Difference in AHI between two machines

[alphabettie]

I have the vantage but bought the PB 420e for travel since I am gone 4 nights a week. Both are capable of giving me data.

I did a little trial to see if the numbers lined up but.....anyway, I did three days on each one and here is the difference:

Vantage three-day AHI 9.3--this includes mostly hypops with less than 2 apnea index. pressure is 10-17.5
Vantage 95th percentile 15.4


PB 420e: Apnea index of .8
Apnea with CA index .1
Hypops index 2.4
Flow limited (what is that?) .5
Acoustical Vibrations (does that mean I still snore?) 6.6
Runs 33.7 (not sure what that is)
Pressure 10 to 17.5
90th percentile: 17
My last 96 hour record looks like mountains.

Do I need different pressure on the two or just take it as I feel okay. Since day 1 in December, I have worried about the high number of hypops on the vantage but the Dr. said to ignore that data.
If I had been on the PB for all this time, I would not have worried.
Since I think I still need to find the best pressure range, I was just wondering if anyone had any opinions. It will be a while before I can get to the doctor as my schedule and his do not jive.

[NightHawkeye]

Thanks for posting. I'm dealing with a high hypopnea index myself, so it's good to see that's there's so much variation between machines.

From what I've read, physicians can't even agree among themselves as to what constitutes a hypopnea. Apparently, there is no standard definition, quite a lot of variation, and xPAP machines can't measure oxygen desats anyway, which are a required part of hypopneas when scored in polysomnography. No doubt, that's why your physician wasn't concerned.

I've used just two machines, the Remstar-auto and BiPAP-auto, with similar results, but that's probably to be expected given that they're made by the same manufacturer. I finally seem to have gotten my AI consistently below 1.0, so I'm beginning to think about looking into HI which usually runs between 2.5 and 5.

Recently, as my AI has been low, I've had no significant oxygen desats, so the high HI for me doesn't seem to mean much. I'm at the point of changing pressure though to see what effect that has on AI and HI, but I doubt that it will have any real effect on therapy effectiveness.

Just my experience, for what it's worth.

Regards,
Bill

[roztom]

The software between the manufacturers probably detects and scores events diferently.

That shows us that at least for the software that the results may be some what subjective.

DO you have your sonnogram results?

Which of the machine results seem to jive with your sleep study?

Best,

Tom