New machone questions

[Brian2]

Hi everyone, I changed from an S8 apap to the S9 apap a couple of weeks ago. i am still using the same mask. The results on the new machine don't seem to be as good as on the S8. My average pressure on the S8 was 10.4 and AI/AHI average was 2.5. based on these figures i set the pressure on the S9 to 9 and 18.

I have averaged a pressure of 13.8 for the last 14 days and an AHI 0f 1.7. but I think I read somewhere that Resmed have changed the way they record this data and so the lower reading does'nt mean much. Is the rule of thumb still that less than 5 is "normal"?

I do seem to wake up a lot more and don't feel as refreshed in the morning. Any suggestions on where to start would be appreciated.

many thanks

[STL Mark]

I was curious as I read what your settings were on the S8.

[Bobby269]

I use the S9 Autoset but only use it on the Cpap mode. Some one gave me the exact machine and it took a week for me to experience the same results in
regards to AHI'S. Both machines were set to the exact same settings. For me the lower the AHI the better I feel.

[robysue]

I have averaged a pressure of 13.8 for the last 14 days and an AHI 0f 1.7. but I think I read somewhere that Resmed have changed the way they record this data and so the lower reading does'nt mean much. Is the rule of thumb still that less than 5 is "normal"?

The algorithm for scoring hypopneas was changed between the S8 and the S9. My recollection is that folks here at cpaptalk have routinely assumed that the S8 tends to aggressively score Hs---i.e. there is an assumption among S8 users that the machine tends to overscore Hs. The S9 is much less aggressive in scoring Hs.

And, of course, there's the new FOT algorithm for determining whether the upper airway is open or closed when the machine detects an apnea in progress.

So the relevant parts of your data are the HI on the S8 and the HI on the S9. Seeing a drop there would be expected.

I do seem to wake up a lot more and don't feel as refreshed in the morning. Any suggestions on where to start would be appreciated.

What pressure range were you using on the S8? Were you running in a tighter range on the S8 than you are on the S9? It's possible that with an max pressure of 18, the S9 is "overreacting" to events such as snoring or flow limitations by continuing to increase the pressure to a range that is not particularly comfortable for you, and quite possibly not needed by you since your AHI is low enough without the additional pressure and you were feeling fine at lower pressures on the S8.

I'd set the pressure range to be the same as it was on the S8.

Also check to make sure that the EPR setting is the same. A lot of RTs set EPR = 3 as a default on the assumption that the larger decrease in pressure on exhale will automatically be more comfortable. But for some folks, that 3cm drop in pressure on every exhale is not as comfortable as a smaller drop or even no drop at all.

And some people are sensitive enough to be bothered by the FOT algorithm.

[Brian2]

Hi Robysue, Thanks for the feedback. I set the S9 the same as the S8, which is what i thought best to do. I just got the S8 out of storage ans cheched the data;
Pressure for the year was 11.0 (10.4 for the last month I ised it)
AI was 0
HI was 2.5
What i couldn't find was any data for EPR, in fact i hadn't even heard of EPR until i bought the S9.
I have just set the EPR to 2 and full time. It was set a ramp only and 1

maybe I just need to give it time.
many thanks to Robysue and everyone else on the forum. I don't use it very often by the information and knowledge here is priceless.