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Are my apnea events being accurately recorded?
RE: Are my apnea events being accurately recorded?
We can't tell you if you do or do not have apnea because you can't determine that with a CPAP machine that has good data let alone one that has questionable data. These are not diagnostic machines and using one affects your breathing which makes it impossible for us to know if what we are seeing is spontaneous breathing or induced by the machine. For all we know these are central apnea that you are inducing on yourself by using this machine, without a sleep study and better data we can't draw any conclusions. Your machine/program supposedly flag central apnea but it isn't in your case so what does that mean? I have no idea because I don't even know if this off brand machine and program are compatible with each other and the programs capability appears questionable at best. With a Resmed Autoset we would at least be able to know if these were real events, hypopneas, OAs or CAs but we still would not be able to diagnose you and know what events are spontaneous and which are treatment induced.

If you want to know if you have apnea, plain and simple you need to get tested. There are many ways to do it and there is no reason you should have to wait a long time to do so. There are companies like AXG diagnostics that offer tests online (order and they send you equipment then you send it back and they score) if you can't find a local place to get tested by (should be easy though). If you put as much effort into getting tested as you are now trying to interpret bad data you will get it done quickly and get the answers you are looking for.

As for proceeding with this machine I already told you your only option. Manually count what appears to be events, determine "AHI", adjust pressure until "AHI" is the best you can get. Then realize you have done everything you can with this machine and either be satisfied with the results or unhappy with them. Lower pressure is usually better unless higher pressure helps reduce AHI so start low and work your way up, if you feel sleep is getting better you can keep going up, if you feel sleep is getting worse stop or go back down. I assume pressure is your only setting to change so it really is that simple.
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RE: Are my apnea events being accurately recorded?
I just looked more closely at your first 2m graph. 2M (or 10m or 60s) presumably identifies the timespan of that particular graph. There appear to be 10 larger blocks, so 2m is 120 seconds, divided by 10 is 12 seconds each. 6 smaller blocks in each larger block means the smaller blocks are 2 seconds each.

The chart marks an obstructive apnea of 10.7 seconds duration. This confirms the small blocks are 2 seconds each on this graph. This apnea does indeed look like an obstructive apnea. Some the breaths immediately before the apnea suggest a flow limitation which worsened and became a full obstruction.

Note the faint grey line on the flow graph. This looks like it might be the "zero line" where flows above that are inhalations and below that are exhalations. It's interesting that on the 60 second graph, the inhalations are shaded gray.

The little bumps in the otherwise flat areas of the graph might be cardio ballistic effects. However, it appears the software is counting those little bumps when it calculates BPM, resulting in an absurd result. If you look at a 60 second graph, you'll see the software calculates a BPM for every increase above the zero line. When there are normal breaths, BPM calculated for that breath is in a reasonable range of 13 to 15. So the total BPM calculation is very flawed because it is including those small oscillations that are not really breaths.

The other flat areas on that graph might be either OSA or CSA but not flagged by the machine. It looks like the machine cannot adequately handle the cardio ballistic effects. It may be that they are throwing off the OSA/CSA detection.

Bottom line: this machine might work as a fixed-pressure machine for a simple sleep apnea situation but not as an auto pressure machine (because it appears not to be detecting apneas correctly) or for a complex situation. It is clear that the total BPM report is wrong, and it certainly looks like apnea detection (and AHI computation) is wrong too.

Have you had at least an at-home sleep test? That would evaluate your situation and give you some data to work from. If you are willing to pay for that yourself, rather than waiting to see a doctor and having them prescribe an insurance-covered test, you could try one of the on-line vendors of sleep tests. If you do that, get a Type II rather than a type III test, as Type II tests are more complete. The only Type II test provider on our list of sleep test providers is http://axgsleepdiagnostics.com/

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RE: Are my apnea events being accurately recorded?
Ok, here's something else that you can try. Get a recording pulse oxymeter -- I got a Contec 50F from the walmart online store for ~$80. It doesn't require a prescription, and it's not real expensive. Wear it while you sleep, and load the data files into OSCAR. Normal breathing your oxygen saturation will wriggle up and down by a percentage point or two or three, but if you are having apneas then there will be noticeable much deeper dives in your oxygen saturation.

Once you figure out how to synchronize the timing of the data report with the timeline of the pulse-ox data, you will have a much better idea of what is going on. (And you can post OSCAR views of your pulse-ox data and we can make something of it.)

(I use my pulse-ox as an independent measurement of apneas, and it follows what my cpap machine shows very well. I have a particular concern that my excessive sleepiness causes me to doze off in all sorts of situations where I'm not wearing the CPAP. The pulse-ox is much more portable and it has told me that I for sure have apneas if I doze off in front of the TV...)

Another device that you can get without a prescription is a Fitbit (which I have) or an Apple Watch which works better. Both of them have oxygen saturation monitoring and will flag if they think that you have apnea. Again, I find that my fitbit, pulse-ox, and cpap data track closely.
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RE: Are my apnea events being accurately recorded?
If you see cardiac oscillations on an apnea it's more than likely a central. The old 420E made a living doing that.

