Hello Guest, Welcome to Apnea Board !
As a guest, you are limited to certain areas of the board and there are some features you can't use.
To post a message, you must create a free account using a valid email address.

or Create an Account


New Posts   Today's Posts

Isn't Resmed's Expiratory Pressure Relief really Inspiratory Pressure Support??
This may be futile, but I'm going to try anyway. When a CPAP titration is done, it tends to be a high pressure compared to titration on bilevel, because a single pressure is required to resolve OA, and H (including obstructive flow limits that result in hypopnea and RERA). A bilevel titration will generally be lower, with EPAP titrated to treat OA and pressure support for other events. A common bilevel titration protocol is that EPAP is increased until CA is controlled and where SpO2 is low, EPAP is increased for PEEP (positive end expiratory pressure) which increases O2 saturation, and IPAP (EPAP+PS) is used for hypopnea, ventilation and other objectives.

When a Resmed CPAP or APAP is setup to use EPR, It will not usually hurt treatment efficacy, UNLESS the titrated pressure is critically low. This can happen in simple OSA that is resolved at low pressures. Similarly, people that are self titrating and using low pressure, can end up "stuck" at 4 cm CPAP pressure when CPAP pressure is under 7, and EPR is at 3.

I think Sleepster's CPAP titration of 13 clearly falls into the category of a conservative titration. Using Auto CPAP, he could easily set his pressure lower, and the auto algorithm would increase pressure high enough to prevent most apnea. Using EPR, his obstructive apnea was fully treated and the "pressure support" provided good results for hypopnea. The use of bilevel with EPAP min 5.2, EPAP max 9.2 and PS 4.4 (IPAP 13.6) show just how conservative his original titration was.

I think we are arguing semantics here. I believe that the Resmed CPAPs provide therapy equivalent to a bilevel limited to 3-cm pressure support, and that the titration principles for bilevel are applicable. Those titration approaches will not work with a Respironics machine which must be titrated as a conventional CPAP with conservatively high minimum pressures. The pressure relief on a Respironics CPAP is not equivalent to bilevel because it returns to the CPAP pressure before inspiration begins.
Post Reply Post Reply
(11-27-2017, 05:17 PM)Walla Walla Wrote: I get where Sleepster is coming from. When titrations are done the pressure is set for all events not just obstructive events. By setting the pressure to also include Hyponeas it allows room for the EPR to be set without resulting in OA's. It takes less pressure to remove OA's than it does Hyponeas. That's why a DreamStation Bipap can use a variable pressure support. The EPAP can stay at a lower level to take care of OA's while the IPAP can increase to take care of Hyponeas.

I'm really glad you stuck around!

To the extent that the patient suffers from hypopneas that require a higher pressure to resolve than the OSA pressure, I agree with you. 

But, if that were the case, I'd hope that the sleep technician would enable EPR to obtain the benefits of the EPAP, IPAP, and pressure support, rather than just sending the patient out the door with a titration that was higher than necessary on expiration.
Post Reply Post Reply
I'm not aware of any CPAP titration that even discusses the use of bilevel parameters, or EPR.  I have seen Flex mentioned.
Post Reply Post Reply


(11-27-2017, 05:20 PM)Sleeprider Wrote: This may be futile, but I'm going to try anyway.

...

I believe that the Resmed CPAPs provide therapy equivalent to a bilevel limited to 3-cm pressure support, and that the titration principles for bilevel are applicable.  Those titration approaches will not work with a Respironics machine which must be titrated as a conventional CPAP with conservatively high minimum pressures.  The pressure relief on a Respironics CPAP is not equivalent to bilevel because it returns to the CPAP pressure before inspiration begins.

I think you and I have been in agreement on almost everything since the beginning, and I agree with you now as well, with one exception:

With Respironics, regular C-Flex works as you indicate.  However, A-Flex/C-Flex+ do NOT return to inspiration pressure before inspiration begins.  According to the documentation, A-Flex/C-Flex+ looks like Bi-Flex, but with a 2cm level of Pressure Support (no matter which EPR setting you use).   

