EERS Experiment Data (sherwoga)

[slowriter]

I tried EERS for two nights, and the one impact that was clear was the significant (20%) increase in median TV.

I gathered the parts to test EERS as I was having some treatment emergent CAs, which went away around the same time, so I had nothing to conclude on impacts on CAs. Why I didn't feel the need to continue.

[sherwoga]

I tried EERS for two nights, and the one impact that was clear was the significant (20%) increase in median TV.

I gathered the parts to test EERS as I was having some treatment emergent CAs, which went away around the same time, so I had nothing to conclude on impacts on CAs. Why I didn't feel the need to continue.

I think my Central Apneas were declining when I started this effort, but they had lasted for well over a year and a half.  My knowledge of my sleep performance as of October last year was limited to my AHIs as reported at MyAir.com.  That was total AHIs, i.e., not further classification was available at MyAir.  

At that point 

• I went to a new pulmonologist, 
  
• became aware in his office of the clinic mode of my machine, 
  
• searched online for a manual, 
  
• obtained one at the Apnea Board Forum, and
  
• the rest is history.  
  

My daily AHIs up to that point were very inconsistent, occasionally in the low 20's.  When I imported data into OSCAR from my AirSense 10 Autoset the first time more than a year of data was dumped all at once.  It was NOT detailed data as it had all been acquired in the machine itself without any SD Flash Card (none was inserted by my DME supplier or prescribed by my first pulmonologist and I wasn't aware enough to get one myself).  But the data was detailed enough for me to see that the higher AHIs corresponded to nights with higher CAIs.  My OA events were pretty low throughout.  

The evidence for what I am claiming was a declining CAI comes from the statistics page of OSCAR in Monthly Mode. I'm inserting a capture from a current summary page below.  OSCAR apparently only reports one years worth of data at a time.  I still see in the report a weak downward trend in the monthly averages of AHI (read from right to left) and CAIs.  As of October I was still operating well above 5.  My first pump setting change occured on Nov 6 and you can see an immediate drop in both AHI and CAI.  It doesn't look to me like OAIs went down much at all.  

   

A significant part of the decline after Nov 6 is due to EERS use, but in a very sporadic randomized way during the designed experiment, which is still ongoing, but is to end later this week or early next week.

[Geer1]

The problem is that you are not trying to figure out EERS but rather trying to find a magical setting with too many variables and an unclear understanding of what the finish line looks like. You need to learn the basics about the different settings and make informed decisions on when and why to change them rather than continuing this guess and check game.

1) EPAP is important in that it is required to hold the airway open. The reason you were told to keep EPAP the same is that EPR and PS are used to increase flow by increasing IPAP while holding EPAP constant. This makes sense and varying it as another variable does not. You have the odd obstructive apnea so might need to consider EPAP setting but that would be the only reason to change it. 

2) EPR (and PS once bilevel) is called pressure support. Larger EPR/PS induces larger flow, this is a simple mechanical process as pressure differential is what causes flow and the higher the differential the higher the flow. Increased flow is what allows EPR/PS to overcome flow limitations, therefore if you are having flow limitations you want higher EPR/PS (within reason, too high of PS can cause issues especially since different stages of sleep have different levels of ventilation requirement). You have already proven you need EPR of 3 if not higher PS hence why you are now looking at a bilevel. Continuing to think you might find a magical setting at an EPR of 2 or lower is a waste of time.

3) EERS length determines the amount of CO2 you will rebreath. The amount of CO2 you should be rebreathing is determined by the amount required to maintain your CO2 levels above the apneic threshold (when your body decides not to breath). In the study they were targeting 1-2 mm Hg above the wake eupnic level which must accomplish this. They also mention that if you go too high you run the risks of increasing respiration rate or heart rate (as the study calls them tachypnea or tachycardia) which I personally have encountered when one of my mask vents became partially blocked and it is horrible... I saw your example of high respiration rate and it is ridiculous to ignore that as your breath waveform looked like complete trash, yes the reported respiration rate was not necessarily what was being indicated but that doesn't mean the breathing was not an issue... If that breathing was being caused by the EERS you need to avoid it, if it wasn't caused by the EERS you have some other breathing issue causing that situation you should get looked into. EERS length isn't a variable, there is an ideal length and that is what you should have been trying to find. There may be minimal changes in tidal volume at different PS levels that will modify CO2 levels and thus EERS length may need to vary slightly but for example one of your EPR 1, EERS 12 tidal volumes was 700 and EPR 2, EERS 12 was 720. The change in EERS length if any would be minor(as in mm's not 6 inches). 

Without access to a CO2 monitor (assuming they are expensive or hard to get, not sure as I haven't looked into it) then what seems like the obvious way to try and size an EERS would probably be to first titrate the patient's XPAP machine as best as possible to deal with obstructive apnea, hypopneas and flow limitations and then start with a short EERS length and slowly increase it (1 inch at a time) until the patient's number of central apneas declines. Then you might want to add another inch or two just to provide a bit of buffer room but we won't know that until we can see how patients react. 