Good eye on the floating -0- line.
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RE: Are my apnea events being accurately recorded?
Thanks, everyone. I ordered a recording pulse oxymeter (Contec 50F). I'm thinking I can use it while sleeping without wearing the cpap, so then I could get an idea of if I am having apneas when I'm not using the cpap, then also use it while using the cpap. That could help give me an idea of if I'm having treatment-induced apnea events.

I tried wearing the cpap mask while awake and holding my breath to simulate an apnea event to see if I could time my pulse and figure out if it is picking up cardian oscillations or not, but I honestly wasn't able to tell. I'm not sure if it is indeed my heartbeat or if it is just the machine fluttering a bit from the air pressure slightly changing for reasons such as leakage or small movements etc.

I have not had an at home sleep study, no. A few years ago a doctor ordered what was supposed to be a polysomnogram, then I get a phone call about a home sleep study being sent to me, which was not what I was expecting, and when I contacted the doctor to ask about why they said they were sending me a home sleep study when he specifically said he was ordering a study that I would have to go to a sleep lab to have, he tried to cover and acted like that's what he intended to order, which it definitely wasn't. I'm almost certain that doctor was in early stage dementia (he was in his late 80s) as he was constantly making odd mistakes and even ordered the wrong blood test for me one time. (I didn't keep seeing that doctor for very long.) Then the sleep study never did arrive in the mail like they told me it would, and when I called the sleep lab to ask where it was they said that it should have arrived and they would "investigate", but I never did receive it.

Yes, the "60s" means 60 seconds. There are buttons to choose to display 30 seconds, 60 seconds, 2 minutes, 5 minutes, or 10 minutes. For each mode, it displays "Xs" or "Xm" to indicate on the left of the graph. Thanks for pointing out that the faint line is a "floating zero". I had previously assumed it was some sort of moving average.

So, for now, I will see what happens when I get the recording pulse oximeter and get what information I can from that, and then hopefully know something for sure when I finally get a sleep study. I've been waiting a long time but I don't have a ton longer before I go to the sleep lab; I don't know how long I will have to wait after that to get an actual sleep study, though. At the moment I am in a fairly rural area, which might be part of why there has been such a wait.
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RE: Are my apnea events being accurately recorded?
The recording pulseox meter arrived.  I used it last night *without* the CPAP to see if I can rule out treatment induced CSA.  I'm having difficulty figuring out how to upload it to Oscar, but here are three screenshots from the program that came with the pulseox, two times it went below 88%, and one other random selection:


Is anyone able to help me get any information from the graph?  I counted two times when my oxygen went below the red dashed line indicating 88% and seven times when it went below 90% but above 88%.  Also, the line seemed much flatter in the beginning when I either had yet to fully fall asleep or had not been asleep very long yet.  I'm also wondering if there is anything significant about the sudden drop and then gradual increase in pulse in the middle image.

I finally know a date for my polysomnogram btw.  It is going to happen the night of April 7th.

Thank you, everyone!
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RE: Are my apnea events being accurately recorded?
Go the report page that has Total SpO2 Events and see how many you got. The default value for desaturations is probably 4%. Change it to 3% and then run the report again.
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RE: Are my apnea events being accurately recorded?
The drops occurring at 15:45 and 19:36 look to be artifacts. They are usually caused by bumping the probe. The one at 16:52 is a little strange. Combined with its drop, your pulse dropped about 18 beats a minute. I was thinking of a rapid hand movement, but your pulse didn't seem to recover for over 30 minutes. Because your heart rate is appearing to be elevated earlier, was this after a brief walk or exercise? If so, then it would make sense.

- Red
Crimson Nape
Apnea Board Moderator
Useful Links -or- When All Else Fails:
The Guide to Understanding OSCAR
OSCAR Chart Organization
Attaching Images and Files on Apnea Board
Apnea Helpful Tips

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RE: Are my apnea events being accurately recorded?
It definitely wasn't after a walk or exercise.  I was asleep.

(03-28-2022, 01:38 PM)Rubicon Wrote: Go the report page that has Total SpO2 Events and see how many you got.  The default value for desaturations is probably 4%.  Change it to 3% and then run the report again.


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RE: Are my apnea events being accurately recorded?
Your average SPO2 was good with only the odd brief drops below 90% so no serious concerns. There are a fair number of "events" with index of 25/hr most of which must just barely meet the 3% cutoff, I assume if you set that to 4% the index would drop substantially. The main thing that catches my eye is the periodic nature especially between 16:40 and 17:20. There are very few desaturations during that period but the fluctuation is still obvious, it isn't smooth enough for me to believe it is good breathing but not bad enough or inconsistent enough to make me think it was due to obstructions. The consistent periodic nature makes me believe it was a period of central based periodic breathing and I think this further confirms a likelihood of central apnea being your issue. Again the only way you can actually confirm this is with a sleep study though.

You should use the CPAP tonight and see how the data compares to see if it seems to help or not. The event index (events/hr), basal SPO2 (average) and time below SPO2 % are the main things to compare.
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