Feeling Narced on a Deep Dive?

[KnowledgeIsPower]

Thanks for the insight everyone, these posts helped clear up a lot of my questions If I do plan to dive deep more regularly I will probably go for a Deep Diving Speciality course in the future to help with air management and other aspects of training that are important beyond the AOW deep dive.

As a Neuroscientist I definitely agree about our lack of knowledge on this subject. Nitric Oxide is a very important retrograde neurotransmitter that scientists still debate as we still don't know how it works exactly, but its ability to communicate with a broad number of neurons is very important to its effects on the brain's neurotransmission. Of course it has to be produced with the fusion of Oxygen, but I suspect the increased atmospheric pressure at these deeper depths catalyze this reaction to occur more quickly.

 

[Yobubba]

It's hard to share some of my experiences with narcosis with out exposing myself as breaking a few rules.
Sneaky is a word I like to use when describing the effects of deep diving on air. I can't trust my judgment and temptation to deviate from my dive plan is... well, sneaky I have some great ideas no one has ever though of before when I'm narced but trouble remembering what they where when back on the surface. 130 feet is a good limit for the safe sport of recreational diving, a well thought-out limit and within that narcosis is manageable.

 

[TSandM]

I have written this before, and I'll keep putting it out there. Just because you don't feel any different, doesn't mean you aren't narced. Like the girl on the barstool, who doesn't realize that the Black Russians have gotten to her until she tries to stand up (yes, I was that girl), the diver may not feel anything that signals cognitive impairment, at least until that impairment is really severe.

Studies that have looked at narcosis have shown that there is a training effect -- if you do your math problems on the surface, you will do them better underwater than someone who has not seen them before. What no study has looked at, to my knowledge, is how a diver functions when presented with unexpected information that needs to be processed and acted upon. This is where I have found my weakness with narcosis -- at 100 feet, I have a significantly decreased ability to a) notice, and b) correctly analyze, new information. This becomes important when doing navigation, or when the information may indicate a looming hazard or a need for a change in the dive plan. Even while I am failing to react appropriately, I am unaware of doing so; I look at whatever it is and go, "Huh . . . that's odd," and swim on. I have tried to teach myself to recognize that dull "huh?" as a signal that I am not firing on all cylinders, but the state of impairment decreases insight and awareness as well, so it doesn't work. The only things that work are to stay out of complex situations at that depth, or to use helium.

Am I unwilling to go to 100 feet on a warm water reef dive? No. My risk assessment is that it's unlikely I will have to process novel information on such a dive. Somebody runs out of gas, I've done enough air-shares to do that "half-drunk". Complex navigation is not an issue. The surface is an option. I'm okay with that. Deeper or more hazardous (eg. Cave) dives, not so much.

 

[Storker]

I suspect the increased atmospheric pressure at these deeper depths catalyze this reaction to occur more quickly.

I'd like to get some more substantial background on that before I'm willing to consider that that hypothesis is more than a WAG.




*Warning: über-geeky elaboration below*

The reaction between N2 and O2 to NO is thermodynamically unfavorable (equilibrium constant of 4.5e-31 at 298K, and the enthalpy of reaction is 180 kJ, i.e. you have to add 180 kJ of heat for each 2 mol of NO formed.), so no matter the catalyst, energy has to be added to the reaction system to make the reaction go towards NO. Pressure won't help, since the number of gas molecules is equal on both sides of the reaction, and a catalyst will only increase the speed of degradation of NO to N2 + O2.

 

[TSandM]

I'm not sure it's NO that's involved. I don't believe the neurochemistry of the halogen anesthetics is understood (at least it wasn't, the last time I looked around for information), but it's not a reaction involving chemical bonds -- the anesthetic is not, to my knowledge, metabolized in any way. Something about the dissolved gas is playing havoc either with neuron internal chemistry or with signaling. To my knowledge, N2 is theorized to behave in the same way, and does not require oxidation to have its effect -- which would make a lot of sense with what we know about narcosis, which is that it clears very rapidly if the diver simply ascends. On the other hand, NO is very short-lived, so maybe you have something there.

 

[FinnMom]

Most people tend to say they have never noticed being narced. Occasionally something may cause them to realize their mental sluggishness but usually the same impairment and memory impairment keep you from noticing it. Something like this might help you notice your impairment:

Try playing a simple game. Your buddy holds up x-many fingers and you respond with x+2 fingers (3 figers => 5 fingers). Or buddy holda up x-many fingers and you respond with x-2 fingers, or twice as many etc.
Certain international hand signs are not an acceptable answer

 

[diver 85]

OP------the mind is a powerful thing, some hear things & believe they are 'supposed to' feel a certain way ---just cuz they heard (about) it........I've been on over ?300 'deep dives', maybe a lot more(I don't keep track of them---anymore)-the deepest to 175--and---to the best of my knowledge--never have gotten narced......I would venture to say most here have had the same experience(s) as you & I.......

 

[Pullnglide]

As most have said, it affects people differently. Personally I don't really notice anything until @ 140' with air on any given dive and I have definitely been messed up worse than a football bat past 140' on air; however all of those dives are in 45 degrees F water. I know I'm narced and I handle it the best I can and enjoy the dives.

 

[tursiops]

I'd like to get some more substantial background on that before I'm willing to consider that that hypothesis is more than a WAG.




*Warning: über-geeky elaboration below*

The reaction between N2 and O2 to NO is thermodynamically unfavorable (equilibrium constant of 4.5e-31 at 298K, and the enthalpy of reaction is 180 kJ, i.e. you have to add 180 kJ of heat for each 2 mol of NO formed.), so no matter the catalyst, energy has to be added to the reaction system to make the reaction go towards NO. Pressure won't help, since the number of gas molecules is equal on both sides of the reaction, and a catalyst will only increase the speed of degradation of NO to N2 + O2.

And, in any case, the "atmospheric pressure" doesn't change with depth.

 

[Storker]

Try playing a simple game. Your buddy holds up x-many fingers and you respond with x+2 fingers (3 figers => 5 fingers). Or buddy holda up x-many fingers and you respond with x-2 fingers, or twice as many etc.
Certain international hand signs are not an acceptable answer

This time of the year, I'm using thick 3-finger mitts. I don't need to be narked to have a problem playing that game



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