The issue with flow limitations is that they either make it so not enough air is being inhaled or causing CO2 to build up which causes arousals, in the later case EERS makes that worse by adding even more CO2... How did you feel after sleeping with EPR off and 18 inch EERS? Like crap? If you felt like crap that should have been expected, if you didn't feel bad then the flow limitations likely aren't causing arousals and significant build up of CO2. If flow limitations are limiting oxygen intake then you can confirm that with an oximeter.

I see you have committed to a Vauto, do yourself a favour and change your approach. Lets target finding ideal settings and this should start with Vauto mode, EPAP = 5, PS = 4 and probably no EERS to confirm presence of centrals. I see from your last post that centrals were a problem so should be apparent off the get go due to the higher PS. If so try your EERS 6 inch model and see if it gets centrals under control. If your flow limitations and centrals both look good congratulations you probably already found close to ideal settings now try them out for a while to see how you consider your sleep to be. If you aren't having centrals then a longer EERS should not help, if you feel you are getting bad sleep try a shorter model. If graph shows flow limitations appear to be an issue try bumping up PS slightly (go in slow steps like probably 0.5). If obstructive apneas are a problem increase EPAP. 

Make informed logical decisions rather than guess and check. There are too many variables and you will never hit the target if you keep shooting blindly.

[slowriter]

While much of this is accurate itself, you're being awfully pedantic. I'm pretty sure sherwoga understands much of it already, for example.

[Geer1]

While much of this is accurate itself, you're being awfully pedantic. I'm pretty sure sherwoga understands much of it already, for example.

This forum recommended I get my grandfather to try EERS. No way I would do that unless I felt comfortable that I would know how to properly set it up and after seeing  a 2 month test in which another user has struggled to do so or learn much about the process I have little comfort in the situation and I believe EERS could cause issues that a lot of people with less understanding would not even realize is an issue.

For example that ugly breathing example Sherwoga posted. That could very well be a significant issue being caused by EERS (Sherwoga would be able to confirm if his breathing normally looks like that or if it appeared to be induced by the EERS but he already kind of indicated that he was noticing it more with EERS). What do you believe the long term effects of breathing like that would be? 

Sherwoga seems bright but lots of other members being recommended EERS struggle to even operate OSCAR let alone know how to read it in detail and properly treat themselves. I just think people need to be a little more careful with EERS and that a better way of figuring out EERS sizing needs to happen before it causes issues.

Edit: And Sherwoga, you may already know a lot of what I am saying. The reason I am posting it is for others reading the thread that might not know. Personally I don't recommend anyone perform another test the same as this but that is just my opinion.

[sherwoga]

While much of this is accurate itself, you're being awfully pedantic. I'm pretty sure sherwoga understands much of it already, for example.

This forum recommended I get my grandfather to try EERS. No way I would do that unless I felt comfortable that I would know how to properly set it up and after seeing  a 2 month test in which another user has struggled to do so or learn much about the process I have little comfort in the situation and I believe EERS could cause issues that a lot of people with less understanding would not even realize is an issue.

For example that ugly breathing example Sherwoga posted. That could very well be a significant issue being caused by EERS (Sherwoga would be able to confirm if his breathing normally looks like that or if it appeared to be induced by the EERS but he already kind of indicated that he was noticing it more with EERS). What do you believe the long term effects of breathing like that would be? 

Sherwoga seems bright but lots of other members being recommended EERS struggle to even operate OSCAR let alone know how to read it in detail and properly treat themselves. I just think people need to be a little more careful with EERS and that a better way of figuring out EERS sizing needs to happen before it causes issues.

Edit: And Sherwoga, you may already know a lot of what I am saying. The reason I am posting it is for others reading the thread that might not know. Personally I don't recommend anyone perform another test the same as this but that is just my opinion.

Thank you for your input.  

Only thing I would like to address here is the worry that the EERS is causing my squirrelly flow pattern.  I emphasized that that graph came from last night's data and that I did NOT use the EERS last night.  But in response to your highlighting this issue, I went back to my experimental log and looked for other nights without the EERS and found multiple examples where the pattern is present (once for 2.5 hours) when the EERS was not used.  I conclude there is no cause and effect here (although doing so is dangerously close to an OFAT   at least trying to be funny! ).  

That is not to say that I believe that all other potential users of the EERS shouldn't be equally as cautious as you indicate.  

Further, it is appropriate to try to address this flow problem.  I'm hoping that, as multiple others have suggested, increased pressure support will help.  The Vauto will be the tool I will use next to find out. It will remain to be seen whether the EERS is also necessary to control central airway events.  Based on my historical data I think it will be.  Theory guides, but experiment decides!!! 

