AVAPS-AE on MY Trilogy - Ongoing

[-SWS]

Recap notes.

1) Madalot is gradually exploring an auto-EPAP range of 9cm through 12cm (auto-EPAP range applied against old AVAPS side-sleeping settings as baseline)
2) Waning tidal volumes might warrant increasing Max Pressure above 23cm (adjust PS-range's ceiling)
3) Over-ventilation or discomfort during side-sleeping might warrant dropping Min PS below 9cm (adjust PS-range's floor)
4) After exploring auto-EPAP 9cm through 12cm, Madalot might decide to explore auto-backup rate, 8cm backup rate, and/or lower Min EPAP values with continued doctor approval
5) Hoping to gradually explore changes to one treatment dimension at a time--or as few as possible---to help isolate emergent treatment problems (e.g. Madalot's initial PTB plummet)

[Madalot]

Great recap, -SWS. Thank you.

The pulsing during exhalation...is my theory about it plausible?
The machine trying to determine what I need?

I may not increase the max EPAP for another night or two. Tired and hurting badly after laying on one side for 7 hours last night.

[-SWS]

Madalot, I don't think that pulsing during exhale is intentional pressure-probing. I could be wrong. I suspect it reflects a need to fine tune triggering the EPAP-to-IPAP transition, or fine tune cycling the IPAP-to-EPAP transition---or fine tune both machine transitions. These parameter definitions are from one of your old posts (bold, underlining added by me):

Trigger Type: The device can be set to trigger breaths based on automatic flow thresholds or specific flow settings. You can select either Auto-Trak or Flow Trigger as the Trigger Type. When Auto-Trak is selected, the Auto-Trak trigger initiates based on automatic flow thresholds. When Trigger Type is set to Flow Trigger, Flow Trigger Sensitivity and Flow Cycle Sensitivty become active and the trigger initiates based on the Flow Trigger Sensitivity Setting.

Flow Trigger Sensitivity: Flow Trigger is the initiation of inspiration when the patient's inspiratory effort causes flow to increase by the Flow Trigger Sensitivity Setting. If you set the Trigger Type to Flow Trigger, the Flow Trigger Sensitivity Setting displays. You can increase or decrease the setting from 1 to 9 l/min in 1 l/min increments. A flow trigger occurs when this value is set to any setting from 1 to 9, the ventilator is in exhalation phase, the minimum exhalation time has expired and the flow increases by the Flow Trigger Sensitivity Setting.

Flow Cycle Sensitivity: If you set the Trigger Type to Flow Trigger, the Flow Cycle Sensitivity setting displays. You can increase or decrease the setting from 10 to 40 percent (%) in 1% increments.

I pulled this directly out of the manual.

That first Trigger Type parameter is set to either "Auto-Trak" (auto thresholds) or "Flow Trigger" (manual thresholds). If set to "Flow Trigger", then the thresholds are manually set using the pair of sensitivity parameters in the above quote. Anyway, I think that pulsing during EPAP might indicate a need to dial-in one or both of those sensitivity values. Leaks can supposedly exacerbate threshold detection problems.

Do you happen to know what values the above three were set at immediately prior to sending in your Trilogy for service? Your June 2011 settings can be found here.

[Pulmonette]

Can I interrupt this discussion to ask a question?

What parameters are you using to adjust EPAP? In reading other posts, I can only fine references to treating obstructive apneas, or improve oxygenation in a couple of other diseases (but those diseases usually have something to do with heart failure).

Thanks.

[boots]

You could look in DirectView under prescription history. Might have to flip through the sessions to find it depending on how often you download. SWS is correct on the pulsing issue and the trigger/cycle needs to be fine tuned. Someone with perfect lungs would have problems triggering a vent at 6L.

[Madalot]

I just got out of bed, having gone to bed at 11pm and out at 10am. Yousa, am I stiff and sore.

I'm reading the posts but admit I'm not "in my body" enough to totally comprehend it. However,

As far as the Trigger settings, they've been the same for a LONG time:

Trigger Type - Flow Trigger
Flow Trigger Sensitivity - 6
Flow Cycle Sensitivity - 25%

One thing I DID notice this morning (while trying to decide whether to get up) was that this "pulsing" I'm experiencing on EXHALE (very weird thing might add) is happening after I shift. I tend to hold my breath (difficult for me to move and breath at the same time) and the pulsing was happening every time after I shifted.

I'll read more on this later today when I wake up more - or tomorrow as I've lost so much of today as it is.

[boots]

This is a DirectView screenshot. The person is trying to trigger the vent, but isn't generating enough flow to get a spontaneous breath. The trigger was set to 5L. If you see this in your waveforms then your trigger is set to high.

[-SWS]

Many thanks, Boots. Madalot, may I suggest taking a detour from changing auto-EPAP to fine-tune triggering and cycling?

[Madalot]

Many thanks, Boots. Madalot, may I suggest taking a detour from changing auto-EPAP to fine-tune triggering and cycling?

I have no issue doing that. The Triggering & cycling was fine on regular AVAPS. The only thing difference, NOW, is the EPAP can go from 9-10. Everything else is the same as before (I did NOT up the max EPAP to 11 last night, which is probably a good thing).

Based on what I've described, what would you and Boots suggest be the first change? And should I go back to straight EPAP of 9? But that wouldn't help know if the Trigger changes were helping since straight EPAP of 9 didn't have this issue. Obviously thinking out loud here.

Suggestions?

[Madalot]

This is a DirectView screenshot. The person is trying to trigger the vent, but isn't generating enough flow to get a spontaneous breath. The trigger was set to 5L. If you see this in your waveforms then your trigger is set to high.

I'm anxious to review this, but my desktop computer won't load my data into DirectView right now (hard drive going bad I believe). I CAN and will load it into my Netbook, but that's more difficult for me physically since I have to drag everything to a place to load it (plus my Netbook is slow as molasses).

I am interested in hearing suggestions but until I can look at the data & waveforms as suggested, I'm not changing anything more. I hope to look at it today, but it maybe tomorrow or even Monday before I get that chance.

[Madalot]

This is a DirectView screenshot. The person is trying to trigger the vent, but isn't generating enough flow to get a spontaneous breath. The trigger was set to 5L. If you see this in your waveforms then your trigger is set to high.

Boots -- which waveform are you looking at here? I've got my netbook up and the data loaded. Waveform choices are: Breaths per Minute, Flow, I:E State, Leak, Pressure, Vte.

Which one???

[boots]

Flow

[Madalot]

Flow

Oh dear. What I'm seeing when I look at the Flow Waveform is NOTHING like what you are showing. I think what I see is all bunched together, where you are looking at it in a shorter timeframe. How can I spread it out rather than looking at hours instead of minutes?

NEVER MIND...I figured it out...looking now.

[Madalot]

Okay -- this is what I found. This is just ONE that looks like this. What the heck does this mean???

[boots]

I'm pretty sure that's one. I would have to see the pressure graph below that and the breaths per min above.


The downward spike means that it is a ventilator triggered breath (aka. mandatory breath)