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[CPAP] New user: How many clear airway events is too many?
New user: How many clear airway events is too many?
Hi all,

First, thanks for the treasure trove of information this forum represents, and for OSCAR!

I'm a new CPAP user; I've been using the machine for about a month.  I have a ResMed AirSense 11.  Settings:  5-15 cm H2O.  I'm not able to adjust most of the settings myself; I have to call in to my provider and they change them remotely.  I've been issued both Philips Respironics DreamWear nasal pillow and full masks; I'm not sure which works better for me, if either.

Background information about me:  27 year-old male, 6'0", 167 lbs, nonsmoker, nondrinker, if that matters.  My initial diagnosis, based on a home sleep test, was mild obstructive sleep apnea.  I recently learned I have a deviated septum, and I'm hoping to get surgery for it this summer. My ENT says my throat looks normal and he doesn't think a mandibular advancement device would help.

Despite the, uh, mildness of my diagnosis, subjectively, I feel exhausted and sleepy from the moment I wake up to the moment I go to sleep, almost every day, no matter how much I sleep (or whether I use CPAP, or which mask I use).  It's really impairing my work and my relationships, and I'm feeling pretty frustrated, desperate, and, frankly, frightened.

I honestly have no idea whether the CPAP is helping.  I have mediocre nights and bad nights, both with and without it.  Lately I'm thinking I have more bad nights with it.  What's particularly disturbing me is that my machine reports an AHI between 5 and 10, occasionally as high as 15 or 20, each night. It characterizes most of these events as clear airway.  This is consistent between both the nasal pillow and full face masks.  In OSCAR, the events it's classifying as clear airway are consistently flow rate flatlines of 10-20 seconds, sometimes but not always with a more ragged waveform on either side.  I've embedded below a screenshot of a typical night in OSCAR, a segment of the same night zoomed on some of the clear airway events, and a snippet from the worst night I've had.

Typical night:


Typical night zoomed snippet:


Worst night zoomed snippet:


I guess I just want to ask, is this frequency of clear airway events, combined with no clear benefit from CPAP, typical in the first month of therapy?  Should I be worried about the clear airway events?  I admit I'm tempted to give up the CPAP, as it doesn't seem to be helping and sometimes feels like it's making my sleep problems worse.  Should I just stick it out and hope it will get better?

Thank you for your time and assistance!
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RE: New user: How many clear airway events is too many?
Why can't you can't you change your settings yourself? You can access the clinician menu really easily and you can change everything yourself, just hold both "my sleep" and "options" buttons for a few seconds. or did your DME specifically forbid you to change it? which i've never heard of.

That's waay too many CA events in my opinion but also you have a lot of leaks! You see the LL (large leak - grey zones) the therapy is doing nothing when you have a leak which is 25% of the night. if you fix the leak you will have less events! The AHI is most likely hugely under reported since the machine can't figure out anything when there is a large leak.

It's also not unheard of to not feel a huge change after a month, some say it can take up to a year and there is never a "huge" difference but gradually you start feeling better. But you can probably reduce your events a lot and improve your sleep quality.. So first thing is find a mask that doesn't leak so much! Or maybe you are opening your mouth during the night? Do you have fewer leaks with the FFM?

Looks like you have EPR (expiratory Pressure relief) off? i'm new here but i think that's the usual recommandation to start lowering CA events, EPR on 2 to start while augmenting the min pressure to 8. But i'm sure someone more knowledgeable will confirm Wink Did your sleep study have CA events? 

For next time also please hide the calendar so we can see the full stats on the left, just click the date. And we also need the Flow limit graph if you can (you can resize the graphs) it's probably the most important chart.
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RE: New user: How many clear airway events is too many?
You are able to adjust the settings yourself. A healthy number of posters here have a provider (DME or sleep center); those posters change the settings. IMO the institutional priority is to get you compliant and get your AHI numbers below 5. If you do it on different numbers than they programmed, and your AHI is reduced, I don't think they'll care.

Top priority: deal with the leaks.
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RE: New user: How many clear airway events is too many?
First, Narcil did an excellent job giving an overview. I’m just going to dig in a bit deeper…

To start, please read the link in my signature on “Organising your OSCAR charts”. The format specificed in there is what we prefer on this forum. Folks may ask for something else afterwards, but getting a picture of the entire night using that format is a good starting point.

