Anyone Switched back to Airsense after Aircurve?

[Lifeisabeach]

I was serious, but clearly mistaken. Thanks. I just didn't thik that it could be turned off in vauto. Do you know why they have it S and not Auto?


The Aircurve product page does imply otherwise though:

"The AirCurve™ 10 VAuto is an auto-adjusting bilevel machine that uses the comfort of both the AutoSet™ algorithm and Easy-Breathe waveform in its VAuto algorithm to treat patients with challenging obstructive sleep apnoea conditions who can benefit from greater pressure support."

I just started using VAuto mode yesterday due to my own ongoing difficulties getting my AHI under control. I'm very familiar with how S-Mode "feels" with Easy-Breathe on vs off, and right now, in VAuto Mode, it feels like Easy-Breathe is on. I don't have that rapid transition from IPAP to EPAP and vice-versa that I had when in S-Mode when E-B was off. Dog Slobber is correct that the option to enable or disable E-B isn't present when in VAuto mode, so either E-B is automatically on for this mode as it feels to be from my brief experience so far, or my impression is flawed due to the difference in the pressures now being delivered.

I should make my position clear.

I don't know whether Easy-Breathe is always present in VAuto mode.

It's not an option presented in the VAuto mode menus, nor is it mentioned as being present when in VAuto mode in the clinical manual. But, I certainly accept that it might be always on in VAuto mode (just not the default, as that suggests it can be turned off).

Easy-Breathe was brought into this discussion as evidence that the Air-Curve algorithm or sensitivity must be different than the AirSense, and my position is there is no evidence of that. If Easy-Breathe is an undocumented element of the the AirCurve algorithm, it could also be undocumented within the AirSense algorithm.

The fact is; there are a few people making claims that they use different algorithms or have different sensitivities to flow limitations, but the claims are just based on "feel". No one has yet to supply a comparison of an identically configured AirCurve to an AirSense.

Why not?

Oh I understood your position. Sorry if it sounded I was disputing it. I forgot early on that E-B wasn't "toggle-able" in VAuto mode until you mentioned it (I knew of it from the clinician's manual but it had been some time since I last read it over). But anyway, yeah, I totally get that just because it "feels" like it may be on or that it "feels" like there is a difference between one model vs the other doesn't equate to an actual real difference. In my case, I'm basing my "feeling" on very different pressure deliveries (VAuto dramatically dropped my pressure from what my fixed S-Mode was set to). I could adjust my S-Mode to match what VAuto is giving me and experiment/compare, but it'd still be somewhat subjective, maybe academic at best since it wouldn't change anything, and wouldn't address the question as to whether or not the AirSense behaves in the same manner.

[Apneak]

Even with the same settings, same pressure range, same support, I'm getting more CA events with my aircurve. Can someone explain why that might be? With my airsense my ahi was regularly averaging below 1.5, with my aircurve it regularly averages above 2.5....I just don't get it.

I would switch back to the airsense, but I am observing smoother more consistent flow curve on the charts with the aircurve, which is why I'm inclined to keep it if i cam figure out whats goin on.

[Apneak]

One thing I also noticed was the way inspiration times are recorded or interpretted....

Aircurve

Screenshot 2020-06-28 11.53.49.png (75.91 KiB) Viewed 1052 times

Airsense

Screenshot 2020-06-28 11.57.30.png (96.07 KiB) Viewed 1052 times

The inspiration time chart on the aircurve remains remarkably flat. Whereas on the airsense it moves dramatically from ~1 to ~3s throughout the night...But as you can see, both the machines here are recording insp time differently. It seems as if the start times of the inspiration are different.

[Lifeisabeach]

Even with the same settings, same pressure range, same support, I'm getting more CA events with my aircurve. Can someone explain why that might be? With my airsense my ahi was regularly averaging below 1.5, with my aircurve it regularly averages above 2.5....I just don't get it.

I would switch back to the airsense, but I am observing smoother more consistent flow curve on the charts with the aircurve, which is why I'm inclined to keep it if i cam figure out whats goin on.

Is one device older than the other? How much so? One may simply be starting to fail. I experienced this here... I was getting inconsistent results between a newer AirCurve and a much older S9 unit despite them having the same settings. When I replaced the older one, I picked up a gauge manometer to test everything out and found the older unit wasn't delivering the pressure it was set to.

BTW, my stats off the S9 were actually BETTER than what I was getting off the AirCurve, even though the S9 wasn't delivering the set pressure. Basically it seems like my pressure needs had come down, and the S9 was simply failing to a level that coincidentally matched those current needs.

[Apneak]

Yes one is 2 years older, should still be fine.

[Apneak]

I think that the aircurve is more sensitive in it's response to flow limitations

I actually own both the AirCurve and the AutoSet and I haven't noticed any real difference in response to flow limitations.
I have actually done a lot of experimentation with the various settings on both models.
Now I am not saying that what you think you are experiencing isn't happening but I don't think it is very common at all. Most people who go to the bilevel don't want to go back to single pressures even with adding in EPR to make it a bilevel.
While I can do well with EPR at 3 (which is essentially PS of 3)....I do prefer PS of 4 so I prefer the AirCurve.
Any random small difference in response I normally attribute to the normal variations in sleep from night to night in general.

If I use PS of 3 on the AirCurve and EPR at 3 on the AutoSet.....I can't see enough difference to impact anything. I don't see a difference in response to flow limitations but then again I don't have many or much in flow limitations to respond to. I never have had many Fls.

Perhaps this is just another one of those YMMV things that pretty much comes with everything related to cpap.

Hi Pugsy,

I've been testing and investigating further. In fact, one of your posts somewhere else clued me into what may have been going on...You have posted a couple of times regarding Pressure Support induced Central Apneas. And I believe you are correct. The extra pressure support in my Bipap does in fact induce central events, and your explanation for it made sense too. Because the drop in pressure at the end of the inhale is such that it creates momentarily negative pressure, so the gas from the lungs rushes out before there is sufficient build up of CO2 to trigger a new breath, correct? So if I understand correctly, both overly high Epap pressure as well as overly high Pressure Support can induce Central Events, and lead to sub optimal air exchange? This is quite a tricky situation, and I'm surprised that the sleep labs don't pay more attention to it?

For instance, let's say you have a inhale/exhale pressures of 10/6. That may be too much pressure support, so if you move to a 10/8, you may get less central events? However, if you have a 10/10, that may be too much EPAP, and so you may get more Centrals, even though you've minimized your pressure support....Is this correct?

This is frustrating, because though I can clearly see a positive correlation in my data for Central Apneas and Pressure Support, as well as Central Apneas and EPAP, I NEED a higher pressure to smooth out the inhale flow-curve (UARS). UGGGH.

Is this making sense? Thanks so much. You have been very insightful/helpful to this community.