Taking my VAUTO to recess

[coldfeet7]

Do you remember recess from elementary school? I'm 68-years old and my recollection is that it was a time for fun, a time for play. 

Well, I am tired of studying the world of PAP, of being a student. I need to get out of the classroom so I decided to play. My relatively new VAUTO has several more settings than my Airsense 10. I haven't been able to find a single, clear source - a document - to explain how all of this works together. So...  its time to play.

I went into the clinical menus and just starting altering one thing at a time to extremes and seeing how it felt in the mask. Ti min, Ti Max, Trigger, Cycle, IPAP, EPAP and PS. I find IPAP, EPAP and PS very clear, but those other four needed to be more 'real', more experiential to me. Ultimately, I want to put the aerophagia bully in its place.

So I pushed them to extremes. Ti Max of 1. Then tried breathing and watching the VAUTO display for how the pressure gauge moved. Closing my eyes and gauging how it 'felt'. Was it ending too soon, starting too soon, did my breathing feel nature, did I notice my breath being 'pulled' or 'pushed' by the machine.

Then Ti Min of 2 or .1 and then repeat the above lab.

I came away with some insights and tonight I'll see if I am on the right track. (Obviously not with settings at extremes.)

I am not advocating that everyone do this. You might need more classroom time, you might just want to set it and forget it. Fair enough.

But I am interesting in hearing from those who have taken this more hands on approach to get to know their VAUTO. I'll share my results as my trials continue.

Care to share yours?

[SarcasticDave94]

Of course there's the clinical manual you could order at the top of the page, and asking Apnea Board members about various settings works too.

What you're doing may or may not work for one reason. CPAP, even the VAuto, are sleep therapy machines and setting edits may not appear to have changed anything to a person that's awake.

[Sleeprider]

I think the experimentation is a good idea to work out a problem you are experiencing. It will be interesting to see what you come up with and how it works out. Aerophagia is a tough problem to solve, and I often advise looking for a compromise between AHI (pressure) and bloating (comfort). Trigger, cycle and time of inspiration can certainly play a role, and I look forward to hearing what you think works.

[SevereApnea]

Excellent Idea: this is a good strategy, but do try to keep it simple.

I can only speak from my own experience.

The Vauto has many more variables and therefore more levels of confusion.

Firstly, if you change more than one variable at a time then you won't know the cause of the effect you may be experiencing.

Secondly, what you "feel" while experimenting while awake for a few minutes may be very different to what you "really feel" the next morning after a number of hours of sleep.

Most of the Vauto settings can be left at default: Ti Min 0.3 Ti Max at the 2 sec default TS Medium and CS Medium.

The Trigger and Cycle sensitivities can be used to fix/correct a specific issue.

For example for most of this year I had the TS set to High, but have now come back to TS Medium and CS also Medium. I changed the TS back from TS High to TS Medium based on trying to understand where some of the Side Effects of therapy are coming from. TS = Medium now feels more comfortable (during the night) and no increase in my CA count anymore, so at the moment I have no more need of TS High. This means my body has adapted. 

Much of my thought processes of trying to "Understand" what the Vauto was doing physiologically were shown to be flawed. Things have a way of being counterintuitive.
If I increase This Setting then I can expect That Result, right? No so! For me this did not always pan out. I suspect this is because the pendulum of our body's homeostatic mechanism over-reacts in one direction and then settle down over time.

At the moment I am only making changes once a week, even small changes, and looking for trends in my dataset.

Having said that, this works for me, being of the slow and methodical type. I really just need to know what is going on under the bonnet so to speak, so that at some stage down the line when my requirements with CPAP change, I will understand the principles behind what I need to adjust. For others a more intuitive approach might work better. 

If you can avoid it, try not to change any thing during each night, unless it feels Really Bad/Off/Terrible. I found that if I got the settings horribly wrong and woke up after an hour or so feeling terrible (Headache, Chest Pressure, Heart Palpitations, waking up sweating e.g.), and then made a change in the settings (sometimes 4x per night, blush) then the side effects of the first hour still carried over into the next hour or sleep session and it was impossible to figure out cause and effect. Along the way you can expect a few difficult nights.

Lastly, you really do need to keep a daily Diary/Log Book, unless you have a perfect memory!

Here is a sample from my spreadsheet: the weekly correlation numbers between Chest Inflation and increasing Pressure Support are trending down, so I am encouraged that at some stage I might be able to slowly increase my PS even higher.

[attachment=40478]

Good luck, and do share what you have learnt, we will be most interested.

[coldfeet7]

Great replies everyone! Thanks for sharing and giving guidance on my recess time....  I'll reply in more detail to your replies later, but for now I have a question.

Can OSCAR display the Ti min, Ti max, and Trigger and Cycle settings?  I can't find them poking around in the window panels (I have been known to overlook things that others point out are right there).

It could be handy to have them displayed in the machine settings area when going back to make comparisons.

[pholynyk]

>>> Can OSCAR display the Ti min, Ti max, and Trigger and Cycle settings?

I'm working on it, and it should be ready for the next release.

[coldfeet7]

Great!

Will it be able to extract the past values already loaded or does the import process have to pull them from the SD card during import and then is going forward only? (I suspect it is the former since I would guess all of the SD Card data is imported and it is all in there.)

Let me give a shout out to the developers of OSCAR. It is such a stable (which is so critical) and powerful product.

[pholynyk]

Normally OSCAR only imports forward, but with a database change you will have to rebuild the database, so it will go back and start from the beginning..

[coldfeet7]

I seem to have finally dialed in my settings to get a sub 1 AHI pretty consistently. The biggest affect seems to have been carefully placing a pillow that keeps me off my back. That has allowed me to keep pressures just low enough to keep aerophagia at manageable levels.

Despite these results, I am still prone to nodding off if I sit still for long. (I attribute this to Pregabalin side-effects and PLMs that are not being helped). All attempts at PLM reduction (gabapentin, pramipexole, pregabalin, getting off coffee, etc.) have failed due to unacceptable side-effects. I am not sure where to turn next.

BUT the main reason for my post today is an unexplainable drop in my SpO2 that has been happening. The chart below shows two large, sustained drops below 90. This has happened on several occasions. (Sorry, the capture doesn't show a .63 AHI, my bad). I also didn't capture the pressure graph, but it was very consistent though both the drop and recovery of each large disruption. My inspiration time is over 2.5 times as short as the expiration time. Not sure if that is relevant.


   

This zoom into one of the drops doesn't seem to explain it. The flow rate is consistent, no significant leaks or flow limitations, no significant change in the pulse (though is a little lower than usual since I have been taking the Pregabalin). I do have a lot of periodic limb movement registered. Probably 30-40% more than a typical night.

   

Anyone have a idea where these drops are coming from?  What should I be looking for?

[Sleeprider]

Nothing apparent from those charts. You might try comparing against respiration rate, tidal volume and minute vent.