"Odd" Waveform?

[Rubicon]

On TOF (not the TOOF) a poster submitted this waveform:



and asked

Does anybody know what may have caused this?

[lazarus]

Waaay above my pay grade. Sorry.

But my first thought was: 'With stuff like SleepRes V-Com going on out there getting inserted into the circuit, I wonder whether flow tracings can still be trusted to always represent a patient's natural breathing.'

[Rubicon]

Yeah well that thing looks bogus to me, I'll bet you could duplicate whatever comfort they claim by lowering xPAP by 0.6 cmH2O, going to Slimline 15 mm tubing, changing Rise Time if whatever mode you're using has it and/or adding EPR @1.0 cmH2O.

Need some before/after from somebody using it.

[lazarus]

Most certainly bogus.

I just wonder whether it could also affect the accuracy of a waveform on a treatment machine or could cause a patient to breathe differently.

I don't know.

[Rubicon]

I'm not seeing how they can get away with selling it. It's simply a pressure reducer (aka "prescription alterer"):



The device is registered as a "connector".

https://www.accessdata.fda.gov/scripts/ ... 7&lpcd=BZA

Trying to pull a fast one. As soon as somebody realizes that it alters therapy that's going to be the end of that.

[Miss Emerita]

I think I've seen this identified as expiratory mouth-leaking. I guess that happens when someone closes their mouth when they inhale but lets it open when they exhale. Would that make sense?

[lazarus]

that's going to be the end of that.

Reckon Jason will have to give back his cut?:

https://youtu.be/18b9hMFKpf4

(Just a joke. In all fairness, HE gets no cut and only recommends it for straight CPAP with no EPR, not for bilevel or APAP.)

(Edit was adding disclaimer in parens.)

[lazarus]

Would that make sense?

Looks/sounds right to me.

But then I don't understand squigglies.

If you are right, I wonder what you win?

Uncle Rubicon is said to be very generous with thread prizes.

[Rubicon]

I think I've seen this identified as expiratory mouth-leaking. I guess that happens when someone closes their mouth when they inhale but lets it open when they exhale. Would that make sense?

Interestingly, that's what a response there was:

I can tell you for certain that it's "exhale puffing", whereby you inhale through your nose and exhale through your mouth. It's usually accompanied by some decline in tidal volume. The reason I know is that I produced that waveform while awake this morning by breathing that way. It's just the last 25 seconds, but enough to see the characteristic shape, where the exhale is completely missing. If asleep it would be more regular like yours.

Except...

[Miss Emerita]

Lazarus, could the squiggles be cardioballistic artifacts? And Rubicon, what is my prize?

[lazarus]

Lazarus, could the squiggles be cardioballistic artifacts?

Dr. K just DMed me to ask if that question could please be removed.

I told him no.

[chunkyfrog]

Looks to me like the audio waveform of Uncle Jedediah croaking.
(Somebody had to go there.)

[Rubicon]

And Rubicon, what is my prize?

Sorry, no prize.

While the second graph is mouth breathing (that poster generated the waveform while awake to try to duplicate the original one), they are NOT the same.

[Rubicon]

The device is registered as a "connector".

https://www.accessdata.fda.gov/scripts/ ... 7&lpcd=BZA

Trying to pull a fast one. As soon as somebody realizes that it alters therapy that's going to be the end of that.

Also, seems to me "registered" and "approved" are 2 totally different things.

[Rubicon]

...going to Slimline 15 mm tubing...

Also need a bacterial filter: