Heliox for recompression chambers

[ Follow Ups ] [ Post Followup ] [ California Scuba Diving BBS ] [ FAQ ]

Posted by MHK on May 01, 2001 at 12:06:56:

This came across another list that I'm on and the person who posted this is a trusted friend of mine so I thought I'd offer it up here for consideration...

As I noted in an earlier post, I've begun using a 50/50 Heloix on deco, but the studies are pretty crude analysies up to this point so we've been, in essence, the guinea pigs..

Just for thoughts....

From the Diving Medicine Online Newsletter:

Effect of combined recompression and air, oxygen, or heliox breathing on air
bubbles in rat tissues.

J Appl Physiol 2001 May;90(5):1639-47
Hyldegaard O, Kerem D, Melamed Y.

The Institute of Medical Physiology, The Panum Institute, University of
Copenhagen, 2200-N Copenhagen, Denmark.

The fate of bubbles formed in tissues during the ascent from a real or
simulated air dive and subjected to therapeutic recompression has only been
indirectly inferred from theoretical modeling and clinical observations. We
visually followed the resolution of micro air bubbles injected into adipose
tissue, spinal white matter, muscle, and tendon of anesthetized rats
recompressed to and held at 284 kPa while rats breathed air, oxygen, heliox
80:20, or heliox 50:50. The rats underwent a prolonged hyperbaric air
exposure before bubble injection and recompression. In all tissues, bubbles
disappeared faster during breathing of oxygen or heliox mixtures than during
air breathing. In some of the experiments, oxygen breathing caused a
transient growth of the bubbles. In spinal white matter, heliox 50:50 or
oxygen breathing resulted in significantly faster bubble resolution than did
heliox 80:20 breathing. In conclusion, air bubbles in lipid and aqueous
tissues shrink and disappear faster during recompression during breathing of
heliox mixtures or oxygen compared with air breathing. The clinical
implication of these findings might be that heliox 50:50 is the mixture of
choice for the treatment of decompression sickness.


Follow Ups:

Post a Followup




[ Follow Ups ] [ Post Followup ] [ California Scuba Diving BBS ] [ FAQ ]