The second reason I'd like to take a very short extension on that "highly addictive" vacuum topic is because I'd like to back up and at least briefly talk about those A+A or H+H pressure-increase requirements for the Remstar Auto algorithm. Bill and Doug have been serving the valid point that APAPs tend to slowly raise pressure. I want to make sure that correct point is not lost.
Now a confessional about A+A/H+H for Bill. When I mentioned much earlier that I was chuckling like a mischievous child, it wasn't because you were being set up. It was the exact opposite! I experienced a vicarious "satisfaction laugh" at knowing the A+A or H+H requirement served your position well. Now why that laugh felt mischievous is beyond me. My best guess is that I felt mischievous or guilty for even hypothetically assuming your position and thus consciousness---even if for but a small scope in both time and awareness. Curious philosophical response on my part and equally curious regarding some fairly convoluted psychology. So what's new?
Anyway, here's an interesting Respironics web-site chart showing those slow APAP pressure increases that Bill and Doug have been talking about all along:
There are a couple things I find interesting about that chart. One, of course, is the slow pressure response we've been discussing all along. The other is the fact that the first apnea or the first hypopnea is not even treated. Rather it is cautiously discarded. Within a running three-minute time window the second apnea or the second hyponea is what causes the slow pressure response in the algorithm.
In my view this is yet another typically cautious APAP pressure response. As a side note, proactive APAP pressure responses typically proceed and ideally obviate the need for the hypopnea- and apnea-reactive type pressure responses that you see above. Since confessionals are in order for tonight, I admit the third reason I wanted to back up and highlight the above altogether cautious pressure response is because we have been trying to ascertain just why APAPs administer all that caution.
One compelling theory in this thread entails algorithmic caution relating to the treatment of vacuum-based tongue blockages. Another theory entails homeostatic-based pressure caution relating to the avoidance of central events (that can be both pressure-induction prone and difficult for the APAP to distinguish from equivalent obstructive events). Why is the above pressure-response chart relevant toward that present line of inquiry? I believe it's relevant because the above "pressure-cautious" apnea case is virtually identical to the "pressure-cautious" hypopnea case that is also reflected above.
The reason I find that last statement compelling is because there can be absolutely no vacuum-based tongue blockage in any hypopnea case--simply because the airway must be at least partially open for any hypopnea to occur. In at least the hyponea case, then, we must conclude all that the pressure-delivery caution relates to concerns in the patent descriptions relating to: 1) central induction, and 2) inadequate means of central differentiation.
Just a "technically minor" hypopnea thought, although I didn't manage to get much silliness in this time... However, there's always another day for that!
Thanks for letting us explore these topics in your thread, Needsdecaf. I couldn't help but notice that you're getting excellent advice from the well-seasoned experts. You sure can't go wrong with that!! .
