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Totally Confused by Airsense 10 Data - Centrals - Problem machine... ?
#31
(12-09-2016, 11:34 AM)robysue Wrote:
(12-09-2016, 02:15 AM)mymontreal Wrote: My average pressures seem pretty low (which is great), but I struggle to see how my current data ties back to my typical "no cpap" sleep study AHIs of (25-64), zero CAs and a titration test, that recommended pressures of 12+

Any additional thoughts ?
One night in a lab does not always represent what's going on. Although "over titration" is rarer than "under titration" it does happen. You may have had a nasty cluster that night shortly before you woke up which lead to the final recommended pressure setting.

Do you have the summary graphs from the titration study? They would show exactly when the pressure was adjusted and why it was adjusted each time.

Quote:My machine settings have now been unchanged for 2-3 weeks and given that my median pressures are so low, I'm thinking of trying a night of straight CPAP at a fixed pressure of 6 or 7, to see what happens to the data... ?
It's certainly worth a try. Not everyone does better on APAP than fixed CPAP. I'd say it's well worth experimenting with fixed pressure for 3 or 4 nights to see what happens.

Robysue - attached is the summary table from my titration study back in 2008 - the titration graphs don't show very much and are a bit blurry, but here is the table:

[Image: 3wzlQbAl.png]

On the basis of this, they originally prescribed a pressure of 12 & whilst I agree this matches to the lowest RDI value, how about pressures from 5 to 9... ? Does not look like they tried any lower pressures and I suspect some people (maybe me...) may do better on lower pressures... ?

You will also note that with this CPAP titration, there only appeared to be Hypopnea events (no centrals and no obstructive events).
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#32
Reread my post #24.

Rich
Apnea Board Member RobySue has posted a Beginners Guide to Sleepyhead Software here:  http://www.apneaboard.com/wiki/index.php...SleepyHead

Download Sleepyhead
Organize your Sleepyhead Charts
Post from Imgur


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#33
(12-09-2016, 06:14 PM)richb Wrote: Hi again mymontreal. I want to go back and look at some of the questions that you had earlier in our ongoing discussion.
You asked: "1. Where are the OA events... in every sleep study I had, I had mainly OA (with quite a few H) - here, there appears to be no sign of any OA events, even when the pressure is as low as 4 or 5... ?
2. Still surprised that average pressures are so much higher since we turned off EPR ?
3. What is relationship (if any) between # of CA events, and the "Cheyne-Stokes Respiration %" that I oft see ?"
Regarding question #1: Two different things could have happened to you. The first and least likely is that you are a different person than the one who had the original sleep study. By that I mean that you are cured somehow of most of the OA events found in your original sleep study. You did mention a surgery. The other possibility that I am considering is that you were completely misdiagnosed in your previous sleep studies (it happened to me). You never did have Obstructive Apnea. What you did show were Hypopnea and Apnea events. Based on the Sleepyhead graphs that you posted it appears that you continue to show Hypopnea and Apnea events. Question #3 is relevant here. CSR or Cheyne Stokes Respiration is a particular pattern of Central Apnea. The respiration pattern looks like a sine wave. My machine produced long intervals of CSR at fairly low pressure. CSR has also been associated with Congestive Heart Failure. Most of the research on CSR has been done on CHF patients. I do not have CHF but I did have machine induced CSR. You most likely do not have CHF and it is only an issue if you get an ASV machine. For question #2: EPR lowers your exhalation pressure and thus lowers your overall average pressure.

Now, you have made some good progress in taking charge of your treatment. I like your idea of using straight pressures and gradually lowering your pressures to see if the Centrals and Central Hypopneas go away. I said Central Hypopneas but I don't know for sure if that is what they are unless I and others can see the wave forms of the individual Hypopnea breaths. You need to highlight 5 minute intervals of your Flow waveform so that you can see the individual breaths during a Hypopnea episode. Hypopnea breaths look similar to normal breaths but are much reduced in size. Obstructive Hypopneas on the other hand have a flattened top more like an upside down box. The top is flattened because the inhalation flow is cut off or partially cut off and is followed by the exhalation. You may be able to reduce the Central events which include CAs Hypopneas and Cheyne Stokes respiration by lowering your pressures. You have to try anyway. You may find that these CA events can't be substantially reduced or eliminated. If this is the case you would be a candidate for an ASV machine. You would also be a candidate for a different Sleep Doctor. I found mine at my "local" University Teaching Hospital. So, keep working on this and post some of those 5 minute wave forms along with your other data.

