AVAPS-AE on MY Trilogy - Ongoing

[Guest]

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

OK, really trying to keep up here.

If those are mandatory breaths, why do they appear to be at a faster rate than the "non" mandatory breaths?

Could that downward deflection represent patient effort, and therefore be patient breaths?

[-SWS]

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.

Where those flow-graph lines get thick and dark.... We're looking at quite a few oscillations per second. No doubt you're feeling those as rather quick pulsations. Those pulsations are much quicker than the pressure-probes Respironics employs on PAP machines to differentiate central from obstructive apneas---many more oscillations per second here. My best guess is that when you shift, your flow manages to repeatedly fluctuate in and out of your cycle/trigger zones. Holding your breath and/or presenting multiple inspiratory/expiratory "hitches" in the shifting process might result in a series of response/counter-response oscillations.

If that's what's happening, dunno if you CAN correct it by fine-tuning cycle & trigger sensitivity... It's up to you whether you think it's worthwhile to experiment with the Flow Trigger and Flow Cycle sensitivity settings---to see if you can eliminate the oscillations. Alternately, you might experiment with your own voluntary breath-control patterns as you shift in bed.

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

[Guest]

Where those flow-graph lines get thick and dark.... We're looking at quite a few oscillations per second.

Looks darn near 60 cycle, which would make it electrical interference. Can you blow it up some more?

[-SWS]

I'm game for that theory. However, electrical interference wouldn't manifest only when she shifts---unless she's moving a high-current device like a heating pad in the shifting process.

Madalot, do you have any high-current devices that might factor in as you shift?

[Pulmonette]

Or maybe an iffy machine ground.

[Pulmonette]

Or filter failure.

I would think that thing would have a "notch" filter to get rid of 60 Hz.

Maybe went on the fritz for a bit, but that certainly seems bizarre.

[Madalot]

Okay -- I'm going to try to answer/provide info in the order you all asked, but forgive me if I screw it up.

Boots asked for the waveform with BPM & I:E Ratio -- here that is:




Someone else (sorry I can't remember who) asked me to spread the original waveform out a little bit more. Here that is:



Now -- what is on the circuit with the Trilogy. The Trilogy is on a cart, plugged into a heavy duty Power Strip that has a 20' cord. On this full time is: Trilogy, Oxygen Concentrator, Humidifier (stand alone unit), and Ipod Dock/Speaker (small one). Before bed, I plug in my Kindle Fire & My Smartphone.

I don't use any heating pads or anything of that nature.

[-SWS]

We'd need 180 oscillations every 3 seconds for 60 Hz. We can rule out electrical noise across the flow sensor leads...

[Madalot]

Alternately, you might experiment with your own voluntary breath-control patterns as you shift in bed.

I will TRY to be aware of the time when I wake up and shift positions, then look at the data tomorrow to see *IF* it correlates. Turning over, in itself, is a challenge, but I'll try to watch the time.

I'll also try to be SURE that the pulses come ONLY after I shift positions and not just randomly.

Is it safe to assume that my electronics plugged into the cart most likely AREN'T the culprit?

[-SWS]

Is it safe to assume that my electronics plugged into the cart most likely AREN'T the culprit?

I'd definitely rule out your electronics...

Those pulses probably aren't pressure-probes used to differentiate central from obstructive apneas either. Although the picture below is Resmed's forced oscillation technique, we can see those methods must wait a few seconds after exhalation----to allow for typical post-expiratory pauses:



Your pulses commence too early to allow for ordinary post-expiratory pauses. Experimenting with cycle and trigger sensitivity settings might help. It's up to you whether you'd like to play with the sensitivity settings now or another day... Again, spurious leaks can exacerbate threshold detection problems. So work on leaks if you think they might contribute to the pulsations.

[Madalot]

Leaks bring up a question. I'd like to confirm what I have been told.

Leaks for the Trilogy with my mask should be 60 l/m or under. My leaks typically run in the 30's. Last night's stats:

Min Leak: 33.1
Max Leak: 46.6
Avg Leak: 37.25

If this is to be believed and the guidelines I'm given accurate, then leaks cannot be the issue, right?

If I'm misunderstanding or just wrong, please steer me in the right direction.

[-SWS]

Min Leak: 33.1
Max Leak: 46.6
Avg Leak: 37.25

If this is to be believed and the guidelines I'm given accurate, then leaks cannot be the issue, right?

Not necessarily. The algorithms are pretty good with near-constant leaks. However, small, transient leaks during breathing transitions are the ones that can wreak havoc with BiLevel threshold detection---but especially when Auto-Trak is turned off.

Here's one plausible scenario:
bumped mask while shifting in bed===> small, brief leak during perfectly normal moment of very little patient flow===> threshold detection now confused===> false cycling or triggering

The above confusing transient leak can be much smaller than your typical Max Leak numbers. It only needs to be relatively brief, and well-placed with respect to your normal transitory moments of low-magnitude flow. So your nightly averages and max leak numbers don't necessarily exonerate leaks as a contributing culprit.

[Madalot]

Interesting. Not to add more "what ifs" to an already busy mix but I wonder if I should revisit trying Auto Trak.

[boots]

Trying auto-trak is a good idea or lowering the trigger setting. I believe auto-trak is lower than 6L.

[boots]

This resembles your tracings.