Meaning of ResScan Apnea graph

skantner · Post by **skantner** » Sun Aug 10, 2008 5:54 pm

Can someone help me understand what the number in the box means in the graph snippet below - I've circled one of them. This is from Rescan 3.3 and shows events over a 5 minute time interval. I realize the red symbol is for an Apnea event, but I don't understand what the number in the box represents

Thanks!

//Scott

Slinky · Post by **Slinky** » Sun Aug 10, 2008 5:58 pm

My understanding is that it indicates how many seconds that particular apnea event lasted.

Snoredog · Post by **Snoredog** » Sun Aug 10, 2008 5:59 pm

think it is how many seconds the event lasted either that or it was judging a bikini contest

skantner · Post by **skantner** » Sun Aug 10, 2008 6:03 pm

Thanks for the quick response. That happens to be the only graph without a legend. I was a bit puzzled because a couple of them have numbers as high as 20-24 in them, and I thought that might be kind of high for an apnea event. Maybe I'm expecting too much of my machine - i.e. that it should respond before the event gets to be that long.
//Scott

Slinky · Post by **Slinky** » Sun Aug 10, 2008 6:13 pm

Well, how wide of a pressure range do you have your Vantage set at?

IF I remember correctly, it raises the pressure .2 cms at a time in response to an event. But maybe I'm remembering that .2 cms raise in pressure as the Ramp speed, not the apnea response speed.

Regardless it takes any autoPAP longer to respond from 4 cms to 13 cms than from 8 cms to 13 cms.

Ideally an autoPAP would be set w/a minimum pressure 1-2 cms below an in-lab titrated pressure and 1-3 cms above an in-lab titrated pressure.

Or at least from 6-7 cms of pressure to say 15 cms of pressure. Narrow that pressure range and get a better response. Or leave it wide open at 20 cms but move the lower pressure up gradually but start at least at 6-7 cms not 4 cms.

Velbor · Post by **Velbor** » Sun Aug 10, 2008 7:48 pm

Yes, those boxed numbers reflect the length of an apnea episode in seconds.

While ResMed AutoPAP machines can be set, and data is reported, in increments of 0.2cm, that is not the limit of their speed of response. Here is an example from an AutoScan data export:

4/30/2008 3:09:00 AM 7.8
4/30/2008 3:10:00 AM 9
4/30/2008 3:11:00 AM 10
4/30/2008 3:12:00 AM 10.8

Thus, in three minutes, pressure can be seen to increase by 3.0cm, or 1.0cm per minute. This rate of increase appears to be fairly typical, but does not seem to be the maximum possible:

5/14/2008 8:18:00 AM 7.8
5/14/2008 8:19:00 AM 8
5/14/2008 8:20:00 AM 9.6
5/14/2008 8:21:00 AM 9.8

Here we see an increase of 1.6cm in one minute. I don't know what the maximum is. In any case, the ResMed AutoPAP obviously can respond quite robustly!!

Slinky · Post by **Slinky** » Sun Aug 10, 2008 8:04 pm

Thanks for the correction and clarification, Velbor. You're peach!

skantner · Post by **skantner** » Mon Aug 11, 2008 10:00 am

Right now I'm set from 9.0 to 11.0. The sleep study landed at around 10.4. They originally set my range from 9.0 to 12.0. I knew full well that anything much over 11 would blow the mask off my face, so I just set it back when I got it home.

skantner · Post by **skantner** » Mon Aug 11, 2008 10:03 am

Velbor,

Thanks for the insight and examples. The sleep tech was doing a hard-sell on the Resmed machine for the reason you sited - fast response. ( I didn't argue hard in favor of any other machine (e.g. M series) because of my insurance situation.)