logically the pressure at that connection must be more than from the CPAP machine in order for oxygen to get into the mask and mix with air from the CPAP machine, but once the oxygen is into the great volume of the mask compared to the oxygen tubing what pressure increase results (but it must still be more than from the CPAP)? (I don’t know how oxygen regulators work, you quote litres per minute, that’s volume of course, not pressure. Time to test your doctors’ knowledge of physics?

Oxygen, BTW, is a whole nuther risk factor including fire. Many materials will spontaneously ignite when oxygen content in the air is very high – greases/oils, for example, so hopefully the medical people briefed you on what to avoid in mask sealant, skin conditioners, makeup, etc. and to keep hoses and masks clean. I’ve seen a check valve advertised to keep oxygen out of the machine if it quits blowing.

[Mary Z]

I don't believe the pressure of the O2 is comparable to the pressure of the CPAP. For one thing the small tubing used for the oxygen could not handle the pressure of the CPAP machine/hose. Most home oxygen is delivered at 2-6 Lpm, 6 is very high. I doubt the pressure at the mask would change very much. (I'm just a nurse who has experience with O2). You're right, it's usually delivered at the mask, but some machines have an extra piece to the tubing that connects from the machine to the tubing with a bleed in there. You're right, a knowledge of physics would be helpful!

[BigNortherner]

Mary Z:

The CPAP hose is not capable of much pressure, I'd take typical oxygen hose any day for pressure.

Volume of O2 (LPM or such) is probably what the body needs, here we are trying to guess what that would do to pressure inside the CPAP mask.


Big Daddy:
An "oximeter" is a device that measures oxygen in the blood, commonly by shining light through a fingertip, it does not deliver oxygen.