Understanding OSCAR data, would love some help please

Hi there - I am in Australia, and was diagnosed with sleep apnea after an overnight sleep study in a hospital back in October. AHI of 15, and Nadir SpO2 (lowest level of oxygen saturation a person reaches during sleep) was 87%.

I have been using a company here that conducts overnight sleep studies, sells CPAP equipment and assists with monitoring how you are going etc. I have purchased a Resmed Airsense 11 CPAP machine, which I am really liking. I have tried a wide variety of masks, I got close to deciding on a Resmed F20, small size, but have been getting leaks early in the morning below the mouth area and sometimes above the nose, enough to wake me up which is super annoying. Last night I tried for the first time the Löwenstein LENA Full Face Mask, which seemed to go really well and not leak anywhere near as much.

I used an SD card in my CPAP machine for the first time last night, and would love some help with understanding the data please. My goal is to get my AHI down to zero each night! Figure I may as well have a great goal. I have been using CPAP for about 2 weeks or so. Am fairly comfortable with it now, had a few hiccups here and there with getting used to it but am feeling very positive about it. Definitely am feeling less tired during the afternoons (was getting very sleepy in the later afternoon time each day before using CPAP).

According to the Airsense app I am going pretty well to very well, but I love LankyLefty's opinion that the Airsense app is not really that useful! So I am very interested to try and understand what this OSACR data is showing. (This is just from last night of course - I am planning to download my data each day from now on and keep a record of it.)

I take 10mg of Escitalopram per day due to a bit of anxiety I was getting during menopause, and from the little I have researched I am wondering how much impact this could be having on my sleep. Other potentially relevant factors RE sleep apnea are - I am currently around 85kg or so but have been working at steadily losing weight (i.e. fat, not muscle) during the last year and have lots about 10kg so far, and would like to lose about 10kg more.

Have included the OSCAR data from last night (I have followed the tips from Apnea Board about how to present the data in the most useful way, but please let me know if I should add anything else!) Have also put the main components from my sleep study results onto one page in case that is helpful to have.

These community forums are SO fantastic to have RE getting used to CPAP and trying to be proactive with our health efforts.

Welcome! You're off to an excellent start, with good numbers and a great attitude.

During normal sleep, most people have a few events -- CAs if nothing else -- so just be aware that most of us would say an AHI under 1 is excellent.

I see that your sleep study noted a fair number of arousals after periodic limb movements. You might want to read this to see whether it suggests some questions to take to your doctor:

https://my.clevelandclinic.org/health/d ... sleep-plms

Your flow limitation graph is a bit busy. Do you have nasal congestion?

Some people are bothered by FLs; some people aren't. You can see whether reducing them helps you, and EPR is a good tool for reducing FLs, especially when they are in the lower airway. In addition, many people find EPR comfortable because it reduces your pressure a bit when you exhale.

Since you have very few obstructive events, I would recommend leaving your pressure range where it is and trying an EPR of 2. If you like it, and you're not seeing an uptick in obstructive events, you could try an EPR of 3.

It looks like you aren't getting the 7 to 8 hours of actual sleep that most people need. Anything you can do to address that?

Hi Miss Emerita - thank you for taking the time to reply. Sorry I haven't replied sooner, I have only just realised that you posted a reply to me. (I had thought I would get an email notification if someone replied but maybe this website doesn't work that way or I haven't set that up, not sure.)

Since I made my first post on here (which was the one you replied to), I have been reading quite a lot of info from the Sleep HQ website, and watching lots of videos from there. I decided last night to try a fixed pressure on my ResMed 11, so CPAP rather than APAP mode. I used 12.6 cm as that was my 95% pressure. I am using the Lowenstein Lena full face mask. I am not using ramp or EPR - I got the sense that both of these tend to be not recommended if people can manage without them?

Would appreciate any insights on better understanding the data from last night. (I had quite a late night but do want to aim to get to bed earlier in general). Shortly after I had gone to bed I added a VCOM and that helped ease the feeling of starting the night straight off the bat with a higher pressure than I was previously used to from using APAP, when my start pressure was 9cm. (There is a break in the data early in the morning as the front clip piece of my mask accidentally twisted right off and I had to get up and take it off to click it back on.)

