Volume of N2 accumulated in dive

[Daryl Morse]

Just wondering, what is the approximate volume of N2 (in scf) that accumulates in body tissues and fluids during a typical dive (e.g, 100 fsw for 20 minutes). Approximately what volume still remains to be off-gassed by the time it's safe to surface?

I realize there isn't an exact answer to this question. I'm just interested to know the approximate order of magnitude.

 

[Dr Deco]

Hello Daryl:

The volume of dissolved nitrogen in a short dive is highly variable. As a “rule of thumb,” one can say that a man of average weight will dissolve one quart of air per atmosphere (33 fsw) after 24 hours at pressure.

Very little of this dissolved nitrogen will actually appear as gaseous nitrogen in bubbles. Some tissues (adipose = fat) can generate a lot of free gas (bubbles) with no particular consequences. Other tissues (ligaments around joints) appear to less tolerant and will indicate this with pain (“the bends”).

Dr Deco :doctor:

 

[Stryker]

Dr. Deco,

So am I correct in saying that fatty tissue develops nitrogen bubbles on every dive? Since you have a buildup of nitrogen as the dive goes on, is the fatty tissue the first place the nitrogen develops or does muscle tissue build up nitrogen quicker?

I guess the way I read your response is that nitrogen bubbles in fatty tissue is normal, but in joints and ligaments is the bends. I guess it just didnt sound right to me. Thanks.