Oxygen Levels W/O CPAP

Tielman · Post by **Tielman** » Fri Oct 22, 2010 1:51 pm

resistance wrote: Here are the desaturations zoomed in, but at that level, the software does not show SPO2 levels under 70. So the minimums all look like 70:

You have to change the scaling options in the menu, the default is 70, but you can change it to something lower to show the detail.

HoseCrusher · Post by **HoseCrusher** » Sat Oct 23, 2010 1:23 am

Resistance,

Notice the gray line just before the events...

That means that the unit lost signal. The event occurred while it was trying to re-gain the signal. When you see a gray line, you need to basically ignore the data following it for a minute or so.

It looks like all 3 events occurred after loosing the signal. When I see that, I call them artifacts.

You can explore this by simply starting the pulse oximeter, then slip it around on your finger and put it back to where it originally was. You can experience wide variations in the data while you are sitting very calmly in a chair breathing normally. The wrist mounted units have less problems with this because the sensor is secured better, however I like the data displayed on the finger tip unit.

It is important to play around with these units a little. This identifies the strengths and weaknesses of the unit, and helps a lot when you are looking at the data trying to figure out what is going on.

Slartybartfast · Post by **Slartybartfast** » Sat Oct 23, 2010 2:05 pm

Those instantaneous drops and near instantaneous rises look suspicious. like they're movement or loss of signal related.

I have the same unit and sometimes, upon loss of signal, apparently the unit sometimes records a negative or positive spike. I have tried hiking with my CMS 50E on my index finger, and holding it in place with my thumb and middle finger. And even though doing so results in minimal movement, the resulting report is mostly gobbledygook. That's a technical term. Any chance that when you removed your mask in your sleep you might have also dislodged the 50E so it wasn't getting as good a signal? All that said, it might be worth trying to sleep another night without CPAP to see if the same thing happens.

Just for grins, and to experience what it feels like to go below SPO2 of 90%, try sitting in a chair with the 50E on, and hold your breath for as long as you can and watch the oxygen level. It should initially be 96-98%. By the time you hit 90% I guarantee you that you will be wanting to breathe really badly. I saw spots at 88% and decided I had enough. Imagine what doing that all night at levels far below that does to you over time.

OutaSync · Post by **OutaSync** » Sat Oct 23, 2010 2:58 pm

If you look closely at those zoomed up diagrams, you will notice a black (dark gray) line just before each sudden drop. That color indicates a disconnect, making all of those dips, thankfully, artifacts.

Still a good idea to wear your mask all night

Bev

resistance · Post by **resistance** » Sat Oct 23, 2010 4:41 pm

Thank you for your replies. I hope you are right and those are just artifacts. Yes, the grey line of signal loss is always followed by a sudden drop. I also find the numbers like 40 or 50 too low to be real. But on the other hand;

- Why did those spikes appear only after taking the mask off?
- Why do corresponding high pulse rates appear?
- Why do I feel worse than ever the next day, with high blood pressure, headaches, etc.?
- When I had my first PSG in the hospital I had many desats around 70, which were considered very dangerous by my doctor, and none of them were artifacts.

I don't want to sleep without CPAP just to test how low my oxygen levels will go, so for now I can only hope that the spikes are only artifacts.

BTW, I also hope there really is an explanation why I still have severe daytime symptoms after 6 months of CPAP therapy. (I think I'll have to start a new thread about this soon)

NotMuffy · Post by **NotMuffy** » Sun Oct 24, 2010 4:00 am

resistance wrote:- Why did those spikes appear only after taking the mask off?.

Can you post the corresponding D/L?

I think there is a high likelihood of the sensor being displaced during a maneuver like that.

- Why do corresponding high pulse rates appear?

Same signal, same artifact.

- Why do I feel worse than ever the next day, with high blood pressure, headaches, etc.?

In this particular case, your overall sleep appears greatly disturbed after 0600 (BTW, you seem to be a DSPS kinda guy).

- When I had my first PSG in the hospital I had many desats around 70, which were considered very dangerous by my doctor, and none of them were artifacts.

Well, "IMHO", it is only that THESE particular examples are artifacts. It could be that valid data may be buried in there, but from a purely diagnostic point of view, those examples must be tossed.

SleepTechulous · Post by **SleepTechulous** » Sun Oct 24, 2010 4:59 am

NotMuffy wrote:
resistance wrote:-
- Why do corresponding high pulse rates appear?
Same signal, same artifact.

I agree?

Wow this is definitely an anomaly right here.

SleepTechulous · Post by **SleepTechulous** » Sun Oct 24, 2010 5:30 am

Yeah, I posted in this thread as well. Very strange.

SleepTechulous · Post by **SleepTechulous** » Sun Oct 24, 2010 5:36 am