Adding helium: some numbers to think about narcosis.

[dewdropsonrosa]

I'll be very interested to see the results of the EEG study!

One of the more interesting theories that I've seen about narcosis* is that the fatty myelin sheaths around nerves have excellent nitrogen uptake. Once full of nitrogen, their physical properties change and the cognitive impairment of narcosis is a result of nervous system signals bouncing in atypical ways.

(* I am out of the house and don't have my research library login with me. I'll try to figure out a citation later.)

 

[Dominik_E]

Indeed sounds like a very interesting study!

 

[RayfromTX]

@Dr Simon Mitchell I can split this off to a different thread but if we are going to talk about actual mechanisms that cause narcosis, this may be an appropriate time. I have wanted to start a thread about this for awhile and wanted your opinion on it.

We know that many people do things that fall outside of accepted practices and we know they don't talk about it on the internet because of the firestorm that it would cause. We know that people have bounce dived to 300 feet on air for many many years and based on the PPO2 at that depth, oxtox should be a major factor. Narcosis is of course quite a factor at that depth especially depending on CO2 levels. I have heard many opinions but nothing more credible that explain this by the theory that the narcosis actually "buffers" or "inhibits" the toxicity of the O2 by inhibiting the neurological reaction of the O2. How is this discussed in the scientific community or is it just dismissed?

Should I remove this post, start a new thread or do this in a more private area?

 

[Angelo Farina]

Should I remove this post, start a new thread or do this in a more private area?

I think that what you wrote triggers me memories of the theories for high depth diving in air which were developed here in Italy 40 years ago by a pioneer of scuba diving, named Raimondo Bucher.
If you do not know who he was, read here:
BUCHER, Raimondo
Unfortunately there are not many info on him on the Internet, in English.
Bucher did work for many years as a coral hunter, diving at 100-120m with air and a standard twin bottle.
He developed his own techniques and equipment, including Bucher fins, a special wet suit with minimal compressibility, minimal water friction and of a brilliant yellow color for maximum visibility, modified regulators (which he renamed as "offer regulators"), he was against the usage of any sort of BCD, and for ascending he did develop a constant-volume inflatable ascent balloon (similar to the one employed in "no limit" freediving, but smaller, so that the ascent speed was constant at 10 m/minute with no action required for controlling valves, etc.).
He was mainly concerned of narcosis, oxygen toxicity and CO2 accumulation. He did understand that CO2 plays a primary role in narcosis, and that Nitrogen was counterfeiting Oxygen toxicity, allowing to dive well below the medically-accepted toxicity limits.
According to Bucher it was of utmost importance to avoid CO2 production and retention. His modified regulators allowed to breath compressed air with almost no effort, despite its higher density and viscosity, and were the inspiration for the legendary Scubapro Pilot regulator.
His low-friction wet suit and super-streamlined equipment without BCD or any hanging equipment did allow for moving in water with reduced effort, with the help of short fins with large surface for efficient kick. All was focused to avoid CO2 accumulation, as this was causing narcosis much more than Nitrogen.
His theories have been strongly opposed, at the time, both by scientists (who did not have any first hand experience) and by the first proponents of technical diving, who were pushing for gas mixtures, rebreathers, dry suits, wing BCDs, side-mounted bottles, etc..
Bucher and his wife, Luciana Civico (probably the deeper female of past century) continued diving well below 100m, in air, even in their eighties, using their own equipment, obtained modifying low cost gear for recreational use.
Of course, if his theories had been widely accepted, a whole sector of scuba industry had collapsed, and all the training courses for deep diving and technical diving had to be modified or, simply, cancelled...
Here an article, in Italian (but Google Translator is your friend, here) recalling his theories: RAIMONDO BUCHER: IL DA VINCI DELLA SUBACQUEA – UN ARTICOLO SENZA TEMPO | www.edicolamarescoop.com