You asked about nasal congestion - I do get a bit of nasal congestion sometimes but it's not usually too bad, I have bought a saline nasal rinse kit to help with that and use a eucalyptus type balm as well. I watched a video on Sleep HQ which talked about the superiority of nasal masks if people can learn to not open their mouths at all while they sleep, and would like to try getting used to a nasal pillow mask. (I tried a few diff types of them a month ago when I first started on CPAP but I just needed the 'simplicity' of a full face mask to get used to it all to start with.) I don't much like the feeling of having my mouth taped shut, but I have ordered a different type of mouth patches/tape today that I will have a go at getting used to using. I hated the psychological pressure of lying in bed knowing I mustn't open my mouth (when it is un-taped), I found I just couldn't mentally relax enough to drop off to sleep with the anxiety of knowing that if my mouth did open then all the air would gush out of it, which I found to be a freaky feeling.

I am a side sleeper, I did not sleep on my back at all during my 6 hours of sleep in my in-lab sleep study, but am also planning to check this further with the SomnoPose sleep app on my phone.

Emma.A wrote: ↑

Tue Dec 17, 2024 12:13 am

I watched a video on Sleep HQ which talked about the superiority of nasal masks if people can learn to not open their mouths at all while they sleep, and would like to try getting used to a nasal pillow mask. (I tried a few diff types of them a month ago when I first started on CPAP but I just needed the 'simplicity' of a full face mask to get used to it all to start with.) I don't much like the feeling of having my mouth taped shut, but I have ordered a different type of mouth patches/tape today that I will have a go at getting used to using.

Do you breathe through your mouth or your nose when you are awake?

Many people who breathe through their nose most of the time during they day assume that they must use a full face mask or tape their mouth just in case they occasionally open their mouth during the night. That's just not true. If you breathe through your nose when you are awake, there's a good chance that you breathe through your nose at night and that there's no need to tape your mouth shut just to use a nasal mask or a nasal pillows mask. And it's also the case that if you have the occasional, rare bit of mouth breathing at night, it's not such a huge problem that you have to use a FFM or mouth taping to prevent it. It's much better to look at the leak graph in Oscar or SleepHQ and use that data to figure out if your leak problems are severe enough to warrant using a FFM or taping your mouth.

I am using the Lowenstein Lena full face mask. I am not using ramp or EPR - I got the sense that both of these tend to be not recommended if people can manage without them?

Ramp:
Most people here discourage the use of the ramp for a couple of reasons:

First, many of the people here have real difficulty feeling comfortable breathing at the default beginning ramp pressure of 4cm. And when people are using the ramp and complaining that there's not enough air to inhale comfortably, the easy solution is turning the ramp off.

Second, Resmed machines don't record OAs, Hs, and CAs during the ramp period. The Resmed engineers seem to assume that if you are using the ramp, then you are probably still awake during most of the ramp period. Hence, what's the point of recording the events? On the other hand, when people use a long 45 minute timed ramp, there's a very high probability that they will fall asleep before the ramp period is over.

So the standard assumption here is that if you can comfortably breathe at your full pressure (if you're using CPAP) or your minimum pressure setting (if you are using APAP), then there's no real reason to use the ramp in the first place. If you can't comfortably breathe at your full/minimum pressure setting, then using the ramp set maybe 1, 2, or 3 cm less than your pressure setting is usually a better solution than using the default beginning ramp pressure of 4 cm.

EPR:
Most people here typically use EPR, even if they could (theoretically) manage without it. We simply disagree with LankyLeft's views about EPR and APAP. (LankyLeft seems to have a real aversion to both, but our real life experiences tell us otherwise.)

There are a few people who find that setting EPR = 3 can trigger an excessive number of CAs because it can set up CO2 overshoot/undershoot cycles where they blow off too much CO2 at the start of the cycle. But these people make up a small minority of CPAP users.

There are many, many folks who have real trouble feeling like they can comfortably exhale at their pressure settings. And EPR helps significantly with that problem. And feeling comfortable with breathing while using the machine is important: If you can't comfortably breathe with the machine, it makes it far, far harder to get to sleep with the mask on your nose. And if you are not able to exhale comfortably, then your sleep is also likely to be more ragged and you're more likely to wake up to small, but irritating things that you might other wise just sleep through.

So you need to ask yourself: Is using fixed pressure at 12.6cm with no ramp and no EPR making it more or less comfortable to get to sleep than using a reasonable APAP range (maybe something like 9-15) and EPR set to whatever setting feels most natural to you?

Would appreciate any insights on better understanding the data from last night. (I had quite a late night but do want to aim to get to bed earlier in general). Shortly after I had gone to bed I added a VCOM and that helped ease the feeling of starting the night straight off the bat with a higher pressure than I was previously used to from using APAP, when my start pressure was 9cm.

