Woofer777 - OSCAR Analysis

[Woofer777]

I've completed the first phase of testing at Fixed Pressure = 9 and EPR = 2.  The 4 day averages by events are:

CA = 6.6  OB = 2.8  HY = 1.7  RE = .1  AHI = 11.1   Results varied from AHI = 9 to 14.  

In general, sleep has been far more comfortable with the lower pressure level (compared to 12 and higher upper limits).   Unfortunately, overall numbers are not better -  with slightly higher OB.  Centrals remain high.  As a further note, I am unable to perceive any differences in quality of sleep night to night, even though numbers have varied. 

Tonight  (and for 4 nights) , Fixed Pressure = 7 and EPR = 0.  Unless, based on above results, a different test settings would be recommended?

[Geer1]

Yeah try 0 EPR now.

[Woofer777]

I've completed the second test with fixed pressure 7 and EPR 0.   Centrals and obstructive events improved some while Hypopneas and RERA increased significantly.

Below is the average results from each test so far.

Fixed 9 EPR 2: CA = 6.6  OB = 2.8  HY = 1.7  RE = .1  AHI = 11.1   Results varied for AHI = 9 to 14.  4 nights

Fixed 7 EPR 0: CA = 4.4  OB = 1.8  HY = 6.7  RE = 1.7  AHI = 13.1   Results for AHI varied = 11 to 16.  3 nights

If screenshots for a typical night on either test above would be helpful let me know.

Sleeprider/Geer1 - Thoughts on next steps?

[Sleeprider]

I would think the fixed pressure 9 with EPR 2 was much more comfortable, in spite of higher CA, than the higher hypopnea and RERA. Going back to my reply where we started this fixed pressure, I think the next step is to try lower pressure with EPR 2. Let's start dropping the fixed pressure in 1-cm increments to 8.0, then 7.0, but keep the EPR. http://www.apneaboard.com/forums/Thread-...#pid438288

[Geer1]

Yeah so mild improvement of CA with no EPR but restrictions worsened as would be expected. As Sleeprider said now we pick a setting to use (I agree with EPR 2 as long as that felt better to you) then try different pressures to see what effects they have. Can try both lower and higher pressures. Lower may help with CA but if you go too low obstruction/restriction will get worse. Higher might help the obstruction and restriction present but might make CA worse.

[Woofer777]

I will next test Fixed Pressure 8 and EPR 2.

Yes, the higher levels of hypopnea and RERA were more uncomfortable with EPR 0.  (Although, not nearly the discomfort as when I had sustained high pressure levels when using a variable range with higher upper limits).

This is a slow process, however,  it does allow a more systematic approach for the data collection. 

I'll report back here with the next test results.

[Woofer777]

I have tried different settings during the last few weeks, with the summarized results below.


       Fixed 9 EPR 2: CA = 6.6  OB = 2.8  HY = 1.7   RE = .1    AHI = 11.1   Results varied for AHI = 9 to 14.  4 nights


       Fixed 7 EPR 0: CA = 4.4  OB = 1.8  HY = 6.7  RE = 1.7    AHI = 13.1   Results for AHI varied = 11 to 16.  3 nights

       Fixed 8 EPR 2: CA = 7.9  OB = 5.8  HY = 1.9    RE = .9    AHI = 15.6

     Fixed 10 EPR 2: CA = 7.9  OB = 1.5  HY = 1.4    RE = .0    AHI = 10.9   

Var 10 to 11 EPR 3: CA = 6.3  OB = 3.3  HY = 1.3    RE = .0    AHI = 11.1

   Fixed 10 EPR 3 CA = 5.1  OB = 3.0  HY = 1.0  RE = .0     AHI = 8.9   4 night average

From what I can observe, the fixed 10 EPR 3 has provided the best results so far, and is the setting I have used for the last 4 nights. When I increased the pressure to  variable 10 to 11, it did not have any effect on the obstructive events.    The pressure when set at 10 to 11 stayed closer to 11 during the night, but did drop down below at various times. 

I have felt the best during the day with current settings and seem to have decent sleep experience during the night. (i.e. breathing is comfortable, and no issues with mask).

Ob events are occurring together with CA events typically, and still mostly clustered in 2 to 3 main clusters. 

I'm inclined to stay at current setting for another week before possibly trying Fixed 10 EPR 2 again,  for more extended time period as that has the lowest OB and low HY.  

I would be interested in comments and interpretations of the data from above test settings.  If screenshots for any of above are desired, let me know.

[Geer1]

Instead of trying 10/2 again I would try 11/3 for multiple nights. It will give you the same EPAP as 10/2 and help draw more conclusions on whether higher pressure helps. Then depending on results could try 12/3 to further figure out if higher pressure helps.

[Woofer777]

I will stick with 10/3 for the next week.   Do you feel that 11/3 might be different than 10-11 /3 ?  I've tested that level and it was less effective than 10/3, and more difficult to tolerate while sleeping even though only 1 higher.

The other thought I had was on the 10/2 results.   If centrals from my data are not controlled much by various settings, and not treated with my current machine, wouldn't the low O and H combined ( less than 3) , be considered a success?   At least until I get overnight lab study in a couple months? 

Stated slightly different, should my goal be to arrive at a setting where O and H combined are at lowest levels independent of centrals?   And then see if centrals gradually go away?

[Geer1]

I wasn't sure how many days you tried that setting (sounded like only one) and it is possible you react to pressure changes so a fixed pressure is more interesting to me to be able to compare easily. What I usually do is vary EPR to find which seems to be best. Vary pressure to see effects of it and find best range. Then try a range vs fixed pressure to see if it is advantageous. Sometimes you have to revisit EPR if the pressure has a noticeable effect.

Overall there isn't an obvious trend in that data but part of the reason is because of multiple variables being adjusted and because you have two complications known to easily affect results (central apnea and positional apnea). The best indication on pressure effects is if you look at EPR 2 results (since it is the only EPR you really tried at multiple pressures) and there was a reduction each time you increased the pressure. Your worse results were at the lowest EPAP (6 cm when using 8/2 setting) in which both your obstructive apnea and central apnea were worse.

Obstructive apnea can be the cause of central apnea in the same way that central apnea can be repetitive. The obstruction causes large amplitude recovery breaths which wash out CO2 which triggers a central apnea and then the central apnea might cause a few more before breathing returns to normal.