Rapid Breathing-Fractured Sleep-Out of Breath

[Fixit50]

DME said my order was shipped!  Two days later they said it was on hold because the settings specified by the Doctor did not match BiLevel settings!  The doctor's office claims the DME told them all was good But the DME says they don't have proper settings and they need those.  I've told the DME that I was fine if they shipped using Resmed Default setting but they say they need valid settings provided by the doctor.  Sounds like the two entities are not talking.  
Here's what the doctor had in the prescription for settings:

• Bilevel Initiated:  Yes
  
• Pressure range min:  4
  
• Pressure range max:  13
  
• Ramp delay: 20 mins
  
• Mask F20 Large
  
• Humidification: Heated
  

It looks like he left out PS and a few other things.
I'd like to cancel this order but I called another DME and they said they would need to have a clean prescription that included settings so the same thing could happen!  This may be a case of the devil you know vs the one you don't know.   
I've got to make some decisions here and I thought I'd see if anyone with some DME experience may have some ideas.

[Fixit50]

I got things straightened out with the DME.  I motivated them to call the doctor’s office while I stayed on the phone, and they got some updated settings verbally and that’s all it took to mollify the DME.  It took a 1-minute phone call to resolve an issue that held up my order by 5-days.  Why it took 5-days to make a 1-minute call is anybody’s guess, but I digress. 
 
I got my VAuto yesterday and spent last night with it.  The 1st thing I did was get rid of the ‘modified-settings’ (the ones I waited 5-days for..) and replace them with something more reasonable.  Very good night’s sleep indeed!  I kept the chin strap on just so I can get the feel for the adjustment process in a less challenging environment. 

Comparing last night with the VAuto, against the AirSense (APAP) my 95% Flow Limit dropped by a factor of 6.  I’m going to see if I can lower it a bit more and then remove the chin strap which I know will be a whole new field.  I’ll post some screenshots soon.

[SingleH]

Glad to hear your got things sorted and have your hands on the new device.

Positive news regarding the improvements on just the first night. Makes senses to use the chinstrap first and optmise that as much as possible. You know the strap solves a problem and combining the two should therefore give the best outcome in terms of figures, but of course you want to work on comfort and will be interesting to see how it works without. In reality I think you may need a collar or something to keep your jaw in position, as the jaw dropping open and in turn causing problems seems to be a common issue.

[Sleeprider]

Fixit, take some time to change your profile information to the Vauto. https://www.apneaboard.com/forums/usercp.php

No surprise the Vauto is working well and is more comfortable. Once you go bilevel you'll never look back.

[Fixit50]

Thanks for the comments SingleH and Sleeprider and yes, I updated my profile to the VAuto.
 
I’ve done some experiments with settings and would like to explain and maybe solicit some comments.  I should point out that I changed the default value of Ti-max.  I increased this from 2.0 to 2.2 secs.  I did this because some fraction of my breathing, when it looked healthy, had inspiration times of 2.1 seconds, so I thought it may not be good for the VAuto to cut that short.  Let me know if this was not such a good idea. 
 
Here is a snip of the first night with the VAuto.  
   
Good night’s sleep!  Be mindful that I was sleeping well using the AirSense APAP provided I used the chinstrap as I did here.  The main difference I see using the VAuto is decreased flow limits.  Seems like going from EPR=3 to PS=4 is significant.  Compare the Flow Limits in the snip above with that of the snip below from the AirSence APAP.  Just the machine changed! 
   
So why not try to further reduce these flow limits?  I bumped PS to from 4 to 5 and you can see the results below. 
   
There are 4 consecutive OAs with simultaneous high Flow Limits.  At the far right there is a string of CA but I was drifting between sleep and wake there and some others may consider that normal, though I don’t usually see that many.  So why did the increase in PS have this effect?  Is this kind of a change something one needs to acclimate to over time, before seeing the true result?

Continued in the next post #46:

[Fixit50]

Continued from above post #45:

Next, and continuing with the chinstrap, I decreased the PS to a mid-value of 4.4.  Results are seen below and are still worse than what was seen the first night using PS=4.0.  
   

So returning to PS=4.0 as per the first night, yielded results virtually identical to that first night with the VAuto seen here.  I’d like to know what the guidelines and process are for zeroing in on the optimum value for pressure support.  Perhaps there is a better way of going about this.
 
