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dataq1 wrote: ↑

Sat Jan 15, 2022 8:30 am

My question is about the labeling of the pattern, CSR versus PB. If the wax/wane cycle must terminate in a Central ?

Your question is confusing. Wax/wane cycles don't need to terminate at all.

Morbius wrote: ↑

Sat Jan 15, 2022 8:55 am

dataq1 wrote: ↑

Sat Jan 15, 2022 8:30 am

My question is about the labeling of the pattern, CSR versus PB. If the wax/wane cycle must terminate in a Central ?

Your question is confusing. Wax/wane cycles don't need to terminate at all.

Probably poorly stated on my part, an illustration might be easier to clarify: In the wax/wane cycle beginning at 03:15:27 waning seems to begin 03:15:36 and subsequently drifts off to a apnea that is labeled as a CA. (that I referred to as "terminating" that cycle)

In order to be labled as a true CSR, must the apnea be a central?

dataq1 wrote: ↑

Sat Jan 15, 2022 9:50 am

In the wax/wane cycle beginning at 03:15:27 waning seems to begin 03:15:36 and subsequently drifts off to a apnea that is labeled as a CA. (that I referred to as "terminating" that cycle)

In order to be labled as a true CSR, must the apnea be a central?

Are you asking what ResMed thinks or what I think (although I rely a lot upon AASM for help)?

You could also have central hypopneas as the respiratory event. Whichever, once you start having obstructive stuff you fall into the area of CSBD.

ResMed's "intelligent algorithm" checks cycle lengths, and if they're using the 40 second rule I could see how that area could be flagged as CSR. But again, I'd be looking more at 60+ second cycles.

That said, Cheyne Stokes is a sign of something else. If you think it's of cardiac origin, you need an echo. If you think it's of neurological origin, it's probably not, as the only neurological CSR I've ever seen was on comatose patients.

Morbius wrote: ↑

Sat Jan 15, 2022 8:55 am

Thank you, your comments very helpful.
Yes, Resmed can do whatever they please, however when they label (or mislabel) it causes patients and doctors to react.

As a patient my immediate fear was some early indications of heart failure or mini stroke. My cardiologist was likewise prepared to order new echocardiograms and a bunch of other diagnostic tests based on Resmed's classification. And of course the whole prospect is frightening.

I'm not completely at ease, but far less alarmed now that someone lead me to the AASM scoring criteria.

Thanks for your input.

dataq1 wrote: ↑

Sat Jan 15, 2022 10:13 am

...based on Resmed's classification.

OK but ResMed's classification is correct. What needs to happen is you have to ask your guy if ~40 second cycles are significant in your case, not that it's colored green. This requires the mandatory "clinical correlation".

ResMed just stuck that in there to make sure anything that should be looked at, gets looked at.

FYI primary CSA cycles are about 40 seconds.

Just sayin'.

Hi Morbius,

Nice to see you again. Your posts are always so helpful!

Resurrecting this thread to illustrate and clarify what has been said before. The attachments are copied from the Airsense 10 clinical manual.
Note also: "The waxing periods (hyperpneas, typically 40 seconds in length)... while the waning periods (hypopneas or apneas, typically 20 seconds in length)... "

I think this is somewhat different from what Morbius was saying. I don't have the AASM guidelines to hand, so I'd be interested if Morbius could confirm if they are the same or different.

Nice schematic to differentiate between Resmed’s classifications. Setting aside the the time intervals, it seems that the CSR is distinguished by a clear waxing period, while Periodic breathing cycle begins with (almost) no waxing period.

Is anyone assuming that Resmed's sensing/interpretation is the same
as that used in a medical setting?
We know it's good; but is it clinically reliable; or just a close approximation, if that?
There are many increments between a single grain of salt and a liter of natural saline.

chunkyfrog wrote: ↑

Wed Jan 19, 2022 12:25 pm

Is anyone assuming that Resmed's sensing/interpretation is the same
as that used in a medical setting?
We know it's good; but is it clinically reliable; or just a close approximation, if that?
There are many increments between a single grain of salt and a liter of natural saline.

I don't think a fairly simple breathing machine - even one as good as the Autoset - will match the results of a full PSG with a skilled technician. From what I've seen over the years I think Resmed tend to be a bit on the safe side, recording some false positives, which is as it should be. If you're getting a lot of green In your charts, especially if combined with centrals, then it would be prudent to have it checked out. It may be nothing, but if that was my chart I'd want to be sure.

Correct!

Respirator99 wrote: ↑

Tue Jan 18, 2022 10:47 pm

I think this is somewhat different from what Morbius was saying. I don't have the AASM guidelines to hand, so I'd be interested if Morbius could confirm if they are the same or different.

Sure, but if

Morbius wrote: ↑

Sat Jan 15, 2022 10:12 am

I'd be looking more at 60+ second cycles.

and ResMed says

"The waxing periods (hyperpneas, typically 40 seconds in length)... while the waning periods (hypopneas or apneas, typically 20 seconds in length)... "

then we are both saying the same thing. Cycles are typically 60 seconds (or 59.0 +/- 4.9 seconds if you want to use Hall et al).

Unless what you're asking that's different is...

...different.

Dataq1, please show your doctor a typical wax/wane/CA stretch from your flow rate. Also try to quantify, over (say) a two-week period, how many minutes per night exhibit this pattern. Your doctor may find that information helpful.

You should really be involving your medical people in this. I think you've gotten a lot of clear answers to your questions here, but the fine judgment calls concerning your particular case (e.g., length of cycle) should be made by a doctor, I think.

It can be scary going through various tests to see whether there's something seriously wrong -- been there, done that -- but at a certain point you need to remind yourself that it's good to do. Either you'll get a clean bill of health and a lot of peace of mind, or you'll get a jump start on treatment for what ails you.

Morbius wrote: ↑

Sat Jan 15, 2022 8:24 am

dataq1 wrote: ↑

Sat Jan 15, 2022 7:50 am

When you say cycle time I assume that you mean the time interval between peak of wax to the next peak of wax. Is that what you mean?

Yes.

However, point of order:

If the respiratory events were all apneas, then cycle time would be from the beginning of one apnea until the onset of the next.

Since there are intervening hypopneas in the original sample submitted, the cycle time is from one zenith in airflow during the respiratory phase to the next.