Interpret Software Results

[MaskedMan]

Ok, so I got an autopap machine with software on my own dime. I've only had it a night so far. I was glancing around in the software at the demo patient files. Are there any good resources out there - websites, books, ec - on interpreting the data/charts/facts/figures the machine has collected or info on what would considered 'normal'? (not that I strive to be normal anyway, just curious )

I understand the software is showing the apneas, hyoapneas, pressure needed to eliminate, etc and charting all of that over time and more. Now I'm looking to learn more about what all those facts and figures means.

thanks for any help!

[Guest]

What machine and what software do you have?

[johnnygoodman]

Howdy,

Here is a tutorial derek wrote on interpreting Encore Pro data:

viewArticle/Encore-Pro-Respironics-CPAP ... Derek.html

Johnny

[MaskedMan]

I have the GoodKnight 420E and SilverLining software. I understand the software itself and the data it presents to a degree. It provides the info on apneas, hypoapneas, apneas with caridiac oscillation, runs of flow limitation, leakage, etc, etc.

I suppose I'm after trying understand what it means to have such-and-such a figure for "runs of flow limitation" - what does this mean to the body, what is range one should expect as healthy, etc.

Another example is what does an apnea with cardiac oscillation means in more detail than "an Apnea/CA is an apnea event where cardiac oscillations were present" - looking for more meat on what that means, what its impact is, why one would have an apnea with CA vs without CA, how that compares to a typical or "normal" person etc.

Medical school is out of the question for me so I was hoping to locate some good resources on these types of things.

[Guest]

I would suggest using the Search function. (As I am wont to do!) For Keyword enter: cardiac oscillations and for Author enter: -SWS for the most succinct answers to your questions. (Pretty much any keyword WITH the Author: -SWS will get you lots of factual information.

Here's an excerpt of a post by -SWS:

Posted: Sun Apr 03, 2005 2:38 pm Post subject:

...on the 420e I do register occasional central apneas. The 420e algorithm deduces with a specificity of 100% and sensitivity of 62% that central apneas occurred if cardiac oscillations have been detected. When cardiac oscillations are detected by the 420e the patient's throat is open and acting as a cardiac oscillation wave guide. The event is then detected and scored as a central apnea. If no cardiac oscillation is detected the 420e assumes a closed throat condition is present and the event was therefore obstructive. _________________
-SWS

and here are excerpts from another of his posts:

Posted: Sat Jan 15, 2005 12:50 am Post subject: Re: Settings

Flow limitations, flow limitation runs, and hypopneas are collectively the source of debate within the sleep industry and medical/scientific community in general. The above need to be defined according to Puritan Bennett's criteria, but first I want to give you the over-simplified definition that we patients use, that just so happens to not match what Puritan Bennet means by the above. The over-simplified definition is comprised of how much airflow is occurring in a patient's breath:

1) snore=slightest airway obstruction and least stifled airway obstruction
2) flow limitation=slightly more stifled or limited patient breathing
3) hypopnea=even more limited airflow than flow limitation
4) apnea=no airflow whatsoever

The medical community also goes into how long the obstruction lasts as part of its criteria regarding which of the above event types an obstruction will be categorized. Absolutely no airflow whatsoever for a very brief moment might be categorized as a hypopnea rather than an apnea. There are subtle differences in how these events are "scored" throughout the international medical community and among manufacturers.

With that said, the above definitions only speak of degrees of airflow and time durations of obstruction. They do not speak of the underlying nature of the airway failure which can often be determined by the very waveform shape of the patient's limited breath. Puritan Bennet and other AutoPAP manufacturers factor in the waveform shape of a patient's limited breath.

So "flow limitation run with amplitude decrease" is a restricted airflow (several breaths actually, hence "F.L. run") that also occurs with hypopneas (hence the "amplitude decrease" part of the name). This would be an example of what are called "concomitant hypopneas". A concomitant hypopnea is a flow limitation and a hypopnea together, which as you can see just doesn't gel with that over-simplified definition above. But, the underlying failing airway mechanism that causes a typical "flow limitation" is not the same airway failure that causes a "hypopnea". They can, indeed, occur simultaneously, and when they do IFL2 will trigger on it because of the unique waveform shape.

