Feedback on first night OSCAR data

Hi, just started using a CPAP. I've been trying to read up on how to interpret OSCAR data but would appreciate people's input. Using a Resmed N30 nasal cushion. Woke up feeling more rested than usual. I highlighted a couple of areas. One in the middle of the night and one early morning. Is that a leak from the mask in the middle of the night or bad SD card data? Had ramp off, 4-20 range and EPR 3. I'm thinking I'll try EPR off and see what happens? Or just bump up the minimum to 7 instead? Thank you!

Welcome! It's great to hear you felt more rested after using your machine. As you get more and more used to the new experience, I'm betting you'll fell more and more rested.

I don't know what happened in the weird gap; maybe someone else can tell us that.

You have a nearly constant low-level leak. This doesn't compromise your therapy, but you might sleep a little better without it. Try refitting your mask after watching some videos on how to fit your particular mask. You can also try using the machine and mask during the day or evening while you're awake and see what little adjustments will get you to zero leaks. It will probably be most useful to do this lying in bed and shifting around from one sleep position to another.

I'd say leave your EPR on at 2 and raise your minimum to 6. That way you'll get the benefit of EPR all night long and avoid any possible wake-ups from changes in how much your pressure drops when you exhale. (The machine can't go lower than 4, so if your EPR is 2 and your pressure is 5, you'll only get a drop of 1.)

If all goes well over several nights with EPR of 2 and minimum of 6, then I'd suggest you raise the EPR to 3 and the minimum to 7. This is partly for reasons of comfort and partly because EPR helps with flow limitations (unless they originate in your nose). But let's see how you do with EPR of 2 and min of 6 first.

You have a fair number of CAs toward the end of the night. I'm willing to bet those are coming after arousals. If that's right, then as you have fewer arousals, you'll have fewer CAs. So for now, just bracket the CAs. You can spot arousal breathing pretty easily; it's deeper and messier-looking than normal asleep breathing.

Thank you! That's really helpful. I'm going to give those things a try (mask fitting and change EPR and minimum). I did use a microSD card with adapter since I don't have an SD card reader but do have a microSD reader. Wonder if that did it. Resmed website says it'll work but not recommended due to not meeting medical device electronic standards or something. Will see how it looks the next few nights.

vtcpapuser wrote: ↑

Sun Oct 27, 2024 12:52 pm

Thank you! That's really helpful. I'm going to give those things a try (mask fitting and change EPR and minimum). I did use a microSD card with adapter since I don't have an SD card reader but do have a microSD reader. Wonder if that did it. Resmed website says it'll work but not recommended due to not meeting medical device electronic standards or something. Will see how it looks the next few nights.

Better buy an SD to USB adapter for your computer. Those are cheap, and usually reliable (I had one break after many years of use).

If your recording gets messed up, during the night, because you use an SD to microSD adapter, there's nothing you can do about it.

If it's only the SD to USB adapter misbehaving while reading, you can see your correct data with another adapter.

Thanks for the feedback everyone. I found the N30 mask was slipping off a lot. Got a p10 and it's much better for leaks and staying on, but I still do find the headgear slips off the top of my head. I guess I'm more active a sleeper than I thought I was. I'd be interested in getting an AirMini at some point as I like to travel. It would be nice if the mask was natively compatible with it. I like the minimalism of the p10 but need a different headgear. I can't seem to find any alternate p10 headgear that is a bit more elaborate. I even thought of clipping it to my hair, but I don't have enough Any recommendations for what mask to try next? Something like a p10 but with more 'robsut' headgear. p30i? I'm considering an N20 too as the N30 was pretty comfortable, but just leaky.

You might take a look at the new F & P Solo mask. It has an under the nose cushion version (reminds me of the N30) as well as a nasal pillow version. I tried the under the nose cushion version earlier this summer but the nasal pillow version is newer and I just heard about it. The Solo is silent like the P10 and N30 but the headgear is maybe a little more robust but not horribly so.

The ResMed Swift FX nasal pillow mask has similar nasal pillows to the P10 but the headgear is probably a little more stable but it's vented air isn't diffused so it isn't silent and that vented air can be really annoying.

Here's a link to the Solo information page at F & P
https://www.fphcare.com/us/my-sleep-apn ... gIoPfD_BwE

vtcpapuser wrote: ↑

Sun Oct 27, 2024 8:19 am

I highlighted a couple of areas. One in the middle of the night and one early morning. Is that a leak from the mask in the middle of the night or bad SD card data? Had ramp off, 4-20 range and EPR 3.

Looking at this image:



I think that the "missing data" is caused by a very, very large leak rather than a problem with the SD card or the microSD card with adapter that you used to load the data into Oscar. Here's why: When data is displayed in this stretch, the reported leak is sky high---well into the range where the machine can have significant problems detecting the flow rate into/out of the lungs---that's why the reported flow rate is also so small. In other words, the missing data is from periods when the leak was just so large that the machine could not track your breathing even though it was trying to track your breathing.

And the machine is flagging apneas in the places where it manages to pick up a faint trace of air flow into/out of your lungs because there are periods where it thinks the airflow into/out of the lungs for 10 seconds or more is close to 0 L/min, but the machine also still thinks it's got a good enough trace of your flow rate to just stop recording any data all together. The apneas in this time period are labeled as "unknown apneas" (UAs) because with the size of the leak, there's no way that the machine can accurately evaluate the data from the FOT algorithm that is used to determine whether a given apnea is an obstructive apnea (OA) or a clear air way apnea (CA), which is typically assumed to be a central apnea.

Also worth noting: Since the machine is really not able to track your breathing during this time frame, there's no way to tell if any of those UAs is actually real or not. Just as important, since virtually all the air the machine is pumping into the system is being lost to the massive leak, your airway may not have been sufficiently pressurized enough to stop obstructive events from occurring, particularly during the time periods where the machine simply could not track your breathing because of the massive leak.

If we look at the session information, we can also see that the machine apparently turned itself off and back on a number of times during this same time period. If you have Auto Start and Auto Stop both set to "on", that would easily explain why the machine turned itself off and on: When it couldn't detect any breathing for a few minutes (because of the leak), it turned itself off thinking that you must have removed the mask without turning the machine off. When it then detected your breathing again, it turned itself back on, but the massive leak was still there and within a few minutes, the machine found itself unable to track your breathing again.

My guess is that you finally woke up around 2:20 and noticed the leak. You fixed the leak probably by putting the nasal cushion back into the correct place under your nostrils and then went back to sleep. If that wake was short, you might not even remember it.



Looking at this image:



Here the leak is not very large---as in it's well below the Resmed definition of a large leak (24 L/min). So the machine is not having trouble tracking your breathing.

The breathing looks ragged enough that combined with the fact that it's the last hour before you woke up, that I'd say this is most likely what we often call "sleep-wake-junk" (SWJ) breathing. Most likely you were somewhat restless during this period and bouncing back and forth between a very light sleep and a wake stage. If that's the case, those CAs that are recorded are likely either normal "sleep transition centrals" that can occur as you drift off to sleep and control of your respiration is handed over to the automatic nervous system OR they are normal pauses in your wake breathing.

Do you remember waking up earlier than normal and lying in bed kind of dozing, but not getting back to a sound, deep sleep?

I'm thinking I'll try EPR off and see what happens? Or just bump up the minimum to 7 instead? Thank you!

I'm not sure I'd recommend changing the EPR setting or pressure range just yet. Before I would feel comfortable making those kinds of recommendations, I'd want to know if you had any problems falling asleep at the beginning of the night. And whether you slept through that massive leak in the middle of the night.

