NItrigen Narcosiss

[dilligaf]

Stogey:

Back in the 80’s and early 90’s, before trimix was readily available, I often did deep air dives to 350 FSW. Yea… I was a little young and dumb, but I did learn a few things about narcosis and how to handle things.

First when diving deep on a daily bases, narcosis becomes less of a problem. The body becomes accustom to the affects and I believe there is both a learned and physical tolerance to narcosis. The real problem with diving deep air is the O2 toxicity factor… something your body will tolerate differently each day.

As mentioned by previous posters, your body will also handle narcosis differently from time-to-time; however IMO, if diving often, the variations are GENERALLY not severe.

IMO, the best way to handle the effects of narcosis is very simple… be a good diver! A diver that is properly buoyant and is moving effortlessly through the water is much less likely to experience narcosis. Always be relaxed, when you get to the bottom, take a minute to relax, check your gauges and compass, get your mind focused and get your bearings. Always be aware of your surroundings and conditions… and that of your dive buddies. A focused mind is less likely to be affected by narcosis.

Anyways… I hope this helps,

Dave

 

[BigJetDriver]

Folks,

I'm very glad to see that most, if not all, of our respondants on this subject have been paying attention to their training, and to the literature on the subject.

To boil this down a bit, it really is very simple:

(1) Narcosis is a PHYSIOLOGICAL fact. Everyone, without exception, suffers from narcosis under given conditions. Someone who says he or she has never been affected by narcosis is (a) lying, (b) stupid, (c) someone who has never been deeper than ten feet, (d) or, in the case of most average recreational divers, someone who has not done enough diving yet to recognize the creeping onset of its symptoms. (It can be very subtle.)

(2) No one performs BETTER when impaired. You may perform adequately for the given conditions. You may be able to work through your impairment, if conditions remain stable and the routine remains the same. You may learn, through practice, to COMPENSATE for your impairment. (This is the same as learning to compensate well enough not to attract the attention of your local police when you drive home with a few beers under your belt. You may get away with it, but you are still DRUNK!)

(3) If the conditions change, and ESPECIALLY if multi-tasking is required under critical time pressure, you WILL perform significantly worse, even to the point of failing to achieve your well-ness potential. This is simple truth and physiological, as well as psychological fact.

Can we defeat the effects of narcosis? Yes, we can to some extent. Nitrox is one method. By reducing our nitogen load, we can help to delay the onset of narcosis. As we go deeper, trimix and heliox can moderate or remove its effects. Training, recognition, and repetition of safety drills can help us respond properly when impaired by it.

Can we totally escape the effects of narcosis? No, we cannot. Anyone, and I do mean ANYONE who tells you that he or she CAN, is one of those in category 1(a) or 1(b) above, (Brett Gilliam not withstanding)!! :11:

This is a serious subject, and I do not wish to make light of it. We have lost some outstanding, deep-technical divers, due to their arrogant insistence that a lot of deep diving made them somehow immune to the effects of narcosis, and that they could "handle" it. Alas, they are no mas.

P.S.---To paraphrase Mr. Natural: "Get the right gas for the job, kids!" :sunny

Rob Davie

 

[BigJetDriver]

(1) Back in the 80’s and early 90’s, before trimix was readily available, I often did deep air dives to 350 FSW. Yea… I was a little young and dumb....

(2) First, when diving deep on a daily bases (sic), narcosis becomes less of a problem. The body becomes accustom to the affects and I believe there is both a learned and physical tolerance to narcosis.

(3) As mentioned by previous posters, your body will also handle narcosis differently from time-to-time; however IMO, if diving often, the variations are GENERALLY not severe.

(4) A focused mind is less likely to be affected by narcosis.

Dave

Dave,

(1) It is good that you now recognize that. We all have done some (really) dumb things. I know I have.

(2) You may be able to work through it but....IT NEVER BECOMES LESS OF A PROBLEM.(See above post.)

(3) This is incorrect. They CAN be very severe. (See above post.)

(4) This last is quite true.

Glad you survived your learning curve!!

Rob Davie

 

[Dr Deco]

Hello Readers:

Alcohol-and-Pilots Story

It is my understanding that repetitive and learned tasks can be performed by individuals who would be deemed inebriated. As long as nothing new comes along that requires a change in procedure, they are relatively fine. Some other responders made similar comments and proffered a few stories of some “off line” tests.

Narcosis

Narcosis is a highly variable effect. It is for this reason (among others) that an individual is always constantly present when inhalation anesthetics are being administered. There is not a set dose for every given body weight. It is so variable that an anesthetic dose for one patient could kill another.

In a similar fashion, nitrogen (really just another anesthetic gas) is variable from diver to diver in the effect that it will produce. I suspect that much of the “accommodation” that is noted is simply a reflection of the ease of a repeated procedure.

Dr Deco :doctor:

 

[dilligaf]

Dave,

(1) It is good that you now recognize that. We all have done some (really) dumb things. I know I have.

(2) You may be able to work through it but....IT NEVER BECOMES LESS OF A PROBLEM.(See above post.)

(3) This is incorrect. They CAN be very severe. (See above post.)

(4) This last is quite true.

Glad you survived your learning curve!!

Rob Davie

Rob,

Yea… somehow I managed to survive and I’m still able to do a little diving. There is no reason to dive deep air in this day and age and I don’t advocate deep air diving.

