Narc'd? First Deep Dive...

[lamont]

I think this really plays a role . . . When I was a newer diver, I had buoyancy control problems and fretted about it a lot, and that's when I had this "hallucination" of uncontrolled ascent. That's not really an issue any more, and the last episode was the "regulator not working" one. I think there's a disinhibition function that allows a minor preexisting anxiety to spiral out of control and the perceptual narrowing makes it the center (or the entirety) of the diving universe at the time.

Yeah, actually now that you mention it, last time I was down at olive den and narc'd I had a "regulator not working" daydream. But I could look at my thought processes with some detachment and conclude I was just narc'd and there was nothing wrong with my regulator and those thoughts went away...

I have become gradually much better at being able to swat down stray negative thoughts like this before they go anywhere...

 

[drbill]

I know I can get narced in 100 feet of water based on pre-dive analytical tests at the surface repeated at depth. When I dive to extreme depths, I know I'm narced but not to enough of a degree that I can't perform the functions I need to (filming, not heavy task loading) with significant impairment. As I've written before, as long as I can find, frame and follow my subjects at those depths, I'm functioning as well as I need to. Of course there is always the possibility of equipment failure and how well one reacts while at those depths.

I think many of us have heard that divers differ in their sensitivity to narcosis... both between individuals and within the same individual under different conditions. Many of us have also heard that frequent divers can "adapt" to some level of nitrogen in their systems. Since I usually do 250-300+ dives a year, I'm thinking I must be in that category.

However, I know excellent divers who are narc'ed "ghost white" at similar depths.

 

[Drewski]

Hi All:

Sorry, I was on the road yesterday and didn't get a chance to respond to this LIVELY discussion.

Lamont, as I said from my earlier post:

Please explain to me the "mechanism" behind how Nitrogen Narcosis affects the brain and results in changes to perception, abilities and mentation. When you can do this, scientifically, then we'll have a conversation about "comparing" it to ETOH.

You responded with:

It does appear though that at least some of the anesthetics like halothane and isoflurane affect GABA-A receptors which place them neuropharmacologically more similar to benzodiazepines and EtOH than your state of denial will accept.

Anyway, I'm claiming an analogy between diving under narocosis and driving under the influence as comparable human psychological issues involving equal amounts of denial and rationalization. The mechanism of action is largely irrelevant.

THEN you said:

The more I think about it the more this is completely laughable, and a good example of why no matter how much diving Drewski has done his logic is flawed and not credible.

and:

EtOH and Benzos affect primarily GABAergic receptors, Ketamine and PCP are NMDA receptor antagonists, LSD and DMT are 5-HT2A receptors antgonists , cannabis affects anandamide receptors, opiates affect opiate receptors, MDMA is a 5-HTergic reuptake blocker and releasing agent, etc.

and THEN, my favorite:

They've all got widely differentiating mechanisms of action, and from where I'm sitting its up to you to prove that N2 is so substantially different from them, and that diving is such a different kind of activity that the analogy between driving under the influence of any of these chemicals cannot be applied to diving under N2.

Ok, let's take this stuff one item at a time.

First, WHY insult me like you did? I wasn't rude to you. I didn't say you were "wrong" or that "no matter how much diving you've done, YOUR logic is flawed" or that YOU were in "a state of denial" (your words about me, I might add). I just stated an opinion and then asked a question.

Second, although you gave some citations concerning anesthetics, how they bind to chemical receptors and - I love this term - how they "neuropharmacologically" affect the brain and body, you still didn't answer the question DID YOU? Nothing of what you said explained how the increasing pressure of Nitrogen on the brain and nervous system affects a diver.

Third, after you couldn't explain it - and let's just be clear here, you couldn't explain it - you seemed somewhat frustrated. So, on your next post, you tried the old "bait and switch" routine. You said it was "up to me" to prove that "N2 is so substantially different" from the other agents you discussed and "that the analogy between driving under the influence of any of these chemicals cannot be applied to diving under N2."