Next, There is no reason you cannot manage your own machine. Go get the manual for your machine from here: https://www.apneaboard.com/adjust-cpap-p...tup-manual

As Narcil said, you need to figure out the leaks. I assume you are using a nasal mask or pillows and you are mouth leaking. If you want to stay with the nasal masks, you will need to use mouth tape or a soft cervical collar to stop the leaks. You can always get a full-face mask like the ResMed F30 or Evora F&P to try. Some CPAP suppliers (see the link at the top of the web page for “Supplier List”) allow a 30-day trial.

Now, onto your charts. I think you are getting close, but I noticed that your worst night had different settings than the other two, so we will discount that for now.

Your median pressure is close to 8 and the max is just over 10. Try the following for a few nights. You have cut off the flow limitations, so I am guessing you need EPR. Give it a go and we can always dial it back if needed.

Min pressure 8
Max pressure 15
EPR 2 full-time
No ramp
Response standard

That should help with things and hopefully be comfortable. Give it a go and let us know how things proceed. There are others things we could faff around with, but let’s take it slow.
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RE: New user: How many clear airway events is too many?
Hi all, thank you for the detailed and helpful replies!  I'll try to go point by point.

I'm glad to know that I am able to adjust my machine's settings manually.  I have successfully entered the clinician menu and done so.

Re: leaks, I see what you mean.  I have both a nasal pillow and a full face mask; I get leaks sometimes with both.  With the pillows, it may be mouth leak.  With the full mask, I think it tends to be around the nose if I move at night and jostle it.  I haven't managed to get low leaks consistently, but I'll keep adjusting the straps and trying.

I've slept three nights, using the full face mask, with the settings PeaceLoveAndPizza suggested.  Foolishly, I forgot my SD card for the second night, so I only have second-by-second data for the first and third.  As you can see, one has little leak, the other quite a lot.

8 May 2024


10 May 2024


I'm not sure what to make of these data, or how I'm feeling.  I've felt pretty decent in the mornings, very tired in the afternoons, and, sometimes, better again in the evenings.  I'd be grateful for any further advice; thank you again!
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RE: New user: How many clear airway events is too many?
Something of note that's seeming to be a pattern, you get clusters of Central Apnea both during the first and last hour of sleep sessions. It's probably a SWJ meaning sleep wake junk. A person's breath control while wake vs sleep has some trouble in the handoff especially when transitions are several times in quick succession.

If this is the correct label for those clusters, they may diminish over time.
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RE: New user: How many clear airway events is too many?
Dave is spot on about the early/late clusters being SWJ.

Looking at the chart, your best sleep was between 00:30 and 01:10, then again from 02:30 to 03:10. In the first case your pressure was around 13 IPAP and 10 EPAP, the second was lower at 9 IPAP and 6 EPAP. 

I would give a try to the following:

Min pressure 10
Max pressure 12
EPR 3 full-time

That gets you into to the effective range to manage your arousals. I reduced the top end for comfort and also to see if/when you would max out the pressure. You could leave the max at 15 if you choose.

Depending on how that goes, we may want to try reducing EPR a bit to see how it affects the FL's and CA's.
Post Reply Post Reply
RE: New user: How many clear airway events is too many?
Thank you again!

Three more nights below. I tried the nasal pillow mask again on the first night, but on subsequent nights I felt like I couldn't get enough air through it and switched back to the full face.  I've been feeling okay the last few days--not great, but not terrible.

Subjectively, I often feel like I have difficulty breathing out all the way while using the CPAP.

11 May 2024


12 May 2024


13 May 2024

Post Reply Post Reply
RE: New user: How many clear airway events is too many?
Fair play to ya. Let’s focus on the 2nd night for now…

Flow limitations look good with EPR=3, though we need to keep an eye on things. The pressure range seems to work, but I suggest increasing the top end a bit to give more headroom. Keep an eye on the leaks as well.

Min pressure 10
Max pressure 14
EPR 3 full-time

If you have no objections, I think a soft cervical collar is the next logical step. You can read more about it at the link in my signature “Soft Cervical Collar”. That will help keep you from chin-tucking and keeping the airway open. A flatter pillow or CPAP pillow will help as well.

While we could change your pressure settings, i would like to see how things go with the collar first. Read the link and give it some thought. I have attached a graphic showing how to measure for the SCC.

Attached Files Thumbnail(s)
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