There's nothing in the data that screams, "HERE IS A PROBLEM THAT MUST BE FIXED!"

Your leak line is exceptionally good---basically no excess leaking for almost the entire night.

There's no snoring going on. There are some flow limitations that if you were using APAP would have led to increases in pressure. But they stay well below the .5 line and you report that you do have some problems with nasal congestion. So they may not even be "real" in the sense of being part of an sleep disrupted breathing pattern. But they might be, and that would indicate that a change back to APAP might smooth the flow limitations out.

Your overall AHI is a bit higher than most people here like to see, but still quite acceptable from the world of sleep medicine. The obstructive AHI is excellent---which indicates that a fixed pressure of 12.6cm is enough to prevent your airway from collapsing.

The CAI is higher than a lot of people around here would like to see, but it's not alarming. There is, however, the pesky note in your sleep test results that says "Some respiratory events had a morphology suggestive of CENTRAL apnoea." So it's worth watching the CAI number rather carefully over time. One bad night is just that: One bad night. But a whole string of nights where the number of your CAs seems to be too high is something else---particularly if you're pretty sure you were asleep when the CAs were scored.

CAs are strange things. Real ones are caused by the brain forgetting to send the signal to "inhale now" to the diaphragm. The physical trigger for inhalation is the level of CO2 in the blood. People with real central sleep apnea appear to have problems with keeping the CO2 level in an appropriate range---they first "blow off" too much CO2, reducing the level of CO2 in the blood to the point where the brain quits sending the "inhale now" signal, and so breaths are missed. But that allows too much CO2 to build up in the blood, and the result is that once the breathing restarts, there's a tendency to hyperventilate and blow off too much CO2 again.

Then there's this: When we transition to sleep, the control of our respiration is handed off between two parts of our nervous system, and part of that handoff involves resetting the CO2 trigger for "inhale now" a bit higher. So it's not uncommon to miss a breath or two when we're transitioning to sleep. On an in-lab sleep test, these things are not scored as CAs since they're a normal part of the process of falling asleep as long as normal sleep breathing starts up once sleep is established. But our CPAP machines don't have EEG data available and so they will score such a sleep transitional event as a CA. That's why pugsy and I and others so often ask people, "Do you think you were asleep?" when people are asking about centrals in their data.

Now CPAP/APAP therapy can also affect things. Some CPAPers have real trouble with CAs emerging at pressures above 10cm. Some CPAPers have trouble with CAs emerging if EPR is set too high. With only two nights of data available, it's hard to say whether your higher CAI on the night where you used straight CPAP at 12.6cm was caused because your pressure was above 10cm all night long or whether it was just a "bad night."

On both of the nights where you've posted data, there also seems to be a correlation between when the CAs are scored and what appears to be restless periods based on the breathing pattern. In particular, in the data for Dec. 17, everything after about 6:20 appears to be "sleep-wake-junk" breathing. In other words, it looks like you were probably not sound asleep, but rather bouncing back and forth between wake and a light sleep, possibly because you had woken up, but were not yet ready to get out of bed and face the day.

Hello robysue1 - Wow, thank you so much for all of this excellent feedback and information! I really appreciate it. Many of the things you have explained have added to my depth of understanding. I had what felt like a good night last night, I made the rookie error though of inserting the SD card but not pushing it in properly, so then my data wasn't recorded to view on OSCAR. (I was tempted to get the "Magic Uploader" from Sleep HQ but they are too expensive for me to justify really needing one. I have ordered a second SD card so that I can make sure there is always one in the machine even when I have clicked the other one out to download data off it.)

My data just from the Sleep View display on the ResMed 11 screen said I had a total AHI of 2.9 and within that it showed 0 obstructive AI and 2.9 Central AI.

(I am really bummed though that I can't view the OSCAR data to see how many possible events went unflagged by the ResMed system! I have ordered a Sleep HQ O2 ring and am really looking forward to integrating viewing my blood oxygen data soon. I use the Sleep HQ platform as well as OSCAR.)

I had 8.2 used hours, leaks were 0L/min.

I reduced the CPAP fixed pressure from 12.6 to 12.4 last night. I am thinking, if I am noticing I am consistently getting zero obstructive AI, then I can try reducing the pressure incrementally over time and try and work out the lowest pressure I can manage at and still have zero or close to zero obstructive AI.