Well, when I went to school (and it's been a few years), the scientific method being taught first involved "observing" what you were interested in studying. Based on your observations, you then "hypothesized" a relationship. Then you set up an experiment and "tested" your hypothesis. If your tests indicated the hypothesized relationship was NOT likely random, you reported the results and discussed conclusions.

BUT, what YOU are suggesting is that the behavior of N2 and the other anesthetics has ALREADY proven to be similar (just because YOU said so) and it's up to ME to disprove it. Well, that's NOT the "scientific method," is it? To use a more current example, your "logic" goes something like this:

• Drewski says he's thinking about becoming Islamic.
• He hangs out with his Islamic friends.
• The third cousin of one of Drewski's Islamic friends is suspected of funding terrorism.
• Drewski needs to prove to us he's NOT a terrorist.

See what happens when you make ridiculous assumptions? One could conclude just about anything. That's why there is proven method of research to investigate stuff instead of just "saying it is."

BUT, I'm willing to take this discussion a step further. I'll answer the question you posed, the one I really don't have to answer. You asked me to prove "that the analogy between driving under the influence of any of these chemicals cannot be applied to diving under N2." OK, that's easy.

I go into a bar. Let's say I'm an occasional social drinker. It’s been a rough day on ScubaBoard. I have 5 beers over one hour then leave. A few minutes later I swerve on the road and get pulled by a passing cop. I pass only a few of the sobriety tests the officer gives me and blow a .15 on the meter. I think everyone reading this would probably agree that I’d be just as drunk regardless of if the bartender said “don’t worry about it, you’ll be fine – you can handle it,” or if I had attended a MADD meeting earlier in the evening warning about the tragedies and consequences of drunk driving. The point is, my attitude about drinking wouldn't have affected the outcome.

Now, let's change the scenario. I'm a new diver. I don't read ScubaBoard (GASP!). My instructor tells me that Narcosis is a problem, but one that can be managed. He discusses the warning signs, how to "manage" narcosis during a deeper dive, what to be careful with. My friend, who's taking his dive lessons at another shop, does the "home reading" and glosses over narcosis. He reads ScubaBoard instead and gets LOTS of opinions. He’s told that "diving deep on air is BAD, AVOID it at ALL costs because you WILL get narc'd and you could DIE!" During his class, the instructor makes an offhand remark that "everyone diving deeper than 80 FT gets narc'd to some degree." He hears it and believes it.

A few months pass. My friend and I do several dives, between 30 and 60 FT. We decide to do a boat dive on a wreck, 110 FT deep. Neither of us is EAN trained, so we dive air. When we get to the bottom, my friend acts "weird." He starts laughing, doesn't respond to hand signals and is in obvious danger. He's narc'd. I get control of him, help him to the anchor line and we head to the surface. Back on the boat, he can't remember any particulars of the dive or what happened. I, on the other hand, remember everything including how I "rescued" him off the bottom, what depth we were at and our BT when the incident happened.

So what was the difference between my friend and I? For argument's sake let's say both of us are about of equal size and weight. We took similar classes and have identical experience. BUT, I was told that narcosis could be MANAGED. I believed it. My friend, on the other hand, learned that he would probably get narc'd no matter what he did and, while in class, his instructor more or less confirmed this. So, he got narc’d because he believed he would.

This "effect" is called “anticipated behavior modeling” and was observed and tested with divers as test subjects back in 1965 by George Milner and Tom Mount (the same guy who's head of IANTD today). For a summary of the study, click here. DAN also discusses this "issue" in terms of decreasing diver "anxiety." For that article, click here. The key finding to take away from this study is that purely on the basis of knowledge, education and ATTITUDE, one can be better prepared for the effects of narcosis and perform better in the actual environment. Diver experience, in this study, was NOT a factor that contributed to performance differences between the groups.