Rich

pressure.

Hi Rich and all

I have taken a couple of sample nights and zoomed in to a 5 minute window around some Central and Hypopnea events - not sure what the resulting waveform shows, but would be grateful for any additional input from You or other posters - feel free to let me know if you would like me to zoom in on a different part of the graph.

Date 12-09-16, AHI=2.92, Original SH graph:

[Image: Vubwfmdm.png]


Date 12-09-16, AHI=2.92, 5 min zoom on a CA event:

[Image: 0d2VFmIm.png]

Date 12-09-16, AHI=2.92, 5 min zoom on a H event:

[Image: iscKz53m.png]





Date 12-03-16, AHI=8.88, 5 min zoom on Central events:

[Image: IJCU5O3m.png]

Date 12-03-16, AHI=8.88, 5 min zoom on Hypopnea events:

[Image: GNaAh23m.png]



And one final piece of data Smile

Date 11-19-16, AHI=11.48, 5 min zoom on a period of supposed CHEYNE-STOKES breathing... :

[Image: XmKOSs3m.png]


Thanks, Mike
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#34
Hi Mike. Thanks for the detail. Your graphs are showing fairly classical Central Apnea breathing. Notice that just prior to declaring a CA event your graph shows a darkened low amplitude waveform. This is your machine putting out a low frequency (4HZ) pulse of air. The resulting resonance shows if your airway is open or closed. In your case the airway shows that it is open. You just stopped breathing. Classical Central Apnea. You also have some mild periodic breathing showing up. Periodic Breathing shows up as a rising and falling pattern like a roller coaster. If you look at your Hypopnea cluster http://imgur.com/iscKz53 you will see the periodic breathing along with instances of very shallow breathing for more than 10 seconds. Those are marked as Hypopneas. Some of the shorter duration Hypopneas weren't scored When you look at the very shallow breaths you see that they resemble your normal breaths only in miniature. Your airway is still open but your breathing is just very shallow. Thus I would characterize them as Central Hypopneas. Your AHI is pretty good but your sleep might be more disturbed by instances of periodic breathing and shorter duration Hypopneas that are not scored as Hypopneas. Do some searching through your Flow graph and look for more instances of Periodic Breathing that are not getting scores. You may also want to get a recording Pulse Oximeter to look for O2 desaturations. These can also disturb your sleep and raise your blood Pressure. Finally I think you have too much separation between your EPAP and IPAP pressures being 5 and 9. This differential can cause CO2 washout which aggravates Central Apnea and causes Periodic Breathing and Hypopneas to escalate to full blown scored CAs. I would move the 5 to 6 and after a couple of days move the 9 to 8. You will be doing a self titration to find a sweet spot where your pressure is low (but not so low that you have Obstructive events) and you have a minimum of CAs and Hypopneas. There is a chance that your present setting is optimal but I will be very interested in seeing your graphs as you progress through settings. Stay in touch.

Rich
Apnea Board Member RobySue has posted a Beginners Guide to Sleepyhead Software here:  http://www.apneaboard.com/wiki/index.php...SleepyHead

