[HN Gopher] The anesthetic effect of air at atmospheric pressure
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       The anesthetic effect of air at atmospheric pressure
        
       Author : luu
       Score  : 97 points
       Date   : 2023-08-14 05:37 UTC (17 hours ago)
        
 (HTM) web link (pubmed.ncbi.nlm.nih.gov)
 (TXT) w3m dump (pubmed.ncbi.nlm.nih.gov)
        
       | sergioisidoro wrote:
       | What if instead it's helium that is a slight stimulant?
        
         | jlawson wrote:
         | Do stimulants reduce reaction time? Waking someone up isn't the
         | same as actually improving their performance.
        
           | LoganDark wrote:
           | Some people can treat their ADHD using stimulants, and your
           | reaction time tends to be better in that circumstance
           | (citation needed though, I guess).
           | 
           | IME, too much stimulants causes hyperreflexia, but I'm not
           | sure if it's because of a decreased reaction time.
        
         | AnotherGoodName wrote:
         | Essentially true by definition. If something is the norm then
         | replacing that norm with helium and seeing enhanced performance
         | isn't signal of the norm being restrictive. It's signal of
         | helium being performance enhancing.
        
         | adrian_b wrote:
         | The effect of nitrogen varies with its pressure, i.e. with its
         | concentration, while no changes are seen when the helium
         | pressure is varied.
         | 
         | This allows the conclusion that nitrogen has anesthetic effect
         | and helium does not have stimulant effect.
         | 
         | Because it appears that the anesthetic effect of inert gases
         | depends on their molecular mass, being much stronger for heavy
         | gases like xenon, it is possible that helium also has an
         | anesthetic effect, but one that becomes noticeable only at
         | higher pressures than can be safely tested.
        
       | makeworld wrote:
       | Are there any historical relations to this? For example has
       | nitrogen concentration varied across centuries? Or have
       | innovations occured more frequently at higher altitudes?
        
       | pdc56 wrote:
       | How many minutes until someone applies to YC with HaaS Co -
       | Helium and facemask as a service subscription startup.
        
         | crdrost wrote:
         | This was roughly speaking my first thought as well. I thought
         | "Well we always laughed at the sci-fi depictions of people with
         | big cans of air for sale, come pay for premium filtered air ...
         | but this is how that all starts, isn't it. Rich people pay for
         | an air that might make them think 10% faster, then as it starts
         | to normalize to the middle-class, they care less and less about
         | pollutants in the air and eventually we just regard that as a
         | poor-peoples' problem."
        
       | That-Dude wrote:
       | _It concluded that the nitrogen in ambient air slightly but
       | measurable impairs human performance compared with a non-
       | anesthetic gas such as helium._
       | 
       | This seems like a massive reach. Is it not possible the body is
       | just perceiving that something is "wrong" about its current
       | situation while breathing helium and is activating a threat
       | response? The study authors didn't even bother to monitor heart
       | rate, let alone blood concentrations of adrenalin and cortisol.
       | This might have been a neat study in 1975 but it is not nearly
       | rigorous enough.
        
       | superkuh wrote:
       | The action potential is an electrical manipulation of reversible
       | abrupt phase changes in the lipid bilayer. Normally the lipid
       | bilayer is in a liquid phase but the the switching out of
       | monovalent sodium for bivalent calcium ions changes the number of
       | phospholipid carboxyl head groups each ion is electrostatically
       | associated with. This changes the heat capacity and causes the
       | lipid membrane to become a solid/gel phase. The action potential
       | itself is the propagation of this solid phase.
       | 
       | This is how thermodynamics can effect neurons. And this is why
       | dissolving gases into the lipid membrane, like nitrogen in the
       | article, cause change the thermodynamic properties like the heat
       | capacity and retard the solid phase a bit. Light gases increase
       | liquidity. That's the anesthetic effect that reduces firing
       | rates. And that's why local atmospheric pressure matters in gas
       | anesthesia dosing.
       | 
       | It's not that the old hogkin-huxley purely electrical circuit
       | model is "wrong", it's a fine approximation of some effects. But
       | it certainly can't explain the reversible uptake and release of
       | heat during a passing action potential, nor the changes in
       | birefringence and optical scattering, nor why nitrogen can act as
       | an anesthetic like in this case.
        