Want me to “prove” this MORE directly? Look at what you said in this thread:

Everyone is narc'd to some degree below 80 fsw. The level of impairment is highly situationally dependent, and you can learn strategies to work around the impairment, but you're still impaired. The only way to remove the impairment is helium.

I've had perceptual narrowing at 80 fsw on 30/30 trimix...

Below 80 fsw is where I can feel my thoughts start to "loosen" due to the effects of narcosis. I'll typically start to daydream a little bit and need to concentrate a little bit more to stay focused.

...now that you mention it, last time I was down at olive den and narc'd I had a "regulator not working" daydream. But I could look at my thought processes with some detachment and conclude I was just narc'd and there was nothing wrong with my regulator and those thoughts went away...

So, Lamont, there IS a BIG difference between N2, alcohol and the other anesthetic agents you mentioned. No matter how much you “know” about beer and drinking, if you drink 5 beers you can still get drunk and still become impaired. But, it’s NOT the same for diving. All things equal between two divers, if one diver has been taught about the effects of narcosis, is prepared for it and has the right ATTITUDE, 5 ATM of pressure won't always impair this diver, even when the diver has minimal experience. BUT, conversely, if the another diver was told of the "negative effect" of narcosis and was also told that he or she "couldn't prevent it," the diver WOULD most likely be impaired. This effect, identified as “anticipated behavior modeling,” is NOT something that occurs when one consumes alcohol.

So, my response to your challenge is that, YES, diving with N2 is “substantially different” than driving with alcohol.

And, YES, given today’s changes with gas and technology, I’m ALREADY diving EAN below 80ft and wouldn’t dream of diving air below 150 FT.

 

[lamont]

First, WHY insult me like you did? I wasn't rude to you.

"Fewer posts... More dives." is a snide, dismissive and rude way to end any post.

That snide ending along with the rest of your "metal toughness" and "build up tolerance" junk royally pissed me off.

I didn't say you were "wrong" or that "no matter how much diving you've done, YOUR logic is flawed" or that YOU were in "a state of denial" (your words about me, I might add). I just stated an opinion and then asked a question.

I'm sick and tired of people who have been diving deep on air for decades justifying it based on their belief that they're 'better' than other people because they feel they can handle it and that they can gain 'tolerance' and in some cases that learning to dive with helium will get you killed and that deep air is a better/safer path, and then backing it up with their 'years of experience' to shutdown any debate. I've run into other salesmen peddling what you're selling before and I'm sick and tired of it.

Second, although you gave some citations concerning anesthetics, how they bind to chemical receptors and - I love this term - how they "neuropharmacologically" affect the brain and body, you still didn't answer the question DID YOU? Nothing of what you said explained how the increasing pressure of Nitrogen on the brain and nervous system affects a diver.

Nobody knows precisely what the mechanism of action is of any of the anaesthetic gases. Different drugs appear to affectly vastly diffferent receptors in the brain and they all affect many of them so that the the leading theories are that you can't distill them down as a class.

Let me be clear: *Nobody* knows. If you check out the latest edition of Cooper, Bloom and Roth it will have the best information available which isn't in the primary literature and without having opened the book I can tell you that it amounts to that the mechanism of action of anaesthetic gases is current an area of active research about which little is known conclusively -- and the focus of that research will be on halothane, N2O and other medically used gases primarily and not N2. Based on your experience diving I assume you should know this. That you're asking this question means that you're not very well informed or else you're just being disingenuous with that question (I assume the latter -- which incidentally is another thing that pissed me off).

Third, after you couldn't explain it - and let's just be clear here, you couldn't explain it - you seemed somewhat frustrated. So, on your next post, you tried the old "bait and switch" routine. You said it was "up to me" to prove that "N2 is so substantially different" from the other agents you discussed and "that the analogy between driving under the influence of any of these chemicals cannot be applied to diving under N2."

