Confused interpreting sleep data

[SleepyMcDonald]

Hey,

I am a beginner CPAP user, I have only been using CPAP for a few days and trying my best to optimize the settings. I'm trying to read sleep data using Oscar and i have couple of questions regarding the data.

First it seems that during OA events there is no almost always no flow limitation, as can be seen from the first attachment. Also I found odd that the OA event ends with an exhale, is that normal? I would imagine in a common scenario it would end with big inhale?
   

Also sometimes when there is flow limitation, the breathing pattern looks quite erratic to me. Seems like there is sometimes an extra inhale but flow rate is negative, at least that's how i would describe it. See second attachment
   

[PeaceLoveAndPizza]

Start off with reading the wiki, particularly the “optimising therapy” link in my sig…

In the first example you can see the flow limitations at the peak of the inhale (above the middle line). See how they are flattened? That’s the flow limitations occluding the airway. You took a slow, long inhale, held your breath during the flow limitation, then exhaled stale air. Very typical pattern.

The second is not as erratic as you may think. Lots of inspiratory flow limitations and some snorting. Quite normal in fact. 

Post some OSCAR charts when you are ready for someone to review…

[SleepyMcDonald]

Thanks for your explanation, reading the wiki also has been helpful.

I can definitely see how in the flow rate chart the waves are "flattened". But to me it is confusing how in the flow limit chart the levels stay at 0. Intuitively I would imagine the value should be closer to 1 since there is almost a total obstruction during the apnea.

[PeaceLoveAndPizza]

My apologies. When I said "above the middle line" I meant the flow rate graph, not the flow limit graph.

In the flow rate graph the inhales are above the middle/zero line, exhales below the line. Flow limit chart is measured from zero to 100, with zero being no occlusion and 100 being completely occluded.


Obstructions are rarely 100%, most are from a slight collapse of the airway. Plenty of good info in the wiki about apnoeas. 

https://www.apneaboard.com/sleep-apnea-i...leep-apnea

https://www.apneaboard.com/wiki/index.ph...leep_apnea

[Deborah K.]

Your flow limits are so low, you can safely ignore them.  If you want advice on optimizing your treatment, you need to post a full OSCAR page, following the instructions given on the OSCAR page.  With a chart to look at, we can probably give you good advice on what settings to change.