.

deltadave wrote:Y'know, with the topic of abdominal-thoracic asynchrony going on in the other thread, this would be a great time to microanalyze belt activity in "." and see how it behaved. Mayhaps we can finally define if these were obstructive- or central-oriented, and whether it is an "SDB" problem or simply an "S" problem (and frankly, given the amount of sleep disruption and severely delayed REM onset, antidepressant effect cannot be ruled out here):

Here's a link to the useful graphs and discussion in that thread for those who are following along:
viewtopic.php?f=1&t=61000&p=573565#p573559

jnk wrote:

LoQ wrote:

jnk wrote:For example, if the patient was using an S8, those would probably be counted as hypopneas.

If the patient was using some other machine, those would probably be counted as flow limitations.

And if the patient was using an S9, they probably wouldn't be counted at all, since the patient will likely get 0.0 AHI that night!

Can you have a hypopnea without flow limitation?

Isn't whether it is a FL or hypopnea really about different aspects of the flow graph? Mightn't you have both?

There are many answers to that question.

From a sleep-tech point of view, they are two completely different things. If it's one, it ain't the other. Even flow limitations get divided up into different kinds, and when "flow limitation" is spoken of in that context, it is actually usually shorthand for "inspiratory flow limitation," as I understand it.

From a home-machine point of view, it really depends. An aggressively scoring machine is likely to call some flow limitations hypopneas. S8, for example. One brand says it treats hypopneas. Another says it treats flow limitations. Part of the reason for that is patent issues, not clinically significant issues.

From a common-sense point of view, I agree that "hypopnea" is just a name given to a great big obvious flow limitation that does something else besides limiting flow. That way of looking at it, though, is using the terms much more loosely than most professionals would use them, unless it is a doc lecturing non-sleep-medicine people. It depends on context.

Scientifically speaking, it is VERY useful to be very specific in how all the events are divided up and named. That's what science does. BUT, from an OSA patient's point of view, I maintain that the names given to all the stuff that messes up sleep don't really matter for most of us unless we are troubleshooting a problem.

That [being] said, the names do very much matter in the cases where NotMuffy is troubleshooting someone's treatment, as he did here, since, as NotMuffy so elegantly pointed out, ignoring flow limitations isn't smart in the treatment of a patient that is still sleepy and tired, as so many of the patients NotMuffy tries to help on this board are. And too many labs seem to figure 'hey, why bother documenting flow limitations if insurance ain't payin' for UARS anyway these days.'

That is only my personal interpretation and point of view on it, though, which doesn't always line up so well with the real experts.

Whoa, whoa, whoa.

I am so confused.

My data so far (admittedly not many days) shows a consistent 0.0 FL index, through nights such as the one when, for example, my indices were as follows:

1.1% of night in PB
CA: 2.7
OA: 4.8
H: 6.5
FL: 0.0
VS: 229.0
RERA: 3.0
AHI: 14.0

Obviously the greater does not appear to include the lesser, at least in the way that EncorePro presents the data. I would have thought that OAs, Hs, RERAs, and VSes all stemmed from some sort of "flow limitation." But with the FL index at 0.0, it doesn't. What am I missing (be gentle with me, I'm researching madly and trying to learn) in the meaning of "flow limitation"?

This thread didn't help me much: viewtopic/t61196/viewtopic.php?f=1&t=55 ... on#p521014

Drowsy Dancer

Ah, scungilli!

Unfortunately, those guys didn't run the sum channel (or if it's a popular RIP brand, even have the module to do that):



This is from a diagnostic portion of the test (the chest lead, as previously shown, blew up during CPAP).

Also the biocals used to synchronize signals at the beginning of the study stink, but these should be synched (the snores must occur on inspiration, they match up with the thermistor, the inspiratory limb of PTAF needs to be on the positive side and the belts match up).

deltadave wrote:those guys didn't run the sum channel...

However, "TS", we can still manually compare belts to look for dyssynchrony:



and in this area, even though there seems to be some significant flow limitation with scored events, synchrony looks to be fairly well maintained.

However, while getting some nice dyssynchrony and/or reduction in sum channel amplitude would lend support to obstruction, the absence of those phenomena does not mean the events are central. I mean, with obvious flow limitation and snoring in this case, we are absolutely certain there's obstruction underfoot.

Drowsy Dancer wrote: . . . I am so confused. . . . What am I missing . . .

Sorry about that. My attempts to generalize, based on my nontechnical takes on things, are often more confusing than enlightening.

My only point (and I think I thought I had one) was that labs/centers measure one way and home machines measure other ways. So the definitions have to change depending on context. That is why, in my opinion, the most important thing to remember as a patient when researching this stuff is to pay attention to the context.

For a lab/center, the point is often a matter of which specific results from specific measurements taken a particular way can be given a specific name as a standardized label. However, in the grand scheme of things for us as patients, we have to remember that the measurement of the event is not the same thing as the event itself, and that breathing that falls outside the labels can still affect us.

In other words, if I stop breathing for 9.999 seconds, is that an "apnea"? The answer for me, as a patient, is that the answer doesn't matter to me. If more pressure makes me feel better, I don't care whether what was prevented was an "apnea," a "hypopnea," a "flow limitation," an "RERA," or whatever. All I care about is feeling better at the best pressure for me.

That being said, when someone's team needs to make a case to insurance that more work needs to be done in troubleshooting the breathing of a suffering patient's sleep, those definitions matter A LOT to someone in that circumstance.

Learning the deeper meanings behind the technicalities of how measurements are made and what those measurements mean is very useful and educational to all of us patients who want to understand what the experts accomplish. Still, I am well aware that I will never BE one of those experts, since they have to have what it takes to interpret and apply the meanings behind all the squigglies when it comes to giving doctors assistance as the doctors diagnose patients and assess treatment success or lack thereof.

At least, that's how I think I understand it.

I wiwsh someone could/would put a subject line back on SAG's threads. She had some good ones but I can't tell one . from another!

Lizistired wrote:I wiwsh someone could/would put a subject line back on SAG's threads. She had some good ones but I can't tell one . from another!

I guess the "SAG" you're talking about is "secret agent girl."

I was confused for a minute. I've always thought of StillAnotherGuest as "SAG" since he's been here a longer time than secret agent girl was. StillAnotherGuest often signs his posts "SAG."

To add to the confusion..
Some quotes from a topic a year ago:
viewtopic.php?p=435605#p435605

rested gal wrote:

ozij wrote:Happy New Year's Day, SAG, Muffy, Notmuffy and deltadave.

Do you guys realize that someone who couldn't know better has given SAG's nick to a great poster called Secret Agent Girl? (Bet she's masquerading on purpose.... she wouldn't even say what her equipment was...). Gave me quite a jolt, the first time I saw that. But I guess that's what happens when you have multiple presonalities -- you loose one, gain one....

Hmmm, maybe the should be rephrased: Happy New Year's Days, gang.

O.

ROTFL!! "gang" works!

Happy New Year to sleepydave, too, although that was wayyy over at another place, another time.

I suppose Secret Agent Girl could be SAGrl for short. Or SecAG. Or SAgG. Or...She Who Wears Dark Glasses And A Funny Hat.