         | Robelius wrote:
         | Are you saying that what's happening is the permeability of the
         | cell membrane changes with their physical states (from a scale
         | of "more liquid" to "more solid")and that change impacts the
         | transmission rate of the neurons? And an example of this would
         | be an anesthesiologist putting you under is them making your
         | cell membrane more solid to increase the resistance those
         | neuron transmissions experience, just like adding more
         | resistance to a circuit to reduce the voltage?
         | 
         | Disclaimer that biological sciences aren't my strength so I'm
         | just trying to understand what you're saying.
        
           | superkuh wrote:
           | No, it's not about ions going through the membrane or
           | membrane pemeability. It is not about resistance to ions flow
           | across the 10nm they travel perpendicular to the membrane.
           | Transport of ions across through ion channels are _required_
           | for the effect but the membrane itself (usually) is not
           | leaking and I 'm not talking about changes in leakage.
           | 
           | It is about how the various ions like Na+ and Ca+2 associated
           | with the membrane itself to change the membrane's physical
           | properties. When there's lots of light gas anesthetic
           | dissolved in the lipid membrane keeping the heat capacity low
           | (disordered) it is thermodynamically harder (requires more
           | energy) to form the organized 'solid' (actually more like a
           | gel) state that propagates as the action potential.
           | 
           | ref: https://arxiv.org/abs/1805.11481 - good overview paper, 
           | http://erewhon.superkuh.com/library/Neuroscience/Lipid%20Mem.
           | .. - other papers/books on the subject.
        
         | tiffanyg wrote:
         | _Mm-hmm, Mm-hmm... Oh! Oh, yeah... mm, mm. Mmm!_
         | 
         |  _I know some of these words!_ *
         | 
         | More seriously - thanks for that description! It's always
         | interesting to see just how many "principles" &/ "laws" etc.
         | (our compartmentalized / simplified models) underlie certain
         | kinds of physical behavior (and, sort of, emergent properties
         | thereof). Even just sticking together enough of the simplest
         | models can be kind of surprising and not so easy to reason
         | about / handle with much "facility".
         | 
         | I've never learned much about anesthesia, and the little bits I
         | have learned, here and there - and usually only in very
         | specific contexts, makes it so most of this info doesn't really
         | stick in my head. So, I appreciate getting a bit of refresher /
         | learning every now and again. Particularly, in how it ties
         | together with everything else involved.
         | 
         | Thanks!
         | 
         | * https://youtu.be/sl2W85KKzgc
        
         | topaz0 wrote:
         | Worth noting that, while this model has been around for a few
         | decades, it does not have many adherents among neuroscientists.
         | Which is not to say that it is wrong necessarily, just that I
         | wouldn't want readers to get the wrong idea that this is a
         | consensus view.
        
           | genewitch wrote:
           | neuroscientists are just mad that "gut feeling" is actually
           | the truth, and we're generally being manipulated by the
           | billions of microbes in our guts. Simple example: why do
           | people crave cake when they're on a diet that doesn't allow
           | cake? There are microbes that convert stuff in grasses (corn,
           | etc) into opioids. Opioids are great, make us feel great, and
           | if we are used to having opioids and suddenly stop, we go
           | into opioid withdrawal.
           | 
           | I haven't really put a fine point on the grand theory of gut-
           | mind-body interaction, but i'm fairly certain that nearly
           | every disorder or disease that isn't external (like radiation
           | or malaria) will eventually be traced back to gut flora, from
           | auto-immune disorders to depression.
        
             | gamblor956 wrote:
             | Cake does not generally contain grasses...and if it were
             | true that there were trains of gut flora that converted
             | sugars to opioids almost everyone in America would live in
             | a perpetual state of intoxication. Sugar withdrawal is also
             | not even remotely similar to opioid withdrawal.
        
       | mholm wrote:
       | A 10% increase in reaction time could be fairly significant in
       | many sports. Could we start seeing football players, sprinters,
       | or baseball players breathing from masks between plays?
        
         | kaibee wrote:
         | Forget sports. I want my surgeon to be on a heliox mix when
         | he's doing a complicated operation on me.
        
