how does apnea causes desaturation play out in time? - Printable Version +- 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 does apnea causes desaturation play out in time? (/Thread-how-does-apnea-causes-desaturation-play-out-in-time)

how does apnea causes desaturation play out in time? - cathyf - 03-23-2022 Partly because I'm OCD, but I'm intrigued by the question of aligning my cpap data and pulse-ox data. So I'm looking at this ugly 59-second apnea that I had and wondering if I placed the pulse-ox data too early, too late, or just right? I'm pretty sure that this view is showing that I put the pulse-ox data set a few seconds early -- because I climb halfway out of the desat before I've taken my first recovery breath. But then I'm thinking where SHOULD the climb out of the desat go? Right at the first inhale after the apnea? Or is there a couple of seconds lag while the blood gets oxygenated over a couple of breaths and a bunch of heartbeats? I suspect that the only way to answer this question is to use a pulse-ox that's directly connected to the cpap machine so that it's really getting the same timestamps on the data happening at the same time. Since the one that goes on a ResMed machine is like $1000, not too many people have them, but I was pretty sure that we had a couple of members who did, right? If any of you are reading this, what do you see in your data? How quickly does your SpO2 recover after an apnea? (I can also comment that a single minute-long apnea means I feel like total crap the next day!) RE: how does apnea causes desaturation play out in time? - SevereApnea - 03-24-2022 hi cathyf, nothing wrong with being OCD! here are three of my charts with the longest OSA I had on the For Her with the ResMed/Nonin Oximeter combo plugged in to the machine. [attachment=41026] [attachment=41027] [attachment=41028] as you can see there is some variable delay between the start of OSA and nadir of p02 and then some time after first breath ends the OSA the HR peaks and the p02 recovers a little later I can only assume the timestamps are correct because the data is imported straight from the SD card into OSCAR, but have knowledge no about how the data is recorded in the machine itself. But this is as expected from my earlier tests with oxygen saturations falling with voluntary breath holds. It takes a while (while awake anyway) for my pO2 to fall with long breath holds and long sequential breath holds. Post #6 here: http://www.apneaboard.com/forums/Thread-Is-Mild-Hypoxaemia-incur-from-low-APAP-pressure