+- Apnea Board Forum - CPAP | Sleep Apnea (https://www.apneaboard.com/forums)
+-- Forum: Public Area (https://www.apneaboard.com/forums/Forum-Public-Area)
+--- Forum: Main Apnea Board Forum (https://www.apneaboard.com/forums/Forum-Main-Apnea-Board-Forum)
+--- Thread: How Leaks impact AHI (/Thread-How-Leaks-impact-AHI)
How Leaks impact AHI - Dawei - 06-11-2012
Recent experience has demonstrated to me just how mask leakage affects AHI numbers reported by ResScan software, and perhaps this example may be of interest to others.
During a four night period (June 3-6), my 95% Leakage rate was 50.4 and the AHI for that same period was 12.5. During the next four-night period, the 95% leak rate dropped to 7.8 and the AHI was 2.6! A leak-elimination tip from a fellow board member is responsible for this dramatic change, but the numbers clearly show how excessive leakage skews AHI reports.
RE: How Leaks impact AHI - Sleepster - 06-11-2012
(06-11-2012, 07:19 AM)Dawei Wrote: but the numbers clearly show how excessive leakage skews AHI reports.
If the leak is large, the machine can't measure AHI in any meaningful way. If you dig a little deeper, and look at the components of he AHI, they become even less meaningful. The machine cannot, for example, distinguish between a CA and a OA when there's a large leak.
The bottom line is this. If you have large leaks, regardless of the reported AHI, your therapy is ineffective.
RE: How Leaks impact AHI - Dawei - 06-11-2012
Along the line of what you suggested, Sleepster, I noticed that when significant leaking is present, I see lots of yellow (unknown) event markers mixed in with the red markers on the ResScan events graph. I don't see much in the way of CSA markers, but the software actually announces with those yellow markers that it doesn't recognize the leak events.