Exhale Pressure Relief article, Your EPR may be too low

This article is quite interesting.

http://www.montanasleepsociety.org/Docu ... nd%202.pdf

Unfortunately it is just a power point and we don't have the explanation for the assertions made in it.

But what I noticed is that the doctor states that EPR of 4 cm-H2O or less is okay for breathing relief but doesn't benefit increasing tidal volume. Tidal volume is the amount of air you inhale and exhale in a breathing cycle.

Tidal volume is a new term for me and the power point explains it.

The doctor recommends EPR of 6 cm-H2O or more, but also warns that too much relief can result in airway passage instability.

I think basically that if your EPR is too big the air pressure splint isn't there and a passage way collapses, but that is just my theory.

My S9 Elite only does an EPR of 3 cm-H2O maximum. So it provides for comfort, but not significantly improved tidal volume.

The author makes the assertion that the PAP settings depend on the tube used as well as the face mask. He underlines the sentence about the tubing and air pressure settings. I don't think my sleep doctors even thought of that.

Also, it takes about CPAP settings to assure a pre-set tidal volume. I am curious as to what machine does that?

Unfortunately I don't know all the acronyms used.

I would be very interested in the technical evaluation of this article by others who might have a better understanding of the issues.

I AM NOT interested in chatter.

There are other articles at:

http://www.montanasleepsociety.org/Page ... minar.aspx

Interesting and understandable presentation on the titration and setting of bilevel pressures. Your machine is a cpap machine and most of what they are talking about is the setting of pressures on a bilevel where larger differences between IPAP and EPAP can be achieved. I will answer your question on tubing and mask but I found the answer on preset tidal volumes in the presentation.
The newer cpap machines have a setting to change tubing type/size and Resmed makes it easy to change between mask types.
They calculate a determined volume which can be used on an AVAPS machine.

sleepy1235 wrote:But what I noticed is that the doctor states that EPR of 4 cm-H2O or less is okay for breathing relief but doesn't benefit increasing tidal volume. Tidal volume is the amount of air you inhale and exhale in a breathing cycle.

you seem to have missed slide 2.

Thanks, I don't know if everything in the presentation is correct but it's certainly some stuff to think about.

palerider wrote:

sleepy1235 wrote:But what I noticed is that the doctor states that EPR of 4 cm-H2O or less is okay for breathing relief but doesn't benefit increasing tidal volume. Tidal volume is the amount of air you inhale and exhale in a breathing cycle.

you seem to have missed slide 2.

Going back to slide #2,

Expiratory positive airway pressure (EPAP)
Provides the baseline PAP level
Maintains upper airway patency during expiration

Would this baseline PAP level be the same in CPAP? In other words, for bilevel therapy, the EPAP would be the minimum pressure needed to prevent obstructive events, then pressure support for IPAP is provided to promote ventilation?

Now turning back to EPR as a variation of bilevel. If EPR is applied to the minimum necessary CPAP pressure, wouldn't the airway become increasingly unstable with higher EPR?

It does seem to me that straight cpap would be the calculated pressure needed. And if EPR was optional and not in the calculations that a higher EPR setting in that instance would be decreasing your effective pressure, and possibly increasing AHI.

Sleeprider wrote:

palerider wrote:

sleepy1235 wrote:But what I noticed is that the doctor states that EPR of 4 cm-H2O or less is okay for breathing relief but doesn't benefit increasing tidal volume. Tidal volume is the amount of air you inhale and exhale in a breathing cycle.

you seem to have missed slide 2.

Going back to slide #2,

Expiratory positive airway pressure (EPAP)
Provides the baseline PAP level
Maintains upper airway patency during expiration

slide 2:

Possible Indications for Advanced PAP Modalities
COPD
Neuromuscular disease
Thoracic cage abnormalities
Obesity hypoventilation
CheyneStokes respiration
Opioid induced central apnea
Other forms of respiratory insufficiency

ie, the presentation isn't addressing your run of the mill sleep apnea situations. typical of sleepy's misinterpretation and over complification of things.

I think the important thing to note on the subject anytime it's mentioned here (in any type of post) in case new users are reading is "if you slap EPR on your prescribed apap or cpap settings without monitoring, you may be comprimising your therapy". I know this is clear to our long time users, but it did take me some time to grasp the concept! It's not something that comes across right away to new users.

If my epap with EPR of 3 is adjusted a tick too low, bad event clusters happen, but my ahi remains below 5. However, my epap is well below 6cm and generally I don't have any issue as long as I stay on my side.

Best,

Mike