Hi Avi --
I know this thread goes on and on (and on!), so it's really easy to lose track. However, waaaay back on page 2, you'll find this comment from me:
BrianinTN wrote:
-SWS had helped JIMCHI in another thread by dictating a matrix of possible settings to improve his luck with the ASV. Ultimately, that's what I'm trying to get at here as well -- where should I go first?
What I was hoping for with my thread really was a proposed experimental design
with a theoretical backing behind it. That caveat is really important; it's the reason why I really want to avoid the "turn this, change that" approach that can make drawing conclusions specious at best.
As for your other comments: you're certainly right that there are limitations to the data I can collect at home. I'm sure this is part of why ozij recommended a pulse oximeter. As for the 20 minute stuff, thanks for pasting that; I'd familiarized myself with the titration protocols from both manufacturers weeks ago, but I'm sure people stumbling upon this thread will find it useful. The reason why it's not terribly relevant to the discussion is that the protocol is about
stabilizing patients. There are two reasons why it just doesn't end up being relevant in my case:
(1) I don't have the home ability to make changes on my own during the night. I can only count on the ASV to make changes and witness the next morning what they were and how they happened.
(2) The logic is backwards. In the titration, if there are events (instability), then you make the appropriate changes to obtain stability (low AI, low HI, etc.). There's no reason to spend much time on a setting that isn't working because, since the ASV is making adjustments using its sliding window (4 minutes in the case of the Respironics ASV, if I recall correctly), you've let it run its course so to speak. Once you've narrowed the EPAP and PS parameters for it and reached a stable end point, you're "done." In
my case, however, I'm not stable! And what makes it worse, I'm not stable over the course of an entire night -- and a whole night has an awful lot of data variability in it. At what point(s) in the night were the settings not ideal, and what would have been the responses to changing certain settings at that time? Indeed, it's tough to answer these questions.
It's also worth noting that the titration protocols are intended for precisely that -- titration, which is usually a one night ordeal. People's numbers at certain settings can and often do improve over time, despite starting out with a high AHI at those very same settings. Similarly, I'm not the first person on these boards to be "stabilized" in the lab multiple times during the titration, only to discover that those settings didn't work out in the long-term. This is, I'm sure, why ozij was encouraging me to give it more than just one night at any given setting before completely giving up.
Anyway, back to the original quote of yours, JIMCHI and I do have a bit in common, which is why I'd keenly eyed his thread. Indeed, the high amount of variability -- one night that's quantitatively good and the next night that's quantitatively bad, even with the same settings -- is what is most vexing and frustrating about this. I wish he had continued responding on his thread, because I would have loved to have seen how it played out.
