Can you measure the actual fraction of inspired oxygen delivered when connecting O2 to your CPAP/Bi-level?

[raisedfist]

So if room air is 21% FiO2, generally it's accepted that every increase in LPM is about a 4% increase in the FiO2. But with CPAP or Bi-level, depending on the pressures used, dilution occurs. So 2LPM delivered by a nasal cannula is not the same as 2L delivered by connecting tubing from a concentrator to an xPAP. Just wondering how you would measure the amount of oxygen you are getting. Or, do you just have to work backwards and look at your data to see how many LPM you actually need.

[Goofproof]

If the O2 compressor is in the same room you are using it guess where the O2 is coming from. the room by you are using it from. that changes the result as does the vent rate. mine runs in a room with no people or pets in it. And I run 3 lpm instead of the 2 lpm the doctor ordered because I realize it gets diluted as long as it's venting. It matters little as you keep breathing. Jim

[palerider]

So if room air is 21% FiO2, generally it's accepted that every increase in LPM is about a 4% increase in the FiO2. But with CPAP or Bi-level, depending on the pressures used, dilution occurs. So 2LPM delivered by a nasal cannula is not the same as 2L delivered by connecting tubing from a concentrator to an xPAP. Just wondering how you would measure the amount of oxygen you are getting. Or, do you just have to work backwards and look at your data to see how many LPM you actually need.

Look at the vent rate curve for your mask to figure out how many liters per minute are venting out of there. then you can do some calculations to see what replacing 2-3 etc lpm with 95% O2 does to the numbers.

Or you can just get yourself an inexpensive O2 meter and measure it. ('s what I did).

[Jeff8356]

A couple of references to help determine just how much diluted O2 you are getting:

http://nurseyourownway.com/2016/03/29/o ... ationship/

And this one:

http://www.apneaboard.com/wiki/index.ph ... _with_CPAP

Both give you the formulas to figure it out. The second link is xPAP specific.

[klm49]

So if room air is 21% FiO2, generally it's accepted that every increase in LPM is about a 4% increase in the FiO2. But with CPAP or Bi-level, depending on the pressures used, dilution occurs. So 2LPM delivered by a nasal cannula is not the same as 2L delivered by connecting tubing from a concentrator to an xPAP. Just wondering how you would measure the amount of oxygen you are getting. Or, do you just have to work backwards and look at your data to see how many LPM you actually need.

I wouldn't be concerned about this, just get a recording pulse ox so you can determine if you are getting enough O2 and go from there.

[ChicagoGranny]

I wouldn't be concerned about this, just get a recording pulse ox so you can determine if you are getting enough O2 and go from there.

You are right, but some people like to math.

[Morbius]

Or you can just get yourself an inexpensive O2 meter and measure it. ('s what I did).

Back at the shop, that's what they (I am not saying "we", as "I" was the one that sent "them" out to work) did. Oxygen analyzer sensor at the mask, just before exhalation port, measured @ steady state (obviously cause unplanned leakage would cause FIO2 to plummet). Measuring FIO2 becomes more important when using BiPAP (I see there was a rant... err, "discussion" about the use of that term) in treating combined disorders (like Covid when you, or they, or whoever, run out of V60s)(and thank God omicron isn't as bad as Alpha or Delta!).

So other than that, how's everybody doing? Looks like Froggy doing well, Pugsy the same as ever...

So Happy New Year everyone! See you next year!

[palerider]

Or you can just get yourself an inexpensive O2 meter and measure it. ('s what I did).

Back at the shop, that's what they (I am not saying "we", as "I" was the one that sent "them" out to work) did. Oxygen analyzer sensor at the mask, just before exhalation port, measured @ steady state (obviously cause unplanned leakage would cause FIO2 to plummet). Measuring FIO2 becomes more important when using BiPAP (I see there was a rant... err, "discussion" about the use of that term) in treating combined disorders (like Covid when you, or they, or whoever, run out of V60s)(and thank God omicron isn't as bad as Alpha or Delta!).

So other than that, how's everybody doing? Looks like Froggy doing well, Pugsy the same as ever...

So Happy New Year everyone! See you next year!

I had my fill of V60s last year with my brother in the hospital for several months, and "respiratory" people that didn't seem to really understand how to set them up for his needs..

Anyway, I'm just hoping this year doesn't suck as badly as last year did.

Happy New Year to you too!