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Does EPR/CFlex change Flow Rate shape or I:E ratio? - Printable Version

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Does EPR/CFlex change Flow Rate shape or I:E ratio? - KeepSmiling - 11-01-2022

For (Auto) CPAP

I do not know if the Respironics and Resmed exhale pressure relief (epr) work the same way other then the fact the pressure decreases.  

I thought epr just drops the pressure when exhaling without changing anything.

Today I noticed that the I:E ratio is different when EPR was set to 3.

On a ResMed Elite 9, when I set the EPR at 3, when awake I would feel I ran out of time inhaling because the machine was exhaling, then I had to quickly exhale because I run out of time and machine is inhaling.  I have to talk myself down from panicking. 

I also ended up increasing the pressure because was waking up with a foggy headache and then migraines.  Then increased pressure even more, not sure if machine was going so may not be actual pressure.


RE: Does EPR/CFlex change Flow Rate shape or I:E ratio? - Sleeprider - 11-01-2022

Typically EPR will cause the inspiration time to be shorter and may slightly increase tidal volume. We use EPR with many members to directly treat flow limitation and hypopnea. Your experience of running out of time when inhaling with EPR at 3 is not typical, and is probably more related to lack of experience with the pressure support during inhale. It might be interesting to take a look at your daily details chart with Flow Rate, Mask Pressure, Inspiration Time, Flow limitation. With the Aircurve VPAP machine we can use settings to adjust the minimum and maximum inspiration time, and also trigger and cycle sensitivity, but these settings are not available on the Airsense CPAPs. EPR looks and feels identical to bilevel pressure support, but is limited to 3 cm of difference between inhale and exhale.

CFlex is another beast entirely. It predicts your breath cycle and switched to relieve pressure near the end of inspiration, and then increases pressure near the end of expiration to preserve the "CPAP pressure" before inspiration begins. This can feel like the CPAP pacing your breathing. I don't like the Philps Flex and it has no real therapeutic use. If you aren't comfortable with it, your choice is to change the setting or turn it off. The Philips machines will not generate any of the graphs I described above except Flow Rate. Start with the Wiki http://www.apneaboard.com/wiki/index.php/C-Flex


RE: Does EPR/CFlex change Flow Rate shape or I:E ratio? - KeepSmiling - 11-01-2022

Sleeprider,

First of all thanks for the info about CFlex. I have been trying to use AFlex for someone like EPR without results.

Because I needed a pressure of 18 on the Elite 9 to feel half OK, I decided to get the VAuto. I will start a new thread for it. It was Fed EXed to my surprise, so I should be getting it tomorrow.


LOL at [[[Your experience of running out of time when inhaling with EPR at 3 is not typical, and is probably more related to lack of experience with the pressure support during inhale.]]] I can walk and talk, I should be able to close my eyes and breath. But I understand what you are saying. I did not use CFlex on my REMstar Auto. The first time I used AFlex (on another machine) I turned it off. I have been playing with EPR for about 7 weeks.


RE: Does EPR/CFlex change Flow Rate shape or I:E ratio? - Sleeprider - 11-02-2022

You're going to really like the Vauto. We really need the charts because Ti Max adjustments are dependent on respiration rate and I:E ratio. There are many factors that can go into departures from default settings which are normally okay for most people, but certainly not ideal for all. Be sure to go into the User CP and keep your profile and machine use up to date. I was unsure what device you were actually using and had to cover the subject a bit differently based on your profile info or a Resmed Auto M Series, but with apparent experience with a Resmed.


RE: Does EPR/CFlex change Flow Rate shape or I:E ratio? - KeepSmiling - 11-02-2022

Sleeprider,

Sorry for the confusion, my beloved Respironics Auto M Series died the end of August. Spent a couple of days without treatment and shared a Respironics System One Auto before I was able to get a hold of a Resmed Elite 9.

Let me assure your previous post was extremely helpful especially the CFlex comment and link. (I am helping others get treatment/better treatment.) I know that it is not one size fits all. Unfortunately the more I need to know the more I do not know. I did not realize how far Sleep Apnea has advanced in the last decade.

I am waiting for delivery of my new Resmed AirCurve 10 VAuto.