           | _Adam wrote:
           | If your operation has reached the point where milliseconds
           | matter..something likely has gone wrong.
           | 
           | I'd be curious to see data on how other cognitive metrics
           | change in absence of atmospheric nitrogen. Abstract reasoning
           | / mental math abilities / etc. It's possible some actually
           | improve, just like I might rush and make more errors while
           | doing something after drinking a few coffees.
        
         | slau wrote:
         | While scuba diving, nitrogen narcosis stops the instant you
         | ascend a bit (the typical recommendation is to reduce the
         | ambient pressure by one atmosphere). I don't think there is
         | anything in this study that indicates the effect lasts more
         | than a few minutes after exposure ceases.
        
           | jjk166 wrote:
           | Depending on exactly what one's doing, it's easily
           | conceivable that the exposure can be concurrent with the
           | activity. Maybe not football, where lugging around a
           | compressed gas tank on the field is likely impractical if not
           | dangerous, but a sport like Formula 1 or many E-sports would
           | likely be quite conducive for an individual, and other sports
           | like wrestling or swimming could probably be done entirely in
           | a room with a modified atmosphere.
        
             | ambicapter wrote:
             | I've always wondered if fighter pilots ever had a system to
             | pump different gases into their masks whenever they
             | encounter a high-stakes situation.
        
               | MaxwellsDaemon wrote:
               | Here comes the juice!
        
         | scythe wrote:
         | Would be awkward for moving sports. My first thought upon
         | seeing this was that it would be a real improvement in the
         | _Melee_ reaction tech-chasing meta.
        
         | Raidion wrote:
         | You already see this. Google "NFL oxygen masks". I'm sort of
         | surprised I haven't heard about it in the context of shorter
         | physical sports: I'd wonder what effect it would have on an
         | 100m/200m/400m time or shotput distance to oxygen saturate like
         | free divers do.
        
           | CamperBob2 wrote:
           | Elsewhere in the thread, someone claims that oxygen has a
           | similar narcotic effect. Does the NFL use a helium-oxygen
           | mixture, or pure oxygen?
        
       | slau wrote:
       | 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
       | nothing about this, so I'll let others comment.
       | 
       | The interesting thing about this research is that it sort of
       | makes sense, and yet is very surprising. We're basically
       | continuously narked, we're just so used to it we don't even know.
       | 
       | Fun fact: the exact cause of nitrogen narcosis is not exactly
       | understood. It is most likely the fact that at higher partial
       | pressures nitrogen is able to enter the fatty tissues surrounding
       | our nerves. Except for helium, no other gas exists which does not
       | have some form narcotic effect at higher pressures.
       | 
       | Considering the prices of helium, this also explains why many
       | deep divers are starting to consider rebreathers.
        
         | jerf wrote:
         | "We're basically continuously narked, we're just so used to it
         | we don't even know."
         | 
         | Just because one direction on the gradient means that we
         | respond in a way that looks like a narcotic does not mean that
         | the other direction will respond in the opposite manner.
         | 
         | I'm sure the nootropics folks would have discovered being
         | _super not high_ by now if it were as easy as breathing a
         | mixture that doesn 't have nitrogen in it.
        
           | hn8305823 wrote:
           | > I'm sure the nootropics folks would have discovered being
           | super not high by now if it were as easy as breathing a
           | mixture that doesn't have nitrogen in it.
           | 
           | Maybe this is what Oxygen Bars are actually about but nobody
           | knows it yet.
        
             | karagenit wrote:
             | O2 actually has a stronger narcotic effect than N2, so
             | probably it would have the opposite effect if any.
        
           | gojomo wrote:
           | 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 environmental lead? How many people
           | & orgs remain oblivious to the cognitive deficits caused by
           | high indoor CO2 levels?
           | 
           | I hope mind-hackers do some fresh research on this, with the
           | advantage of 2023 levels of wealth/free-time/returns-to-
           | improved-cognition/SCUBA-equipment. There could be some
           | potential for positive surprise around what you're "sure"
           | should've already been discovered.
        
