Therapy using Lumis 150 ST

[Geer1]

I am curious to see a zoomed view around 1:25 when RR is on backup rate and inspiration time is extended but TV still down. Curious if it shows signs of restriction or just small long breaths.

The one thing this does show is that you don't really have desats until MV falls below 5 (almost to 4). That is one lesson we could carry over to IVAPS if switching back (target MV of 5 likely sufficient). Lower MV target might have be enough to keep RR up.

The only way to avoid desats on ST is higher backup rate (IBR 13 might work and be beneficial) or higher PSmin which could potentially be helpful but as you can see the issue with fixed PS modes like this is that 80% of the night you are in nrem and have good breathing and you only really need assistance 20% of the time when in rem. That is where IVAPS in theory is better for you. I think you could work up to PS of 5 but wouldn't go higher than that.

The really tough thing is knowing if depressed but supported respiration is better or worse than spontaneous respiration with odd desat. Both could be intrusive to your rem sleep in different ways and I don't see how a guy could tell what is best without EEG data.

[StuartC]

Zoomed view attached. 

There really is very little time that I can see spent at fixed RR during sleep. Most of the non-spontaneous triggers appear to have occurred at the end of the night when I was waking up / dozing.  And spontaneous RR was high so I do not know how I would go at fixed RR of 12, perhaps not too bad because PS is relatively low, but I might try that too.

I am planning to thoroughly test different backup rates before thinking of changing pressure.  I do think that I can reduce desats with PS = 5, and I actually think it would be sensible to try, but lots to try before that.  Better to first gather data at PS = 4 to compare against to make better informed decisions about which value of PS to continue on with.

Yes, learning about suitable MV values is part of the goal of using ST.  And if I can get ST with IBR working, next step is iVAPS with PS max = PSmin (to confirm that it behaves  the same as ST with IBR) and then only increase PS max in increments of 1.

[Geer1]

Fixed BR of 12 would probably be more of a comfort issue when awake then an issue when asleep.

I believe IBR of 12 or even 13 should work ok and it would only ever trigger during rem (maybe the odd awake periods). Main thing I would be curious about is if it drives RR like it did on IVAPS or if spontaneous breathing would keep resetting it. With IVAPS I believe it is the combo of IBR and target MV that causes issues and that shouldn't be an issue with ST.

Part of me wonders if PSmin of 3 would be adequate on IVAPS then you could use a range of 3-5 or 3-6. Once you start limiting PSmax soon as you hit rem sleep and RR slows PS will likely hit PSmax. If PSmax is just low enough to maintain breathing then RR won't depress but if PSmax is too high it will cause you to get stuck. I don't know that getting stuck is necessarily a bad thing but based on your comments on feel on IVAPS I have assumed it isn't good.

[StuartC]

I might not post charts every day while I am on ST mode, but I did see a couple of things in last night's chart.

Firstly, I did not change any settings, so this is still BR = 11. Spontaneous trigger was 95% and cycle was 99%.

I only saw one period of controlled breathing.  The relationship that interested me was the way SpO2 dropped as Ti increased, which does make sense.  The Vt chart, not shown, followed the Ti chart, which is logical.  Now I have Ti max set at 2.5 s for comfort when I get into bed contrary to the recommended setting of 2 s.  Perhaps I should try reducing that, possibly over a few nights  by 0.1 s every night.

I also had an extra desaturation that has a hypopnea at the start.  The chart shows a clear breathing disturbance but not a completely obstructive apnea.  It set off a little bit of periodic breathing, but that did not last long.  The second and third hypopneas were similar but with less cyclic breathing afterwards.  The fourth hypopnea was after my alarm, so it is not as interesting.

[Geer1]

I looked through your data and I actually feel like IVAPS was doing a decent job in the end. Even when the machine was driving your respiration rate and supporting you the breathing was a lot more consistent then I expected and pretty limited signs of poor sleep, arousals etc. The limited data on ST has been noticeably more inconsistent and at a couple instances shows some signs of obstruction that I assume the IVAPS would have helped deal with.