I completed the purchase a couple of hours ago and my contact still says delivery will be Wednesday. But I still have four nights of data to collect with my current equipment before I switch.  So if I can discipline myself to keep on my current plan, it will be Friday night when I switch. Admittedly I'm excited to get the new pump!

[Geer1]

That breathing is not normal, I would try and figure out when it is occurring and if possible why especially if it is occuring with any regularity.

If it has something to do with flow the extra ps of vauto might help so watch to see if it helps. If flow etc doesnt seem to help it I would be looking for doctor's advice to explain it.

Your tiredness etc could be as simple as that breathing. 

Back to EERS how did you settle on sizes? From what I see in thread 6 inches is around 60 ml then you also have elbow, mask and part of vent swivel. Just a guess but your 6 inch is likely in the 100-150 range already and 18 inch version around double what the studies use. Maybe I missed something though.

[sherwoga]

That breathing is not normal, I would try and figure out when it is occurring and if possible why especially if it is occuring with any regularity.

If it has something to do with flow the extra ps of vauto might help so watch to see if it helps. If flow etc doesnt seem to help it I would be looking for doctor's advice to explain it.

Your tiredness etc could be as simple as that breathing. 

Back to EERS how did you settle on sizes? From what I see in thread 6 inches is around 60 ml then you also have elbow, mask and part of vent swivel. Just a guess but your 6 inch is likely in the 100-150 range already and 18 inch version around double what the studies use. Maybe I missed something though.

I estimate that the extra volume in the adapter and swivel valve (call them connectors) is no more than 10 to 15 cc.  That is rough but a visual examination of the 6 inch tube along side the connectors suggests that the connectors add dead space the equivalent of less than an inch each.  The 6 inches is 58 cc. A 25% increase would add about 15 cc bringing the total to about 73 cc.  The 12 inch tube is 116 cc (2 times 58) without the connectors or 116 plus the same 15 for 131 cc.  The 18 inch would be 174 (3 times 58) plus the same 15 for the connectors or 189 cc.  Further the volumes stated in the article were just as approximate and not corrected for additional dead space in the connectors.  I remain cautious but unworried.  I have thought about it a great deal.  

Further, those flow patterns have been what this is about since pretty early in this effort.  High PS hopefully will address those patterns, but the higher PS will probably bring on the centrals through the more efficient removal of carbon dioxide from my blood and then the lowering of the impulse to breathe.  That is to say the ventilation mechanism will get all messed up.  The EERS will hopefully turn the centrals back off by modulating the efficiency of carbon dioxide removal from my blood.  Just how much is needed is what I am committed to investigating.

For now in the absence of the Vauto, my experimental results pointed me to an EPR of 3 and a EERS of 12 inches resulting in multiple nights with AHI's below 2 (i.e. all measured events are low) but the lousy, ugly, squirrely ... flow patterns persist.  Bring on the Vauto! It will be great to have data in hand the next time I see my pulmonologist.  That's my plan.

[Geer1]

I believe you are supposed to include mask which would be substantial and something you didn't account for.

I don't believe that is flow limitation if that is what you are thinking. Not sure what to call it but almost looks like your diaphgram is tremoring or something along those lines causing your breath to change direction during both inhalation and exhalation. Asynchronous breathing might be a term worth researching, it seems like it might be similar or eventually point you in the right direction.

[sherwoga]

I believe you are supposed to include mask which would be substantial and something you didn't account for.

I don't believe that is flow limitation if that is what you are thinking. Not sure what to call it but almost looks like your diaphgram is tremoring or something along those lines causing your breath to change direction during both inhalation and exhalation. Asynchronous breathing might be a term worth researching, it seems like it might be similar or eventually point you in the right direction.

I suppose for some very rigorous scientific purpose the volume inside the mask counts in calculating total Rebreathing Space.  I look at this as being a case of a change.  The EERS is inserted into the supply line creating an increase in Rebreathing Space and it is that increase that I am and have been focused on.  Further, technical articles I have read where experimentation is reported discuss the volume of the EERS in increments of 60 cc or so, i.e., not particularly rigorous.  But if I grant an additional 50 cc inside the mask, we still don't get to 300 with the 18 inches of EERS tubing.  

You are the first to propose something like the diaphragm tremoring.  I will certainly be discussing the flow patterns with my pulmonologist as soon as I can.  A review of asynchronous breathing hasn't yielded much for mild breathing problems.  It seems to be related to some very severe breathing disorders.  And nowhere have I found any breathing flow patterns of any sort offered as evidence of asychrony.  A search for diaphragm temors or flutters was a bit more useful, just because the words seem to give a better description of what appears in my patterns.  Also, they lead to the idea that my phrenic nerve might be involved if this is the correct assessment.  At least those observations provide starting points to discuss with the doctor.