djhall wrote:Is this just one of those situations where real life experiences often don't reflect the theory, so experience tells us EPAP handles snores and flow limitations better than IPAP, despite the guidelines, or am I missing another part of the theory?
Yeah, when real life hasn't read the manual.
Also common sense comes into play.
In general we have been told that EPAP for obstructive stuff and IPAP for hyponeas.
Snores and FLs are normally an indication of some sort of upcoming collapse of the airway....which may or may not grow up to be an obstructive apnea or hyponea but from what I have seen with my own reports and other peoples...EPAP is sort of like APAP minimum pressure and those pesky snores and FLs go away real easy with just a little more EPAP or APAP minimum.
Stent the airway open better at the base level and those little early signs of an impending collapse just don't happen.
Now how much of it might also depend on is the collapse part of exhale or inhale...I never could figure out how to get a handle on that and to be honest...that's digging real deep and IMHO why not just fix it the easy way first if it needs to be fix.
I have some examples somewhere (will try to dig them out if I have time and show you) where I had more snores and FLs than I wanted...bilevel machine...EPAP at 9 and PS of 4 (my favorite) with available max IPAP at 20...so the machine could have used IPAP to kill the FLs and snores..but it didn't/couldn't/didn't even try. So IPAP couldn't/didn't prevent them and it had lots of room to do so. Maybe it has to do with the response time.
When I increased the EPAP to 10...poof the FLs and snores all but disappeared.
So EPAP fixed it...IPAP never did anything all that exciting. It wasn't like I was using fixed bilevel either. I have almost always used auto adjusting pressures because my REM stage sleep event sometimes take steroids and are particularly difficult to deal with..not always but sometimes. I sleep right through some big changes in pressure and have no unwanted side effects like aerophagia or ear problems or stuff like that.
Past experience has shown me time and time again that minimum APAP or EPAP minimum...seems to be the most critical setting in not just my situation but in the others that I have helped. Get that minimum APAP (or EPAP minimum) set optimally and the top end doesn't really have to do much.
I prefer PS of 4...3 isn't too bad and 5 isn't either but above 5 PS, I have seen correlation between higher PS and emergence of complex sleep apnea in more than an occasional person. Now most often it has been when PS was fix (like ResMed machine) and people try PS of 7 to 10....which can make a person feel like they are hyperventilating and when looking at the high number of centrals...I guess they did. So that's why I like to keep PS around 4 or so...just as a precaution. Less chance for unstable breathing O2/CO20 exchange causing centrals.
So that's why I suggested a little more EPAP...past experience with hundreds and hundreds of ugly reports that turned beautiful despite what the manual might say would maybe work better.
In this situation here with potential ear problems I was really torn with the suggestion to add 1 cm to IPAP and it may not have been the ideal thing to do but 4 PS is more comfortable than 3 PS but OP here may have to use 3 PS.
I will see if I can find those images when I increased the minimum EPAP last fall in response to just a little more "clutter" than I wanted to see. Clutter being FLs and snores mucking up an otherwise nice looking report. I felt fine, slept fine...just didn't like the clutter. If increasing the EPAP had presented a problem like aerophagia or whatever...I would have just learned to live with the clutter. While it isn't pretty...I felt no different on those nights than I did when I had nice clean no clutter reports.
My number one goal has always been good sleep first...feel decent...and not a perfect AHI or beautiful report.
That's why I don't freak out with a little leak either. It doesn't wake me up...not big enough or prolonged enough to really impact therapy and trying to fix a leak often causes more sleep disruption...so the cure is worse than the disease and I see no need to try it.
Edit: A little bit of clutter clusters discussed in this thread
viewtopic.php?f=1&t=89894&p=826177#p826177
As you can see sometimes the pressure increased and sometimes it didn't and clutter happened despite the machine being able to go to 20 IPAP...so IPAP couldn't prevent it. Only way to have more IPAP baseline in my situation would be to increase PS and I don't like to do that..it isn't as comfortable and more PS might trigger some centrals so increasing EPAP is more comfortable in the long run and gets the job done. So since I am lazy and really like my comfort...I go with what is easy and more comfortable with less potential risk (even though small risk) for creating breathing instability issues.