I really appreciate all your info RE central AI - yes that is the one I find pretty "scary" but I do feel hopeful that is not going to be a huge issue for me, touch wood. My father had Parkinson's disease, he passed away a few years ago, in his early 80's. (He had another bad fall in his nursing home and contracted pneumonia.) He had COPD and AF, and a range of other health issues. Since being diagnosed with sleep apnea and learning lots about it, having known almost nothing prior to that, I now suspect he likely had sleep apnea, I don't know if he was ever diagnosed with it though (I can't ask my mother as she passed away from breast cancer in 2002). I don't recall him ever having any kind of CPAP device in my childhood home or any home he lived in subsequently. I know there is a connection between neurological conditions such as Parkinson's disease and central apnea - but I am not wanting to get really paranoid about it. I have been trying to educate myself about treatment emergent central apnea, I still don't 100% understand all about that topic, but will keep learning about it.

I don't breathe through my mouth during the day, and I think I only would at night if I was badly congested, which is very rare; if I have a cold etc, which I rarely get. I know when I first tried the nasal mask at the very beginning of using CPAP it really bothered me, the way air would gush out of my mouth if I opened it even a little bit. It psychologically was a huge block to my brain to be able to relax enough to fall asleep, as it was so mentally disruptive and abrupt when it happened and jerked me out of dropping off to sleep. Like I knew even if I was to slightly stretch or yawn a little bit, that if my mouth was to open it would suddenly happen. It was like that "don't think of a pink elephant" thing, and of course you straight away see a pink elephant in your mind! So the feeling of a little bit of tape over my lips is more a comfort to me that I am not going to open my mouth unless I need to and choose to make a real effort to.

I wore one of the X shaped smaller mouth tape shapes all of last night, inside my full face mask, just to help myself get used to the feeling, and it was fine, I was totally comfortable with it on, and am really happy about that, previously the feeling of it has bothered me. The main reason I am still planning to try out a nasal pillow mask now that I am more accustomed to using CPAP is to see if having less bulk on my face (from the full face mask) is more comfortable. I am side sleeper so sometimes I am aware that there is a risk I could get leaks when I am slightly pushing my cheek into my pillow too much. The ResMed full face mask I was using a few weeks ago was really bad for that, getting leaks around the seal, whereas the Lowenstein Lena one I have been using for a week or two is much better - I learned about it online, my provider had not shown it to me as an option but was able to lend me one to try when I asked about it, and it is designed for people using higher pressure - which I am not doing at around 12 I think, but it still has meant way less leaking for me. Which has been great as the hissing of the leaks from around my chin and cheeks when I was using the ResMed full face mask, plus with the pressure building during the night as I was on APAP then, would always produce enough of a loud hissing sound to wake me up (and my husband too) resulting in more interrupted sleep.

I also am interested in trying to transition to a nasal pillow mask because I watched some great videos where Nick from Sleep HQ interviewed the VCOM inventor Dr. William Noah, and he has several reasons as to why using a nasal pillow mask is a great goal to aim for, such as how that physical arrangement of the pressure arriving only through the nostrils and not over the whole lower face as in a full face mask, helps very effectively to dilate the nostrils. Some people he knows of have been able to avoid having nasal surgery as a result of changing to a nasal mask. (If you haven't watched the videos and are interested to watch them just let me know and I can send the links. There are two particular videos on this topic; for the second one you need to have a Sleep HQ Pro membership to watch it, but that level of membership is free for the 1st month in any case.) During the videos Dr Noah also talks about KPAP, a new algorithm he has been working on to make CPAP more comfortable for people who find it difficult to use, to do with the fact that he has realised that the inspiratory pressure can be reduced, he says it is the expiratory pressure that is the really important one for providing the mechanical splint to the airway for people who suffer rom the airway collapsing to some degree during sleep. Have you heard about KPAP yourself yet?)

From watching one of those videos yesterday I leant that the best place to put my VCOM was not straight in front of my mask (as I had in the recent night's data that I posted here) but rather in between the short lighter weight tube I have purchased and the actual ResMed tube. (I can't place the VCOM between the tube and the CPAP machine as it is a Climate line heated tube and has the electronic little pins as part of the end of the tube.)

Thank you again - I find it so supportive to have people such as yourself be so generous with their experience and input.

P.S. - It is the day after I wrote the above - I made sure my SD card was clicked in properly last night, so have added the OSCAR data from last night here, as I so appreciated your insights from the last time I did that.