With that said, I can see we may have some disagreement (see #2 & #3). The key word here is experienced. An experienced diver will foresee potential problems, abort dives if he does not feel right, and have the ability to control or manage what Mother Nature has to offer. An experienced diver will manage his dive and the environment whether on air or mix and please note the dive management begins before you enter the water. I’m not only talking about planning the physical aspects of the dive, but also the mental. Being relaxed, disciplined, and knowing how your body feels are just as important as the type of gas you use.

Yea… so I believe narcosis can be managed/controlled and an experienced diver therefore will as a general rule not have severely different reactions to narcosis.

I think often times divers get to caught-up in the gauges, books, tables, etc and forget the most important thing of all – awareness. Many years ago, as a divemaster on a tech boat, I had the privilege to dive with many top tech divers including Brett Gilliam and Tom Mount. In those days, being young and dumb, all I can say is it was a very humbling experience to dive with Tom. He is by far the best diver I’ve ever seen. Why? His level of awareness! He knew his condition and that of everyone around him, he was always aware of the environment and how to deal with it, and every other aspect of the dive.

His awareness has always stuck with me and I continue to this day attempt to have his level of awareness.

Dave

 

[BigJetDriver]

Rob,

Yea… somehow I managed to survive and I’m still able to do a little diving. There is no reason to dive deep air in this day and age and I don’t advocate deep air diving.

With that said, I can see we may have some disagreement...

Dave

Dave,

With that said, we have NO disagreement... :bang:

Rob :35:

P.S.---Tom Mount is indeed an awesome man!

 

[miketsp]

Over the years I've seen quite a few discussions on this subject and the general consensus is that you may not feel narced but you are. Well I recently confirmed a trip to Cuba for February where we have some deep dive dives planned and I just got back off my holidays where we spent 3 weeks diving, many dives in the 30 - 35m range. So I thought I'd take the opportunity to run a quick test. I made up a slate with a whole series of additions & subtractions of 5 digit numbers and on every dive below 30m I would do half a dozen and note how long it would take. I also did the same at the surface to control whether or not I was tired that day or doped by the Dramine etc.
I found that although I was a little slower at depth on the first 2 days, after this there was no difference between surface & at depth performance.
So my feeling is, that at least in my personal case, there is definitely an increased tolerance after a couple of days diving.

 

[mempilot]

Mike,

Where NN will really rear is head and kick your butt is when you are involved in a stess inducing problem - entanglement, 'something' leaking air behind your head where you can't see it, a lost dive buddy, lost anchor line, etc... The combination of stress and narcosis can quickly lead to making the wrong move or wrong decision resulting in a bad ending. Obviously, these effects get more profound the deeper you dive. At 33m, you are at what most technical divers consider a reasonable END (equivilent narcotic depth). While impaired at this depth, one's ability to solve simple problems may be sufficient. For an inexerienced diver, the effects of NN at 33m may be enough to dissorient them in a stressfull situation, while a more experienced diver may be able to force themselves to slow down, control their breathing, and break the problem down.

I first experienced the effects of NN on a 115' dive. I didn't think it was affecting me, until I got myself caught in some monofiliment line. Since that day, I have made many extended range dives in the 135 to 185 fsw range, with one 'stupid' dive to 205 fsw. Do your same test at these depths, and you will notice a big difference. That is why I have enrolled in a Trimix course this month. In the near future, all of my dives, in regards to nitrogen narcosis, will be back in the 60 - 100 fsw range.

Many tech agencies advocate the use of helium to maintain an END of 100' or less when possible. Hopefully, in the near future, as more people seak out the training coupled with experience, Normoxic Trimix for recreational depths will take hold as the next recreational mix, much the way Nitrox did not so long ago. The cost of He is currently high from fill stations, but so was Nitrox when it was first labeled a voodoo gas by recreational training agencies.

 

[-hh]

Mike,

Where NN will really rear is head and kick your butt is when you are involved in a stess inducing problem...

Or even a change from "routine" conditions.


For example, if you normally do a fairly low stress/exertion dive, then you may be avoiding conditions in which you could spike your CO2 retention and increase your Narcosis level.

Personally, I had an unpleasant Narcosis experience several years ago towards the end of a long dive trip where I decided to swim hard on an descent to catch up with a buddy who was ahead of me, which resulted in a CO2 spike and a "Cold" Narc.

Probably the worst aspect of this incident was trying to figure out what was wrong and initially thinking that it couldn't be Narcosis because I was only at literally half the depth that I had been diving two for the past two weeks. But lo and behold, it was.

Narcosis is something that you have to be prepared to encounter, "anywhere, at any time", even though there are generalized expectations for where/when it probably won't be a major concern.

-hh

 

[dilligaf]

Or even a change from "routine" conditions.

-hh

IMO… a good diver makes things routine, even when things could go completely astray. This is accomplished by recognizing problems before they occur, making correct decisions, using sound judgment, and using proper techniques to make situations easier. To me, it is as equally important as the gas we choose to use.

Unfortunately, there are far too few good instructors or instructors that can not only teach the “book” but also teach how to avoid potential problems and make all dives routine. So many divers end up learning far too many things the hard way. Gas mixes are an easy answer to reduce “panic situations”, but they are not a substitute for having the ability to instinctively recognizing and deal with problems… so there never is a “panic situation”.