AVAPS-AE on MY Trilogy - Ongoing

Believe me when I say I know. I just wish I knew in 2010 what I know now. If I hadn't been so scared and trusted them more back then, I can almost guarantee I would be certain I was getting the best treatment possible now instead of settling like I've done.

I was doing okay all things considered. I'm just so glad they are interested and willing to help me with this new mode. Because you can bet your sweet bottom no one in my life knows enough to help.

I feel very lucky.

So since this is about Auto EPAP (the AE of AVAPS-AE), mayhaps a closer look might prove fruitful.

This is a view of 2 hours (~1200-1500 breaths) so the individual breaths are lost. However, the EPAP (lower baseline) behavior can be seen:



If that looks familiar it's because it's the "Proactive" Respironics Search:



aka "AutoWingin"" (crank it up, see what happens, crank it down, see what happens).

-SWS wrote:That strategy is reminiscent of Respironcs' old hunt-and-peck---a constant searching routine for the right pressure based on ongoing flow-curve analysis. By contrast, this is ongoing or scheduled FOT analysis.

I believe that pretty much sums it up. Instead of roundness, flatness, got a good beat, easy to dance to (or whatever), it's measuring improvement in the flow (implying decreasing resistance) of the FOTs.

Well, I'm going to keep going with this, at least for now. Same settings as last night.

mollete wrote:So since this is about Auto EPAP (the AE of AVAPS-AE), mayhaps a closer look might prove fruitful.

This is a view of 2 hours (~1200-1500 breaths) so the individual breaths are lost. However, the EPAP (lower baseline) behavior can be seen:



If that looks familiar it's because it's the "Proactive" Respironics Search

For newcomers, that bottom contour line is Trilogy's auto-EPAP feature at work. The scheduled nature of Trilogy's "FOT search" stands out a little more if you scan the bottom contour line from right to left. Look for repetition-based symmetry in this ongoing contour pattern: a pair of half-squares high, a pair of half-squares low, a pair of half-squares high, a pair of half-squares low, etc. Quite the hunt-and-peck routine using FOT... Thanks Mollete.

Moving into the 15 minute view, the algorithm becomes a little more clear:



It takes about 7.5 minutes before the FOT turns on, does a Popt routine, increasing pressure by 1.0 cmH2O and checking the response, then checks again, then does a Pcrit routine, dropping the pressure by 1.0 cmH2O.

A couple of discussion points:

• Since the settings on this night look to be EPAPmin 9.0 cmH2O EPAPmax 10.0 cmH2O, these tight restraints do not allow us to see exactly how the algorithm works (i.e., the aforementioned graphic suggests there will be 2 Popt/Pcrit routines before it decides whether or not there's improvement/degradation; and
• Since the pattern mechanically repeats the entire night, it is suggested that the AE algorithm does not think there is anything to mount an assault on.

I have gone two nights now with the EPAP range from 9-11, with a goal of getting to 12. Assuming you are using my data as the examples, I would be happy to give you access to more, especially since I am increasing the range. Just say the word.

Not much to say from my end other than these FOTs can be uncomfortable on my chest. Doesn't exactly hurt, but I feel them in my chest. I have no idea why.

I have Dropbox on this Netbook (my scanner is down since my desktop is down). When/if you want more data, tell me and I'll put it in the folder for you.

mollete wrote: A couple of discussion points:

• Since the settings on this night look to be EPAPmin 9.0 cmH2O EPAPmax 10.0 cmH2O, these tight restraints do not allow us to see exactly how the algorithm works (i.e., the aforementioned graphic suggests there will be 2 Popt/Pcrit routines before it decides whether or not there's improvement/degradation; and
• Since the pattern mechanically repeats the entire night, it is suggested that the AE algorithm does not think there is anything to mount an assault on.

Madalot wrote:I have gone two nights now with the EPAP range from 9-11, with a goal of getting to 12... Not much to say from my end other than these FOTs can be uncomfortable on my chest. Doesn't exactly hurt, but I feel them in my chest. I have no idea why.

In light of what the FOT-searching algorithm is doing, I'd suggest a more comfortable next change might be to drop Min EPAP by 1cm rather than increasing Max EPAP by 1 cm---especially since you could never tolerate your supine settings of 12cm while side-sleeping. The FOT-based search routine seems to add to your discomfort. Continue closely watching tidal volumes and PTB.

I uploaded the data from last night. One thing I can say is that the leaks you all believe may be part of this equation are when I'm supine. I'm 100% positive of that. I thought so before, but last night I did NOT sleep supine at all and my leak line was much better with no real spikes. I would guess this is a mask/gravity issue, which makes sense. Maybe a new mask will help.

Last night's has things that concern me. Comparing Daily Detail Averages 9/1/13 to 9/5/13 (Last night):

BPM: 11.54 to 9.7 (I don't think I have ever dropped below close to 11)
IPAP/EPAP: 19.21/9.56 to 19.36/9.4 (this is in line so is okay)
Leak: 39.25 to 36.82 (been over this and it's not bad anyway)
Minute Ventilation: 5.56 to 4.51
PTB: 92.12 to 84.26 (even 92 is down, but dang)
Peak Flow: 30.28 to 27.99
Ti/Ttot (%): 24.95 to 21.94 (clueless on this)
Vte: 473.97 to 453.13 (which is fine, still above the minimum of 400)

I am not sure what is going on or whether I should be concerned about this. And being unable to access the data from the old Trilogy (and I found out this morning I screwed up trying to back it off my old desktop so that's gone, dammit) I cannot ascertain, for certain, whether the problems began on this Trilogy or the old one.