Next, I substituted a cervical collar in place of the chin strap.  I think it does a good job of keeping my mouth closed.  I discovered that I had to keep the collar quite loose for it to be effective, otherwise I was getting consecutive OAs.  Not clear why.  After loosening, the result is close to what is seen with the chin strap.  Both the chin strap and the cervical collar keep me free of the rapid and irregular breathing, which I regularly observe when using the F20 mask alone.
 
Tonight, I plan to use the F20 mask alone, with no collar or chinstrap.  I’m expecting to challenge the VAuto and my ability to optimize its settings.  I’ll start with the settings Sleeprider suggested earlier.

[SingleH]

Hi,

I had a look at your screenshots and its great to see you are already getting good results. Its taken me 3 months to achieve a single night of 0.0 which has never been replicated and 4 months just to get figures reliably under 5, however I suspect my "patient" is a bit more complex.

Anyway you had discovered for yourself a well known issue on here, that large increases in Pressure Support result in the generation of CA's, which in turn at least from my observations seem to then also be accompanied by OA's.

Do not increase pressure support by more than 0.2 at a time and then you need to leave it to see if the body to adapts to it. AFter some days the CA's will reduce slowly and you may be able to increase PS again. If they do not go down, you may have to turn it back, but I think you need at least 7 days to observe what happens first.

My observation is if you make a very large increase in PS it seems to have some long lasting effect that can results in CA's lasting for days if not weeks and you will have to end up waiting a long time for them to go down, and even turning the PS back down again still doesnt clear them fully. As I said earlier I managed to hit a sweet spot of 0.0 along with a few other nights of 0.5 but then made a couple of uninformed large changes that sent CA's through the roof. Even putting it back onto those settings didnt make them go away until I dropped PS way back down again. I've then had to slowly build up.

As you already achieved an amazing 0.0 on your first nights use, I would strongly advise to only make the smallest incremental changes that the machine offers. 0.2 for PS and pressure settings and 0.1 for the time settings. You are already at a point of just needing to fine tune.

Do the test without the collar and chinstrap, without changing any settings. Look forward to see your results.

[Fixit50]

Thanks SingleH, for your comments and observations.  Interesting about having to make small changes with Pressure Support.  Yes, I stumbled on that one!  I’ll be mindful of that going forwards. 
 
As a practical matter AHI has never really been my problem.  I think the short summary of my long-standing problem is high flow limits leading to strained breathing, and high pressures, likely resulting in CO2 build-up, along with the rapid and highly irregular breathing waveform, all resulting of course in comfort issues, and fractured sleep.  That is not to say that I understand it all, but that’s the best I can come up with.  My AHI (with the AirSense APAP) has always been below 3.0 and typically below 1.3 with occasional nights at 0.0.  
 
Last night I used only the F20 Full Face Mask alone.  I think the results are encouraging.  See the snip below:
   

The Flow Rate waveform is good except for a few minutes scattered between 6:25am and 7:10am.  This is a big improvement in the Flow Rate appearance.  See the snips below.  The top 75-second snip below represents the worst looking waveform from last night, where the bottom shows a typical worst 75-second sample using the AirSense APAP under the same condition:  
   
 
The improvement is bigger than the snips may suggest, since the poor looking waveform with the VAuto occupies a much smaller percentage of the night compared with the APAP.  This is reflected in the statistics where last night’s Tidal Volume and minute Ventilation are quite good.  These were often degraded with the APAP, when median Tidal Volume for the night dropped as low as 300ml compared to the 560ml seen here. 
 
The Flow Limit looks quite good in the stats from last night.  Looking at the top snip, you see two marked areas where it is higher than 0.75.  This is new with the VAuto and I didn’t see those large peaks with the APAP.  Flow limit peaks with the APAP rarely went above 0.5.  I’m not sure why the difference. 
 
I’d like to improve upon this if possible.  All I can think of, is to increase PS in the small increments you suggested.  Another possibility would be to increase the Ti-min and possibly decrease the Cycle Sensitivity.  The idea with the latter, would be to keep the machine from triggering on some of the short-lived pulses that may not reflect actual or desired breathing effort. 
 
I’d like to invite any ideas on how to best achieve further improvements.

[SingleH]

Regarding the first screeshot I can only assume those two large flow limitations are due to some kind of positional obstruction. I would continue to observe and see if they occur from time to time, and then compare with the use of a collar and/or chinstrap. Your flow limits appear to be well under control now as your 95% is zero.

Regarding the waveform, the improvement is clear with Bilevel and a waveform of sorts is now present rather than the chaos seen before with APAP.


