What's with this newbie data?

[HalfAsleep]

Would someone mind clarifying what "flow limit" is? I don't know a) what the chart shows or b) how it might be experienced while sleeping.

[Sleeprider]

Rather than directly answer your question, lets look at it. Create a closeup of the flow rate during a period of high flow limitation. It should be no longer than 2-minutes in the screen shot. Really focus on the flow rate line by making it taller. Also, right click in the left margin of the flow rate, and Format the Y-Axis to add a dashed line at zero. I shall return and check your homework .

[HalfAsleep]

Rather than directly answer your question, lets look at it.  Create a closeup of the flow rate during a period of high flow limitation.  It should be no longer than 2-minutes in the screen shot. Really focus on the flow rate line by making it taller.  Also, right click in the left margin of the flow rate, and Format the Y-Axis to add a dashed line at zero.   I shall return and check your homework .

Okay, Teach. This could take a while. 

[HalfAsleep]

Hope this one that trails off into a row of polar bears baying at the moon does the trick.... (Good thing this is not an ekg, by the looks of it.)

[Sleeprider]

Okay, this graph gets an A.  Nicely done and exactly what I was looking for.  Now let's figure out what is going on.

First, girl you have some serious flow limits and pretty good snoring going on.  We have what the machine flagged as a CA followed by some really irregular breathing that may be arousal or recovery breathing. We want to focus on what comes after that green line, but we can come back to the apnea later.  Everything above the red dashed line is inhalation, and everything below that line is exhale.  So a downward sloping line is not an exhale when it is above the zero-line, but is diminishing inhalation flow rate, got it?  Right after the green line is an inhale, but it never really gets off the line. It is so flow limited the flow rate never even reaches 10 mL/sec and the top edge is all jagged.  That is such an obstructed inhale it causes a snore.  The three following breaths get some volume (flow), but are unsteady, with flat-tops that eventually tail off to the exhale line.  This shows a lot of inspiration effort and not much success in getting air. The exhales are short and could reflect partial exhale through the mouth which or you just didn't have much in your lungs to exhale. 

Finally at 02:34:55 you have a nice inhale with a flow-limit and snore at the peak, followed by proper exhale.  This is followed by four normal breaths, followed by a breath with a jagged flat top which is another flow limit an possible snore, and three more mildly flow-limited breaths.  

Does this explain flow limitation?  Stay tuned, this has important implications for your treatment. The solution to those flow limits would normally be pressure support, but what happens when we use EPR with higher pressure, or the bilevel corollary, pressure support?

[Sleeprider]

Going back to the CA, it looks really obstructive to me, because it is simply a failed inhale where flow falls to zero long enough to score the apnea. Most apnea we see on the forum follows an exhale. The person exhales and flows goes to zero until breathing resumes at the next inhale. You are such a wierdo that you do this? Maybe RERA which is a series of increasing flow limitations leading to arousal? I think this explains why you might still be feeling quite tired.

If this is typical of what is being flagged as CA, then we are currently using the wrong approach because those are severe flow limits that qualify as apnea, and they are OBSTRUCTIVE, not central. The airway is open, because you're still trying to inhale, but this is a bizzare OA. I have to find a good image to show the difference, but first...You have FL and RERA.

[Sleeprider]

What a normal OA looks like is a pause in respiration, normally following exhale. At least I think I'm fairly normal, but others may disagree. Note the exhale and no air movement occurs, and breathing resumes with recovery breaths, often flow limited (flat-top).

[HalfAsleep]

You are being wonderfully informative,just the level of explanation I need. I have to digest and mull over for a bit.

PS
1. There were no snores..... Could there be other vocalizations SleepyHead doesn't capture as a snore?
2. The night on my 2 minute snapshot above was the night you had me at 8-8 pressure and 0 EPR, so pressure range is not one of the variables that's making this picture.

[HalfAsleep]

As I understand what you're saying...

This chart is a little further along on the same night.



The two CA's (the first with an itty bitty snore) look like typical OA's, hard effort to breathe after an exhale, followed by a successful inhale and some busy-looking follow-up breathing. However,, there's no flow limitation, so they must be CA's?



Then on this one I'm working all kinds of hard and not getting much of anywhere. There's only 5 struggles long enough to qualify as apneas, but there's additional struggle going on between the first three and the last two.



No significant mask leak for either image.

[HalfAsleep]

On this one, I am getting air, but not a very robust inhale, since the flow is limited. And besides, just trying to get that inhale is quite a lot of work, as evidenced by the jaggies on the way up.



Could this pattern be positional? AKA I have skinny throat syndrome? Giraffe neck syndrome, so air up and down has a long way to go? I have positioned my neck such that I've limited the flow, e.g. by drooping the head or tilting it back?

Hardly any snores registered in any night. Sometimes one in a night.


I think my sleep study grossly underestimated my struggle.

Incidentally, when the mask is leaking (I also checked nights with 5-15 pressure with 2 EPR), the breathing issues look pretty much the same.

I got your basic concepts in these examples, SleepRider, correct?