Download Sleepyhead
Organize your Sleepyhead Charts
Post from Imgur


Post Reply Post Reply
#35
(12-11-2016, 09:44 PM)richb Wrote: Hi Mike. Thanks for the detail. Your graphs are showing fairly classical Central Apnea breathing. Notice that just prior to declaring a CA event your graph shows a darkened low amplitude waveform. This is your machine putting out a low frequency (4HZ) pulse of air. The resulting resonance shows if your airway is open or closed. In your case the airway shows that it is open. You just stopped breathing. Classical Central Apnea. You also have some mild periodic breathing showing up. Periodic Breathing shows up as a rising and falling pattern like a roller coaster. If you look at your Hypopnea cluster http://imgur.com/iscKz53 you will see the periodic breathing along with instances of very shallow breathing for more than 10 seconds. Those are marked as Hypopneas. Some of the shorter duration Hypopneas weren't scored When you look at the very shallow breaths you see that they resemble your normal breaths only in miniature. Your airway is still open but your breathing is just very shallow. Thus I would characterize them as Central Hypopneas. Your AHI is pretty good but your sleep might be more disturbed by instances of periodic breathing and shorter duration Hypopneas that are not scored as Hypopneas. Do some searching through your Flow graph and look for more instances of Periodic Breathing that are not getting scores. You may also want to get a recording Pulse Oximeter to look for O2 desaturations. These can also disturb your sleep and raise your blood Pressure. Finally I think you have too much separation between your EPAP and IPAP pressures being 5 and 9. This differential can cause CO2 washout which aggravates Central Apnea and causes Periodic Breathing and Hypopneas to escalate to full blown scored CAs. I would move the 5 to 6 and after a couple of days move the 9 to 8. You will be doing a self titration to find a sweet spot where your pressure is low (but not so low that you have Obstructive events) and you have a minimum of CAs and Hypopneas. There is a chance that your present setting is optimal but I will be very interested in seeing your graphs as you progress through settings. Stay in touch.

Rich

Thanks Rich - great info!

I've now read through some of the guides and watched a number of Youtube videos and think I at least have a better understanding of what constitutes a real CA event and what is probably fake... Smile

Thanks to SleepyHead, it's fascinating to be able to zoom in on events and actually look at what's happening in terms of breathing...

I think I also now understand that there is sometimes no clear breakpoint between one type of event or another... all depends on how the specific machine algorithm interprets it...

Quick question - if I look at the attached zoom that covers both a CA event and an OA event (rare for me...), there doesn't appear to be a lot of difference between them ? The OA event is apparently 16 secs and the CA event is apparently 25 seconds, but in both cases there appears to be ZERO flow-limitation, so why is one defined as an OA and the other as a CA... ?

[Image: OEDT4IEm.png]

Thanks
Mike
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#36
Mike. I agree that it is hard see the difference between the 2 events. The dark low amplitude nearly flat lines prior to the events being scored is the machine trying to determine if the airway is open. The machine puts out a 4 Hz air pulse that sets up a resonance in an open airway. The machine may have got it wrong. But one thing to look at is the shape of the recorded breaths to see if they are cut off or flat across the top. If this is the case it indicates that the inhalation was cut off while in progress. In the event marked OA there appears to be a tiny flat top inhalation prior to the total pause in breathing. That could indicate the collapse of the airway and therefore the machine got it right. You did mention that you have occasional OAs. Look at the other graphs showing scored events that you previously posted. You will see that the breath waveforms surrounding the CAs and periodic breathing all have fairly pointed tops indicating that the airway was open. It appears that OA events are rare in your case. Another thing to look at is your breathing during periods where no events are scored. You may still see disruptions in your breathing that can disturb your sleep.

Rich
Apnea Board Member RobySue has posted a Beginners Guide to Sleepyhead Software here:  http://www.apneaboard.com/wiki/index.php...SleepyHead

Download Sleepyhead
Organize your Sleepyhead Charts
Post from Imgur


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#37
(12-14-2016, 07:25 PM)richb Wrote: Mike. I agree that it is hard see the difference between the 2 events. The dark low amplitude nearly flat lines prior to the events being scored is the machine trying to determine if the airway is open. The machine puts out a 4 Hz air pulse that sets up a resonance in an open airway. The machine may have got it wrong. But one thing to look at is the shape of the recorded breaths to see if they are cut off or flat across the top. If this is the case it indicates that the inhalation was cut off while in progress. In the event marked OA there appears to be a tiny flat top inhalation prior to the total pause in breathing. That could indicate the collapse of the airway and therefore the machine got it right. You did mention that you have occasional OAs. Look at the other graphs showing scored events that you previously posted. You will see that the breath waveforms surrounding the CAs and periodic breathing all have fairly pointed tops indicating that the airway was open. It appears that OA events are rare in your case. Another thing to look at is your breathing during periods where no events are scored. You may still see disruptions in your breathing that can disturb your sleep.