-SWS wrote:

mollete wrote: A couple of discussion points:

• Since the settings on this night look to be EPAPmin 9.0 cmH2O EPAPmax 10.0 cmH2O, these tight restraints do not allow us to see exactly how the algorithm works (i.e., the aforementioned graphic suggests there will be 2 Popt/Pcrit routines before it decides whether or not there's improvement/degradation; and
• Since the pattern mechanically repeats the entire night, it is suggested that the AE algorithm does not think there is anything to mount an assault on.

Madalot wrote:I have gone two nights now with the EPAP range from 9-11, with a goal of getting to 12... Not much to say from my end other than these FOTs can be uncomfortable on my chest. Doesn't exactly hurt, but I feel them in my chest. I have no idea why.

In light of what the FOT-searching algorithm is doing, I'd suggest a better next change would be to drop Min EPAP by 1cm rather than increasing Max EPAP by 1 cm.

Honestly, I'd be willing to do anything you all suggest. I'm frustrated, at this point, with the lack of communication of my medical team. I know we all agree I should keep them in the loop, but when I can't get return phone calls (which I can't seem to get) and they aren't all that interested in this experiment, it's a bit difficult.

I am trying to be good, listening to what you all say (trying to understand some of it) and NOT making any radical changes AND giving each change several nights before deciding how it feels. I'm caught between being the "guinea pig" here and making sure my medical team knows what we're doing, which at this point, they don't because they are too far behind where we are. And for me, I like where WE are better. We're doing something.

Now -- that all being said. If you guys think lowering the minimum IPAP to around 8 (so we would be 8-11) -- I'm good with that. Say when and I'll do it.

jnk wrote:But I'd also like to say that I've been impressed in this thread by how far some others on this board have come in some ways, too.

I must admit you've got my curiosity pi-cued there, Jeff.

Like who and how?

~SWS suggested that I not make any additional changes for last night (unless I went back to straight AVAPS). Used AE again on the same settings (max EPAP of 11). Felt the chest discomfort a split second before I felt the first FOT and as Mollete said, about 7 minutes or so into it. Some of the FOTs seem pretty strong, while others are barely noticeable. I woke up a time or two during the night, sometimes feeling FOTs, sometimes not.

There IS something I have noticed about this Trilogy and/or the AE Mode. It is not as friendly about letting me inhale when *I* want to as opposed to when it thinks I should. If it gives me a mandatory breath, it seems like it figures I can't inhale on my own because a lot of the time, it won't let me. Say I'm still awake, but don't inhale on schedule. Before, I would feel the mandatory breath, then go ahead and take a breath either with the machine or immediately after. This machine/mode -- won't give me an Inhale (at 18). It sits at the EPAP of 9 instead.

I'm wondering if THAT might explain the decrease in PTB??? Thinking out loud here.

The night was fairly uneventful. I stayed on my right side from 11pm until 5:30am, then flipped on my back for the last 50-55 minutes. Loaded the data and everything is back up to the new normal. The leak information confirms that my serious leaks occur supine (they are at the very end of the graph, which is when I moved at 5:30).

So, when given the word, I'm ready to move on to either Min EPAP at 8 or Max EPAP at 12.

Oh -- I am supposed to talk (really talk, imagine that) to my RT today. I'm not sure how she's going to feel about where we are, but hopefully she'll be on board with it.

Quite a few "0"s. Exactly "0", and for the same duration every time:



Since they seem to behave independently of the flow, these must be that Auto-Zero of the Solenoid that we were talking about before.

mollete wrote: Since they seem to behave independently of the flow, these must be that Auto-Zero of the Solenoid that we were talking about before.

Those 18 brief pressure spikes to 0cm nicely fit the pattern of how an auto-null solenoid valve should function: quickly purge or null pressure to atmospheric. What about auto-null triggers and rate of occurrence on Madalot's machine? Above we see 18 out of 77 breaths entail auto-null. The above 18 solenoid purges (to 0cm) occur around the time of a FOT-based search. I just quickly glanced at one of Madalot's Trilogy sessions---only to see that not all FOT searches entail auto-nulling. Similarly, auto-nulling might occur in the absence of FOT. Additionally the auto-null timing or intervals are not evenly dispersed throughout the data.

I wonder what the criteria might be for auto-nulling. Do AVAPS and AVAPS-AE maintain the same criteria for auto-nulling (I only have a subset of Madalot's AVAPS-AE data sessions)? And lastly, I have to wonder if Madalot's loaner Trilogy is auto-nulling at a normal or excessive rate.

Boots, can you perchance tell if your Trilogy pressure-spikes to 0cm as frequently as Madalot's loaner Trilogy? Do you ever see isolated occurrences of around 18 out of 77 breaths?

That spike to 0 is a ventilator triggered breath. My patient triggered breaths are lower than hers, so mine spikes to 0 more. I believe most ventilators have that downward spike indicating the vent is giving a breath. I usually use PC-SIMV, but have ran the trilogy in timed mode and all breaths spike to 0.

mollete wrote:

jnk wrote:But I'd also like to say that I've been impressed in this thread by how far some others on this board have come in some ways, too.

I must admit you've got my curiosity pi-cued there, Jeff.

Like who and how?

Well, out of everyone on that list, I think "Guest" has probably come the farthest. Guest used to make some really ugly posts back in the day, as I recall, and used to get his/her feelings hurt rather easily. Kinda like me.

But either you and -SWS are getting clearer, or I've just come a long way in finally understanding a few things you two say to each other, because I think you both do some absolutely amazingly educational work with what you post on this board for others to read and learn from.

Just my odd way of saying thanks to you two.

I'll shut up now.

Or at least try.

Hopefully, I've come a long way with that.