WatchPat Study questions

[Centennial2]

Recently got a sleep study:
   

How many Obstructive events were observed?
How many Hypopna events events were there?
How many Clear airway events were observed?

What exactly is pAHI4% and PAHIc4% ?

About oxygen desaturations, am I reading this correctly, there was one event where the O2 dropped between 10 and 20 percentage points from some value? And the saturation was less than 85% for six seconds.?

Can anyone help on any of these questions? 

(By the way I posted this question on "that other board" and no one was able to answer my questions, no one even tried)

[Jeff8356]

Centennial2,

It would help if you posted all the pages of the report. Redact any personal info before posting.

[Centennial2]

There were only two pages of WatchPat data, the other pages were medical history and doctor's recommendation (so not pertinent to my question)
   
   

How many Obstructive events were observed?
How many Hypopna events events were there?
How many Clear airway events were observed?

What exactly is pAHI4% and PAHIc4% ?

About oxygen desaturations, am I reading this correctly, there was one event where the O2 dropped between 10 and 20 percentage points from some value? And the saturation was less than 85% for six seconds.?

[Brazen]

As I read it...

Obstructives and hypopnea events are combined into the pAHI4% number.
(peripheral Apnea Hypopnea Index measured by 4% oxygen desat)
134 total events and 16.3/hr average (total events/total sleep time)

pAHIc4% would be Clear Airway/Centrals
1 total event, in REM sleep

Oxygen desat is a sudden drop. So if you're at 95% and O2 drops to 90% that would be a 5% desat.

You're correct, this report shows 1 drop of 10-20%.
O2 between 85-81% for 0.1 minute (6 sec)

I don't know accuracy of the WatchPATs compared to PSG.

[dataq1]

As I read it...

Obstructives and hypopnea events are combined into the pAHI4% number.

IMO,  apneas and hypopneas are NOT combined in this study. My reasoning is that this Watchpat study CANNOT combine these because the study did not measure either type of flow event. 

And the reason; because the Watchpat did not measure ANY flows at all, good bad or indifferent

As best as I can tell, Watchpat measures  volume changes in peripheral arterial bed of the finger and assumes that those volume changes are in response to respiratory distress.... and (there is where the problems begin)... those arterial changes are only caused by respiratory distress.

That said, I am open to contrary views, but it seems to me the Watchpat study (as it pertains to apneas and hyponeas)  is based on assumptions and extrapolation.  

[Brazen]

@dataq1
I completely agree with you.
I was stating numbers as reportedly captured by the watchpat to answer the questions. (Per the watchpat brochures via google)

I too doubt the accuracy of WatchPAT tests, just didn't get into that.