Nitrogen narcosis

[wedivebc]

Hi jomar, do you know that oxygen and nitrogen have the same narcotic power? In other words, there is no difference between nx and air about narcosis (there is a huge difference concerning deco, but that's another topic)

Do you have any science to back that claim?

 

[wedivebc]

Could not have said it better myself, and especially relevant is the "breathing part"!

On another note, and make of it what you will, this from a 'test' Tom Mount and some associates performed back in tbe 80's with new divers from, IIRC, a unniversity dive club / courses in Miami. They used two separate groupings over a period of time and set them test to do during the dive/s. They found in the cases where the instructor told the group they would get severly narced at 30m / 100ft, the majority did and on the whole pergormed the test poorly. Of the other group that was told there would be some effect from narcossis but as long as they were aware of such they could ' handle' it, the majority did 'handle' it, and the majority could perform the tasks set. However, in the end, the standout best 'performer' was a person from the first group, so again goes to show one shoe does not fit all.

So a take-away from all that is never overlook the power of suggestion, especially those divers that are just repeating ancedotes of what they have heard, or expect will happen to them, at depth. But dont get me wrong, narcosis cerainly does exist, and has proven a killer, but if you read some of the preceeding posts, and the above quote, you should realise that there were plenty of exceptions to the 'rule'.

But if I had my choice between air and gas (trimix), well it would be gas every time of course

Oh, and to the videographer I 'offended' a few pages back, your are right, there is more to shooting u/w video than just press and play. I, personally, just found it less demanding than u/w still photgraphy is all.

Funny, I was just looking that up before I read your post All About Narcosis...

 

[boulderjohn]

Nitrox: Narcosis myth?

 

[ginti]

Do you have any science to back that claim?

Well, science is not really exact in this field, as you know, but you can have a read here if you want to get an idea: Calculated Confusion: Can O2 Get You High?

The opinion of an expert in the post of @boulderjohn above; although it is only an opinion, it is one of the bases of my comment.

LOL. In a way, Nitrox DOES help with narcosis: it gives you more BT so that helps with thinking slower.

I can't argue against this

 

[boulderjohn]

The opinion of an expert in the post of @boulderjohn above; although it is only an opinion, it is one of the bases of my comment.

That opinion is not strongly stated, and it is referring to the study that suggests there may be a benefit in using nitrox in terms of narcosis.

Even though the study suggests a benefit, it is at best a small one.

 

[ginti]

That opinion is not strongly stated, and it is referring to the study that suggests there may be a benefit in using nitrox in terms of narcosis.

Even though the study suggests a benefit, it is at best a small one.

Agree, which is why I highlighted that it is "only" an opinion. At the end of the day, opinions are not much important in science, are they?

The article I posted add a little bit. But it's just a little bit, science is not really very developed in this field and there is not much we can do besides using the few data we have and the experience.

 

[wedivebc]

Agree, which is why I highlighted that it is "only" an opinion. At the end of the day, opinions are not much important in science, are they?

The article I posted add a little bit. But it's just a little bit, science is not really very developed in this field and there is not much we can do besides using the few data we have and the experience.

Well you stated in a rather authoritative 'voice"
@ginti said: ↑
Hi jomar, do you know that oxygen and nitrogen have the same narcotic power? In other words, there is no difference between nx and air about narcosis (there is a huge difference concerning deco, but that's another topic)

which is why I asked for the science behind it

 

[ginti]

Well you stated in a rather authoritative 'voice"
@ginti said: ↑
Hi jomar, do you know that oxygen and nitrogen have the same narcotic power? In other words, there is no difference between nx and air about narcosis (there is a huge difference concerning deco, but that's another topic)

which is why I asked for the science behind it

Let me clarify The reason for my comment was that often people (especially new divers but not only them) think that nitrox courses are there to use a gas mix that performs better against narcosis. But the main reasons for nitrox are others: to increase ndl bottom-time or to reduce surface-time between repetitive dives.

That said, you are right, I should have used a less authoritative approach. I hope nobody misinterpreted what I wrote.

 

[dmaziuk]

While I agree with your first sentence I would have to respectfully disagree with your second, particularly or precisely the words "most folks are fully capable..........". If I am to understand the rec limits as 40m / 130ft then I would say that most experienced divers would / should be, but not necessarily your twenty odd dives a year diver, and there are a lot of those.

This is a tangent, but here's Dr. Mitchell's take on rec limits in relation to gas density, work of breathing, and CO2 retention. Well worth checking out as CO2 "dark narc" is supposed to be the worst of 'em.

 

[wedivebc]

Let me clarify The reason for my comment was that often people (especially new divers but not only them) think that nitrox courses are there to use a gas mix that performs better against narcosis. But the main reasons for nitrox are others: to increase ndl bottom-time or to reduce surface-time between repetitive dives.

That said, you are right, I should have used a less authoritative approach. I hope nobody misinterpreted what I wrote.

I keep hoping a study will clarfy the issue one way or other. but since narcosis is so subjective that even Tom Mount's study I posted above shows why good research is so hard to find. On the subject of nitrox offsetting narcosis, the amount of oxygen that is in play once you get enough partial pressure of gas to feel a difference the O2 would be of little consequence. If O2 didn't have other issues at high PPO2 then we could just blast down to 50 meters on O2 and see if it had any narcotic effect.