C-Flex and the I:E ratio
Posted: Tue Jan 09, 2018 11:38 am
This could be considered an extension of an earlier thread: viewtopic.php?f=1&t=113290&st=0&sk=t&sd=a&start=90
Please merge if applicable.
I noticed that my PR DreamStation with C-Flex 3 gives me an "inverse" (greater than 1) I:E ratio:
Whereas my ResMed with EPR 2 gives me a "normal" (less than 1) I:E ratio:
Ideally I would have used CPAP for the comparison as opposed to APAP which gave me different pressures at different times, but the I:E reading is for the entire night, and my APAP pressures were similar for the two nights.
I then tried PR DreamStation with C-Flex off, and that gives me a normal (less than 1) I:E ratio:
My ResMed with EPR off also gives me a "normal" (less than 1) I:E ratio:
Unanswered questions:
1)Are these I:E ratios correct, or is the PR measuring the start of inspiration prematurely when C-Flex is enabled. You can see that there is a plateau of minimal flow preceding increased inspiratory flow, and the machine seems to be marking the beginning of inspiration at the beginning of that plateau
2If they are correct, does it matter, or is this all academic?
I'm guessing that the answer to #1 is that it is a faulty measurement. Why would C-Flex cause the first part of inspiration to be stalled at a low flow rate for a while before starting in earnest? I'm thinking that inspiration should actually be measured from the end of that plateau.
Please merge if applicable.
I noticed that my PR DreamStation with C-Flex 3 gives me an "inverse" (greater than 1) I:E ratio:
Whereas my ResMed with EPR 2 gives me a "normal" (less than 1) I:E ratio:
Ideally I would have used CPAP for the comparison as opposed to APAP which gave me different pressures at different times, but the I:E reading is for the entire night, and my APAP pressures were similar for the two nights.
I then tried PR DreamStation with C-Flex off, and that gives me a normal (less than 1) I:E ratio:
My ResMed with EPR off also gives me a "normal" (less than 1) I:E ratio:
Unanswered questions:
1)Are these I:E ratios correct, or is the PR measuring the start of inspiration prematurely when C-Flex is enabled. You can see that there is a plateau of minimal flow preceding increased inspiratory flow, and the machine seems to be marking the beginning of inspiration at the beginning of that plateau
2If they are correct, does it matter, or is this all academic?
I'm guessing that the answer to #1 is that it is a faulty measurement. Why would C-Flex cause the first part of inspiration to be stalled at a low flow rate for a while before starting in earnest? I'm thinking that inspiration should actually be measured from the end of that plateau.