Narc'd? First Deep Dive...

[dumpsterDiver]

I pretty much dive every other weekend solo on air to 180- 190 feet in warm clear water. I don't recommend this to anyone, but it does give me a perspective on narcosis. If you have done hundreds of dives in similar conditions and gear configurations, the diving part becomes second nature and I personally don't have to think too hard about what I'm doing, it is instinctive. Everything is easy, if nothing out of the ordinary happens.

I also spear fish at this depth and this makes for sometimes completely unpredictable and uncontrollable situations. When I am faced with a minor or major problem at this depth, I need to constantly remind myself... you are narced,, you are stupid.. is my currently proposed problem resolution correct or stupid? I am constantly reminding myself to work on the solution in an extra SLOW manner. This is my personal adaptation to the narcosis, not an immunity. I have many examples of myself doing really stupid things at this depth. Sometimes it is like being stoned..you are just stoned enough to forget that you are stoned until something calls your attention to it.

The issue of exertion and CO2 build-up is huge. You can be fine one minute, but swim after a 50 lb fish and then wrestle with it at this depth and your pulse is screaming and you will very rapidly be wasted.

A lot of times I seem to function fine at these depths and we have videos that show excellent eye/hand coordination (demonstrated by making excellent shots with the speargun on fast moving fish), exhibiting good bouyancy control, breath control etc. all of which are required to spear fish on scuba. However, I am impaired all the time. The narcosis seems to affect my mind more than my arms and legs, although sometimes my tongue or lips will get numb.

A lot of times I have excellent visibility and I am looking around at everything, but I can tell that I am not seeing and processing the images very well. I feel like I am at the grocery store looking at a 100 foot long shelf of canned goods and trying to scan the labels and find a particular item, but there is just too much information, I am overwhelmed and I can over-look a particular item a number of times. Maybe narcosis is like being really ADD?

I view narcosis as a significant hazard and my personal opinion is that certifying people to dive on air below 150 feet is really stupid. Some people could probably handle it, but many people can not reliably function well below only 120 feet. I'm trying to get my buddy to put some helium tanks in his garage so we can do these dives in a safer manner.

 

[gcbryan]

You may be right, Gray, but I've been in very poor visibility more shallow, without ever having anything like this. It's been reproducible in essentially the same site -- Olive's Den (logs at 100 fsw), or the bottom of the I-beams (also 100 fsw). For this reason, I restrict myself to dives above that in the PNW.

(You know I'm not picking on you, I just find you to be one of the more interesting posters in terms of expressing yourself and one of the more openminded as well).

Does body size have an effect on narcosis in the way that if we were talking about administering a narcotic in the ER I might take a larger dose than you for the same effect?

Also, how do you personally describe/explain what is happening to you at 100 fsw in the PNW as opposed to what is happening to you at 100 fsw in the tropics?

One more question. How do you explain the sudden change as in you're OK at 80 fsw and hallucinating at 100fsw. If it's like administering a narcotic in the ER wouldn't the effect be gradual as it would be in slowly increasing the dose of a narcotic.

It's an interesting subject that I don't pretend to have all the answers to. I know narcosis effects me and yet it's a gradual thing and to come close to hallucinating I would need to be almost twice that deep although I would certainly be impaired well before that. It's interesting to hear how it effects others in differing ways. The most interesting incidents to me are when someone reports these effects at shallower depths. I've heard of it happening at 80 fsw.

 

[gcbryan]

I pretty much dive every other weekend solo on air to 180- 190 feet in warm clear water. I don't recommend this to anyone, but it does give me a perspective on narcosis. If you have done hundreds of dives in similar conditions and gear configurations, the diving part becomes second nature and I personally don't have to think too hard about what I'm doing, it is instinctive. Everything is easy, if nothing out of the ordinary happens.

I also spear fish at this depth and this makes for sometimes completely unpredictable and uncontrollable situations. When I am faced with a minor or major problem at this depth, I need to constantly remind myself... you are narced,, you are stupid.. is my currently proposed problem resolution correct or stupid? I am constantly reminding myself to work on the solution in an extra SLOW manner. This is my personal adaptation to the narcosis, not an immunity. I have many examples of myself doing really stupid things at this depth. Sometimes it is like being stoned..you are just stoned enough to forget that you are stoned until something calls your attention to it.

The issue of exertion and CO2 build-up is huge. You can be fine one minute, but swim after a 50 lb fish and then wrestle with it at this depth and your pulse is screaming and you will very rapidly be wasted.

A lot of times I seem to function fine at these depths and we have videos that show excellent eye/hand coordination (demonstrated by making excellent shots with the speargun on fast moving fish), exhibiting good bouyancy control, breath control etc. all of which are required to spear fish on scuba. However, I am impaired all the time. The narcosis seems to affect my mind more than my arms and legs, although sometimes my tongue or lips will get numb.

A lot of times I have excellent visibility and I am looking around at everything, but I can tell that I am not seeing and processing the images very well. I feel like I am at the grocery store looking at a 100 foot long shelf of canned goods and trying to scan the labels and find a particular item, but there is just too much information, I am overwhelmed and I can over-look a particular item a number of times. Maybe narcosis is like being really ADD?

I view narcosis as a significant hazard and my personal opinion is that certifying people to dive on air below 150 feet is really stupid. Some people could probably handle it, but many people can not reliably function well below only 120 feet. I'm trying to get my buddy to put some helium tanks in his garage so we can do these dives in a safer manner.

