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Airsense 10 not flagging apneas?? - Printable Version

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Airsense 10 not flagging apneas?? - Fixit50 - 11-05-2017

I am trying to understand the apparent failure to detect what appears as an apnea on my AirSence 10.  Note in the first picture below in the top left of the Flow Rate graph around the time of the ramp up (auto ramp is enabled with min ramp pressure of 4) where there seems to be some periodic breathing.  In the 2nd picture I zoom in on this area.  Several appearances of apneas can be seen that are well in excess of 10 seconds each.  Why does the AirSence 10 not flag these?  The one on the far right is flagged as an OA but the others are un-flagged.  Does anyone know what is going on here and why these apparent apneas are not flagged?  
Thanks for any help or insight.
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RE: Airsense 10 not flagging apneas?? - ajack - 11-05-2017

I would turn the ramp off, it stops the machine responding. An apnea also has to last more than 10 seconds. It will also help if you keep in one thread, that way people can easily look at your old data and build a picture and the charts are laid out as suggested.

There is a funny constant leak you need to work on. machine set as nasal mask and you use a FFM?

I think your machine is also picking up a breath pulse, I can't see your breathing rate being 37 BPM, or you would be well aware of a breathing issue. You could zoom in and look at the BPM and see what is going on. If it is right, you need a doctor ASAP


RE: Airsense 10 not flagging apneas?? - jaswilliams - 11-06-2017

I don’t think the auto set flags events during ramp.


RE: Airsense 10 not flagging apneas?? - Fixit50 - 11-06-2017

Thanks for this information ajack. 
“I would turn the ramp off, it stops the machine responding.”
I figured this had something to do with the ramp.  I have not noticed any undetected events after the ramp has completed.  It looks to me like the apneas are real but during the ramp period the machine does not detect them as apneas.  Is this consistent with your experience?

“There is a funny constant leak you need to work on.”

Where do you see this?  
I see a constant leak of 17.5 that changes somewhat with pressure.  Is this not the F10 mask vents?  What would be normal for the mask vents? 
 
“machine set as nasal mask and you use a FFM?” 
Yes, I’m using F10 FFM.  Machine is set to FFM.  Do you see something different? 

“I think your machine is also picking up a breath pulse, I can't see your breathing rate being 37 BPM, or you would be well aware of a breathing issue. You could zoom in and look at the BPM and see what is going on. If it is right, you need a doctor ASAP”

What is a breath pulse?  
I’ve been perplexed about the high breathing rates detected by the AirSense 10.  The Dreamstation also logs high rates.  I’ve noticed that when the Flow Limit is active the breathing pattern (Flow Rate graph) become very bumpy, pressures increase and Resp Rate goes up.  An example is seen in the picture below.  
[attachment=3959]
I think the resp rate is very high because of all the high frequency bumps in the breathing pattern.  I don’t understand this pattern.  If you look only at the low points or valleys in the pattern and count cycles you can see a breathing rate of about 15 which is more reasonable.  I think the high frequency bumps are counted as breaths by the AirSense 10 making it detect a higher rate than it is.  What is causing these high frequency bumps in the breathing pattern? 
The next picture shows another example, this time from the DreamStation.  
[attachment=3960]
This one is a little more difficult to interpret but the indicated Resp Rate in the 30’s looks like it could be accurate.  Seems high.  I’m not sure what to make of this.  Any ideas or comments? 


RE: Airsense 10 not flagging apneas?? - DeepBreathing - 11-06-2017

There was a thread a few months ago where member dwd1249 was experiencing some similarly weird flow charts and high respiration rates. You can read all about it here: http://www.apneaboard.com/forums/Thread-Is-my-breathing-shallow?pid=212868#pid212868 After 8 pages of suggestions, and multiple changes to pressures, EPR etc etc it came good. Nobody (including his doctors) really understood what caused it. If you read through the thread you might be able to pick up any parallels to your own situation.

By the way, if you turn off the calendar in your screen shots, it will allow more machine setting details to show up.


RE: Airsense 10 not flagging apneas?? - ajack - 11-06-2017

That's my understanding, that the ramp would work the same with the airsense 10, I would turn it off.

The leak is under 24 leak rate, where over affects accuracy. I just found it odd that it's a consistent flat line. If the 17 leak was with the philips it would be ok, as that shows the bleed air in the chart, but the resmed only shows leaks and not bleed air. The only think I can think of is that the machine thinks you have a nasal in settings and you use a ffm with a different bleed/passive venting rate.

Sleeprider is the guy to help with the funny breath, he has come across it before. I was more watching on the thread. He raised the min pressure till the breath became normal. I don't know if that always works


RE: Airsense 10 not flagging apneas?? - Fixit50 - 11-06-2017

DeepBreathing:  Thanks for the reference to the thread.  I will review it for sure.  

