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Dr Barry Krakow's theory of apnea vs hypopnea vs flow limitation? - Printable Version

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Dr Barry Krakow's theory of apnea vs hypopnea vs flow limitation? - JoeyWallaby - 12-21-2019

What do you think of Dr Barry Krakow's theory of apnea vs hypopnea vs flow limitation?

From 29:00 to 29:54
http://www.youtube.com/watch?v=Syv7YcHbTCI&t=29m0s

Essentially, he says that obstructive sleep apnea goes in a spectrum from completely blocked airway (OA), to hypopnea, to FL, to open airway (breathing without FL).


RE: Dr Barry Krakow's theory of apnea vs hypopnea vs flow limitation? - Sleeprider - 12-21-2019

It's all in the spectrum of obstruction and restricted breathing flow rate. Dr Krakow is pretty much inline with my thinking on the matter. I have spoken many times of a crimped or closed airway being analogous to a crimped hose. What he is saying here is that CPAP is still a traumatic therapy compared to bilevel therapy. It is the reason Resmed CPAP succeeds with 3-cm of pressure support and the Vauto is even better. So few doctors are even aware of flow limitation and the comfort issues of PAP therapy, and Krakow nails it. The issues he goes on to discuss are worth listening to as well. This is a very progressive doctor that does not "bean count" the AHI but looks at therapy as a healing mechanism and is not tied to the insurance "cost minimization" protocol.


RE: Dr Barry Krakow's theory of apnea vs hypopnea vs flow limitation? - Gideon - 12-21-2019

IMHO this topic/thread belongs in the main forum as it applies to everybody. 

Think about it.  It is perfectly logical.  The most illogical portion of the argument is that there could be a complete blockage in the first place, a total blockage, an obstructive apnea.  We know that is real, almost all of us here experience it or experienced it in the past.   

What is the normal state?  Normal is what we all strive for, a completely open, non-obstructed airway.  
What's next?  Something, fatty tissue, muscular tissue, Muscles relaxing, drugs causing muscles to relax, inflammation and swelling in the upper airway, nasal congestion.  These occur at a range of 'effectiveness' in constricting of the airway from effectively nothing to total blockage.

That is total common sense.


RE: Dr Barry Krakow's theory of apnea vs hypopnea vs flow limitation? - Crimson Nape - 12-21-2019

As per bonjour's recommendation, this thread is now in the Main Forum.


RE: Dr Barry Krakow's theory of apnea vs hypopnea vs flow limitation? - ApneaQuestions - 12-21-2019

That's the way I have been intuitively thinking about it.

A spectrum of obstructive phenomena

I would add in an additional classification which is RERA sans-arousal.  I've been calling this RERA-like or Flow-Limited or pseudo-RERA

Then I would also add in a "Duration" attribute.  I have been calling breath cessation of <10 seconds a pseudo-apnea

Also I think of a pseudo-hypopnea which does not quite meet the 10 second or 50% threshold

It's all a continuous spectrum in my head


RE: Dr Barry Krakow's theory of apnea vs hypopnea vs flow limitation? - JoeyWallaby - 12-22-2019

RERAs have been proven to be harmful in studies but as mentioned in my other thread, they're not even required to be marked in sleep studies.

There haven't been many studies on flow limitation without arousal apart from Dr Barry Krakow's, which have shown positive effects of treating it. I don't see why there would be any harm in removing all or the vast majority of flow limitation, which makes the only barrier the cost of BiLevel (if EPR isn't enough) and knowledge/time/etc optimizing settings.

Some people seem to do fine with some degree of flow limitation, while others don't. Maybe it's just a coincidence, but with the same mask, same humidifier settings and everything... once I switched to BiLevel from CPAP and treated my FL, I stopped taking off the mask during the night almost completely  Dont-know


RE: Dr Barry Krakow's theory of apnea vs hypopnea vs flow limitation? - ApneaQuestions - 12-22-2019

somehow did a double post. ignore.


RE: Dr Barry Krakow's theory of apnea vs hypopnea vs flow limitation? - ApneaQuestions - 12-22-2019

Yes I agree. I have precisely those suspicions too (as you know from comments on my thread).
Specifically this post: http://www.apneaboard.com/forums/Thread-Interpretation-Questions-My-OSCAR-Data?pid=324887#pid324887

I'm working on the same hypothesis/assumption that removal of limitations (without an explicit arousal or recovery) may have significant benefits for me.
I see two drawbacks to the current ways of scoring sleep in studies. I summarize them succinctly as..

1) We can't manage things that we don't measure
2) We ONLY manage things that we DO measure.

I think we are on the same page here and that's why you started your other thread about the implications of having optional scoring.
http://www.apneaboard.com/forums/Thread-Implications-of-scoring-RERAs-and-Central-Hypopneas-being-OPTIONAL