A "flow limitation" is a lesser airway restriction that might be caused by nasal or other airway swelling, or perhaps soft palate partial closure. The air is restricted, but not as severely as with hypopnea or apnea. The 420e requires but several of these limited breaths before it will trigger, hence it is referred to as a "run" or "flow limitation run". Puritan Bennett defines a run as follows: "a Run is detected after two respiratory cycles with flow limitation or ten intermediate respiratory cycles and ends after two successive respiratory cycles without flow limitation.

With that attempt at a layman's explanation, let me list Puritan Bennett's event definitions below:

Apneas:

This refers to respiratory Apnea during which there were no representative cardiac oscillations.

Apneas / CA:

This refers to a respiratory Apnea where representative and permanent cardiac oscillations were detected.

Hypopneas:

This refers to a decrease in the amplitude of breathing.

Hypopneas+FL:

This refers to a RUN of Inspiratory flow limitation with simultaneous reduction in the amplitude of breathing.

Acoustical Vibrations:

This refers to detection of acoustical vibrations caused by the patient snoring.

Runs :

A Run is an indicator of a respiratory period with flow limitation, defined as follows: a Run is detected after two respiratory cycles with flow limitation or ten intermediate respiratory cycles and ends after two successive respiratory cycles without flow limitation.

Cycle status:

The analysis of the flow form during the inspiration computed at each respiratory cycle allows their classification in Normal (N), Intermediate (I) or at Flow Limitation (FL). On the trend trace, the higher the trace, the closer the inspiratory cycles are to normal (N). Conversely, a low trace indicates a trend of Flow Limitation (FL). A median trace indicates a trend of intermediate cycles (I).

Happy reading!!!!!!!!!!!!!!!!

[Janelle]

One of the reasons I had a third sleep study was the seemingly (to me) overabundance of CAs on my SilverLining software data. I copied out a 92 hour detailed report and took it to the Dr's NP. She wasn't at all concerned, said that I had showed only 1 on my titration study, none on my first study (hell I only slept one hour at a time without coming completely awake, each time, probably never got into the right kind of sleep). But they ordered the new study. Again, no centrals. But there are still GOBS of them each night, sometimes over 100, and most often they occur at the same length and time as Apneas. This is especially noticeable now that I'm on Xyrem, which can cause problems with breathing, as it completely relaxes the body and all muscles, something else I'm bringing up at my appt. on the 30th.

Even when I first started on the 420, it showed several Centrals a night.

[rested gal]

Do I see Bluefoot Booby footprints all over this? LOL!!

I would suggest using the Search function. (As I am wont to do!) For Keyword enter: cardiac oscillations and for Author enter: -SWS for the most succinct answers to your questions. (Pretty much any keyword WITH the Author: -SWS will get you lots of factual information.

Excellent advice from the accidental Guest otherwise known as neversleeps. (I *think* that's who the Guest was.)

[neversleeps]

Do I see Bluefoot Booby footprints all over this? LOL!!
...from the accidental Guest otherwise known as neversleeps. (I *think* that's who the Guest was.)

Guilty as charged! It just makes me craaaaaazy when I forget to sign in...

[rested gal]

ROTFL at that PICTURE!!! Perfect!! LOL!!!



P.S. Wonder if that's what Respironics uses in their "pretty blue gel" masks.

[ozij]

Too bad you can't have a craaaaazy bluefoot avatar for when you're giving guest appearances.... loved that picture - so eloquent!

Don't you use the "log me in automatically" option?

O.

[neversleeps]

The what??????

Hmmm.... sounds like another search may be in order......

[ozij]

I'm not sure a search will do it.
Take a good look at the login screen (I haven't see it in a loooong time). It has a log me in automatically (or words to that effect) option.

O.