That's a good description of my experience as well except that I don't exert myself at depth for the reasons and with the results that you describe regarding the overwhelming effect of CO2 buildup. Good description. I should add that in my case the depths are usually much less but not always and this is in cold water but then again cold water is what I'm used to and I think that's what this subject is about in part...what one is used to.

 

[Matt S.]

I'm no doctor, or even a practicing scientist anymore. But it seems to be that body weight wouldn't matter much, as regardless of weight, your body does a good job of moving gas around. I think we can all be considered to have similar gas loading which is why dive tables and deco algorithms are possible.

As to gradual effect, it seems to be a process that has a threshold before it really picks up. Like boiling water. Sure, some water escapes to gas phase at room temperature, but there's a big difference between 99 and 100 dec C! The threshold for narcosis may be a function of physiolgical effects of fatigue and stress--permeability of cell membranes, etc.

Interesting stuff. I really want to know how it works.

 

[TSandM]

I don't think it's sudden . . . I think it comes on gradually, but the dives I do tend to go to that depth and remain there for a period, and it's during that period that the heeby-jeebies get me. If I stay at or above 80, I'm absolutely certain that I don't think or process as well as I do on the surface, but I'm not impaired enough to have these episodes.

Anesthetic gases are different from narcotics, in that, because they equilibrate with the blood according to partial pressures, it's only the inhaled concentration that needs to be adjusted. In other words, .5% isoflurane is as anesthetic to me as to you, and does not need to be changed for body size or weight.

I don't have a good explanation for the difference in warm, clear water. My guess is that I'm just as narced, but not anxious, because the environment is not as conducive to worrying about things. I've gotten much more conservative about depth in the tropics after those experiences at home, though; I didn't go below 100 feet in Cozumel, either. What worries me isn't that I'll freak out of nowhere, but that if anything goes wrong, I'm so clearly impaired that I may not make any decent decisions.

Edited to add that the precise mechanism of action of anesthetic gases is not understood, even for the ones we use in surgery. This is why the best predictor of narcotic potency we have is lipid solubility. We don't have a direct measure of what the gas is doing in the cells (or between them).

 

[diveasr]

I'm a newbie and haven't been deeper than 60ft.

But I'm also a dentist, and we "narc" people routinely with different drugs. Speaking of inhalation narcosis, specifically N20, "laughing gas," there are numerous factors that can contribute to the depth (meaning level or intensity, not fsw) of anxiety reduction or "sedation" achieved from N2O.

Yes, individuals can reach a different levels of "anxiety reduction" or "light sedation" with the same rate of administration of N2O, but on different visits.
The same principles should apply with fsw depth, as many factors including ones own level of anxiety at that time, come into play.

As to what is going on at the biochemical level in the brain with N2O: the honest answer is we don't know. Many studies have been done but to date, as far as I'm informed, we don't have an answer.

And to add one last note, N2O abuse leads to neuropathy with many abuser losing sensation in their fingers and other problems. I don't know whether studies have been done to determine if neuropathy is also evident with deep divers that self expose to nitrogen narcosis on a repeated basis.

dont ask me how i know this BUT if you get a can of whipped cream and breath the gas that comes out N2O2, you do this by holding it upright and flicking the thingy wich gets the cream out
so anyway try getting about 50 cans of the stuff and practice doing deco calc, reading, walking, playing with a hackie

 

[lamont]

I'm just noticing that in these discussions of nitrogen narcosis that many other facts are discussed under this heading that are actually distinct. In this case CO2 would still be present if you were shallow breathing and anxiety could still be present if viz was bad even if there was no nitrogen narcosis involved. In other words if I understand your description of this incident in your past this could have happened even on trimix or to look at it another way, it could have happened at 50 fsw.

I've had perceptual narrowing at 80 fsw on 30/30 trimix. It was the first time I ever tried to tie a loop in cave line underwater with blue gloves on and I got very stressed.

 

[lamont]

You may be right, Gray, but I've been in very poor visibility more shallow, without ever having anything like this. It's been reproducible in essentially the same site -- Olive's Den (logs at 100 fsw), or the bottom of the I-beams (also 100 fsw). For this reason, I restrict myself to dives above that in the PNW.

Olive's Den used to creep me out, too.

 

[lamont]

One more question. How do you explain the sudden change as in you're OK at 80 fsw and hallucinating at 100fsw. If it's like administering a narcotic in the ER wouldn't the effect be gradual as it would be in slowly increasing the dose of a narcotic.

You've got a positive feedback loop, though. 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. If the diver has some anxiety (because its dark and creepy in low viz and there's 14 foot sharks swimming around out there somewhere) then they can start to daydream about what can go wrong, causing elevated anxiety, more CO2 buildup, more impairment in thought process, which leads to more anxiety, etc.

And its not limited to dark, cold, low viz situations. Every couple of months on this board it seems like there's a new thread from a diver who went to 130 fsw on some tropical spot (e.g. The Blue Hole in Belize) and got a full-blow CO2 hit / panic attack and posts on here wondering if narcosis and depth had anything to do with it.

And if you take two divers at the same depth with one diving air and one diving trimix and give them both the same CO2 buildup in their bloodstream the difference in the breathing gas isn't going to make any significiant difference -- although the helium will reduce WOB and help prevent/clear CO2 buildup -- and the effects of that fCO2 in the lungs will get worse with depth.

 

[TSandM]

If the diver has some anxiety (because its dark and creepy in low viz and there's 14 foot sharks swimming around out there somewhere) then they can start to daydream about what can go wrong,

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.