PS is pressure support and while not specifically stated as such when in S mode it is implied by the settings.Details wrote:When I changed the pressure settings I left it in 'S' mode and just changed the IPAP from 12.0 to 9.0.
When EPAP is 6 and IPAP is 9 that makes PS equal 3
PS is just the difference between EPAP and IPAP. So no need to worry about the absence of that particular nomenclature in S mode.
With such a drop in AHI and that has always been centrals it makes me wonder if it was just the PS of 6 that was triggering the centrals. Sometimes it does that in a small population of cpap users whose body is easy to get into the undershoot/overshoot with the carbon dioxide levels which is the ultimate trigger for the brain to tell the body to breathe. With the higher PS the breathing can almost become like hyperventilating and that totally messes up the oxygen and carbon dioxide balance in the body. We don't blow off enough carbon dioxide to tell the brain "it's time to breathe" so we don't breathe.
Actually since pressure changes could possibly be a trigger for centrals in your situation I wouldn't advise messing with Auto mode at this point unless you do so in an extremely tight range. In your situation the ability to roam around might not be in your best interest and unless there's a pressing need to roam around...I wouldn't go there. There's not a lot to be gained in auto mode in your situation but there is an increased risk for triggering centrals in your situation. The reward isn't there to take the risk. It just isn't needed at this point unless you were to see a truckload of obstructive apneas pop up.
