Respironics vs. Resmed Hypopnea Flagging

[bossfan]

I used an Aircurve 10 for the first time last night. Before I used a System One and then for about a week I was using a Dreamstation. I felt like I had a better night than I ever had with a Respironics product. The reports on this forum are right, it is a better machine than Respironics and I encourage everyone that is getting a new machine to insist on Resmed when dealing with your doctor and DME.

I had a significant drop in AHI. I always suspected that my AHI was higher than I wanted to see because Respironics flagged an excessive amount of hypopnea events. Respironics flagged between 20-40 or so hypopneas a night. Resmed flagged 8 hypopneas and my AHI dropped from between 5.0-7.0 to 1.5 last night. Does Resmed respond to hypopneas better? Or is the requirements different on the two machines to determine a hypopnea event? And since this is my first time ever using a Resmed if someone sees something on the chart that points to any adjustment I need to make I welcome suggestions.

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[Pugsy]

Does Resmed respond to hypopneas better? Or is the requirements different on the two machines to determine a hypopnea event?

The whole idea is prevention in the first place.
While there is a small difference in the definition criteria for a hyponea between the two brands it really isn't enough of a difference to explain away the often seen wide ranges of differences in the numbers of hyponeas (or really anything sometimes).

My personal opinion....I think that ResMed's auto algorithm that seems to be (at times) very aggressive/responsive towards flow limitations is why the machine seems to do a better job when settings are the same. Flow limitations are early warning signs the airway is trying to collapse....Resmed's auto algorithm tries to kill them...and when it does the by product is those FLs don't get as much of a chance to grow up to hyponeas or OAs. It's pre-emptively killing the FLs before they grow up to be full blown OAs or hyponeas.

Remember that none of these respond during any sort of event (OA or hyponea)...so when it responds it's always after the fact...except for the flow limitation thing which is more ongoing and dynamic.

All this assuming the FLs sensed by the machine are in the airway and not the nasal cavity...which gives us a reason for a whole different discussion.

[bossfan]

Does Resmed respond to hypopneas better? Or is the requirements different on the two machines to determine a hypopnea event?

The whole idea is prevention in the first place.
While there is a small difference in the definition criteria for a hyponea between the two brands it really isn't enough of a difference to explain away the often seen wide ranges of differences in the numbers of hyponeas (or really anything sometimes).

My personal opinion....I think that ResMed's auto algorithm that seems to be (at times) very aggressive/responsive towards flow limitations is why the machine seems to do a better job when settings are the same. Flow limitations are early warning signs the airway is trying to collapse....Resmed's auto algorithm tries to kill them...and when it does the by product is those FLs don't get as much of a chance to grow up to hyponeas or OAs. It's pre-emptively killing the FLs before they grow up to be full blown OAs or hyponeas.

Remember that none of these respond during any sort of event (OA or hyponea)...so when it responds it's always after the fact...except for the flow limitation thing which is more ongoing and dynamic.

All this assuming the FLs sensed by the machine are in the airway and not the nasal cavity...which gives us a reason for a whole different discussion.

Thank you great explanation as always from you.

I forgot one more question I had. There were 2 Unclassified Apnea events flagged. What is that, I never saw this event with Respironics.

[Dog Slobber]

I forgot one more question I had. There were 2 Unclassified Apnea events flagged. What is that, I never saw this event with Respironics.

An Unclassified Apnea is an apnea where the machine can't tell if the event is obstructive or central.

One contributing factor to not determining is large leaks, but when you had your two UAs there wasn't a large leak. Sometimes the machine just can't tell.

Know the difference is important because obstructive apneas are treated with pressure, Centrals aren't.

[Pugsy]

Respironics machines don't have an event category for unclassified events. That's why you never saw it on their reports.
Just never reported.

As DS explained...for some reason your machine couldn't figure out what to name the air flow reduction it sensed.
Often seen within large leak periods but sometimes (as in your situation) when leak isn't excessive.
We shrug our shoulders and move on.

Often people can have what we call mixed apnea events of some sort...they start off as maybe one category and morph into a different category. This is so common that on sleep lab studies there is a category for mixed apenas.
This makes it really hard for a machine to know what basket to lump that event in....so unclassified is what you get.
Mixed apneas are normal and not big deal unless we have a large number of them.

[bossfan]

I'll ask this question on this thread since I have a chart posted. Why isn't there a clear airway flag event category? Is that something that the Aircurve 10 ASV does not flag?

[Julie]

Look at the graph - do you see an 'Unclassified" green category on the left? That's where the CA's would go - they are otherwise not treated by the machine as obstructives and hypops are, just noted.

[Pugsy]

I'll ask this question on this thread since I have a chart posted. Why isn't there a clear airway flag event category? Is that something that the Aircurve 10 ASV does not flag?

ResMed ASV (and some of their other very high end specialty machines) don't separate Obstructive apneas from central apneas...so there is no separate category.
Obstructive apneas and central apneas get lumped into the unclassified basket.

Clear airway term is a Respironics term for centrals...OSCAR just uses this term because it's based off SleepyHead and the very first SH version was for Respironics System One machines.
I mention this just in case someone doesn't know clear airway equals central.

Now why does ResMed opt to not use separate category for centrals with those high end machines like the ASV??? We never could find specific documentation that explains it but the FOT thing used for distinguishing centrals from obstructives isn't used on those machines so no way to know the difference and with the way the ASV works (assuming its hands aren't tied with restrictive settings) the machine deals with centrals immediately so they shouldn't be a problem and anything left would be obstructive anyway.