Personally, (since you don't really have a solid and reliable starting point regarding the most recent in-lab titration), I would start off with a wider pressure range on the S9 AutoSet, noting the AHI levels and the 95% pressure the machine reports (the pressure that the machine uses 95% of the time while in auto mode).
For instance, you might set it at 4-20 cmH2O ("wide open" pressure range) for several
days. After that period, check average AHI, then see what the 95% pressure is. As an example, if it's something like 12, and the AHI is somewhat high, readjust, tweak, etc. to slowly close the range to something close to 2 cmH2O below the 95% level and 3-4 above the 95% level, (if 95% was 12, the range could be set to 10-15, for instance) and see what happens to AHI over a few more days. You may find that the upper limit needs to be increased to "punch through" some OSA events. Using software like ResScan
will help you quite a bit in analyzing the data. Both are available for free-- go HERE
for directions on how to get them. Also, if you have questions on the software, post them in the SleepyHead thread
or the ResScan thread
and folks can help you there.
It's all trial and error. You can always tweak both the lower and upper limit and test the end result over a period of time. One thing I will say is that the longer period of time you leave it at one particular setting, the more accurate data you're going to get - in other words, don't make a lot of changes quickly over 2-3 days, and don't make large changes all at once. Give your body time to react to the pressure changes. One night's worth of data does not make a trend. 3-4 nights is good, but a week is even better.
Here is a page created a while ago on finding optimum pressure:
Good luck aehjr - I think you'll like the S9 AutoSet.