Confused about Narcosis...

[MXGratefulDiver]

I make a point of conducting an 'exertion test' also.

In deep water (30-40m), when there is no or slight narcosis felt, have the diver fin hard for a few minutes (until breathing hard). Then test again for narcosis.

The results can be surprising... and will teach how the onset of narcosis can drammatically be brought about in a demanding and/or emergency situation.

There is a definite corrolation between CO2 buildup and narcosis ...

... Bob (Grateful Diver)

 

[TSandM]

I got an ugly and personally very painful lesson in the additive nature of narcosis and CO2 during my attempt at my Cave 2 class. As I gave an unexpected problem underwater a bovine and uncomprehending stare (and proceeded to choose one of the wrong answers) I was a classic example of a case of narcosis. I didn't feel drunk, or euphoric, or anxious at all. I was just stupid.

OnceLoyal, one part of your question had to do with whether a diver should proceed, once he knows he is suffering from narcosis. My experience would say that if you KNOW you are impaired, you should get shallower. It's not that you can't float and look at the fishes; it's that any novel issue you might have to cope with is going to be met with far less than an effective, thoughtful response. Literature shows that things you have carefully trained when not impaired will be better executed under the influence of narcosis than things you haven't, and most underwater problems won't be things you have rehearsed.

 

[gcbryan]

I agree with all of the comments. I generally like to differentiate between CO2 buildup, anxiety, and narcosis since they are related but different things and how they work is slightly different so I feel it's generally more accurate to separate them.

I also tend to not work very hard underwater in general and the deeper I go specifically. I would not do a deep dive that also involved a lot of current.

It's best to avoid narcosis as much as possible. Not everyone has access to helium, doubles, stages, etc. so there will be some short exposures into this realm for many.

 

[DevonDiver]

I saw a classic case last sunday....

I was leading a wreck penetration (max depth 34m) into a series of compartments with no natural light and a moderate silt risk. As the penetration progressed (about 25m in), one of the divers became increasingly mal-coordinated, slow and generally became ineffective. I aborted the penetration and we returned on the guideline - with myself keeping touch contact/control on the diver concerned. In the space of a minute, the diver concerned had kicked up enough silt to drop viz to virtually zero and my primary concern was that he kept contact with the line (hence my tactile control of him).

The diver had never experienced narcosis before, despite routinely completing deep recreational dives.

At the surface, I quizzed the diver about his experience. He said that he had become completely confused about what we were doing and severely disorientated (especially in terms of exit direction).... but that he was having a "really great time" in there!

 

[rockjock3]

Take a bit of helium in your tank. Helium=goooooood, nitrogen= baaaaaaad. Helium cures what ails ya.

 

[joolz]

I have an idea of what it feels like I guess. Now that I think back when I was giving hand signals to the DM at 138Ft.

Not to go off on a tangent, but I'd be more concerned about a DM taking a new diver to 138 feet, especially if said diver still has questions about narcosis. That displays an incredible lack of professional judgment on the DM's part.

Also my instructor says that nitrox can actually be worse, which I guess i will do my own research and draw my own conclusion on that one.

Nobody fully understands what causes narcosis, and the current theory is that both oxygen and nitrogen -- or any gas for that matter -- have their own narcotic properties at depth (although we still usually refer to it as nitrogen narcosis since nitrogen is believed to be the primary contributor). At 138', you wouldn't have to worry about being narc'd on nitrox since you'd probably be in convulsions from oxygen toxicity. But nitrox is a separate issue with its own set of risk factors...I apologize from even bringing it up in my original post. It was a careless afterthought.

 

[dkktsunami]

I have an idea of what it feels like I guess. Now that I think back when I was giving hand signals to the DM at 138Ft. It seemed like I hesitated a second from what I was thinking to actually getting my hands to do it. So if 'they" (the infamous they) get narced on a lighter level it is ok for them to stay at that depth or continue further? I always thought that if you get narced you need to get out of there. If you can handle being slightly narced then it is ok....Sorry for the juvi questions. I am just getting a lot of different ideas from a lot of different people lately.

Also my instructor says that nitrox can actually be worse, which I guess i will do my own research and draw my own conclusion on that one.

Simm that is pretty cool with the math problems....

Thanks for the help so far on this.

What's the deal with this? Fewer than 24 dives and you're giving hand signals to your DM at 138'. Like I mentioned earlier in this thread, narcosis affects judgement, and I can think of one hand signal that is very appropriate for this DM.

 

[TMHeimer]

I've never noticed narcosis-at 100 or 130 feet. Science proves I have had it. Dives from day to day vary, as do people with their physiology. I hope I never get in trouble.

 

[DevonDiver]

The next time you are at 130", try doing the 'exertion test'. It can expose the underlying narcosis - and will give you a clue about how narcosis can strike in time of emergency at depth. Make sure you are supervised by a buddy you can trust.

 

[gcbryan]

The next time you are at 130", try doing the 'exertion test'. It can expose the underlying narcosis - and will give you a clue about how narcosis can strike in time of emergency at depth. Make sure you are supervised by a buddy you can trust.

Is that exposing narcosis or creating CO2 buildup?