Ajack: Regarding the leak, I did not know ResMed only shows leaks and not bleed air.  It’s not clear to me how it would know what the bleed amount is to cancel out since I’m pretty sure FFMs have differing bleed amounts.  My F20 seems to bleed a lot more than my F10.  I’ve confirmed the machine is set to FFM in the settings and not nasal.  Good thought though.  Last night the leak was much lower and mostly bounced between 0-3.  This suggests there was an actual leak on the Oct 9 data.  Glad you picket that up as I will now be more careful with the hose connections.
Regarding the funny breathing waveforms with the high frequency bumps and higher breathing rates, if this is not a universal phenomenon then I’d like to pursue this at least to understand better what is happening.  Short of that I can’t tell if it’s a problem or not.  Maybe I should buy a O2 attachment to see what is going on.  If O2 is ok, then I’d imagine no harm is done.  Also, this problem is generally more prevalent during high pressures though I do see it at moderate pressures as well.  I think its tied in with flow limits which I see a lot of every night once I fall asleep.  The problem is that I seem to need the full maximum pressures.  My AHI scores on the ResMed are very good but I once tried backing off the max pressure to 16 and got a series of OA’s while the pressure railed at 16.  It often does go up to 20 and it seems like I need it to circumvent OA’s based on that test.  Last night it railed at 20 for a full 30 minutes straight!  I’m really surprised I slept through the tornado and the noise racket!  Must’ve been tired!
I don’t snore, but maybe there is some low-level vibration in the air channel due to the partial obstruction that is responsible for the bumpy breathing waveforms.  The problem is confirming this and what if anything to do about it.  Perhaps Sleeprider will chime in on this subject since he’s seen it before.  I hope so.

Thanks for sharing your knowledge!


RE: Airsense 10 not flagging apneas?? - dwd1249 - 11-06-2017

(11-06-2017, 04:28 AM)DeepBreathing Wrote: There was a thread a few months ago where member dwd1249 was experiencing some similarly weird flow charts and high respiration rates. You can read all about it here: http://www.apneaboard.com/forums/Thread-Is-my-breathing-shallow?pid=212868#pid212868  After 8 pages of suggestions, and multiple changes to pressures, EPR etc etc it came good. Nobody (including his doctors) really understood what caused it. If you read through the thread you might be able to pick up any parallels to your own situation.

By the way, if you turn off the calendar in your screen shots, it will allow more machine setting details to show up.

How's your nose ?

Since that time all has been fine except one night a few weeks back. I had mowed the lawn on Monday afternoon had some very dusty areas. Monday night slept ok. Got up Tuesday and spend all day with a very runny nose. Tuesday night I woke up a few times with rapid breathing . Wednesday was back to normal.  
I put it down to some sort of allergic reaction to dust and grass seed.


RE: Airsense 10 not flagging apneas?? - Sleeprider - 11-06-2017

Wow! That's messed up!  (not really)...What is happening in this screenshot is about 14.5 breaths per minute.  For some reason, the inhales start and stop with no exhale in the brief pauses, but nearly 5 inhale strokes, followed by an exhale, and repeat.  I have no clue what might cause this, but you eventually get a full breath, and exhale.  It looks like a form of extreme inspiratory flow limitation (that is not a diagnosis).   I'd go through the detailed data and see if that correlates to higher pressure or some other cause.  In this particular case you are near maximum pressure. 

I haven't looked at everything you have posted, and will get back to this after dinner.  There might be something we can try. 


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RE: Airsense 10 not flagging apneas?? - Sleeprider - 11-06-2017

Okay, back.  Looking at other graphs the pulsed inspiration is not limited to only high pressure.  The place where this thread started is pretty obvously a series of apnea resulting from ramp, and the ramp needs to be discontinued. The OA and flow limits are not counted during ramp, but a closeup of that flow rate chart would show that they are prevalent until pressure reaches a therapy range of about 12 cm.  We don't know why this pattern is occurring, but the only way I know to find out is to experiment with the pressure and EPR and see what works.  So far, we have seen no central apnea, so when we see predominately OA, FL and RERA and unstable inspiratory flow, I kind of think higher minimum pressure and higher EPR (pressure support) might be more helpful.  I think you might benefit from bilevel which could apply more meaningful pressure support. 

I'll start with a recommendation of 12.0 cm minimum pressure and EPR at 3. Leave maximum pressure at 20.  Avoid ramp, or start at 8.0 cm for 10 minutes.    I don't see a lot of scored events, but I'm curious what is going on with all the erratic flow rate.  What is going on here at 00:00 or 02:00 that looks like shallower breaths mixed with larger ones?  Why is the net leak rate stable at 15 L/min, when it should be near zero?  Why does it look like you are doing Lamaze breathing? 

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