When to use/not-use EPR

[marbles]

My question is concerning when to use or not-use EPR? I think I have an understanding of what EPR is designed to do.

"Designed to make therapy more comfortable,  maintains optimal treatment for the patient during inhalation and reduces the delivered mask pressure during exhalation."

Meaning when EPR is on the machine will lower the mask pressure from a setting of "1 min to 3 max" for exhalation comfort.

Since using my machine I have had EPR on and set at times to 1 and at times to 3. I did not experience any noticeable difference and could not correlate to AHI being higher or lower.

My questions are:
- When is it advisable for someone use or not to use EPR?
- Should you notice a difference when using EPR? Either in comfort or number of AHI's?
- What indication in Oscar results would show EPR is being helpful?
- Is there a situation where  EPR would not be advisable to use?
- Or, is it just a personnel choice to use or not?

Thank you for any thoughts.

[Gideon]

EPR, you have a good understanding of the comfort aspect of EPR.

The therapeutic aspect of it not so much. Not surprising since the medical community appears to be unaware of this.

Increasing EPR improves the efficiency of your breathing with gains in both oxygen saturation and CO2 desats. Sounds good but the later can cause increased Central Apneas in suseptable individuals when the CO2 concentration in the blood is lowered to below the apneic threshold. Lowering EPR is one of the best options to avoid Central Apneas.

Increased EPR is the best treatment for flow limits, RERAs, hypopneas, UARS and snoring. On other words EPR acts like pressure support on a BiLevel, but limited to either 1,2, or 3 cmw.

[mrmagloo]

Sorry for highjacking but I'm a little confused? I thought EPR / Flex was simply a comfort/compliance thing. Ultimately meaning, the best therapy was without, provided the patient can tolerate the pressure upon exhale and it doesn't affect the comfort. That the only time EPR / Flex did improve things was if it helped with allowing a sounder sleep and the users compliance.

That said, it sounds like Bonjour is suggesting that for someone who normally doesn't use EPR / Flex, and has no problem sleeping comfortably through each night, that EPR / Flex can help reduce some of these listed occurrences?

Sure sounds like my understanding of EPR / Flex is no longer current, that the default should be using them now?

[marbles]

bonjour,
Thank you for your response. That helps but I am still undecided as to the result that would be expected. What should a user be looking at to determine if EPR is needed? Will it be of help or be a hindrance to my treatment?

mrmagloo,
Happy to have your comments. You seem to be an understanding as I do.

[Sleeprider]

EPR is the same as pressure support on a Resmed bilevel. Properly implemented it is not just a comfort feature but definitely treats flow limitations, RERA and hypopnea. If you have upper airway restriction, it helps treat obstructive events and poor therapy. If you tend to have central events, it can make them worse by washing out CO2. There is simply no comparison between the Philips Flex algorithm that is a temporary reduction in pressure, and EPR which is real bilevel. We actually use EPR to treat members, and just work around Flex which sometimes seems to create more problems than it solves.

[mrmagloo]

Thanks SR. I guess my way of thinking perhaps was correct as it relates to Flex, but not so much with EPR. I appreciate the insight.

[Gideon]

Let's back up a step or two and look at basic treatment.

Pure CPAP delivers a single constant pressure.  This pressure is what splints open the airway.  APAP (AutoSet) is what we prefer to see as it can vary the pressure to suit the situation.  For now, let's forget about APAP.

Basic BiLevel delivers two fixed independent pressures, EPAP is Exhale Pressure and is what actually splints the Airway open, It is the equivalent of "Pressure" in a CPAP and does the same thing.  
IPAP or Inhale pressure is the higher of the two pressures.  Once the Obstructive Apneas are resolved with the Exhale pressure (EPAP), IPAP is used to resolve hypopneas, flow limits, and RERAs.
The difference in these pressures is called Pressure Support or PS.  PS is always added to EPAP by convention to get IPAP so IPAP = EPAP + PS
FYI if you were to set the EPAP = IPAP you would have a basic pure CPAP functionally.
The above info is derived from Titration guides.

Because of the way ResMed implemented EPR it actually behaves like a limited BiLevel that is capable of three settings of PS, 1,2,3 cmw of PS.
Over time it was observed that EPR behaved EXACTLY like PS on a BiLevel and since this discovery, we have extremely frequently taken advantage of this to see that users are better treated for their apnea.  We often use Resmed Elite or AutoSet effectively as a limited BiLevel.

EPR is subtracted from IPAP to get EPAP, (EPAP = IPAP - EPR) the opposite of BiLevel so we have to account for the different math, but yes EPR does provide extremely effective therapy in addition to its comfort functions.

The PR algorithm for Flex just does not produce the same therapeutic impact (doesn't mean we don't try)  but is a good comfort feature.

[mrmagloo]

Thank you Fred.

[Hydrangea]

Here's my experience with EPR:

- When I was new at CPAP, I appreciated EPR because it helped me feel less chlostrophobic.  Mentally, I liked the thought of it, and it helped me be more accepting of CPAP therapy for myself.

- After a while, I realized that *because I had my min pressure dialed in so well, to really be a good min pressure*, my EPR was lowering that pressure (on each exhale) that little bit enough to NOT give my air pipes the support they need... and thus I was experiencing apnea due to the EPR.  I lowered my EPR to the min setting (1 on the ResMed, and I forget what on the DreamStation), and it helped.  But ultimately I had to raise my min treatment pressure to compensate for the lower pressure achieved during EPR.  

- After a while longer, I started getting ear clicking and jaw clicking along with my ears popping all day long.  I finally realized it was the EPR causing it (the cosntant - every breath - changes in pressure).  Considering my ears are very sensitive to pressure due to chronic ear infections as a child and young adult, this makes sense to me.  I turned off the EPR, and haven't had a jaw/ear problem since!

[staceyburke]

I'm sorry but I'm trying to learn - I can not find any setting on my 10s VAUTO that is EPR.  Is that the same as PS?  If not how is it different and where is it on the clinician menu?