Central vs. Obstructive

[jmayer180]

I've been on BiPAP for 7 years for my severe mixed sleep apnea. Presumably because of my self-induced (but persistent) morbid obesity I require high pressures (25/20 recommended). My AHI's have never been good - on a good night I break single digits - on average more like in the teens and now for past several months worsening without apparent pattern or reason or other medical problem. My data programs (over the years, Encore, Sleepyhead, now RESMED) have shown persistent central or non-obstructive episodes equal to or higher than obstructive ones. My sleep physician isn't convinced the machines' data can accurately distinguish central vs. obstructive events. He has finally ordered a follow-up repeat sleep lab titration with the instructions to: "start on auto-BIPAP with instructions to attempt change to fixed BIPAP should there be significant obstructive or central breakthrough events which I am expecting." Then BIPAP SV or AVAPS would be considered. And of course the necessity of weight loss is understood. (I have been re-motivated and am in fact making progress there but this is a long, slow process and meanwhile I seek more restful sleep!)

My question is, how could auto vs. fixed BIPAP modalities in any way distinguish central vs. obstructive events?

Currently on RESMED Aircurve 10 VAUTO Bilevel with Mirage Quattro full face mask

[Julie]

bump

[palerider]

My question is, how could auto vs. fixed BIPAP modalities in any way distinguish central vs. obstructive events?

they can't.

[Pugsy]

My question is, how could auto vs. fixed BIPAP modalities in any way distinguish central vs. obstructive events?

Beats the heck out of me. ResMed uses FOT to help it distinguish between central vs obstructive and FOT works the same no matter if in auto or fixed mode.

I think he's going on a fishing expedition. Maybe trying to see if the centrals rear their ugly head in one mode and not another and thus the mode with no centrals could be prescribe instead of progressing to ASV.

[palerider]

bump

too much coffee this morning, dear?

[Julie]

It just sounded like something he needed you to take care of, but that had slipped down the list a bit...

[palerider]

It just sounded like something he needed you to take care of, but that had slipped down the list a bit...

I just go by the little red flags on the side showing which posts I haven't read yet

[Julie]

OMG! Never noticed them before (or realized why they're there), now I know everything!

[palerider]

OMG! Never noticed them before (or realized why they're there), now I know everything!

pugsy clued me in on those some time back... pointed out to me that they're down in the legend on the bottom of the main page... it made keeping up with things so much simpler... though I did walk around for a couple days hiding my face that I'd never noticed 'em before

[jmayer180]

Pugsy,
Thanks for your reply. But what is "FOT?" I can't find that detailed anywhere.
So now, if as I suspect, the CA's are confirmed in both modes, then will I require yet anther study to titrate ASV?

[Pugsy]

FOT is Forced Oscillation Technique which is what the Resmed machines use to figure out if a reduction in airflow is from an airway obstruction or just someone stopping breathing but the airway is open.

Now in a sleep study the tech won't be using FOT (that's something just the machine uses) but would instead be using whatever they use to distinguish a central apnea from an obstructive apnea.
In the lab the tech takes into account whether you are for sure asleep along with respiratory effort or not when they scored apneas.

[palerider]

Pugsy,
Thanks for your reply. But what is "FOT?" I can't find that detailed anywhere.

https://www.youtube.com/watch?v=fDhGpyeYb0c

[Wulfman...]

Pugsy,
Thanks for your reply. But what is "FOT?" I can't find that detailed anywhere.
So now, if as I suspect, the CA's are confirmed in both modes, then will I require yet anther study to titrate ASV?

A little "light" reading for ya.

https://www.google.com/search?q=Forced+ ... 8&oe=utf-8

And, a forum search link.

viewtopic/t113515/search.php?keywords=F ... +Technique


Den

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