Leading psychopharmacological researchers can't explain the actions of N2 on the brain. It isn't just that I can't explain it, nobody on the planet can adequately explain it, for example see:

http://www.sciencenews.org/articles/20040703/bob8.asp

And what I'm arguing is not a "bait and switch". I want to know why it matters what exactly the mechanism of action is. Why is N2 narcosis considered "innocent until proven guilty" when you would never suggest the same thing for drugs with widely differing known neurochemical mechanisms of actions like heroin, PCP, pot and EtOH. The chances that we'll discover the mechanism of action of N2 narcosis sometime in the next 5-10 years and it'll turn out that you were right all along is vanishingly small.

It is a drug. Diving under the influence of N2 at 150 fsw is just as smart as getting hammered on EtOH or any other substance and going diving. That isn't a "bait and switch" that is just obvious to anyone who has given the pharmacology behind drug use in general any thought. The distraction here is that you're trying to use the gap in the exact understand of N2's mechanism of action on the brain to justify and rationalize what you would otherwise know was bad decisions. N2 is simply different from other substances because its exact mechanism of action is unknown which means that in that gap it our understanding all kinds of mythology can be created.

This "effect" is called “anticipated behavior modeling” and was observed and tested with divers as test subjects back in 1965 by George Milner and Tom Mount (the same guy who's head of IANTD today). For a summary of the study, click here. DAN also discusses this "issue" in terms of decreasing diver "anxiety." For that article, click here. The key finding to take away from this study is that purely on the basis of knowledge, education and ATTITUDE, one can be better prepared for the effects of narcosis and perform better in the actual environment. Diver experience, in this study, was NOT a factor that contributed to performance differences between the groups.

Sorry, that doesn't prove anything about drinking vs. narcosis. I've experience "anticipated behavior modeling" with EtOH particularly when I was 16 and wasn't supposed to be drinking vs. long after I turned 21. Tom mount also just replicated the well known effects of "set and setting" on psychedelic drug experience. If you tell someone that if they take acid or pot that they're going to DIE and then give them some, they'll feel a while lot more anxious. And more generally whatever expectations they have going into the experience will color the subsequent experience. I'm completely unsurprised that the same thing happens with N2 and diving and don't see how this differentiates between N2 and any other pharmacological agents.

And that's all I have time for...

EDIT: except for...

But, all this discussion aside, getting "narc'd" is really more an individual's EXPECTATION than EXPERIENCE. What I mean is, if you THINK you will get "narc'd," you WILL get "narc'd." You need to have a mental "toughness" to prevent this.

This is particularly bad advice. You are taking a kernel of truth that you should tell new divers "if you go to 100 fsw you will be narced and you will die" is bad. But neither is convincing yourself that you are immune to the effects of narcosis and you are "tough" enough that it just doesn't affect you. It does affect you. What is important is to understand how it affects you and understand strategies to deal with it. Below 80 fsw some of the first two symptoms of narcosis are short term memory loss and daydreaming. Convincing yourself you'll never get narced isn't the way to deal with these symptoms. The way to deal with it is that you notice that you're having these symptoms and you work around them. If you start having daydreams about regulators failing its important to be able to classify that thought as the start of a 'paranoid narc' and break the panic cycle before it ever gets started. If you are breathing rapidly or shallowly and are building up CO2 and start to experinence the symptoms of narcosis its important to change your breathing pattern to reduce its effects (and avoid a CO2 headache). The reason why it is important to go slowly is not to build up a "tolerance" to it but to learn about it and be able to avoid or mitigate it -- because while we can add He to avoid N2 narcosis we can't avoid CO2 buildup entirely. The first dozen times I went to 100 fsw I know in retrospect that I was hammered because I my SAC rate was bad and I know I was also having CO2 effects and just free-floating anxiety from the depth and the newness of scuba diving, but I didn't know anything about how my mind reacted to narcosis at that point so I didn't know at the time that I was narc'd. Now I have a substantially better ability to detect narcosis, and I've actually used narcosis as a depth gauge before where I've noticed the onset of narcosis and subsequently verfied with my depth gauge that I was passing down below 80 fsw -- it isn't "incapacitating" in any way in the typical case, but I'm immediately aware that I've become impaired. I don't understand this attitude that its better to convince yourself that you build up tolerance so that at 100 or 120 fsw or deeper you "aren't narc'd". You are narc'd, you're just working around it. Become conscious of what is going on and how you are doing it. If you aren't conscious of it you're limited in how you can deal with it because you won't recognize when you're having a bad day and are too narc'd for the dive or when your breathing has gotten bad and you are perceptually narrowing and you need to modify the dive plan or take a rest. Without conscious awareness you can't take conscious decisions to keep yourself safe. Ignorance of what is going on in your own mind/body isn't the answer.

