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The anesthetic effect of air at atmospheric pressure

pubmed.ncbi.nlm.nih.gov

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Re: The anesthetic effect of air at atmospheric pressure

#171

Post by todd8 »

slau wrote: post #5

Just completed my deep (40m/120ft) diver certification. A significant amount of the course was focused on nitrogen narcosis, and how to handle/detect it. Apparently, some divers will start feeling the narcotic effect between 20-30m. Beyond 30m, a significant amount of divers can feel the effects. Beyond 40m is the realm of tech diving, with trimix (helium/nitrogen/oxygen) or even heliox (helium/oxygen). I know nothin…

While I am certified for Nitrox diving, I'm not sure I would actually use it very much. After over 100 open water dives and many dive classes (I was one class away from being a certified instructor back in the 1970s) I realized that I didn't want to do extreme diving. Night dives in the Caribbean are exciting enough. Wreck diving, ice diving, cave diving, commercial diving, hard hat diving all seem too dangerous. Diving in the warm, clear Caribbean was great, and 75% of that experience can be obtained with just a snorkel, mask and flippers.

One of my friends was a commercial diver working on Oil platforms in the North Sea. Out of the eight divers he worked with, he is the only one that lived through it without serious injury.

Re: The anesthetic effect of air at atmospheric pressure

#172

Post by aaron695 »

hliyan wrote: post #147
Luc wrote: post #23

[1975]. Funny concluding paragraph: "Both theories of anesthetic action and the evidence cited in this report suggest that the nitrogen concentration in atmospheric air causes a measurable performance decrement in man, that the "nitrogen blanket" effect suggested by Miles[10] is a real phenomenon, and that human history has proceeded under partial narcosis. Perhaps this explains the current state of world affairs"

I hope this does not catch on. I worry about body hackers trying to live in a hermetically sealed homes with oxygen-noble-gas atmospheres.

[dead]

Re: The anesthetic effect of air at atmospheric pressure

#173

Post by outsidetheparty »

alanfranz wrote: post #145
dekhn wrote: post #140

Earlier quoted context omitted.

I've never drunk it. I don't like high proof alcohol. Once I worked in a very informal lab and we were always looking for alternatives to buying industrial chemicals. I was working with optics, and Everclear came up as a good alternative to denatured alcohol or isopropyl alcohol. My friend who ran a microscope lab said it was pure enough to clean optics... however, since it was illegal to buy in California, we had a…

Why would everclear be better than denaturated alcohol? Usually (I live in Europe btw) denaturated alcol is cheaper and has same proof of drinkable liquids.

The "denatured" part means it contains additives that make it poisonous and foul-tasting.

Re: The anesthetic effect of air at atmospheric pressure

#175

Post by nradov »

bibanez wrote: post #155
extraduder_ire wrote: post #144

Earlier quoted context omitted.

>Except for helium, no other gas exists which does not have some form narcotic effect at higher pressures. According to something mentioned in passing in a Scott Manley (amateur space youtuber) video about deep-sea diving: at high enough pressures you'll get similar effects from helium. It's thought that you can avoid this by subbing out the helium for hydrogen, but nobody so far has been insane enough to try. I assu…

I only have high school level chemistry, but if Helium is a noble gas it doesn't bond and so it can't have a narcotic effect, because it doesn't affect the chemistry of the brain

The narcotic effects of inhaled gasses don't seem to have anything to do with chemical bonds. There's something else going on. Even some noble gasses like argon are highly narcotic.

Re: The anesthetic effect of air at atmospheric pressure

#176

Post by reportgunner »

haldujai wrote: post #152
asdgioanionio wrote: post #117

Earlier quoted context omitted.

You can't judge from Bacardi. It's bottom-shelf, young, and pretty rough. I find it unpleasant to drink neat even at 80 proof. A high-quality, aged rum at 130 proof will be plenty fiery, but not as bad as Bacardi 151 diluted to 130 proof. Of course, the sailors probably didn't drink anything terribly high-end.

> I find it unpleasant to drink I concur, I tried to acquire the taste for 151 in college and even after 4 years of earnest and consistent effort it did not get better. Similar experiments with Everclear and overproof grappa were also unsuccessful. I would not recommend any of these if one is interested in a pleasant drinking experience. Lately I've been finding Bourbon to be enjoyable. Woodford Reserve and Bulleit a…

> Lately I've been finding Bourbon to be enjoyable. Woodford Reserve and Bulleit are well-priced and good introductions in my opinion.

