Really understanding Nitrogen narcosis

[justintx]

...maybe they just think the narcotic effect decreases as you go a bit deeper because they become more narced so that they don't realise they're narced. I mean we all know when we're a bit tipsy on alcohol but have you ever encountered a staggering drunk admitting to the fact that he's drunk?

If this is an accurate analogy (I don't know, as I've never gone beyond short duration dives to ~60 feet, and don't plan on it without another 15-20 dives under my belt, at least), then it raises a question. Forgive me for my newbie question, but here it goes:

When out for dinner, and having a glass of wine, I find that I'm much more conscious of impairment if I plan ahead of time to have a drink, rather than just having one on a whim.

For example, if I drive to a restaurant (and will drive home), I plan to and do limit myself to no more than two drinks, with the second drink being entirely contingent upon any sense of impairment felt after the first. By planning ahead and consciously monitoring the variables involved in drinking (i.e., type of drink, rate of drinking, time in-between drinks, drinking with food versus on an empty stomach, waiting for 20-30 minutes to leave the restaurant etc.), I am able to ensure that at all times I am in control of my faculties and am not a risk to myself nor others.

If, however, I am not responsible for driving, I tend to ignore the contributing variables to impairment and drink a little more freely. One to two drinks can become three or four. All the variables I typically monitor so closely become non-factors in my decision-making. I get so engrossed in the conversation and/or other activities around me that I don't rigidly self-monitor for signs of impairment. In such a case (and I have found this to be universal amongst friends), I don't usually recognize any effect of alcohol until I stand up from the table.

Does this type of scenario play itself out with nitrogen narc? Do you find yourself able to more easily identify the signs and symptoms of narc when you consciously and continuously self-monitor? Have you had a "standing up from the table" incident while diving, where you suddenly realize that dive objectives or other concerns have so occupied your mind that you are much more narced than you thought you would be?

Thanks!


Justin

 

[beester]

Deefstes what you are saying is on the button.

As you say it it's an effect that happens with increase of partial pressure and gas type (depending on solubility).

Your conclusions are correct. It starts affecting you from quite undeep but becomes more noticable (depending on diver) the deeper you go. The only solution to this narcosis is decreasing depth.

I always compare it to driving drunk. One guy who never drinks and on one night drinks a few glasses might barely make it home driving his car. Another guy who drinks regularly might make it home without noticing. However both will probably be unable to react in time if something out of the normal happens (a cat crossing the street).

What I'm trying to say is... a diver who dives deep regularly might say that he never has narcosis. It can be his ego talking or he might genuinly believe this but the fact is he has narcosis. He thinks he doesn't because he's used to the narcotic effect and also his taskloading is not high. So he can get by without any worries even being narced out of his mind. It's only when something out of the ordinary happens that requires his mental powers (the taskloading goes up) that he might feel the effect of the narcosis and won't be able to take the correct action if he can react at all.

In my organisation it's possible to dive deeper on air. I understand that I am always narced if I dive deeper and that this will impact my ability to react or think when my taskloading is upped. But I've only noticed it a couple of times when taskloading was not high. For example diving a cold quary (watertemp 5Ž°C = 42Ž°f).. I was wearing a wetsuit and we were deep (130 feet) and I felt really warm and cosy. I noticed this and drew the correct conclusion that this was narcosis. When we went up past 100 feet the cold hit again as a cold shower

 

[beester]

If this is an accurate analogy (I don't know, as I've never gone beyond short duration dives to ~60 feet, and don't plan on it without another 15-20 dives under my belt, at least), then it raises a question. Forgive me for my newbie question, but here it goes:

When out for dinner, and having a glass of wine, I find that I'm much more conscious of impairment if I plan ahead of time to have a drink, rather than just having one on a whim.

For example, if I drive to a restaurant (and will drive home), I plan to and do limit myself to no more than two drinks, with the second drink being entirely contingent upon any sense of impairment felt after the first. By planning ahead and consciously monitoring the variables involved in drinking (i.e., type of drink, rate of drinking, time in-between drinks, drinking with food versus on an empty stomach, waiting for 20-30 minutes to leave the restaurant etc.), I am able to ensure that at all times I am in control of my faculties and am not a risk to myself nor others.

If, however, I am not responsible for driving, I tend to ignore the contributing variables to impairment and drink a little more freely. One to two drinks can become three or four. All the variables I typically monitor so closely become non-factors in my decision-making. I get so engrossed in the conversation and/or other activities around me that I don't rigidly self-monitor for signs of impairment. In such a case (and I have found this to be universal amongst friends), I don't usually recognize any effect of alcohol until I stand up from the table.

Does this type of scenario play itself out with nitrogen narc? Do you find yourself able to more easily identify the signs and symptoms of narc when you consciously and continuously self-monitor? Have you had a "standing up from the table" incident while diving, where you suddenly realize that dive objectives or other concerns have so occupied your mind that you are much more narced than you thought you would be?

Thanks!


Justin

Good question and other will probably chime in... It depends...

Imo the more narced you are getting the less you realise you are narced until you hit a treshold where you're starting to act really strange (and your buddy realises finaly that this is not normal behavior). However most experienced divers will have an eye out for certain behavior by themselves and others. For example I know I need to head back up (so seriously narced) when I encounter following behavior with myself:
- Taking too much time to figure out the data on my dive computer (like more then 5 secs)
- Forgetting what I saw on my computer or manometer (looking multiple times)
- Paying less attention too my budy
- Feeling warm and cosy (except of course in tropical water )
- Feeling in love with the world and my surroundings... Feeling ZEN. (a great feeling btw if it wasn't for the danger)
- Feeling paranoid... general 'angst' (dark narc)

For me these are some treshhold marks that I'm already quite narced and need to ascend. This does not mean that I can't be caught unaware... everyone can even when looking for signals. Also the danger comes when you are getting beyond your experience level or when suddenly the taskloading increases. You might not be able to react in time or adequate to solve the issue.