Just like my dad you have what appears to be a large dip during your inhalation, where the waveform drops below the zero line.  I had to correct this using a combination of higher PS and as you already mentioned a longer TiMin to essentially to try and "drive through" and override whatever the body was trying to do at that point.

It would be useful to see both a full sceen zoomed out view along with some zoomed in wave form images with the below three graphs pinned in oscar:

Mask pressure graph (blue line)
inspiration time graph
Pressure graph (red and green line)

In regards to increasing PS, you will need to do it slowly. I believe trigger is already set to high or very high which is one way to reduce CA's. Additionally I found reducing Timax also reduces CA's but you need to first check if you have room to do so, I dont know what your TiMax is and you will need to check your Inspiration time graph to check whether you have headroom to reduce TiMax or not. I would leave TiMax alone and just see if you can increase your PS very slowly without triggering CA's.
By the way can you share your I:E and Spont Cycle figures, they are in your sleep report on the unit itself. Also make sure you set the sleep report to "essentials plus" and recording period for your sleep report to daily, as I think it defaults to weekly or monthly.

[Fixit50]

Thanks SingleH for the comments and insights. 

You said: “Regarding the first screenshot I can only assume those two large flow limitations are due to some kind of positional obstruction.”
Yes, this is very possible; I’ll keep an eye on these.

“Your flow limits appear to be well under control now as your 95% is zero.”
Yes, I’m delighted also to see this.  Aside from the PS, the other settings are virtually the same as what I used with the APAP so its pretty clear that the increase in PS from 3 to 4 is responsible for the improvement on flow limits. 

“Regarding the waveform, the improvement is clear with Bilevel and a waveform of sorts is now present rather than the chaos seen before with APAP.”
Well Put!  This tends to confirm my prior hypothesis that, at least in my case, the chaotic waveform was something that came about with the presence of flow limits during certain sleep states, likely REM, deep, or both.  The chinstrap, mouthguard, collar all got rid of the poor waveform by diminishing flow limits via anatomical adjustment.  The VAuto got rid of the poor waveform also by diminishing flow limits, but thru the use of Pressure Support rather than through the use of an anatomical changing device.  These observations enhance our understanding which is always nice.  

Last night I repeated the same settings and again used only the F20 mask.  Results are quite similar.
 
In adjusting Ti-min, is it also advisable to make only small adjustments?  Trigger and cycle are both set to medium which is how I received the machine. For the last two nights (mask only, no accessories) I got two CA’s each night.  Earlier on, I increased Timax from 2.0 to 2.2 because I noticed a small number of inspiration times that were higher than 2.0 and wasn’t sure if I wanted to cut that short.  Most inspiration times are lower than 2.0 however so there wouldn’t be a lot of breaths cut short by pulling Ti-min back to 2.0.  Any thoughts on that?  Perhaps I can try going back to the default value of 2.0. 
 
Also, the machine report shows I:E is 1:2.1 but I don’t really understand where that comes from.  Could it be the max ratio?  When I go to various parts of the flow rate, and directly measure the ratio, I rarely see more than 1:1.9 and also see ratios as low as 1.3.  So again, I’m a little confused about what the machine shows for that ratio. I note that looking at the stats section in Oscar implies I:E ratios and shows inspiration times that agree with what is shown in the machine's sleep report.  Also, the period for the Sleep Report is set to 1-day. 
 
The spontaneous cycle times are high for last night (98.5%) and the night prior.  I imagine this is the percentage of pressure transitions that were triggered by breathing effort as opposed to Timin or Timax limits.  Is higher better?  What would be a good number?
 
Is Inspiration Time important?  What are we looking for here, and why important?
 
Below are some graphs from last night that may provide some insight.  Note that Tidal Volume is 600ml, so I’m a little concerned that increasing PS might make that too high.  Is 600ml getting too high or is there room to move here?  I’m not sure what the limits are, and I can imagine its individual dependent.  Last night shows 600ml, which is the highest I’ve seen. 
   

Let’s zero in on a region where the waveform contains some aberrations.  The snip below shows five expirations all disturbed by two or three pulses.  Only in two of the five cases did these extra pulses cross zero and trigger an added inspiration pressure pulse in the mask.  Where the undesired added pulse in the mask is not seen, it did not prevent the disturbed expiration waveform, so it doesn’t give me a lot of confidence that this can be improved by changing machine settings.  Of course it can’t help to try lowering trigger sensitivity, but I’m not optimistic.  Any thoughts or comments on this point, or what might be done to clean up the waveform seen below?
   
 
Below are pics from my machine report that may be useful here: