Narcotic effect of inert gases at various pressures.

[oneighty]

Fools go where angels fear to tread. (Me)

Years ago I worked as a research assistant in diving physiology. Are any of you up to date on this subject?

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[punpirate]

1. Nitrogen narcosis?

High pressures affect nerve conduction, causing one to feel tipsy.

[oneighty]

3. Yes Nitrogen Narcosis

Narcotic effect is different with each noble gas. As are flow restrictions in the pulmonary system.

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[punpirate]

6. Don't know much about it...

... but as I recall, the degree of effect depends upon the solubility of the gas in tissues (as you obviously know, that's the reason for using helium/O2 mix).

While I don't know much about the diving physiology, I did do some research work for a biochemist who was working on supercritical fluid cell disruption, and the gist of that work was that gas migration into the cell walls depended less on pressure than chemical compatibility. CO2 worked well, argon didn't, etc.

[OffWithTheirHeads]

2. yeah! don't get narked by going too deep.

Also the philosophy of the MSP.

[scubadude]

4. Do you know something I should?

Or any other divers out there?

Scuba

[oneighty]

5. No I do not.

I had to quit the field thirty years ago. I thought maybe somebody such as yourself was personally up to date on mixed gas diving and diving physiology.

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[Billy Ruffian]

7. I might be able to find out, if I can't remember

I was a USN diver many years ago, and a buddy was EOD, then became a Diving Medical Officer. What are you trying to find out?

I've done a 200 ft dive on air, and was very, very buzzed (but still able to complete my task in a timely fashion, it just took intense concentration and some prompting from the surface.)

I've also done 300 ft on a 16/84 mix of O2 and He2. No narcosis at all, but He makes for a longer decompression, and seems to conduct the heat out of your body faster than does N2.

It was a relief to switch over to pure O2 at the 50 ft decompression stop, and an even greater relief to do a surface decompression (do 10 minutes of your 40 ft stop, then come to the surface, get out of the MkV Mod 0 diving rig, and go to 40 ft in the chamber to do your full 40 ft stop

[oneighty]

9. I was Navy EOD also

Who is your doctor friend? I worked for Dr. Ed Lanphier.

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[Billy Ruffian]

10. This guy was EOD active duty

then reserve while attending med school on his own. Made LCDR while in med school, then got med corps commission as LT. Appealed for 'repromotion' (don't know what the real term was) and got it. He might even be retired by now ... we're that old ;-)

He wasn't involved with EOD as a Diving Medical Officer. Watch your PM for the name.

[NNadir]

8. Xenon gas, which is not used in diving to my knowledge, is a

narcotic gas in high enough concentration and pressures. It forms clathrates that interfere with the properties of water in sensitive places like synapses, I believe.

[oneighty]

11. Yes

Second hand information long ago spoke of experiments with rare gasses as fillers. One such study was said to have cost a thousand dollars or so per breath.

A study I was involved in with mice as subjects (human study was hard to do) used Argon. The mice performed well with Argon.

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[Billy Ruffian]

12. Duke University Medical Center

has a pretty large hyperbaric research facility ... have you tried to contact them?

And you still haven't told us what you want to find out B-)

[oneighty]

13. Yes Duke is an important research

center for deep diving.

Information I am interested in is available in GOOGLE of course. I was sort of hoping some DUers might be involved in current research and offer us first hand information.

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[Billy Ruffian]

14. Sorry I can't help with the current research

but you've REALLY piqued my curiousity about what you're checking into!

Come on! No fair! You GOTTA tell us ;-)

[oneighty]

15. An example

Years ago mice colonies were successfully exposed to saturation dives to depths of 100 ATA and brought back alive and well. The gas mixture was Helium/Oxygen with Oxygen partial pressures adjusted to earth normal as required during descent and ascent. Mouse activity was measured mechanically (Exercise wheel) and general activities observed and noted.

Later studies introduced Argon and Nitrous Oxide into the gas mix.

I am curious as I said, if any DUers have been involved in recent studies concerning gas mixes for diving and or space travel life support systems.

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