Definitely watch the video palerider linked to, it's got a great explanation of Flow Limitation with diagrams just past the minute mark.
This is how I think of events, especially as they apply to me.
- Obstructive Apnea (OAs) - 80-100% closure of passage, lasting 10 seconds or longer.
- Hypopnea (Hs) - 50-80% closure of passage, lasting 10 seconds or longer.
- Flow Limitation - Partially closed passage or more fully closed but not lasting 10 seconds. These are one of the key indicators ResMed machines act on to prevent Hs and OAs.
My percentages might be off.
Here's a typical graph when my apnea was not being treated very well. Note the Flow Limit, while not as ugly as yours was present for a good part of the night.
Now look at the Pressure graph, my minimum was too low, the pressure was up and down and often bumped up against the cap to accommodate my
aerophagia . Often the pressure increase simply didn't happen fast enough to address the apnea, thus my high AHI.
Oscar_AHI_260.png
Now let's take a look at a fairly recent chart.
My minimum pressure has been increased from 7 to 11.
Look at Flow Limitation very little, and then a cluster those clusters are likely REM sleep as my Apnea is worse during REM. But more importantly, during one of the clusters of Flow Limitations, look at the pressure graph, there is a correlating increase in pressure. Because my minimum pressure of 11 if keeping the passage open the pressure increase doesn't have to increase by much to keep the airway open.
Only 1 Hypopnea and 1 OA.
OSCAR_AHI_033.png
What's also worth noting, for me is, even though I increased my minimum pressure form from 7 to 11, the net result was less pressure as my median barely raises over 11 and I can't remember the last time my pressure raised above 12.
By increasing the minimum, it's easier to keep the airways open than to open them after they have closed.
Once again, YMMV. This is what worked well for me, and I included the diagrams to help illustrate. Your numbers and treatment are very likely to vary. We also now your initial charts are very different than mine because your pressure jumps to the maximum and spends the night there. This suggests too little pressure and explains your high Flow Limits. And that brings us back to your
aerophagia.
Thus the common thread, try to find a gentle compromise between pressure and your high Flow Limit and
Aerophagia.
