Posted by Steve on May 15, 2001 at 10:27:01:
In Reply to: Evils of Air - A post from George Irvine III posted by AADIVER on May 15, 2001 at 08:08:35:
Just received a reply from George Irvine III:
"Frank, you can repost any of this . Kane is exaggerating to make a point. Indeed you could say that it is so difficult to adequately decompress from an air dive that you are as good as "bent" on all of them."
Agreed, it seems a little inflammatory and an exaggeration to say the least. I have read that some believe that each dive should be considered a deco dive no matter what depth and this seems more realistic but I couldn't proof it.
"This is due to the fact that "DCS" is not confined to the standard pain symptoms or more dangerous CNS symptoms only. The sub clinical symptoms that we hear about, like tiredness and a flu like feeling are more likely immune system reactions to damage caused by the nitrogen tension on the deeper dives as well as bubbles, and the problem getting rid of the nitrogen at all. Nitrox is a little better, but the more helium, the easier it is on you. Clearly, as shown by Doppler, the bubble formation and growth after the dive is the worst, and clearly that is aggravated by the fact that there is plenty of nitrogen to draw from when building bubbles post dive as it is in us anyway. Air is probably the worst possible gas for diving."
Every one day California dive trip that I have done, I very felt tired that night and the next day. IMO, this is particially due to not getting a full night sleep, lugging heavy gear, climbing boat ladders with heavy weightbelts, the swimming and cold water. I've done liveaboards in warm water with five dives a day and have not had that tired feeling. So, how is it that nitrogen is the cause of the tiredness? I have never had flu like feelings.
George, controversy comes in with regard to RBCR as to the cause of this. Some studies show this is caused by the pressure and not just nitrogen pressure, other seem to think that it is cause by high ppO2. I read your post on the techlist last night that you feel that this is caused by nitrogen tension and that they need to proof you wrong.
George what exactly is your hypothesis? It would be a significant scientific finding if helium in anyway relieves RBCR or has others benefits. Helium has some potential side effects that are concerns to me but sometimes the side effects are outweighed by potential gains. If this hypothesis has any foundation maybe a research grant could be had. How hard would this be to proof?
Steve
ps: Good job Frank, I think a few divers are interested in this subject and general deco theory discussions. For those that call this technobabble please bear with us and start threads that interest you.