Got My PulseOx - Now What?

[SithLord]

OK, got my PulseOx (SPO 7500) and recorded several nights. I am now trying to interpret the data. Also trying to correlate the pulse and DeSats with the events charted in Encore Pro. I feel like a newbie all over again when I was trying to understand Encore Pro .

Has anybody found some good websites or articles that put the PulseOx data in context w/ OSA?

Procedures:

• - I set the PulseOx to a 2 sec sample rate. 1 sec would be better I know, but they claim this will only collect 8 hours worth.
  
  - I start the CPAP and PulseOx at same time. The internal clocks of both units are within a minute of each other.
  
  - When reviewing, I set the time scale to relative in the VitaScore detailed zoom so it's easy to match up with Encore Pro detailed report.

Questions:

• - How is O2 DeSataturation Index calculated? Seems to be # of events / time like AHI? Google hasn't helped yet.
  
  - What are the key metrics to watch for? I assume O2 DeSat index, total time SpO2 <89, and the SpO2 distribution.
  
  - Can the PulseOx data help distinguish from obstructive vs. central apneas?
  
  - Can the pulse data help at all with identifying sleep cycles?
  
  - One night I had an AHI of 1.0 (6 obstructive events, 4 hypopnea). From PulseOx I had a DeSat index of 2.4, 24 DeSat events, and total time SpO2 <89 was 12 minutes. 96% of the time the SpO2 was between 90-96. Only 4% of the time was between 88-89. These are "good" numbers?
  
  - Same night as above, I tried to correlate the Encore Pro markers with DeSats/pulse. I assume each H and OA event should match up with a DeSat event? It doesn't appear that way. In one instance I had three H/OA events within 20 minutes and no DeSat events to be found anywhere. I did see some drop in SpO2 but maybe not low enough or fast enough to register as a DeSat? Other times, I see DeSat events with no markers in Encore Pro. All of this is expected?
  
  - I understand there could be some lag after an apnea event and a drop in SpO2. But how much? Seconds or minutes?

As jskinner and others, I want to test loved ones that potentially have OSA with the PulseOx.

• - How low should any of the above metrics drop before being concerned?
  
  - What are "bad" and "really bad" numbers?

I guess overall, I am looking for some rule of thumbs and a "Dummies Guide to PulseOx".

[mindy]

Hi Jeff,

Afraid I can't answer most of your questions but can at least partially address one of them. O2sats are supposed to be around 93 or 94 & above. During my PSG, I had desats with hypopneas down to 85%. I've read on this forum that some have had desats down to the 60s - those are really bad. Mine were considered "mild" although my sleep study wasn't all that accurate because I can't sleep well anywhere other than at home.

Since I have a heart condition they didn't want to leave those desats down to 85% because of the potentially negative effect on my heart.

Hopefully along with other posts, you'll start to get some idea of what to look for. And I'm looking forward to seeing other answers so I can learn more about it too!

Mindy

[RipVW]

Think I found the answer to one of your questions:
"A desaturation index was calculated (desaturations/h) for each sleep state." So, as I understand this, DI is calculated as desaturations per hour.
From: http://www.medscape.com/viewarticle/416977_print