I do think you will need to do some trouble shooting with regards to the large leak. Given that you are using a nasal mask, the first thing a lot of people would suggest is that mouth breathing caused that leak. But it's also quite possible that mask movement is the culprit. If you moved around significantly in bed, it's possible that the nasal cushion got moved or pulled to the point that it really wasn't resting that close to the base of your nostrils and that triggered the leak. As a simple test, you could gently tape the frame of the mask to your cheeks. If that prevents super large leaks, then I'd say we can write that massive leak on this night off to mask movement probably caused by your own movement in bed. It takes a bit of practice to learn how to turn over in bed without causing the mask to move and trigger a leak, but most of us learn to do it in our sleep.

Thanks for the feedback everyone. This is so helpful.

@Pugsy I had my eye on the F&P solo pillow version. It may be the next one I try. In the meantime since my last post, I've been having much more success with the P10 straps. Seems like separating them out more (one low and one high) keeps it in place a lot better. I had one night where it slipped off for a couple of hours. Still too early to say as I'm only 2 weeks in total.

@robysue1 Thanks for your analysis. I fall asleep quite easily and the slightly higher pressure doesn't bother me at all. The large leak in the middle of the night theory makes sense to me. I have woken up in the middle of the night with the mask off my nose. In the first week I think the mask was coming off a lot. Either I pulled it off it my sleep or it wasn't secured well. Sounds like all the data during the large leak period is junk essentially and isn't meaningful. For the last hour, sleep-wake-junk totally makes sense to me. Last 60-90min I'm often (but not always) half awake.

I attached my last night. I bumped it up to 8 just as a try as I seemed to be getting more obstructive events at lower pressures. Maybe should just go back down a bit first and see. Think those CA's are due to treatment or 'sighs'?

vtcpapuser wrote: ↑

Mon Nov 11, 2024 5:15 am

@robysue1 Thanks for your analysis. I fall asleep quite easily and the slightly higher pressure doesn't bother me at all. The large leak in the middle of the night theory makes sense to me. I have woken up in the middle of the night with the mask off my nose. In the first week I think the mask was coming off a lot. Either I pulled it off it my sleep or it wasn't secured well. Sounds like all the data during the large leak period is junk essentially and isn't meaningful. For the last hour, sleep-wake-junk totally makes sense to me. Last 60-90min I'm often (but not always) half awake.

Yep, data during that large leak period is basically meaningless junk.

Also I'm happy to hear that my analysis seems to be pretty accurate.

I attached my last night. I bumped it up to 8 just as a try as I seemed to be getting more obstructive events at lower pressures. Maybe should just go back down a bit first and see. Think those CA's are due to treatment or 'sighs'?

First, a bit of a lesson about CAs in general.

Our sleep breathing is controlled by the autonomic nervous system, whereas our wake breathing is not. And the trigger for inhalation is the build up of CO2 in the blood. When we transition to sleep, the CO2 level to trigger inhalation is set a bit higher than in our wake breathing. And so the handoff for respiration to the autonomic nervous system sometimes involves a "glitch" as the CO2 trigger-level is increased, and that "glitch" involves a temporary pause in breathing that can be long enough for a CPAP machine to flag it as a "CA", but on an in-lab sleep test where the technician has all the EEG data available as well, the event is not scored because it is just a normal glitch due to the transition to real sleep---i.e. it is a "normal sleep transitional CA".

It's also important to remember that our machines can't really tell when we're awake and when we're genuinely asleep. And normal wake breathing has a lot of patterns in it that can look like sleep disrupted breathing problems. In particular, it's not uncommon for people to momentarily hold their breath while concentrating on something, even something as "simple" as turning over in bed or adjusting the pillows. And many people will do some "deep breathing" to relax the body while awake, and that "deep breathing" is often followed by a period of shallow breathing or even a slight pause in breathing to let the CO2 level in the blood stabilize again.

When looking at CPAP data, CAs scored during periods when the person is not clearly asleep are often either normal pauses in wake breathing or normal sleep transitional centrals. Hence it's important to not get overly worried about CAs popping up during times you know you're awake. It's also reasonable to not get overly worried about CAs that follow a clear arousal. (And it's also worth remembering that even people with normal sleep have a certain number of arousals every night.)


