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Flow Rate and Flow Limit Graphs
#1
Flow Rate and Flow Limit Graphs
Back again, we've made progress based on your previous help. Thanks

After several months of searching and researching I'm still dumb founded about "Flow Rate" and "Flow limit" graphs.    Mainly I'm referring to sine waves on "Flow Rate" graph; round tops vs flat tops or just zigzagging lines to my eyes.  My eyes are not trained to understand what I'm looking at.  I can see the more or less straight lines means an Apnea of some kind. Although if I go through the graph for the whole night it appears some were missed entirely. 

I'm baffled by the Y-axis on the "Flow limit" graph.  I think the graph is trying to show how much blockage a person had but I'm not sure.  Is 0.25 a little or a lot of blockage?  Does 1.00 mean possible suffocation?

Results for night beginning 30 Oct 2022:

   
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#2
RE: Flow Rate and Flow Limit Graphs
ovmeadows,

Flow Limitation (FL) - Partial closure of the upper airway, which impedes the flow of air into the lungs.

if it gets more blocked it will appear as a hypopnea or an obstructive apnea

http://www.apneaboard.com/wiki has info
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#3
When do flow limits and flat top flow rate become Significant
I think I understand that flow limits greater than 0.50 are bad.  What about flow limits between 0.00 and 0.50?
Then there are these pesky flat tops (albeit small) flow rates. When do they become significant?  
I'm still not as rested in the mornings and can fall asleep during the day in my easy chair at the drop of a hat or about half way through a 40 minute interesting Sunday morning sermon.  I'm taking Zaleplon 10 mg at bed time + BP med and diabetic meds + prostate.  I'm easing toward 76.
Thanks for your previous help.  

   
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#4
RE: When do flow limits and flat top flow rate become Significant
That inspiratory flow is just being crushed. Since this is not typical for your full-night, my guess is that this is a chin-tuck or similar positional airway restriction.  The chart in this case is grossly under-stating the severity of the flow restriction or limitation. Since we don't really know how Resmed calculates the flow limit index, it's hard to know why it does not grade this considerably higher.  Mainly Class 2 and 7 FL based on this. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4688581/ 

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Sleeprider
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#5
RE: Flow Rate and Flow Limit Graphs
I have combined your two threads that deal with the flow rate and flow limit graphs because they are very closely related. Please keep your therapy threads and questions related to therapy together.
Sleeprider
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INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
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#6
RE: Flow Rate and Flow Limit Graphs
Is this another example of "chin-tuck or similar positional airway restriction".  Very lousy night for me developed nausea during the bath room visit and was unable to fall asleep thereafter.  
   
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#7
RE: Flow Rate and Flow Limit Graphs
The event shown here is a RERA with increasing flow limitation leading to arousal. It is probably positional because you don't have a flow limitation this severe that affects you through the night.
Sleeprider
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INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
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#8
RE: Flow Rate and Flow Limit Graphs
Would this also be a RERA:
   
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#9
RE: Flow Rate and Flow Limit Graphs
Textbook by appearance, however, we don't have any real way to infer respiratory effort other than the increasing appearance of flow limitation in the wave form.
Sleeprider
Apnea Board Moderator
www.ApneaBoard.com

____________________________________________
Download OSCAR Software
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Organize your OSCAR Charts
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INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
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#10
RE: Flow Rate and Flow Limit Graphs
This would appear to be as normal as normal gets for me.

Is this really normal or is flow limitation present?

   
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