Nitrox Not Helping With Narcosis... It's not making sense.

[ajduplessis]

@Hetland: Helium is a lot less soluble than nitrogen, thus less is on-gassed. What is on-gassed (He) do come out a lot faster than N2 thou.

 

[Hetland]

Solubility deals with the amount of gas that can be dissolved in a tissue, and as far as I know, you are correct in that more nitrogen than helium can be dissolved in each tissue.

The controlling factors in tissue loading speeds are the partial pressure of each individual gas, and the size of the molecules of those gasses (tissue type is relevant too, but sort-of a different discussion)

Helium is a smaller molecule, and, if all else was equal, it would dissolve and exolve from tissues at a faster rate (2.65 times) than nitrogen. The slower compartments on-gas helium at a "slower" rate only because they are already saturated with nitrogen at the surface. The faster compartments on-gas helium "faster" (assuming the partial pressure of each gas was equal).

So I think we are both technically correct. Helium does on-gas faster than nitrogen, but because different compartments load at different rates, and because we are already saturated with a high partial pressure (79%) of nitrogen at one atmosphere, and because typical normoxic trimix blends (up to 39-40% helium) will have the same or higher partial pressures of nitrogen, in the majority of real-world cases, nitrogen will load faster......

At least I think so

 

[GAdiver]

Oxygen is just as narcotic as Nitrogen at depth so if you are looking for less narcosis you should probably try helium based gases such as triOx trimix heliox

 

[ajduplessis]

Oxygen is just as narcotic as Nitrogen at depth so if you are looking for less narcosis you should probably try helium based gases such as triOx trimix heliox

Maybe you can back that statement up with some facts please?!

 

[johnkendall]

Maybe you can back that statement up with some facts please?!

Roles of nitrogen, oxygen, and carbon dioxide in compressed-air narcosis

This study shows that O2 could be as much as 2.6 times as Narcotic as N2.

HTH
John

 

[ajduplessis]

Could and should does not cut it. Maybe as an instructor you can inform me which agency teaches this and more importantly what rules/fomula do they apply?

 

[jonnythan]

As far as I know, no instructors or agencies teach that O2 is more or less narcotic than N2.

 

[DevonDiver]

As far as I know, no instructors or agencies teach that O2 is more or less narcotic than N2.

ANDI teach on the premise that oxygen is less narcotic, although it is subject to caveat:

The beneficial effects of using Oxygen-enriched mixtures are:
......
d. A marked reduction in the narcotic effects of Nitrogen. This is especially noticeable in the 100 fsw (33 msw) depths and deeper.

Instructor note: This is subjective and requires more research. It is a fact that Oxygen is more soluble than Nitrogen in lipid tissue. This fact would seem to contradict the subjective reports. The statement above is true as written.

 

[Tigerman]

I smell a troll..

 

[VTscubaDAN]

I'd suggest you read Vance Harlow's "Oxygen Hacker's Companion" (from https://ssl4.westserver.net/airspeedpress.com/newoxyhacker.html) as it explains the questions you're asking in down-to-earth terms. You need to have a firm understanding of partial pressures of gases and compressibility, and how depth/pressure affects them in the human body. Even if you never plan to dive trimix or nitrox, it's great that you're trying to better understand the physiology of diving!