Although I don't think it is necessarily great that IVAPS drives your respiration at times I don't think it is as big of an issue as I first thought it was. And by limiting PSmax and/or even slightly lower MV target I think it could be fine tuned a little further.

Your complaints of not feeling good on it are the main concern and because of that I do recommend continuing to try out ST some more to confirm if you happen to feel any better or worse with it. If you don't feel better then the symptoms might be related to something more than a breathing issue and it seems like you have some other things to look into based on lung test results etc.

I don't know if you struggle from digestive symptoms but if so I would strongly recommend reading a book called The Plant Paradox by Stephen Gundry. I just started reading it today and feel it explains a lot of my health issues which I believe have an aspect of autoimmune to them and since you at least had an autoimmune imagine it might be of interest to yourself as well.

[StuartC]

Thanks.

I was also getting the impression that PS max needed to be cut back, it seemed to me to be what was pushing my RR down and holding it there, causing IBR to kick in and keep going.  If the interaction between RR and volume control (by varying IPAP) is that simple, it should be possible to get it working by starting low and working up.  But I am happy to first trial ST with IBR to see how that goes without the interaction of volume control. One thing I have learned is that the progression through the modes feels like a better approach.

I also feel that the high PS max and volume targets are what caused me to feel the way I did.  I feel like I simply overworked my muscles (intercostals, I presume) and, because I did it every night, I never had enough time to recover.  It happened before when I trialled the Prisma BiPAP in ST with IPAP of 13.  So, I think a pressure that high might be okay for the short periods of REM, but too much for the whole night.

There definitely seem to be some obstructions happening on ST.  I occasionally wonder whether my EPAP is high enough, since I always used to have EPAP at 6 (Pressure of 9 less EPR of 3), but I do think 5 is better.  I get more pressure support with lower EPAP and that does seem to make a difference to both the desats and to my overall AHI, which is much lower than on CPAP.

I am still quite hopeful that I will get iVAPS working, but this time I will approach it with my own knowledge rather than what turned out to be a theoretical figure published in a titration / clinical / other guide document.

[LarissaH]

I also feel that the high PS max and volume targets are what caused me to feel the way I did.  I feel like I simply overworked my muscles (intercostals, I presume) and, because I did it every night, I never had enough time to recover.  

Hi.

This thread caught my eye as my husband was on one of these machines.  What you describe is the reverse of what actually happens.  The machine takes over most of the work of breathing so the muscles are actually rested during the night, and even more so when it completely takes over.  It seems to me that after trying a number of different settings, the reason you aren't feeling better doesn't have anything to do with your breathing, and maybe not even with your sleep.

[StuartC]

It seems to me that after trying a number of different settings, the reason you aren't feeling better doesn't have anything to do with your breathing, and maybe not even with your sleep.

Thanks Larissa

As you suggest, I think this machine, with both the successes and challenges that it has brought, is definitely suggesting something fairly complex and, quite likely, with implications beyond sleep and "simple" mechanics of breathing.  Unfortunately I feel that I am having to approach the problem backwards - from a treatment towards a diagnosis rather than the other way around.  It is just what I have had to do because no medical person has had any success so far making a confirmed diagnosis.  The alternative would be to shrug my shoulders and give up but I am not so good at that.

There does seem to be at least a correlation between the pressures aimed at producing high tidal volumes and the way that I now feel, even if my explanation is not possible.  It would not be the first time I have been wrong!  It would be nice to understand though.

[LarissaH]

Our case was cut and dry so it was clear what the machine needed to be set at.  But in referring to the image with the CO2 which was posted without explanation attached (sorry it won't copy for me) some of your posts imply that your problem is in REM, but your CO2 is high at other times as well.  I do not see the answer to the question "Why is your CO2 high?'

Is that value even valid now?  Is it still high?  If it's now normal are you overtreating?

[LarissaH]

So wait-- you had a normal PFT and they're essentially treating you for respiratory failure? There's the problem. That's impossible.