What's This in Encore Pro Data?

Night before last I noticed yet again some unexplained data dropouts in my BiPAP-auto data. This time, these drop-outs happened to occur at about the same time as a string of apneas. During this period the oximeter data recorded a string of shallow de-sats.

Although it's hard to see, measuring the oximeter de-sats closely reveals that each of the gaps corresponds exactly with a recorded de-sat. However, not all de-sats have a corresponding apnea recorded for them. In fact, it is clear that two de-sats definitely do not have an apnea marker associated with them, or even anywhere close to the correct time. In other words the machine seems to be taking a break from recording apneas when the gap phenomenon occurs. Also puzzling to me is the question of whether the machine is simply responding to the apneas or is there a chance that the apneas are a response to the machine.

These gaps appear not to be power drop-outs, as there are no gaps in the leak data or the minimum and maximum pressure settings.



Any insights appreciated.

Regards,
Bill

1. you are "flat-lining" at 10cm pressure on IPAP especially in hour 1-2 with a run of OA's. 10cm did NOT clear those. Because your AI indice remains high (what I would consider high), you need to increase the Max. IPAP pressure by at least 1cm. You have several 1-hour streatches where pressure is flat-lined, a bit too much.

2. Report is showing FL's throughout the night. I would change the Min. EPAP setting to 8.0cm and see what that change does to those numbers. I suspect EPAP is dropping too much allowing for those FL's which can turn into Hypopnea and even Apnea as the night progresses.

3. I don't see a problem with your leak and snore doesn't appear to be a problem.

Note: because you don't have a problem with snores (only 1 tic) I would not be too concerned about runaways on that machine being triggered by snore. Chronic snoring can falsely trigger the machine into a pressure response, so opening your IPAP Max. pressure up to 12cm should be okay and possibly be enough to clear those OA's.

Your goal should be to lower the number of OA's seen if you study the report and see those OA's look up and note the pressure, if there is an OA there should be a .5cm pressure increase to eliminate those, right now 10cm isn't high enough to clear as Max.=10 so machine cannot do its job.

Great point Bill!! I have had exacly the same question last week. I visited my pulmonologist last week for a scheduled F/U visit, and with the hope of DCing my 2L/min supplemental O2. I asked me to do an overnight pusle/ox that night so that he could decide whether to DC the O2. That night, I adjusted my REMstar Auto min. pressure from 9.0 to 9.5 cm, based on EnCorePro data that I had downloaded on the morning of my sleep doc data. My AHI was 0.3 that morning. After I adjusted the pressure up to 9.5 cm, I hit the ZERO club with AHI=0, AI=0 and HI=0, with those figures continuing since.

I was therefore, SHOCKED when my pulmonologist called and told me mto stay on the O2 since I had SEVERAL desats with my sats dropping to 79% at one point. BTW, I've never had ANY centrals.

How the hell does that happen? Desats WITHOUT apneas or hypopneas???

I'd be beholding for anyone who can shine a light on this!

Chuck

I agree with Snoredog that the IPAP should be raised to at least 12. EPAP 7, IPAP 12 or EPAP 8, IPAP 12.

The way the machine is being used now, it might as well be a resmed straight cpap with EPR turned on. But maybe that's how it suits you best. Each person is different; however, as Snoredog said, that AHI and the flatlining up at the max IPAP pressure line are not what I'd want to see.

Be sure to remember to raise the PS as far as it will go when/if you widen the range between EPAP/IPAP.

Example:

EPAP 7
IPAP 12
PS 5

EPAP 8
IPAP 12
PS 4

I have no idea why tiny gaps occur in your data, Bill.

Chuck -

Perhaps the pulse data would shed some light ... by chance did your pulse data correspond to your desats?

- r

Don't know. Don't have it.

But still, desats with ) SDB events???? Maybe something's wrong with Encore.

C

I would worry about the leak rate too. 25 LPM for the mask, and jumps to 50 LPM. When mine goes over 40 LPM, my numbers and snores go up.

I don't see how a machine rated at 30 LPM can keep up the pressure with a 50 to 60 lpm leak rate. That's the reason I wouldn't buy a Hybrid, at a 44 cm leake rate I would be doomed from the start.

As for as 2L of O2, with the wash-out of the mask, I don't think you would get much vaule from the O2, I cranked mine to 4 LPM, and in the operating room I had them go to 4 LPM. (they ask me!)

Snoredog wrote:1. you are "flat-lining" at 10cm pressure on IPAP especially in hour 1-2 with a run of OA's.

You're close, Snoredog. Actually, the machine is flat-lining at 9.5 cm. It merely indicates 10 cm because of a "feature" in the Respironics Encore Pro software that doesn't allow it to display those pecky 0.5 cm steps. It can only display the 1.0 cm steps, like 7.0, 8.0, 9.0, 10.0, 11.0, etc. (What were those Respironics designers thinking?)

I deliberately set the machine at a little lower pressure in hopes of getting a few more hours of sleep with less aerophagia. You're right, of course, raising pressure does tend to lower the AHI a little. It's kind of a fine line for me though, and at the moment I'm hoping for a little extra sleep with a little less aerophagia because the aerophagia tends to wake me up.

Every now and again I go back to trying out the auto function in the BiPAP-auto in hopes of finding a breakthrough which works just a little better for me.

