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EPR
#11
RE: EPR
(11-24-2017, 05:15 PM)Reznik Wrote:
(11-24-2017, 05:01 PM)Sleeprider Wrote: If we keep it simple, exhale pressure relief, particularly as implemented by Resmed is equivalent to bilevel.  It is available in the mask pressure chart for anyone interested.

Yes, that is my premise.  

Where does one find the mask pressure chart you're referring to?  

My other premise is that Respironics C-Flex is actually expiratory pressure relief, while A-Flex/C-Flex+/Bi-Flex is probably an attempt to mirror Resmed's offering without subjecting them to patent litigation from Resmed...

The respironics Flex is only a brief pressure relief, and during exhale, it only drops pressure up to 2-cm (based on expiratory flow), and returns to IPAP before exhale ends.  So at the beginning of inhale, the pressure is at the CPAP setting.  Resmed drops pressure up to 3-cm, and follows spontaneous inhalation flow.  So if you develop an apnea at transition, the most common time, then you are stuck at EPAP pressure, which is 1-3 cm below your CPAP setting. Here are  comparisons of an Aircurve 10 Vauto bilvel and Airsense 10 CPAP.   I dare you to find any difference in delivered pressure through the mask, although this is two different individuals with different pressures. Note how briefly, the Airsense 10 is at CPAP set pressure, similar to the brief peak at IPAP for the Aircurve.

This is an Aircurve 10 Bilevel with 3-cm PS.

[Image: XU12agG.png]

And this is the Airsense 10 with EPR at 3.

[Image: PEe2mIe.png]
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INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
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#12
RE: EPR
Any chance I can get you moderators to move these last few posts over to the thread that I started on this same subject?  I think they belong there more than here!

------

Yes, I think that those charts make pretty clear that, on Resmed machines, EPR on the Airsense 10 is the same as a Resmed VPAP machine with 1, 2, or 3 cm of pressure support.
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#13
RE: EPR
(11-24-2017, 06:38 PM)Sleeprider Wrote: The respironics Flex is only a brief pressure relief, and during exhale, it only drops pressure up to 2-cm (based on expiratory flow), and returns to IPAP before exhale ends.  So at the beginning of inhale, the pressure is at the CPAP setting.  

You've described C-Flex and Bi-Flex.  

A-Flex/C-Flex+ does not return to IPAP before exhale ends.  It stays 2 cm below IPAP until the user initiates inspiration, and it allows expiratory relief in excess of 2 cm at the initiation of expiration.  In this way, it mirrors the Resmed's EPR behavior.  

However, A-Flex/C-Flex+ differ from Resmed's behavior in that they seem to also end the IPAP much sooner than the Resmed machines do.
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#14
RE: EPR
(11-24-2017, 06:38 PM)Sleeprider Wrote: This is an Aircurve 10 Bilevel with 3-cm PS.

[Image: XU12agG.png]

Is there any way to tell if the Aircurve BiLevel had "Easy Breathe" enabled??
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#15
RE: EPR
The Aircurve 10 does not have an Easy Breathe option, it is enabled on all models at all times when pressure support is applied. In the Airsense 10, it is used to shape the EPR.  There are no settings on either machine as far as I know, however the mask pressure wave-form appears to be what is advertized for Easy-Breath™.

It would be great to see the actual mask pressure wave form on a Philips machine, but I'm certain that with any Flex option, the pressure returns to IPAP before expiration ends.  It is interesting to contrast this with the Resmed EPR which spends a very smallamount of time at CPAP (aka IPAP) pressure; the Resmed spends very little time at EPAP pressure. The two algorithms are nearly opposite in their shape. According to this Philips Respironics publication, Cflex and Aflex return to inspiratory pressure before expirations ends (emphasis added):

Quote:Source: Theory behind Flex pressure relief technologies pp 31-33
Based on these physiological dynamics of the airway, Philips Respironics developed Flex technologies that proportionally decrease pressure at the beginning of exhalation and return to therapeutic pressure before the end of exhalation. As the figure on the right shows, when the patient takes a small breath, there is a small amount of air in the lungs, so C-Flex delivers only a small amount of relief (only at the beginning of exhalation). When the patient takes a large breath and there is a significant amount of air in the lungs, C-Flex delivers a larger amount of relief (only at the beginning of exhalation).

CPAP with Flex vs Patient Flow:
[Image: c-flex_pressure_profile.gif]

With BiPAP and BiFlex, there is a true IPAP and EPAP with some shaping of the flow curve using BiFlex.  In this case, Biflex pressure relief does end before inspritation begins, but IPAP does not engage until spontaneous breathing occurs. 