In this screenshot:



I think the CAs are just normal "sleep transitional centrals"---the kind of thing that would not be scored as a real CA on in-lab sleep test. It's still very close to the beginning of the night and you haven't really established "real, continuous" sleep yet. Add in the fact that there are deep "arousal" type breaths preceding these CAs, and that's more evidence these are not real.


In this screenshot:

Two of the three CAs are clearly post-arousal. So they're likely normal sleep transitional CAs that would not be scored on an in-lab sleep test. The middle one? It might be real. But I'd not be overly worried about it.

More generally, I would not be worried (yet) about the number of CAs on this night, and here's why: Your overall AHI is still below 5.0 and many of the CAs that are scored appear to be post-arousal "events" that are more likely to be normal sleep transitional centrals than real ones.

While treatment-emergent central sleep apnea is a real thing, only a small percentage of new PAPers have problems with it. And the new PAPers who have real problems with treatment emergent central sleep apnea are people who have a CAI that is (usually) significantly above 5.0 and the vast majority of the CAs are real---i.e. they can't be written off as sleep transitional events. What you sometimes see with treatment emergent central sleep apnea are whole chains of CAs caused by the development of a CO2 overshoot/undershoot loop that develops when the new PAPer blows off too much C02, which suppresses the sleep respiration drive to the point where breathing temporarily stops (in the undershoot part of the cycle), and when sufficient CO2 builds up in the blood, there's a tendency to hyperventilate just enough to create another CO2 overshoot. It's this CO2 overshoot/undershoot cycle that causes the excessive number of CAs in treatment emergent central sleep apnea.

And it's also worth remembering: For most of new CPAPers who have a genuine problem with treatment-emergent centrals, the problem resolves by itself in a few weeks as the body adjusts to this new way of night-time breathing. In other words, the usual first recommendation is watchful waiting: If the number of CAs goes down enough over time for the overall, longterm AHI to stabilize below 5.0, nothing else really needs to be done. It's only a very small number of new CPAPers who have a problem with treatment emergent sleep apnea that persists long enough for the problem to be clinically significant enough to warrant moving the patient to an ASV machine.

@robysue1 - Thanks so much for the detailed explanation! I'll continue to keep an eye on things and work on keeping my mask on for the next few weeks and see how it goes

I'm back! A little over a month into using my CPAP. Ended up getting a Resmed N20 (after p10 and n30) and find it much better for staying on. Been using that since mid November, so pretty much everything in the past month on this share link from SleepHQ. I'm finding I'm not having those large gaps with huge leaks and my AHI seems good too. Couple more questions, and maybe something in my sleep data will be helpful. Ignore the odd sleep hours for the first week of data (I was in a different time zone and didn't change the clock).

1. Waking up some mornings with my nose feeling blocked/dry. Normally I breathe well through my nose, no nasal issues. I was thinking of turning up the humidity (currently at 4). Would any adjustments with the pressure help at all? Change the max/min or EPR?

2. Are my leaks too high? make the straps tighter (its comfortable right now, with a bit of wiggle)? Is it ok to have a bit of a leak at long as my AHI is good? Any other detriment to this?

I loved the idea of a nasal cushion or pillow, but alas I think I move around too much. Maybe sometime in the future. The N20 headgear is easy enough to use, just more fighter pilot than I was hoping for

https://sleephq.com/public/teams/share_ ... b0a5a9d33b

Are those leaks waking you up at all?
If not I wouldn't worry about them.
You spent very little time in large leak territory (over 24 L/min). Not enough to really cause a problem.

More pressure or changing EPR isn't going to help the dry nose thing. I would try a little more humidity if it were me and I was having dry nose.

The leaks haven’t woken me up. I increased the humidity by a notch and it definitely helps the dry nose. Traveling now and using the AirMini which I got on a Black Friday sale. Working great so far. Thanks for the help!