Does the Resmed Elite overcount hypopneas?

My AI is low, like 0.2-0.4 nightly, but my HI ranges from 1-5, last night it was 5. I know it wasn't that high in my study. So I wondered if the Elite was too sensitive with counting hypopneas or something.

2girlsmom wrote:My AI is low, like 0.2-0.4 nightly, but my HI ranges from 1-5, last night it was 5. I know it wasn't that high in my study. So I wondered if the Elite was too sensitive with counting hypopneas or something.

I usually divide my hi score by 2 to get more of an accurate idea as the S8 machines do tend to me a little more sensitive to HI than some other machines.

"They" say that the Resmeds tend to score hypopneas aggressively. I rely more on my AI and if that is satisfactory and I feel rested .... I'm easily satisfied, I guess.

But then, I'm also a "sinner" who has a high leak rate due to the "lip flutters" and am too lazy to tape (PoliGrip Denture Gel worked best for me when I had the ambition to use it) and use a non-Resmed nasal cushion mask on the Standard mask selection.

I'm probably NOT the best one to advise you.

I've laid down, tossed and turned for a half hour, never slept, gotten up and checked my numbers and had an HI over 3 with no AI. So I think it does. But the best sleep I've gotten includes both low AI and low HI, so it seems to be recording something pertinent. YMMV.

alnhwrd wrote:I've laid down, tossed and turned for a half hour, never slept, gotten up and checked my numbers and had an HI over 3 with no AI.

Any scoring while wakeful is meaningless for any flow generator. The scoring that all xPAP machines are able to do is only applicable to autonomous sleep breathing

Cheers,

Bill

billbolton wrote:

alnhwrd wrote:I've laid down, tossed and turned for a half hour, never slept, gotten up and checked my numbers and had an HI over 3 with no AI.

Any scoring while wakeful is meaningless for any flow generator. The scoring that all xPAP machines are able to do is only applicable to autonomous sleep breathing

Cheers,

Bill

...which is why I saw my numbers go down when I decided to engage "Settling" for a duration of 15 minutes. That time gives me a chance to get myself and breathing... well... settled... that and that no events are recorded during "Ramping" or "Settling".

2girlsmom wrote:My AI is low, like 0.2-0.4 nightly, but my HI ranges from 1-5, last night it was 5. I know it wasn't that high in my study. So I wondered if the Elite was too sensitive with counting hypopneas or something.

It's been my understanding that the ResMeds (particularly the Autos) count (or respond to, in the case of the Autos) "Flow Limitations", which are partial Hypopneas. If this is the case, than that would account for the higher AHI numbers that people report......compared to the Respironics machines......which don't actually count (but report in the Encore software) Flow Limitations in the Autos.

Den

From the Resmed Auto Clinical manual:

"A hypopnea is defined as a 50 to 75% drop in ventilation. A hypopnea is scored if the 8-second moving average ventilation drops below 50%, but not below 25%, of the recent average for 10 consecutive seconds. In order to avoid falsely responding to central hypopneas, the AutoSet algorithm does not respond to hypopneas but rather to the associated snore or flow limitation".

Thanks for all the replies. I toss and turn and yawn a ton before going to sleep, then sometimes when I wake in the night I may yawn a time or two. I'll probably follow the AI more and just keep an eye on the HI and my tiredness and see how things go. I was a bit more tired today, but my daughter was up in the night so I didn't get a totally full night's sleep.