Rich

Thanks again Rich.

So I think I've now come to the following conclusions about where things stand - do these make sense ?

1. Most of my recorded CA events appear to be real (All at least 10 secs in length and no preceding junk) - however, we still don't know whether they are possibly caused by some underlying health issue, or whether they are machine induced ?

2. As per several suggestions, I will fine-tune the pressure range (or even try straight CPAP) to see what effect this has (if any) on number and duration of CA and H events.

3. I think I have to forget trying to understand, why I no longer appear to have any OA events most nights... Despite hundreds of OA events (and maybe 2 CA events) shown in total of 5 overnight sleep studies over a period of 8 years... just forget trying to understand why they all seem to have disappeared... probably no way to know... Smile

4. Maybe invest in a recording oximeter, to see how low my oxygen levels are falling during the CA events (particularly the CA events that exceed 20 secs...) and any reported periods of CSR - any particular type you would recommend, that would import easily into SH ?

5. Whether it's normal or not (?), I have also noted that on most nights I don't appear to have ANY events during the first 2.5 hours of sleep (unless of course they are there, but being dealt with at low pressure of 4-5)

Thanks
Mike
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#38
I think you are getting a pretty good handle on your present situation. Be sure to take a look at the detail of a nights flow graph in 5 to 10 minute sections to see what your breathing looks like during periods when no events are being scored.

Rich
Apnea Board Member RobySue has posted a Beginners Guide to Sleepyhead Software here:  http://www.apneaboard.com/wiki/index.php...SleepyHead

Download Sleepyhead
Organize your Sleepyhead Charts
Post from Imgur


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#39
So, I've now used the machine for more than 2 months and continue to struggle with what seems to be almost all CA events...

Altering the pressure range seems to have no real effect on my Total AHI or on the large percentage of CA events... Total AHI seems to vary between about 4 and 10. Typically shows as 80-90% CA events and typically shows Cheyne-Stokes breathing patterns for 15-20% of the night, on SOME nights.

Last night is typical - I've now had about 10 days on a very low APAP pressure range of 5.0 - 6.4 and I appear to get the same spread of CA events that I get every night - pressure does hit the upper level (6.4), but I only see ONE hypopnea event for the whole night and ZERO OA events...

Where do I go from here... My sleep Dr continues to advise me that I definitely don't have Central sleep apnea (based on numerous overnight sleep studies over the last 5-6 years) and that I may have a faulty AirSense 10 APAP machine... ?? Sad

Last night's SH Graphs:

[Image: hv4WbCNm.png]

Zoom in on a few CA events/CS breathing:

[img][Image: LJbfwb1m.png][/img]

For comparison, zoom in on a 3 min period of normal breathing:

[img][Image: sNj3uVxm.png][/img]

I really appreciate everybody's input to date, but am starting to pull my hair out in terms of next steps...

Bottom line in terms of how I feel - still pretty tired for much of the day, but not nearly as bad as if I sleep without the machine at all...

Three things I am considering:

1. Try to rent a different manufacturer/type of APAP machine for 30 days, to see if this also shows mainly CA events and CS breathing, with almost no H and OA events ?

2. Start using pulse oximeter to see if there is any real reduction in oxygen levels during the periods when I am seeing the 10-25 second CA events, or when it appears to show Cheyne-Stokes breathing ?

3. Contact the online CPAP supplier where I bought the Airsense 10 APAP machine brand-new approx. 2 months ago, to see if there is any way we can test to see if the machine is faulty ?

Many Thanks
Mike

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#40
Two options I can think of.
1. new doctor.
2. buy a ASV machine on your own dime and be done with it.

It's obvious you won't persuade your current doctor of something he just knows can't be. Of course the data you collect every night says he is wrong. That is a brick wall you shouldn't bang your face against any longer. ASV machines come up used and in the gray markets at substantial discounts. Keep your eyes open, and if the opportunity presents itself, jump on it.
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