Desaturations

[cwsanfor]

Using recording oximeters, what sort of values are you getting when asleep, or what values should be considered normal?

I seem to be having a few desats down to 85% SpO2. Brief, but still there. I'm wondering if that's normal.

Thanks.

[Slinky]

I'm afraid I won't be much help as I have COPD. I had quite a few desats below 85% on CPAP until we added 2L of 02 to the CPAP therapy. Now I stay in the 90%-95% saturations at least 90% of the night and usually more than 95% of the night.

[dsm]

From my own monitoring over the past 9 or so months (intermittently).

These are the rules of thumb I have established for myself

1) At start of night - shd be between 95-97

2) Sleep clinic say that the starting SpO2 % should remain pretty constant all night (varying roughly by say 2 up 2 down)

3) A drop of 4% in a very short period (couple of mins) is considered a desat

4) A worrying desat is when the SpO2 drops below 88%

5) An ideal night (for me) is when the SpO2% remains between 94% - 98% all night

I have some charts on-line if you would like to see good & bad ones

DSM

[Jeepster]

Oxigen Saturation should always be at 100% even if your asleep...

A drop of saturation under 70% is really critical if it is stay under 70% for long period...

Using your CPAP is the best thing to do!

[Slinky]

Sorry, Jeepster. But very few people, if any, ever have 100% 02 saturation at any time in their awake or sleep cycle.

99% and 98% are more the norm for healthy individuals and that average 02 sat does tend to go down somewhat w/age.

[NightHawkeye]

Oxigen Saturation should always be at 100% even if your asleep...

Before I started xPAP, my baseline O2 saturation recorded consistently at 100% using an oximeter. After starting xPAP, the baseline went down to around 97/98%. The difference was that prior to xPAP I was suffering hypothermia a lot and the oximeter reading was simply inaccurate. (There are a lot of articles verifying this for anyone willing to do an internet search, BTW.)

Cwsanfor, my own oximeter data tends to stay above 90%, even with desats while on xPAP, but occasionally I see a very quick sharp drop which is inconsistent with an apnea event. I tend to think it is a measurement artifact. Others here have reported similar results. On the other hand, if the drop you see is a progressive drop over a minute or so, then it most likely is the result of an apnea event.

Hope this helps.

Regards,
Bill

[Snoredog]

When you are a awake and breathing normally you have a baseline oxygen level, for most people that is in the 95 to 97% range, sometimes you can get to 100% but I'd be looking at the calibration or accuracy of the device if that was happening to often.

When you have an apnea event you stop breathing either from a blocked airway or from simply not breathing (central apnea). If your rate drops by 3% that is significant enough to classify a hypopnea as such, if it drops below 89% it becomes medically significant.

so wally: If you are on your bi-pap machine up in the 15-16cm pressure range and your levels are still dropping to 85% at night you have a problem, either the SAO2 monitor/probe you are using is no good or you truly are having apnea events that are causing the SAO2 drop.

My guess why you are dropping to 85%: Last EncorePro reports I've seen of your sleep patterns indicated to me you let your pressure run up too high with that bi-pap machine leading to triple events. SAG thought they were caused by onset events if not mistaken.

But my guess is those triple events are pressure induced centrals which would account for the drop to 85% when you are up in the teen range with pressure and yet your AHI remains fairly low. Put up one of your reports on the night it dropped to 85%, I'll show you where it probably is. You should also be able to correlate that event with your SAO2 time line and see where it dropped to 85%.

So you should NOT be dropping below 89% while on the machine. Almost any pap pressure at all 10cm or above should keep your oxygen levels up near normal levels if obstructive apnea is being properly addressed. If the AHI remains within normal limits and you are still dropping then I would look at the likely hood some of those triple events are possibly central not obstructive.

[Jeepster]

Sorry but my mother died of a pneumony last year and she was connected to a monitor that indicate its O2 saturation... When I ask the Pneumologist what should be the normal O2 saturation It told me that the satiration should always be at 100% or really near 100% ... 99% or 98% is normal too!!

My mother O2 saturation dropped at 65% for about 15 minutes and this cause serious and irreversibles Cerebral necrosis that kill her...

[BrianRT]

Interesting. Usually you have to be on extra O2 to have a consistant 100% saturation. I've found that 95%-98% to be more of a normal range. Of course, normal is relative with your age and/or your condition. A fair number of COPD patients' normal is high 80's. Low 80's and lower is going to cause some serious problems, and need addressed quickly.

FWIW, the lowest sat I've ever seen on someone (that lived) was 34%. This was an acute situation in an ICU, though.

[cwsanfor]

Thanks for your input so far.

I tried the SPO 7500 while walking a mile and then performing my normal daily office routine, and saw pretty clear artifacts with pulse and O2, using the disposable (presumably better) adhesive strip.

From the (only) three nocturnal measurements I've made, I can't clearly correlate the apparent desats with any events shown in EncorePro.

I'm going to try another measurement or so, and vary the pressure down, and then post some charts. I'm not sure I trust my readings yet. I also plan to revisit APAP, just for giggles, even though my AHI is about 50% lower on BiPAP.

I appreciate the offer to look at the charts, but I should get better data first. I'll be back soon.