DCS from O2 decompression

[deepmaxim]

I have self one time a DCS symptomatic directly after change on O2 (6m)... I think it is possible to have a DCS from each gas in breathing gas and not only from "inert" gas like N2 or helium.
Have you the same expirience with O2 bends?
Thanks

 

[StreetDoctor]

Not too sure I agree with you on this one...

 

[Dr Deco]

Hi Deepmaxim:

No, you cannot get DCS from oxygen. Oxygen is used to treatDCS.

 

[deepmaxim]

Oxygen is a pshysical gas, its means, that O2 would be solve in a blood like other gases.
We comming on 6m, before we have another decompression gas like EAN50.
EAN50 has a PPO2 on 6m - 0,8
We go to pure O2 with PPO2 - 1,6
We have now double pressure from PPo2 in a blood with possibility to become a counterdiffusion if a compartiment PPG is to high.
It first.
Second, if a O2 go inside a bubble, we need for eleminating same time like for N2, becouse O2 it not more solve, but in a gas form. (Molecule from O2 must go first over Buble surface like other gases)
Its means, if i have a bubles (silent) in my compartiments, oxygen kann go (and will go) inside, if PPO2 tissue is higher as in a Bubble and gas form O2 in Bubles is not so undangerous...
That was the question, have you see any research for this problem?
Thanks for answer
King Regards from cold Germany
Maxim

 

[rigdiver]

From tests in San Antonio in the 50's it was possible to bend someone on O2, but they went from a Hyper to Hypobaric environment and it quickly went away. Gotta love space research.

 

[DCBC]

From tests in San Antonio in the 50's it was possible to bend someone on O2, but they went from a Hyper to Hypobaric environment and it quickly went away. Gotta love space research.

Ran Arieli of the Naval Medical Institute in Haifa did some studies surrounding aviation accidents involving a sudden loss of cabin pressure. He found that breathing oxygen to overcome the hypoxia resulted in the growth of decompression bubbles and increased the risk of DCS.

 

[brockbr]

Sure - In a very rare set of circumstances, O2 could cause DCS. This is because the O2 causes us to off-gas N2 quicker (this is why we use O2 to begin with and that's why it's called accelerated deco when we use EAN or O2 to deco). Although in practice, the ambient pressure change would probably have been the causal factor.

I'd suspect that it wasn't the O2 that actually caused the DCS symptoms. I'd suspect it was the change in depth prior to the stop where the oxygen change occurred (the move to 6m). It is very common for it to take a few minutes before any DCS symptoms are felt.

 

[deepmaxim]

If you have planned the dive very agressive (not so good isea but..), you have a chance to becomme a DCS from O2 to... Its not soo impossible as you mean. Counterdiffusion is not unknow factor by decompression. I have one rule for me. If i have hard dives (deep and/or long), i change not more directly from gas to gas, but i wait about 2-4 min. and then i go to other gas. I can say you, its work (for me) !
But need more material from research about this theme...
Have asked Dr.J.Wenzel he work in Kölns Aerospace/Marine Dep. He has works on Hydra Project in Köln (over 600m) and means its possible from the pshysologie (gas diffusion rules)...

 

[DocVikingo]

Sure - In a very rare set of circumstances, O2 could cause DCS.

As the studies mentioned (but not fully cited) seem to suggest, indeed it would be a very rare and quite likely contrived set of extreme circumstances under which 02 might contribute to DCS.

Regards,

DocVikingo

 

[Dr Deco]

HI DEEPMAXIM:

If you talk to Jurgend, ask him he remembers Mike Powell from our early days in Bonn and the DFVLR.