GoofyUT wrote:I was therefore, SHOCKED when my pulmonologist called and told me mto stay on the O2 since I had SEVERAL desats with my sats dropping to 79% at one point. BTW, I've never had ANY centrals.

How the hell does that happen? Desats WITHOUT apneas or hypopneas???

Have you thought about getting your own oximeter, Chuck? I can tell you that I can think of several common cardiac related anomalies which would probably manifest as such de-sats. However, not having a degree in these matters, I'll refrain from further comment.

As for the leak rate, it was a relatively good night. Experience has taught me that most of the constant up and down change was due to mouth leaks (or pops). Not a lot, just a little from time to time.

The gaps in the Encore Pro data are a mystery. The stocatto like drop-outs are definitely associated with de-sats, but not with recorded apneas. I remain puzzled as to why exactly these drop-outs are occurring.

Regards,
Bill

Is it possible that the machine is exceeding the set IPAP max pressure briefly but the software (within the machine recording the data) does not record it because it has exceed what it expects to be the max?

One way to test this hypothesis would be to hold your breath briefly with mask on, and cover up the exhaust port(s) to build the pressure up in the system to exceed its max setting ... then look at the data to see if the gaps in your Encore are reproduced.

Just a thought ...

- r

GoofyUT wrote:I was therefore, SHOCKED when my pulmonologist called and told me mto stay on the O2 since I had SEVERAL desats with my sats dropping to 79% at one point. BTW, I've never had ANY centrals.

How the hell does that happen? Desats WITHOUT apneas or hypopneas???

What model number oximeter did you use? Lab setup or in-home setup?

There are other possible (non-apnea) causes of a decrease in SpO2. You may want to ask your doctor to explore the possibility of cardiac arrhythmia or lung disease.

NightHawkeye wrote:

Snoredog wrote:1. you are "flat-lining" at 10cm pressure on IPAP especially in hour 1-2 with a run of OA's.

You're close, Snoredog. Actually, the machine is flat-lining at 9.5 cm. It merely indicates 10 cm because of a "feature" in the Respironics Encore Pro software that doesn't allow it to display those pecky 0.5 cm steps. It can only display the 1.0 cm steps, like 7.0, 8.0, 9.0, 10.0, 11.0, etc. (What were those Respironics designers thinking?)

I deliberately set the machine at a little lower pressure in hopes of getting a few more hours of sleep with less aerophagia. You're right, of course, raising pressure does tend to lower the AHI a little. It's kind of a fine line for me though, and at the moment I'm hoping for a little extra sleep with a little less aerophagia because the aerophagia tends to wake me up.

Every now and again I go back to trying out the auto function in the BiPAP-auto in hopes of finding a breakthrough which works just a little better for me.

GoofyUT wrote:I was therefore, SHOCKED when my pulmonologist called and told me mto stay on the O2 since I had SEVERAL desats with my sats dropping to 79% at one point. BTW, I've never had ANY centrals.

How the hell does that happen? Desats WITHOUT apneas or hypopneas???

Have you thought about getting your own oximeter, Chuck? I can tell you that I can think of several common cardiac related anomalies which would probably manifest as such de-sats. However, not having a degree in these matters, I'll refrain from further comment.

As for the leak rate, it was a relatively good night. Experience has taught me that most of the constant up and down change was due to mouth leaks (or pops). Not a lot, just a little from time to time.

The gaps in the Encore Pro data are a mystery. The stocatto like drop-outs are definitely associated with de-sats, but not with recorded apneas. I remain puzzled as to why exactly these drop-outs are occurring.

Regards,
Bill

I also get gaps in my graphs for no apparent reason. However, mine do not seem to correspond to anything else on my charts, and I don't have nearly as many gaps as there are in your graphs. I get only one or two gaps per night, and sometimes none.

Since my AHI is doing fine and I feel good, I just ignore the glitches in my own data and blame it on unidentified measurement error. I would be more concerned if I had as many gaps as you have.

Keep us posted if you are able to track down the source of this problem.

Moogy

GoofyUT wrote:Bill, I do have my own Nellcor N-395. The data I get off of it DO NOT correspond with the data my pulmonologist got from a Nonin RM2xx. I will rraise the possibility of other causes with him, but I don't have a lot of faith in him.

Interesting! So which instrument is right? Is either right? Was the pulmonologist simply continuing to base his advice on what he saw some time ago, maybe prior to your xPAP therapy?

FWIW, some time back Roger and I had a discussion about quick dips in oximeter data we both were seeing. The only resolution we ever came to was that neither of us quite believed that the quick dips were real. Oximeter probes are sensitive to movement, and it seems reasonable to discount quick dips in oximeter data based on that fact alone. In fact, my software senses movement and marks those times, ostensibly to allow someone interpreting the data to ignore data during those times. Based on the extremely limited technical capabilities of most of the physicians I've seen though, I wouldn't place much faith in their ability to distinguish between movement induced desat indications and true desats.

It also seems to me that cardiac induced desats could occur. However, what I'm not sure of and haven't stumbled across, is whether such desats would change more quickly than pulomonary induced desats. I suspect cardiac induced desats would be capable of changing quickly due to loss of blood pressure though. Still, that wouldn't a true reflection of desaturation, and I can't imagine what the mechanism for 02 therapy helping such quick desats would be.

Regards,
Bill (who freely admits to speculative reasoning)