Last Night - Encore with SpO2 data - example

[Spottymaldoon]

I ran an SpO2 meter (blood oxygen and pulse rate) all last night, and compared that to Encore's read. Some of that data is at

http://richardleveson.com/APNEA_DATA.html

Last night was a great sleep. The AHI was 2.9 and I only recorded 6 apneas during the entire night on the SpO2.

SpO2 meters can give 'artifacts' - sudden low-readings - but I only count an apnea if a low reading is accompanied by a sudden increase of pulse rate. My average SpO2 is 96% and I take 93% as 'marginal' and below 92% as a definite apnea (if the heart races too).

Comments are most welcome!
Best,
Spotty

[NightHawkeye]

I think your assessment is correct. When my oximeter reading dips into the low 90's, it is almost always associated with obvious apnea events. Funny thing is that when I tried just holding my breath while awake, I could never get the oxygen saturation to dip noticeably, so it's hard to imagine sleeping through. No wonder I'd wake up regularly.

I've noticed the "artifacts" too, as have others on this forum. I assume you're seeing short dips in saturation levels, at least that's what I saw, but never could pinpoint the source. I think they're more than just machine artifacts, but they don't seem to be significant indicators of anything.

Regards,
Bill

[Spottymaldoon]

Bill - Yes I tried the same experiment of breath-holding and got a similar result - for a 1 minute breath-hold I found it dipped maybe 3% just after I re-started breathing - a pool of deoxygenated blood (heart?) seemed to gush through. The sleep expert told me that the mechanism which compels us to resume breathing when awake doesn't operate in the same way during sleep. It's not an explanation but it gives a temporary answer until we get into what's actually happening physiologically.
I have tried to reproduce the low SpO2 readings (artifacts) by every reasonable method - including checking if it might be due to my cell phone - but I can't, it just happens. Could be that it's a bug in the software. Low 80s are believable, especially when there's a pulse acceleration, but mine can dip into the 60s which is not. On one occasion I watched the Oximeter go into the 80s while I was awake and I was breathing normally. Also it has nothing to do with finger position as I have tried every imaginable combination.
Best
Spotty

[blctech]

I have a Nonin finger meter that works very well. But I would like to record my O2 and heart rate thru the night. What recording meters work well and are you using software to download the date or just looking at the data on the machine. The software seems really expensive.

Thanks for the help

[drbandage]

I have a Nonin finger meter that works very well. But I would like to record my O2 and heart rate thru the night. What recording meters work well and are you using software to download the date or just looking at the data on the machine. The software seems really expensive.

Thanks for the help

I, too, would be interested in purchasing the appropriate (and affordable) equipment needed. So far, I have nothing but my xPAP machine. Any suggestions about how to move forward would be greatly appreciated.

Thanks,
drB

[Spottymaldoon]

The instument I have (BCI Fingerprint) cost me $300 on Ebay - if I had waited I'm sure I could have got a better price. It has a memory of 14 hours and, in that time, records average oxygen saturation % and pulse rate every 30 seconds. Mine has a built-in printer with 1.5" wide thermal paper and I print this off the following morning. It claims also to be able to download the data to the computer via hyperteminal and a serial port but I haven't yet got mine to do this. Apart from those false 'desaturations' this little unit is fine. I can get three nights easily off 4 AA alkalines BUT when I print I use an external power source because the printer uses a lot of power.

There is a big difference between the night's readings I get with and without the APAP BUT I don't find a terrific correlation between my Encore data (H and OA) and what I see on the oximeter.

I am planning to run a test where I suffer for a night with my APAP pressures set at 4 min and, maybe 4.1 max (or whatever the lowest range is) and then compare the apneas seen on the APAP and on the oximeter. Did anybody try this?
Best
Spotty

[Goofproof]

If I were you I would raise my lower pressure to 6 or 7, 7 cm would be better. From the looks of your leak rate, you may be mouthbreathing, or the mask is leaking at times. everything else looks good. Jim

[Spottymaldoon]

Jim. I'm pretty certain you're right. But could you explain, for the benefit of myself and others, how you reach that conclusion - i.e. (1) that this shows possible mouthbreathing and (2) why raising the pressure will help?

I am confident I have fixed all other leaks except from my mouth.

Best,
Spotty

[Guest]

Thanks Spottymaldoon for the oximeter info.

[Goofproof]

Jim. I'm pretty certain you're right. But could you explain, for the benefit of myself and others, how you reach that conclusion - i.e. (1) that this shows possible mouthbreathing and (2) why raising the pressure will help?

I am confident I have fixed all other leaks except from my mouth.

Best,
Spotty

In Encore Pro, your leak rate line is all over the place. You could use it to saw wood.

5 cm, is very low, at 7 cm you would have more air to breath and a few pressure rises wouldn't happen because you would already be there. The closer you have the pressure on APAP, the faster it can correct for problems.

But A low smooth leak rate is really important, a leak rate over 45, causes me trouble my best nights are at 33 and under, if I hit 36, I start to have trouble. Jim

[Spottymaldoon]

Goofproof says:

In Encore Pro, your leak rate line is all over the place. You could use it to saw wood.

So it is - and my family members have been cruel enough to suggest that is exactly what I sound like I'm doing when asleep! (before APAP)

I think I need to focus on mouth leaks then and I shall try your suggestion and raise the low-end pressure.
Thanks
Spotty

[Snoredog]

I would try taping your mouth then reviewing your report again paying special attention to the leak rate for any improvement.

Your leak rate doesn't indicate to me you are mouth breathing with an open mouth, I would expect with mouth breathing to see >75L/m or higher indicating a Large Leak denoted by solid black marks above the leak chart.

I'm not seeing any LL in your report. You could possibly be just "mouth leaking" not necessarily breathing. But then your Avg. leak rate of 37L/m is not at all bad, but you have some peaks that indicate you are developing mask leak and/or leaking at the mouth. Tape should help you determine if that is the cause.

Your oxygen rate (center column) looks good, yes there are a few periods where it dropped to 92% but that was the lowest I seen. Your heart rate did climb as a result but not that high that I can tell. You could improve on that by increasing your auto:Min pressure from 6.5cm to say 8.0cm. It should not only improve your SP02 levels but it should eliminate those FL's and HI's from your EncorePro report.

But your reports are far from bad. SPO2 levels only become medically significant when they drop below 89%, 92% was your lowest and I have no idea what your base line was, from the report probably 95%.

Your current 90% pressure is 9.0cm. I would try setting the machine to 8.0cm to 10cm and seeing what your reports says.