I posted a link to the manual that so indicates in another thread.  Did you see it?
Post Reply Post Reply
(11-27-2017, 05:30 PM)Sleeprider Wrote: I'm not aware of any CPAP titration that even discusses the use of bilevel parameters, or EPR.  I have seen Flex mentioned.

Read the ResMed Sleep Lab Titration Guide.  There's a detailed discussion of EPR and what it does, including wave forms, on page 20.  It's also mentioned in the CPAP Titration Protocols on page 33.  The first step is "EPR comfort setting - Set to patient comfort (1, 2, or 3)."  

That mean nothing, however, if the technician starts at 4.0cm, as recommended by the protocols, since the patient won't see any EPR until the IPAP climbs above 4.0cm.
Post Reply Post Reply
I missed the link that shows the behavior of CFlex+/AFlex, and I've looked. Give me another shot if it's handy.

The titration protocols I've seen in sleep studies tend to deal with straight CPAP pressure or simple bilevel, and those are conducted as separate phases. All I see is a technician dialing through CPAP pressure in 1-cm increments and failing it after as little as 5 minutes. I have seen completed titrations with less than 1/2 hour of total time on the recommended pressure. The bilevel titrations always start at 4 cm PS and seem to increase PS for hypopnea, and EPAP for OA. Nearly every prescription is for fixed CPAP or BPAP pressure based on very little evidence of efficacy. That's why the forum works so well.
Post Reply Post Reply


(11-27-2017, 05:59 PM)Sleeprider Wrote: I missed the link that shows the behavior of CFlex+/AFlex, and I've looked.  Give me another shot if it's handy.

The  titration protocols I've seen in sleep studies tend to deal with straight CPAP pressure or simple bilevel, and those are conducted as separate phases.  All I see is a technician dialing through CPAP pressure in 1-cm increments and failing it after as little as 5 minutes.  I have seen completed titrations with less than 1/2 hour of total time on the recommended pressure.  The bilevel titrations always start at 4 cm PS and seem to increase PS for hypopnea, and EPAP for OA.  Nearly every prescription is for fixed CPAP or BPAP pressure based on very little evidence of efficacy.  That's why the forum works so well.

I've sent you the links privately.

What you've described is SOP for CPAP and BiPAP titrations, according to the guides that I've read.  5 to 10 minutes is what the titration guides say to wait.  Depending upon the guide, one obstructive event in five minutes (or two in ten) is all that it takes to go up another 1cm in pressure.  Bi-Pap either starts at 4/8, or at the patient's prior CPAP level as IPAP with EPAP 4cm below.   

Come to think of it, that particular protocol supports your view that the CPAP titration results in a number that is higher than needed for obstructive events alone.  Instead, when converting to BiPAP, they assume that the CPAP level is the IPAP, and reduce the EPAP by 4.  

That makes an even more compelling case for the argument that EPR is just a mini-BiPAP.  It keeps the CPAP level as the IPAP and reduces the EPAP by 1, 2, or 3 as defined by the EPR setting.
Post Reply Post Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Pressure raises when there is ca events yankees123 25 646 Yesterday, 11:22 AM
Last Post: Sleeprider
  [Diagnosis] Testing severity of Sleep Apnea with maximum 4 pressure freetime 8 240 Yesterday, 10:21 AM
Last Post: Sleeprider
  Why is that at the same setting two masks feel different pressure TimtheEnchanter 3 124 12-11-2017, 06:24 AM
Last Post: pupcamper
  Pillow vs FFM, pressure conversion formula? kiwii 39 933 12-09-2017, 04:17 PM
Last Post: kiwii
  [Health] Some support for severe fatigue.. tstburn 14 510 12-08-2017, 09:05 PM
Last Post: Patemack
  changing from CPAP to APAP- which pressure to use? cbrts765 16 587 12-08-2017, 09:05 AM
Last Post: Sleep2Snore
  [Pressure] How I decided on my APAP pressure numbers on my own DanGagner 14 349 12-06-2017, 09:26 PM
Last Post: DanGagner

Forum Jump:

New Posts   Today's Posts




About Apnea Board

Apnea Board is an educational web site designed to empower Sleep Apnea patients.

For any more information, please use our contact form.