(11-22-2017, 10:53 PM)Reznik Wrote:

(11-22-2017, 08:56 AM)ajack Wrote: There seems to be a misunderstanding, that I also shared, if you read a recent post. It is common in groups to have a shared falsehood. I too took what was said for granted, that you raise the ipap when you add epr and passed it on.

I now think I was wrong. we aren't working from the epap end and adding PS to increase ipap. you already have the ipap right. So adding epr just gives you, what could be called an epap setting. It shouldn't affect the treatment pressure, be it EPR 1,2 or 3

I'm afraid I don't quite understand what you're saying here.  

EPAP is the pressure that the machine gives during expiration, during any transition from expiration to inspiration (or the other way around), and during any apnea.  In CPAP therapy, EPAP is the same as IPAP.  In Bi-Level Therapy, EPAP is always LOWER than IPAP.

IPAP is the pressure that the machine gives during inspiration.  In machines that are spontaneous, the IPAP is only delivered after the patient initiates inhalation and stops as soon as the patient stops inhalation.  In machines that are timed (or timed backup), the IPAP will be delivered at the programmed time interval to force inspiration even when it has not happened.  In CPAP therapy, IPAP is the same as EPAP.  In Bi-Level Therapy, IPAP is always HIGHER than EPAP.

Pressure Support is IPAP minus EPAP.

When we speak of "increasing Pressure Support," we are increasing the difference between IPAP and EPAP.  So, if IPAP = 8 and EPAP = 5, you have a Pressure Support of 3.  If you increase IPAP to 9, pressure support increases to 4.  But, if you increase IPAP to 9 and EPAP to 6, then Pressure Support remains at 3.

When a ResMed AirSense 10 model is in AutoSet mode, enabling Expiratory Pressure Relief converts the machine to a spontaneous (non-timed) BiPap Mode, where the displayed pressure on the screen is the IPAP, the EPR level (1, 2, or 3) is the amount of Pressure Support, and the EPAP is the displayed pressure minus the EPR level.

So, if a ResMed Airsense 10 is set for 10.0 without EPR enabled, then the patient is receiving EPAP at 10, IPAP at 10, and Pressure Support is 0.  If the patient enables EPR at 3, then his EPAP lowers to 7 (3 below the machine's stated pressure), his IPAP remains at 10 (the machine's stated pressure), and his Pressure Support increases to 3 (IPAP of 10 minus EPAP of 7 = 3).  

Far from getting expiration relief, the patient is actually getting LESS than his prescribed EPAP pressure (7 instead of 10) and a healthy dose of pressure support (3.0) that he may not need and which may actually cause him problems.  The patient may even complain that the machine feels as if it is inflating his lungs when he breathes in.  That's why I say EPR is really Inspiratory Pressure Support, and not Expiratory Pressure Relief.

On the other hand, if a patient is titrated to BiPap therapy at EPAP of 8 and IPAP of 10 and given a $1,700 AirCurve 10 S or VAUTO, that patient could get the same therapy with a cheaper $800 AirSense 10 CPAP or Autoset or an AirMini set to 10 with EPR set a 2.0.  A machine so configured would deliver EPAP 8.0 and IPAP 10.0, just like the more expensive AirCurve 10 when set to those settings.

I'll post in another message (in reponse to Sleepster's question) why EPAP is what matters when it comes to preventing obstructions.

I hope this clarifies things.

(11-23-2017, 12:42 AM)mhehe Wrote: I think you are confusing matters even more. For example in the BiPAP machine that I am using, Res Med AirCurve 10 VPAP auto, IPAP and PS are set. Then EPAP is IPAP - PS. PS is fixed but can be programmed to a lower or higher value. In the titration at home or in the clinic it is normally set at 4.0 cm. to start with. In my case the sleep technician has set the machine in Auto mode with EPAP min of 7.0, IPAP max of 25 and PS of 4.0. The machine starts of with EPAP = 7.0 and IPAP of 11.0. I want my night to start of with an EPAP of 8.0 and IPAP of 12 to handle my OSA and HA.

(11-23-2017, 03:31 AM)holden4th Wrote: My data and graphs tell me a different story. I've got IPAP set to a min of 13, EPAP to a min of 10.5 and a PS range of 2.5 to 5.0 which is something you can do with a Respironics BiPAP but not a resmed BiLevel. On these graphs I note that:

(11-23-2017, 03:31 AM)holden4th Wrote: My data and graphs tell me a different story. I've got IPAP set to a min of 13, EPAP to a min of 10.5 and a PS range of 2.5 to 5.0 which is something you can do with a Respironics BiPAP but not a resmed BiLevel. On these graphs I note that:

All my spikes are on the IPAP  which says to me that the machine is trying to treat my events by raising the IP not the EP. I had 3 Hs, 4 CAs and 4 RERAs. The EPAP level stayed as a straight line all night.

(11-23-2017, 05:55 AM)yrnkrn Wrote:

(11-23-2017, 03:31 AM)holden4th Wrote: My data and graphs tell me a different story. I've got IPAP set to a min of 13, EPAP to a min of 10.5 and a PS range of 2.5 to 5.0 which is something you can do with a Respironics BiPAP but not a resmed BiLevel. On these graphs I note that:

Respironics and Resmed differ in bi-level treatment. Respironics adjust IPAP and EPAP independently while Resmed moves them together, keeping PS fixed.
Given both are world leaders in CPAP treatment, I guess both have their good reasons for going either way, which may just show there is no one "right" answer.

(11-23-2017, 08:42 AM)Walla Walla Wrote: In both the DreamStation and VAUTO  EPAP responds to OA's.  IPAP responds to H's, snoring and flow limitations.