extremely low tidal volume

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yearning4zs
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extremely low tidal volume

Post by yearning4zs » Tue May 14, 2019 9:43 pm

I posted yesterday about my respiratory rate looking too high. Thanks everyone for the answers, the machine was definitely overestimating my respiratory rate. However, this led me to find another issue. In the areas of artificially high respiratory rate, my tidal volume dips down below 100, and minute ventilation drops below 5, sometimes even to 3.7. Does anyone understand what's going on here???

I previously was diagnosed with epiglottic collapse and had surgery to partially excise the epiglottis. I'm starting to wonder if this is still a manifestation of an epiglottis problem. The strange thing is, the machine does not pick up any flow limit during these times...

Please see the below graphs.

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Snoregone Conclusion
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Re: extremely low tidal volume

Post by Snoregone Conclusion » Wed May 15, 2019 2:05 am

Minute vent is tidal volume multiplied by respiration rate, and as long as you get enough minute vent, you won’t be starving for air.

You need to get your leaks down, from what’s visible, but otherwise, doesn’t seem crazy.

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yearning4zs
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Re: extremely low tidal volume

Post by yearning4zs » Wed May 15, 2019 2:32 am

I guess was concerned that minute vent looked a little low too. This is not considered good in terms of overall leak rate? (see graph) resmed gave me a smiley face!

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Jas_williams
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Re: extremely low tidal volume

Post by Jas_williams » Wed May 15, 2019 4:11 am

yearning4zs wrote:
Wed May 15, 2019 2:32 am
I guess was concerned that minute vent looked a little low too. This is not considered good in terms of overall leak rate? (see graph) resmed gave me a smiley face!
Your leak rate is fine, anything less than 24l/m is fine

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LSAT
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Re: extremely low tidal volume

Post by LSAT » Wed May 15, 2019 5:52 am

The machine shown on Sleepyhead does not correspond to the machine in the profile.

yearning4zs
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Re: extremely low tidal volume

Post by yearning4zs » Wed May 15, 2019 6:21 am

LSAT wrote:
Wed May 15, 2019 5:52 am
The machine shown on Sleepyhead does not correspond to the machine in the profile.
sorry, I just updated it. I've been using for her for a few weeks now. Was originally renting and then just recently bought one. The newest one I've been using for 3-4 days. The high artificial respiration rate started then.

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ajack
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Re: extremely low tidal volume

Post by ajack » Wed May 15, 2019 6:22 am

You may be mouth breathing a bit with a nasal mask? Keep and eye on it and I would fix leaks where I can, if for no other reason than they annoy me and arouse me from sleep. I would turn the ramp off, have the start and min pressure on 6, max 10. It's not taking much pressure to resolve any apnea.

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yearning4zs
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Re: extremely low tidal volume

Post by yearning4zs » Wed May 15, 2019 7:19 am

ajack wrote:
Wed May 15, 2019 6:22 am
You may be mouth breathing a bit with a nasal mask? Keep and eye on it and I would fix leaks where I can, if for no other reason than they annoy me and arouse me from sleep. I would turn the ramp off, have the start and min pressure on 6, max 10. It's not taking much pressure to resolve any apnea.
I tape my mouth, so probably no mouth breathing (doesn't seem to be leaking). But definitely leaks maybe from the mask. I could tighten it up a bit I think. The odd thing to me is there is basically no apnea recorded and even no flow limitations sometimes despite the really low tidal volume and minute ventilation. That's also why I'd be reluctant to increase the min-max pressure. My pressure never gets up to my max these days.

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ajack
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Re: extremely low tidal volume

Post by ajack » Wed May 15, 2019 8:27 am

You may find, 6 isn't considered anything more than a starting pressure with the FFM, so it vents properly. You actually might find it more comfortable, as the EPR will be 2cm lower and 4.

See how the leaks go.

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Jay Aitchsee
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Re: extremely low tidal volume

Post by Jay Aitchsee » Wed May 15, 2019 8:41 am

Tidal Volume is the volume of each breath. Your erroneous respiration rate is high because each breath is being counted as more than one smaller breath. These erroneous smaller breaths each have less volume than the correct whole breath; therefore, the reported Tidal Volume for each breath is smaller.
In other words, the Tidal Volume reported during periods of erroneously high Respiration Rates is based on much smaller breaths then you are actually taking.

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yearning4zs
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Re: extremely low tidal volume

Post by yearning4zs » Wed May 15, 2019 8:42 pm

Jay Aitchsee wrote:
Wed May 15, 2019 8:41 am
Tidal Volume is the volume of each breath. Your erroneous respiration rate is high because each breath is being counted as more than one smaller breath. These erroneous smaller breaths each have less volume than the correct whole breath; therefore, the reported Tidal Volume for each breath is smaller.
In other words, the Tidal Volume reported during periods of erroneously high Respiration Rates is based on much smaller breaths then you are actually taking.
very interesting and well noted!

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