Oximeter Question

[Starlette]

My earlier post is not getting any feedback so let me rephrase:

If you get a data reading from your oximeter of 25 total events, would you have concerns that your therapy is working?
EncoreViewer gave me an AHI of 2.5.

Starlette

[Slinky]

The oximeter detects and reports events differently than a CPAP. Not only is the detection method different but the definition of an event is somewhat different. And the number of events is not so important as the number of events PER HOUR.

You are asking us to compare apples (oximeter data) to oranges (CPAP data). We can't do it. No one can.

[Starlette]

That's what I needed to know. Thank you Slinky. I raised an eyebrow of concern when I saw that number this morning.

Starlette

[Lizistired]

Here are my last results: O2 events- 41, Pulse events-79
Most of them are spikes up caused by arrousals, not desats. That's why I said I don't pay much attention to the events.
I don't know anything to do about the arrousals.
I spent less than 1% of the night below 90% so it was a good night.

[HoseCrusher]

A saturation event is scored according to adjustable parameters. You can play with the settings and see how the scoring changes.

A typical value would be to score an event when the O2 saturation drops 4% over a period of 10 seconds. Some oximeter software will default to a 4% drop over 10 seconds, and other version default to a 3% drop over 10 seconds.

Sleep studies use both of these depending upon which scoring system they are using.

Once you see an event, to determine if it is significant you need to zoom in and look at the progression of the desaturation. If it is an immediate drop, it is an artifact. However, if it is a stair step drop, that is real.

Once you determine you have a "real" event, you then need to look at the pulse rate at that time. If there is no change in the pulse rate, the desaturation did not effect your heart. However, if your pulse rate initially slows, then quickly speeds up as the O2 levels drop, then the desaturation is effecting your heart and it is pumping faster to make up for the drop in O2 levels.

The same goes for evaluating pulse events. A good parameter for a starting evaluation of pulse events is to set the rate change to 15 beats per minute and the duration to 30 seconds. A discussion with a cardiologist may help you dial this in a little better.

xPAP machines give you 1 channel of data based upon air flow. The pulse oximeter gives you another 2 channels of data including O2 saturation and pulse rate. While this gives you more information, additional information is still needed. The missing data comes from brain waves, respiratory rate, respiratory effort and leg movement. All of the information from these channels of data are involved in determining a "real sleep disorder event."

The goal is to experience a restful and restorative nights sleep. Sometimes 1 channel of data is enough to figure things out, at other times more data is needed.

[Kody]

Once you see an event, to determine if it is significant you need to zoom in and look at the progression of the desaturation. If it is an immediate drop, it is an artifact. However, if it is a stair step drop, that is real.

Once you determine you have a "real" event, you then need to look at the pulse rate at that time. If there is no change in the pulse rate, the desaturation did not effect your heart. However, if your pulse rate initially slows, then quickly speeds up as the O2 levels drop, then the desaturation is effecting your heart and it is pumping faster to make up for the drop in O2 levels.

Thanks HoseCrusher for this important info, I didn't know this. Usually I don't pay much attention to the number of events, just eye ball the O2 graph pretty closely. Have seen the spikes (artifacts); you were talking about but wasn't sure how much importance to give to those. Looks like the stair drop ones are the important desat's to look into.

[Starlette]

Thank you Hose.

That makes sense.

Starlette