This article is from the Scuba Diving FAQ, by njs@scifi.maid.com (Nick Simicich) with numerous contributions by others.
In it, they had a rat breathing liquid. Is that really possible? Is
there equipment like that for humans?
Yes, it is really possible. The rat was breathing liquid in the scene
you saw in the movie. No, it is not done with people (except with
premature babies to replace missing surfactants - this has been
reported on _Hard Copy_ a US TV tabloid news show, complete with
pictures of the procedures and one of the surviving children). A
widely cited study involved a single adult subject who had one lung
filled with the liquid, but who had problems with pneumonia
afterwards. It is considered highly risky. To pull an old thread on
this from rec.scuba, do a scubasearch with the subject:
^subject:.*liquid scuba
The liquid is a chloroflourocarbon, like freon, but with a higher
boiling point.
 
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