Helium Dilution and Nitrogen Washout: Explained

[@iousjuan5125]

Thanks Chris. Definitely helped. I never saw the stacked N2 reading, but I get it. See you again.

[@creat0r86]

The way I look at it is, if you take the X axis in the bottom nitrogen washout as volume, and starting at FRC, when you finally get nitrogen percentage in the later breaths below 1.5%, you assume that most of the nitrogen has been washed out. Then the total volume of nitrogen per breath (concentration of nitrogen * volume of breath) = amount of nitrogen exhaled = FRC * 0.8

[@ScienceWithChris]

that is an excellent way of looking at it.. it will eventually summate to something close to 100 but the importance is if there is a stall at a certain percentage like 60%. This would result in supsicion of air trapping

[@creat0r86]

@@ScienceWithChris all good, you have one of the best videos on the subject, you explain it really well. Thanks for making it

[@chandreyeesinha4940]

I have one question He dilution method was used to measure RV. Initial He conc.=10% Final He conc.= 6% Volume of spirometer=2L. How much is RV

[@Theodore660]

en.wikipedia.org/wiki/Helium_dilution_technique Calculations given here

[@77deniz]

thanx

[@Danielaf1992]

I don't like the way you teach. Too fast without pauses. Hard to keep up...