BiPAP with Biflex vs Patient Flow

[Image: biflex.jpg~original]
Sleeprider
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____________________________________________
Download OSCAR Software
Soft Cervical Collar
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Organize your OSCAR Charts
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Mask Primer
How To Deal With Equipment Supplier


INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
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#16
RE: EPR
(11-25-2017, 05:06 PM)Sleeprider Wrote: The Aircurve 10 does not have an Easy Breathe option, it is enabled on all models at all times when pressure support is applied. In the Airsense 10, it is used to shape the EPR.  There are no settings on either machine as far as I know, however the mask pressure wave-form appears to be what is advertized for Easy-Breath™.

It would be great to see the actual mask pressure wave form on a Philips machine, but I'm certain that with any Flex option, the pressure returns to IPAP before expiration ends.  It is interesting to contrast this with the Resmed EPR which spends a very smallamount of time at CPAP (aka IPAP) pressure; the Resmed spends very little time at EPAP pressure.  The two algorithms are nearly opposite in their shape.  According to this Philips Respironics publication, Cflex and Aflex return to inspiratory pressure before expirations ends (emphasis added):

Hi Sleeprider,

If you look at the ResMed Aircurve 10 S/VAUTO/ST Clinical Guide, on page 13, you'll see that "Easy-Breathe" is a configurable option that can be enabled and disabled when the machine is in S mode.  

If you look at the Remstar Auto A-Flex Provider Guide, on page 7, you'll find a mask pressure wave chart for both C-Flex and for A-Flex/C-Flex+.  

You'll see that with C-Flex, you are correct that the pressure returns to IPAP before expiration ends, and the machine spends most of its time at IPAP.

However, with C-Flex+/A-Flex, the machine does the opposite.  It reduces pressure prior to expiration and then stays at 2cm below IPAP until inspiration begins.  It spends very little time at IPAP Pressure, and spends most of its time at 2cm below IPAP.  The mask pressure wave form looks almost exactly like Bi-Flex, except that with C-Flex+/A-Flex, EPAP is fixed at 2cm below IPAP, while with Bi-Flex, you can set EPAP to almost whatever you want.

I'm not going to post the charts, because it's a pain, but if you look at them and the text that accompanies them, you'll see what I'm saying.
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#17
RE: EPR
(11-23-2017, 09:47 PM)Reznik Wrote: I would suggest that you read this thread:

http://www.apneaboard.com/forums/Thread-...re-Support

For Resmed machines, EPR does not merely change the pressure during expiration.  What it really does is reduce the pressure at all times except for inspiration, and introduces a pressure boost during inspiration.  This can mean that you get less pressure than the machine's display is showing most of the time, and you can get a boost of pressure support during inspiration.

If were titrated with EPR, then you should keep it on a the setting you were titrated.  If you weren't titrated with it, I wouldn't recommend turning it on without talking to your doctor.

If you do turn it on, watch out for more obstructive apneas since the pressure is effectively turned down by the amount of EPR, and watch for the feeling that your lungs are being inflated like balloons when you breathe in.  The feeling becomes worse as you increase the EPR.

And then there is the simple patients experience......

Titration with no EPR at 16.8cm H2O. Complained of difficulty in breathing out at first consultation and was advised to turn of EPR to 3 to help with expiration. Result- lots of CA but also mask issues and leaks in early days. However, through help in this forum and experimentation, have now turned off EPR with continually lowering IPAP to extent of not feeling like I can't breathe against the violent flow of air.

Am now at 10.6 cm H2O with mostly low >1 AHI. Not showing off but trying to say, nothing can be black and white-formal titration or not. Its what suits you and the delicate balance we all have to find individually.
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INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
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#18
RE: EPR
(11-26-2017, 09:41 AM)Apnea Infant Wrote: Titration with no EPR at 16.8cm H2O. Complained of difficulty in breathing out at first consultation and was advised to turn of EPR to 3 to help with expiration. Result- lots of CA but also mask issues and leaks in early days. However, through help in this forum and experimentation, have now turned off EPR with continually lowering IPAP to extent of not feeling like I can't breathe against the violent flow of air.

Am now at 10.6 cm H2O with mostly low >1 AHI. Not showing off but trying to say, nothing can be black and white-formal titration or not. Its what suits you and the delicate balance we all have to find individually.

Oh, I totally agree with you.  I suspect that in-lab sleep titrations are often wrong for a variety of reasons.  People have asthma and allergy attacks.  The bed is too hard, or too soft.  The pillow is different.  etc.  Most of the people that I know who use CPAP have lowered the pressure and are doing just fine.

My statements assume that your titration was correct.  I realize that's a big assumption!  Smile
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#19
RE: EPR
Keep it simple, the higher the number the less pressure you have to breathe against.
Put another way, the higher the number, the less pressure there is when you breathe out.

Clear as mud!
I am NOT a doctor.  I try to help, but do not take what I say as medical advice.


Every journey, however large or small starts with the first step.

Sleep-well
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