ResMed -v- Respironics APAP algorithms

DME_Guy wrote:It's because it lowers the pressure throughout the entire breath, it's not as effective. There is a chance the pressure won't come back in time to stop an apnea.

That makes sense (to me, anyway). But I thought bi-levels operated under the same premise as EPR in that the pressure is lowered throughout the entire exhalation. Are they not as effective for the same reason?

Rastaman wrote:My concern is how they both work and which one is more effective overall. Is it Resmed? Or is it Respironics? Both are great right? But which one does it's job better if you take c-flex out of the equation?????

I believe you already answered your question earlier. You have other variables to work with - sleep hygiene primarily. Also, you haven't worked on tweaking the Resmed much and tracking your AHI.

It's interesting, to me, that when we take EPR (used generically) out of the equation we do not include the Goodknight Auto in the discussion of "what's best?". I mean there are really three popular apples in that basket then.

It seems from what a number of folks have said, including RG, that the PB Goodknight 420E is a really good machine with another different algorithm and a lot of flexibility so perhaps it's algorithm is even "better", whatever that means (to me it's angels dancing on the head of a pin).

I think the keys are:

• AHI going down?
  AHI at an acceptable level?
  OSA symptoms reducing or gone?
  Feel better (whatever that means)?

If the answers to those question are yes then the machine's algorithm is working for you. I think all three machines accomplish this for most people so then it comes down to bells and whistles (if you consider EPR a bell or whistle and I don't). I mean what the heck is best anyway?

BRAVO David!!!!!

Well said! I couldn't agree more! (Except that there are FOUR apples: Invacare Polaris)

Chuck

DME_Guy wrote:It's because it lowers the pressure throughout the entire breath, it's not as effective. There is a chance the pressure won't come back in time to stop an apnea.

Yes, that was one of the concerns that sleepydave had about ResMed's EPR in the link I posted, although I think he said it would probably apply to only one breath. If that happened very often to a person throughout a night, it could be more problematic.

neversleeps wrote:That makes sense (to me, anyway). But I thought bi-levels operated under the same premise as EPR in that the pressure is lowered throughout the entire exhalation. Are they not as effective for the same reason?

A bi-level titration at a sleep lab is, if I understand it right, aimed at setting the EPAP (exhalation pressure) first. Setting EPAP at a level where it will prevent all apneas in the first place. Then the titration continues on up to adjust the higher IPAP (inhalation pressure) on up above that -- to clear any snores, hypopneas, and limited flow situations that might remain.

As with masks, one size really doesn't fit all, so it's nice there are machines that go about things differently from each other. C-Flex letting the regular pressure back in before exhalation is finished could bother a few people, so it's cool to have another way (ResMed's EPR) of handling exhalation, if a true bi-level machine isn't needed. It's also nice to be able to use C-Flex in auto mode (Respironics' way) for those who want to use an autopap and get at least some type of exhalation relief at the same time.

Best of all, imho, is the Respironics BiPAP Auto, if a person needs (or wants) BOTH advantages operating at the same time.

GoofyUT wrote:BRAVO David!!!!!

Well said! I couldn't agree more! (Except that there are FOUR apples: Invacare Polaris)

Chuck

Hi, Chuck - glad to see you. Thanks

I said "popular" and I have to judge popular in the context of this board. We hear very little about the Polaris on this board so I know little about it.

David

rested gal wrote:

neversleeps wrote:That makes sense (to me, anyway). But I thought bi-levels operated under the same premise as EPR in that the pressure is lowered throughout the entire exhalation. Are they not as effective for the same reason?

A bi-level titration at a sleep lab is, if I understand it right, aimed at setting the EPAP (exhalation pressure) first. Setting EPAP at a level where it will prevent all apneas in the first place. Then the titration continues on up to adjust the higher IPAP (inhalation pressure) on up above that -- to clear any snores, hypopneas, and limited flow situations that might remain.

Ah, I see. Thanks for clearing that up for me! (I wonder if Resmed's knowledge of this potential problem is the reason they offer the option of setting EPR to work only during the ramp period --when the user is conscious of the relief provided.)

Boy, this sure makes a good argument for having the software! Seems you'd be able to fine-tune the pressure vs. EPR settings to get the best results (lowest AHI) and maximum comfort at the same time.

Another question. I know EPR cannot be enabled in auto mode. But, I don't understand why. Per the ResMed literature:

When the patient exhales, the S8 flow generator detects the beginning of exhalation and reduces motor speed to drop pressure. The patient or clinician chooses one of three comfort levels to determine the degree by which pressure will drop.

If the flow generator can detect the beginning of exhalation in CPAP mode, why can't it detect the beginning of exhalation in APAP mode?