Also try Buffalo Trace, it's one of my three favorite including the two you mentioned.

Re: The anesthetic effect of air at atmospheric pressure

#177

Post by nradov »

slau wrote: post #5

Just completed my deep (40m/120ft) diver certification. A significant amount of the course was focused on nitrogen narcosis, and how to handle/detect it. Apparently, some divers will start feeling the narcotic effect between 20-30m. Beyond 30m, a significant amount of divers can feel the effects. Beyond 40m is the realm of tech diving, with trimix (helium/nitrogen/oxygen) or even heliox (helium/oxygen). I know nothin…

There's no need to handle narcosis, just use more helium. Regardless of whether you subjectively feel it, the effect is always there and increases progressively with depth. Some divers claim that they can adapt to it and minimize the effects through repeated exposure but there's no reliable evidence that really works; I think they're just fooling themselves.

Note that some of the serious narcotic effects that divers feel are often due to CO2, which is even more narcotic than nitrogen. If you exert yourself and don't ventilate effectively then hypercapnia can hit you hard. Adding more helium to the mix also helps with this by reducing the gas density and making it easier to blow off the CO2.

Re: The anesthetic effect of air at atmospheric pressure

#178

Post by pas »

bibanez wrote: post #155
extraduder_ire wrote: post #144

Earlier quoted context omitted.

>Except for helium, no other gas exists which does not have some form narcotic effect at higher pressures. According to something mentioned in passing in a Scott Manley (amateur space youtuber) video about deep-sea diving: at high enough pressures you'll get similar effects from helium. It's thought that you can avoid this by subbing out the helium for hydrogen, but nobody so far has been insane enough to try. I assu…

I only have high school level chemistry, but if Helium is a noble gas it doesn't bond and so it can't have a narcotic effect, because it doesn't affect the chemistry of the brain

It's narcotic effect comes from lipid solubility (and because it basically crowds out other gases - likely oxygen - needed for chemical reactions). So basically, because it's an inert gas it prevents some reactions.

Re: The anesthetic effect of air at atmospheric pressure

#179

Post by nradov »

Aerroon wrote: post #128
gojomo wrote: post #68

Earlier quoted context omitted.

You'd hope mind-hackers would've explored & confirmed/refuted/quantified the effect, but stuff like this often lies underexplored for decades, despite hints like this 1975 study – which actually shows the 'gradient' of clearer thinking continues in the other direction, no hand-wavy extrapolation required. It's what they found! In 1975! How long did it take for society to fully recognize, & remediate, the effects of e…

Maybe it remains underexplored because if you find a significant effect and popularize it, then the substance gets banned. The people interested in using stuff like this have an incentive to avoid scientific research on the subject. Hell, even NAC almost got banned recently.

Don't be ridiculous, no one is going to ban helium.

Re: The anesthetic effect of air at atmospheric pressure

#180

Post by nradov »

marceldegraaf wrote: post #160
slau wrote: post #5

Just completed my deep (40m/120ft) diver certification. A significant amount of the course was focused on nitrogen narcosis, and how to handle/detect it. Apparently, some divers will start feeling the narcotic effect between 20-30m. Beyond 30m, a significant amount of divers can feel the effects. Beyond 40m is the realm of tech diving, with trimix (helium/nitrogen/oxygen) or even heliox (helium/oxygen). I know nothin…

It's due to the narcotic effects of nitrogen that GUE (Global Underwater Explorers, a diving association rooted in tech/cave diving) uses EAN32 (32% oxygen) as their standard breathing gas. They're also more conservative in their recreational diving depths: 30m (100ft) is the recreational limit, beyond that technical certification and a helium-based breathing gas (e.g. Trimix) are required.

I think you misunderstood the GUE standards. Nitrox isn't significant less narcotic than air. They set a 100 ft equivalent narcotic depth maximum limit somewhat arbitrarily because empirically that seems to be pretty safe. Below that depth we add progressively more helium to the mix to limit narcosis as well as gas density (work of breathing).
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