(06-22-2014, 04:29 PM)jcarerra Wrote:(06-22-2014, 04:06 PM)robysue Wrote: Auto PAPs do NOT raise the pressure during an apnea; they wait until the event is over to respond.
The rationale is simple: CPAPs and ordinary Bi-levels are NOT ventilators. In order to try to force an inhalation (i.e. "blow through the obstruction") the machine would have to jack up the IPAP really, really HIGH--as in by 10-12 cm of additional pressure or more. And that kind of pressure change can cause its own problems with sleep continuity.
In other words, CPAPs and APAPs work by preventing the vast majority of events from occurring in the first place.
OK, but my musing has to do with why it is EPAP being raised vs. IPAP?
When the airway collapses completely, it typically collapses during the exhalation. More EPAP makes it harder for the aiway to collapse during the exhalation.
Quote:And does the image look like RERA?Those OAs look like they might just be mis-scored CAs to me. They have a very distinct pattern that is common to CSA and CompSA patterns:
oops nevermind--those were called OAs so can't be RERA by definition.
- Big breaths which blow off too much CO2 lead to
less urge to breath which leads to
shallower and shallower breaths which leads to
blowing off too little CO2 as the breathing becomes shallower and a (central) apnea at the nadir of the cycle, which leads to
Big breaths which blow off too much CO2 ...