Alternate Bilevel

The one thing I like about my Dreamstation One BiPAP is that it can adjust the inhale and exhale pressures separately within the range set for the pressure step. This seems to help because it allows the machine to up my inhale pressure without increasing the exhale pressure as my Resmed Aircurve 10 has to do. This seems to reduce the air I swallow.

Of course, the Dreamstation has some questions regarding safety of the new foam, and since those machines are off the market now I won't have that option in the future. Are there any other bilevel machines that can adjust inhale and exhale separately or were the Philips machines the only ones able to do that?

You are talking about the variable PS on the Respironics bilevel machines??? Is that correct?
If so then none of the "regular" bilevel machine within the other brands have that same feature. They all offer only fixed PS if I remember right.

Now the ResMed bilevel model called the ASV.....now it has variable PS available but that is a whole different class of machine.

Sorry I misunderstood.

Yes, the variable PS is exactly what I'm talking about. I typically start out the night with only a PS of 2 (16/18). 16 seems the minimum exhale pressure I can have without my airway collapsing on exhale. But, during the night, the machine will sometimes take my inhale pressure up to 20, or even into the low 20s temporarily. My Resmed machine has to drag my exhale pressure up with it to 18 or even 19 or 20. And, I think it's at that point I tend to swallow air. My DS1 tends to temporarily take my inhale pressure up, but allows the PS to increase. I don't seem to wake up as bloated with the DS1.

Maybe that isn't an important feature for most, but I really don't want to have to go to the extra level of going to ASV.

Thanks for the answer.

SleepGeek wrote: ↑

Tue Mar 19, 2024 7:44 pm

I have done/can do my Resmed BiPap pressures separately.

With auto mode you can indeed vary the EPAP and IPAP but the PS is going to be fixed and won't/can't vary unless you are using the ASV model. I am using the AirCurve 10 VAuto myself....PS is fixed.

Respironics bilevel machines let people set a range for PS and would auto adjust the PS along with EPAP and IPAP but
ResMed machines can't do it unless using the ASV model.

You know I often wondered what the advantage to variable PS on a regular bilevel machine (non ASV) and I guess you have just described a potential advantage.

I am sorry but I don't know of any other bilevel machine (other than the ASV) that will do what the DS bilevel would do with the variable PS.

Sometimes I also seem to have the opposite problem where the variable PS helps. Sometimes, the limitation is needing a minimum level of exhale pressure. But, on the Resmed that means the Inhale pressure needs to be exhale+PS. So, in those cases the inhale pressure may go higher than needed. With the Philips machine, it can reduce the PS to not up the inhale pressure as much.

So, the advantage of variable PS for me seems to be that it can increase the PS at the high end to keep the exhale pressure from going too high, and at the lower end it can reduce the PS to keep the inhale pressure from being higher than necessary.

Sometimes we have to make compromises and sometimes it seems like our options are horrible.

So if the ResMed IPAP wants to go to 19 and with fixed PS of 2 then it is going to drag EPAP up to 17....no way around that.
Normally not that big of a deal except with pressures up in the high teens it causes you to have significant aerophagia problems and the way to lessen that chance will sometimes sacrifice therapy effectiveness when/if we limit where the pressure can go....
Like if you are okay with 16 EPAP (keeping PS at 2) and 18 IPAP and no real aerophagia issues then that is compromise that is worth considering.
I don't know where your line in the sand is going to be....that figuring out has to be done on a trail and error method.

We don't know for sure what is driving those pressures into the high teens.
ResMed is a bit more "reactive" when it sees the early warning signs of the airway trying to collapse (Snore, Flow Limitations, OAs and hyponeas) than the Respironics machines (I have experience with Respironics bilevels as well as my AirCurve 10 VAuto). So it doesn't surprise me that the DS BiPap didn't go quite as high and then by not going quite so high you didn't have the aerophagia problem. The 2 brands have different auto adjusting algorithms along with slightly different criteria data.

Using the Respironics machine......man.... I have lost all faith in them and I just don't trust them and now they have stopped selling cpap/xpap machines in the US "but we we still take care of whatever machine you now use and still sell masks, etc".... I don't think I would ever want to use their machine again.

Back to ResMed being a bit more "reactive" in response to FLs, snores, OAs and hyponeas....
If your AHI is sub 2.0 consistently and your pressures are still climbing to the upper teens then we have to assume FLs or snores likely driving it. Need to see the OSCAR detailed report to confirm.
Then we might be able to let a little of the FLs slide by and maybe not get a visit from the aerophagia monster.