Domino96 Therapy Thread

[Domino96]

I'm coming up on year of cpap/apap therapy.  March 2nd will mark the year. I've learned a bit (mostly on my own) but still have lots of questions.  Only learned about Oscar in December which has finally given me useful tools to track and fine tune things.  Overall sleep has improved, but my biggest frustration has been inconsistency of results. So, I'm going to start with that question.  My monthly average AHI has ranged from 10.96 early on to 3.44 last month.  During the last month my AHI has ranged from a low of .97 to a high of 6.40 with a median of 3.17.  I use an Airsense 10 autoset with current pressure of 11 to 20 and EPR of 3.  

My question is, should my results be more consistent or is it to be expected that results should vary that much from day to day?  

I have attached screen shots that give an overview of the past month and shots that show the days of the highest and lowest AHI during the past month.

[Expat31]

Hello, 

Thought I would pick up your thread to see if I can help out. 

The big difference in swings I see between the two nights posted, is the tight grouping of apnea events on the night of 21st of January indicating positional apnea. 

In your sleep study, was a breakdown of AHI by sleep position?  (Often sleeping on your back is the culprit)

The other area of concern are flow limitations. Again worse on the 21st,

On the 21st again,  you pressures  were higher, I bet due to these apnea clusters. 

How about the quality of sleep on the night of the 13th with the AHI at only 0.97, was it better?

Let us know.

[Domino96]

Thanks for your reply. 

Sleep study (which was done is a sleep lab) did show sleep position.  I slept on my back the whole night which is not characteristic of me.  I think that it was because of all the wires I was connected to and feeling tied down.  I normally split my time between side and back, but of course you can't tell sleep position from the information we get here.  My apnea is in the severe range (AHI in the mid 40's), and I probably do have some positional issues and since that date I have switched to a flatter pillow which seems to be at least some better.  However, a lot of times when I have tightly clusted events, those will not match up with higher flow limitations.  

Isn't cpap/apap therapy supposed to reduce the flow limitations? 

Overall since beginning therapy, sleep quality is much improved, but I remain frustrated by the inconsistency of results from day to day as fewer events generally mean a higher quality of sleep.

[Expat31]

I will firstly answer your two questions:-

1)  Should the results be more consistent?  
I would say in your case yes, as the general swings in results are much too wide, and the patterns seem to be repeating quite often. 

However, everyone has big swings from time to time, but if it is a continual repeating pattern,the cause should be identified and tried to be resolved. 

2) Isn't cap/apap supposed to reduce the flow limitations? 

Yes, but the scope is fairly limited. In your case you are already at EPR of 3. Beyond that, it becomes the domain of a true bi-level machine, such as one of the Aircurve models.

It seems that you have already made quite a few pressure adjustments already. I don't see any scope for any further pressure changes, until you have addressed the underlying causes. 

On the night of 13th of January, your pressure settings seem quite effective. With the identical pressure settings, they were ineffectual. Just look at the flow rate graph.

Positional apneas. -(some general notes). 

There are two main distinct causes of positional apnea. 

1)     “Crimping” of  the œsophagous airway, whereby the head moves towards the chest causing a significant distortion, enough to block the airway, either partially or completely. In the supine position, it is gravity that is a significant factor, especially in deep sleep when there is a semi paralysis of the muscles. You will have seen many references in the forum to the use of soft cervical collars that appear effective in many cases. 
These collars can also be effective in the foetal side sleeping position, when curling up. I don't think gravity plays a role here. 
Here is a short video presentation that illustrates the crimping effect. Positional sleep apnea-the compelling case for straightening-out upper airways.

2)     The impact of gravity causing your jaw, tongue and soft palate to drop back towards your throat, narrowing or closing your airways. A collar could help here, unless only your tongue drops back, then I found the only solution was to train myself to keep off my back by using a kind of chest brace with tennis balls sown in. Now all OK, don't need it. 
 
To eliminate any potential positional apnea, a collar may be effective see Soft cervical collars.

One further thing, as you had a lab test, were there any doctors useful conclusions ons? 

[Sleeprider]

Events are clustered and strongly suggest "positional apnea". For a little more expansive understanding of the positional apnea issue (also known as chin-tucking) read the Positional Apnea wiki: https://www.apneaboard.com/wiki/index.ph...onal_Apnea You may find a soft cervical collar mostly elinates this problem and allows lower pressure. https://www.apneaboard.com/wiki/index.ph...cal_Collar

Positional apnea obstructs the upper airway and causes clusters of flow limitation, RERA, hypopnea and obstructive apnea. Many times we see CA events flagged where obstruction is high enough to cause an apnea to be flagged (30% or less of baseline flow) but you keep breathing through the partially obstructed airway which appears to the machine like a clear airway apnea. That's mostly what I see in your charts. You may be able to resolve this with revisions to your pillows or sleeping position, but with AHI over 6, I think you are going to need a good collar to correct this.

[Domino96]

In reviewing the event chart and Flow limitations graph, I have noticed that consistently, the hypopneas and RERAs line up with flow limitations but the clear airways and obstructive apneas do not line up with Flow limitations.  Why is this? What conclusions can be drawn from this?  I have attached a example below.

[Sleeprider]

I need to see this zoomed into about a 2-3 minute segment so I can see what is going on with the wave-form. The oscillations look central, but this far out I can't see the flow limits which are usually obstructive.

[Domino96]

Thanks for looking at this.  I've attached some zoomed in samples as you suggested.

[Sleeprider]

Thanks. The events are obstructive and flow limited. You should keep the EPR at 3 and consider trying to resolve positional apnea by avoiding tall or firm pillows, inclined sleeping and perhaps back-sleeping. A soft cervical collar may be needed to avoid chin-tucking. I previously linked to our wiki articles on that topic.

[Domino96]

Thanks.  Just trying to make sense of the relationship of flow limitations to events.  It makes sense that clear airway apneas would not be connected to flow limitations as that is the result of the brain not telling the body to breath, but I'm wondering if my cpap machine is miss identifying CAs as OAs when when there are no flow limitations showing up.  Could they really be CAs instead?  Is there a way to tell if that is happening? Asked another way--are their signs or clues that an event is obstructive without regard to what's showing up on the flow limitation graph?