 

[jimdiverman]

 

[TSandM]

There actually IS literature showing that adaptation does not appear to occur, although the divers report a subjective perception that they are less impaired. The papers are in the Rubicon database, although I'm too lazy to chase them down right now.

I'm with Lamont (as usual). Divers are affected by nitrogen, worse as they go deeper; the degree of effect varies from diver to diver, and from day to day, and seems to be worse if the depth is compounded by dark, cold and poor viz (not just my anecdotal experience, but widely stated). Memory, judgment and reaction time are affected. CO2 retention augments the effect, and CO2 retention also occurs more easily at deeper depths. Divers impaired by narcosis may have difficulty responding appropriately to their environment and handling emergencies.

At what depth those effects are signficant enough for you to dislike the risk involved is something each diver must decide. There IS an alternative to accepting the narcosis involved in diving air to depth, and that is helium.

For me, the principle of keep your END above 100 feet works fine, since that's where I've been repeatedly shown that I'm not processing well.

 

[gcbryan]

My take on this is that adaption to nitrogen narcosis doesn't take place but experience does reduce anxiety as well as CO2 buildup (breath deeply and don't exert yourself below a certain depth).

Since nitrogen narcosis builds up gradually each person can decide what is appropriate for them and for the tasks that they will be doing. One can go to a bar and have a drink and drive home. After several drinks someone else needs to drive but you can still drink up to a point. Looking at fish as one goes down a wall is less demanding than entering an overhead environment (something I have no interest in doing anyway).

Everyone seems to lump narcosis, Co2 build up and anxiety and call it being narced but the last two can exist even on helium unless they are addressed through experience.

I think everyone has a sense of what is too deep for them based on prior experience but it seems in this thread everyone has admitted that anxiety and CO2 can be adapted to while narcosis cannot. Therefore to me everyone is making the same argument and just disagreeing at the cutoff point regarding air and nitrogen narcosis. This is something we all do everyday in all aspects of our lives...risk/reward calculations. Some people go deeper on air and others use trimix and then use that to do cave dives or to penetrate wrecks. Who's to say which is riskier.

 

[TSandM]

I don't think CO2 narcosis can be adapted to . . . I think a diver can learn to avoid practices and situations that are likely to result in CO2 buildup. A fine point, but one I thought was worth making.

 

[gcbryan]

I don't think CO2 narcosis can be adapted to . . . I think a diver can learn to avoid practices and situations that are likely to result in CO2 buildup. A fine point, but one I thought was worth making.

I agree and that's what I meant by breathing deeply and not exerting one's self.

 

[Drewski]

"Fewer posts... More dives." is a snide, dismissive and rude way to end any post.

That snide ending along with the rest of your "metal toughness" and "build up tolerance" junk royally pissed me off.

Ahhh, your RIGHT.

I actually wasn't referring to YOU when I said that. I was referring to the guy I was quoting immediately above that, the one that said "you really shouldn't be diving on air deeper than 50 FT," or something like that.

But, after re-reading what I said, I could understand how one could take that negatively. So, please accept my APOLOGY if I offended you by those words, they weren't directed at you and that wasn't my intent. I figure anyone who owns a scooter probably dives on a regular basis.

I'll reply to the rest of what you said later, I'm leaving for the boat dock in 10 minutes...