Example is ... in my local dive environment we dive in bad vis, cold water, tidal currents, shore dives, boat dives, wrecks, many times deep (+100 feet), deco dives... if a guy who's used to those kind of dives goes to the tropics and doesn't watch out and keep his ego in check he might be in serious ****. No dive planning... not needed we're on holiday. Mmm warm water.... good vis... 130 feet is a normal dive... I can still see the boat from down here... dropping deeper... 160, 170, 180, etc... getting narced out of his mind... you see where I'm going

That's why many countries and organisations limit recreational (ie air dives) to 130 feet. Other will go even further and state going below 100 feet should always be with mix. I myself am in limbo on this. I'm very well aware that big risks are involved but I'm not yet willing to go beyond nitrox/advanced nitrox (gas switching to increase of gassing), to mix. So for the moment I will go to the french riviera in May and will dive the deeper wrecks (on air)

 

[miketsp]

..snip..
Does this type of scenario play itself out with nitrogen narc? Do you find yourself able to more easily identify the signs and symptoms of narc when you consciously and continuously self-monitor? Have you had a "standing up from the table" incident while diving, where you suddenly realize that dive objectives or other concerns have so occupied your mind that you are much more narced than you thought you would be?

Thanks!


Justin

Whenever I dive on air deeper than about 35m I force myself into a routine, look around, check buddy position, check SPG, check computer especially dive time and remaining no-deco time and then keep cycling this routine. I start the routine before hitting 30m and I've definitely found on some dives below 40m that even though I think I'm cycling through at a constant rate I clearly notice that the numbers seem to change faster between cycles with a jump of maybe 2-3 minutes to complete a cycle. So it's definitely taking more time for me to focus on these different items. Yet on other similar dives the cycle really seems to be much faster and constant.

 

[TSandM]

I am completely convinced that narcosis begins when one's head goes underwater. I am a very bright woman, and the number of times I've forgotten the sequence of drills, or gotten turned around with navigation (even on shallow dive) has convinced me that there is something that affects my thinking almost immediately, and it's certainly noticeable at 30 to 45 feet. I don't FEEL any different from normal -- I just have a lot of data points of forgetfulness and confusion underwater that I don't experience doing ANYTHING on land.

 

[gcbryan]

This is too funny! No confusion on land and you double post

 

[gcbryan]

I am completely convinced that narcosis begins when one's head goes underwater. I am a very bright woman, and the number of times I've forgotten the sequence of drills, or gotten turned around with navigation (even on shallow dive) has convinced me that there is something that affects my thinking almost immediately, and it's certainly noticeable at 30 to 45 feet. I don't FEEL any different from normal -- I just have a lot of data points of forgetfulness and confusion underwater that I don't experience doing ANYTHING on land.

Just kidding about the double posts. It happened to me the other day. I think it's a ScubaBoard glitch.

Do you really think narcosis can be the significant reason that you or anyone else has for a navigation problem at 30 fsw? I mean, aren't there so many other more likely reasons at this depth? I agree that narcosis must start on some level with submersion but 30-45 feet?

You're bright, but haven't you ever made mistakes on land? Or forgotten any gear on land? To me, it's overstating the case to look to narcosis at 30-45 feet.

I'm just bringing this up for discussion purposes.

 

[ScubaCoach]

The other day, my wife picked up a coke can at about 110 fsw, and thought it was something special. Once she got back to about 80 fsw, she looked at it like "what the %$#& am I doing with this thing?".

haha, I read that, and thinking about it a few times and picturing that, I started to laugh. That's probably one of the funniest examples i've heard in a while.

hmm, is there a thread on nitro narc stories? haha

 

[knotical]

I am completely convinced that narcosis begins when one's head goes underwater. I am a very bright woman, and the number of times I've forgotten the sequence of drills, or gotten turned around with navigation (even on shallow dive) has convinced me that there is something that affects my thinking almost immediately, and it's certainly noticeable at 30 to 45 feet. I don't FEEL any different from normal -- I just have a lot of data points of forgetfulness and confusion underwater that I don't experience doing ANYTHING on land.

Very interesting. Are you sure it's narcosis? Do you experience this in really shallow water, like 15 feet? Could it be partly the effect of the totally three-dimensional world underwater, as compared to our usual mostly two-dimensional world? e.g. if looking for my friend on land I seldom have to worry about looking above or below me. And navigating on land in landscapes similar to those we've seen our entire lives is different from doing so in underwater scenes to which we've typically been exposed only a certain number of hours.

 

[beester]

30 to 45 feet might be not deep enough to see the effect... but I'm quite convinced like TsandM that the moment the PP increases the narcotic effect starts. Of course I have no scientific data to back this up and this is totaly subjectif but I'm still convinced.

Messing up on navigation or forgetting something we probably all do underwater (deep and undeep)... to notch this up to narcosis might be a step too far. But can clearly remember an instance when we were ascending and I looked at my computer and suddenly saw the no deco time counting down very fast (this was at 80 feet). Totaly strange of course when you are ascending... what happened was we crossed a deepstop depth and my computer went in deepstop mode and was counting down the 1 min at deepstop depth. The counter was at the same place were normally my no deco time is blinking. Well I really was looking at the screen for 15 secs and even then it didn't hit me..

You might say... well that's easy to mess up, but I do deepstops all the time and have this computer already for more then 2 years so I'm really familiar with it. I would never make such a mistake on surface.