johntee wrote:tillymarigold wrote:Snoredog believes that a pressure of 7cm is enough to stop johntee's hypopneas once they start, therefore the machine does not need to increase pressure to eliminate the hypopnea. However, it is not high enough to prevent them before they start, only to stop them once they already have begun. (i.e. Once johntee's airway starts to close, 7cm will open it back up, but it will not keep the airway from closing.)
I'll admit to not understanding that... The machine shouldn't have some pre-determined idea of what my "number" is. If it sees an event, isn't it supposed to increase the then-current pressure to try to stop them? Then if no luck after 3 pressure bumps, it can give up and label it Non-Responsive.
Last night, I increased the Minimum Pressure to 8 (Max still at 13). Numbers got a little better, but now in almost every case, it ignores the Hypopnea events (and even ignored one Apnea event) -- never tried to increase pressure as a response. Kept cruising along at the minimum.
I've highlighted the Hypopneas that it didn't respond to in yellow and the Apnea it didn't respond to in green:
<snipped>Am I misunderstanding how the Auto is supposed to respond? Thanks!
It is exactly how Tilly described it above. It is not that the machine is NOT responding to those events, it knows it doesn't have to, because they are going away at current pressure based upon the duration they are lasting.
There WAS improvement seen going from 7cm to 8cm. Assuming everything was identical to the night before, FL's are completely gone, OA's were reduced to Zero and the number of HI's went down.
If you want to completely eliminate an event from showing up on the report, you have to increase the Minimum pressure to do that. The Autopap will always let some events go by, it does store breathing "patterns" in volatile memory and when it sees another pattern matching that in memory or hard coded in the algorithm it will respond with pressure.
The machine knows what your normal breathing patterns look like, that is pretty easy for it to learn those patterns. If it then sees a HI lasting 15seconds in duration and it goes away doing nothing (remaining at current pressure), when it sees the next HI and it lasts only 12seconds it will again do nothing, if it sees another HI that lasts 20 seconds (5 seconds longer than the first one) then it may start to trigger a response. The indicators of that happening was in your first reports where FL's were seen. If the obstructive event didn't last 10 seconds in duration then that event was a FL.
It is not that the machine is not responding to those events seen, it is more likely they are not lasting long enough for the machine to trigger a response.
If the machine sees they are going away on their own at current pressure, it may do nothing in response to them.
Those regular pressure "probes" seen on your report is the machine probing for events. Your reports look good, you really don't need to change anything.
If you look at your report and you see for half the night it increases pressure from the Minimum by 1cm to eliminate events, you might as well just bump the Minimum up by that amount and it should prevent those events. But there are trade offs with increased pressure, machine gets louder, mask leaks become a bigger problem and some adverse side effects may start to occur such as aerophagia.
At current 8cm Minimum pressure you can now count the number of events seen on your report with just a glance. While the events don't necessarily have to follow any sequence, most obstructive type events do and increase in severity similar to below:
Flow Limitation->Hypopnea->Snore->Apnea
So now IF you assign an arbitrary pressure to each of those above you might see 7, 8, 9 or 10 with Apnea the most severe requiring 10cm to clear. You were at 7cm and FL's were seen, increasing to 8cm eliminated those and reduced the frequency of the HI's seen. Now if you want to eliminate the residual HI's seen you will need to again increase Minimum pressure up from 8cm to 9cm to eliminate those.
You don't have any Snores to speak of, but you can see snores usually happen right before an apnea, so that is why most autopaps chase a snore aggressively. Apply the needed pressure to eliminate the snore you can most likely eliminate the following Apnea.
Your overall AHI is under 5 which is Normal.
someday science will catch up to what I'm saying...