           | genewitch wrote:
           | as siblings commented, pure oxygen gets you high. a couple of
           | breaths of pure oxygen will relieve pain and induce euphoria.
           | I am not entirely clear on the definition of "narcotic" so i
           | may be being redundant.
           | 
           | My issue, though, is i can't find a way to safely generate
           | oxygen for a decent price. I know electrolysis works, but
           | these atomic sieves look safer. They're also difficult to
           | acquire without a prescription, at least from my searches in
           | the US. And i know lithium can react to generate oxygen, but
           | that's not what i consider "safe".
        
             | tonyarkles wrote:
             | Someone else in this thread mentioned diving. When I was
             | doing my advanced open water course, we did an exercise to
             | demonstrate nitrogen narcosis. Super simple test: we had a
             | card with the numbers 1-16 written on a 4x4 grid in random
             | order. You have to tap the numbers in order and it's a
             | timed exercise. We did it on the surface in the boat and
             | again at 30m depth; my performance was maybe 20% slower, my
             | buddy was more like 40-50% slower.
        
         | dsr_ wrote:
         | "Except for helium, no other gas exists which does not have
         | some form narcotic effect at higher pressures."
         | 
         | I assume the narcotic effect of fluorine, chlorine and bromine
         | are basically unstudied...
        
           | genewitch wrote:
           | i got a lungful of chlorine gas once and it wasn't narcotic
           | in the slightest. I wheezed and coughed for about 20 minutes.
        
             | gumby wrote:
             | If you get more of it you definitely won't wake up.
        
         | aaronscott wrote:
         | Your comment about being continuously narked reminded me how in
         | early human history people relied on low-alcohol beer as a safe
         | water supply. So back then it was a double-whammy.
         | 
         | https://www.scientificamerican.com/article/the-conflicted-hi...
        
           | alentred wrote:
           | As far as I understand, historically, alcoholic beverages
           | were primarily invented and used as a water disinfectant. Rum
           | was used in British navy to disinfect fresh water in barrels.
           | Wine was used to dilute it in water till the 20th century.
           | Fun fact, in ancient Greece people who drank pure wine (not
           | diluting it in water) were considered alcoholics and could be
           | publicly denounced. Beer was used as a typical beverage
           | accompanying a meal in many populations (a sandwich with a
           | beer was the closest analogy to the "fast food"). It appears
           | that it is only recently that we have started to consume
           | alcohol for pleasure.
        
             | sithadmin wrote:
             | I'm not sure I buy your claim that rum was ever used to
             | 'disinfect' fresh water on British Navy ships. The 'grog'
             | mix they used was not of sufficient ABV to disinfect the
             | water, as it was handed out at a 4:1 ratio of water:rum. It
             | was moreso about making the daily rum ration difficult to
             | hoard, and much more efficient to transport than beer or
             | wine.
        
               | jaggederest wrote:
               | Grog was at least 10% alcohol, plus lime juice. Navy rum
               | was 65% or 130 proof. That's more than enough to inhibit
               | most waterborne diseases such as cholera (inhibited in
               | wine at 6.25% abv, though wine has tannins and phenols).
        
               | vondur wrote:
               | Yikes, I just checked, and Captain Morgan's is 35%
               | Alcohol. I'm aware of Bacardi 151 (75.5% alcohol) which
               | is like fire water to me. Can't imagine drinking
               | something so concentrated regularly.
        
               | jrockway wrote:
               | I suppose that's why 1 part of rum got mixed with 4 parts
               | water and some limes.
        
           | tobinfricke wrote:
           | Previously:
           | 
           | "Were Early Modern People Perpetually Drunk? (2016)
           | (hypotheses.org)"
           | 
           | https://news.ycombinator.com/item?id=13535868
        
       | nichohel wrote:
       | Typo "signiGicant" in abstract.
        
       | jlawson wrote:
       | I wonder how much it would cost to fill my office with
       | helium/oxygen mix to maximize my productivity.
       | 
       | Would sound odd during calls, though!
        
         | Terr_ wrote:
         | > Would sound odd during calls, though!
         | 
         | I find myself thinking how you might dress or act to disguise
         | it, and then this climactic (i.e. spoiler) scene from "Who
         | Framed Roger Rabbit", and finally anxiety about the weird
         | places my mind goes.
         | 
         | https://www.youtube.com/watch?v=BDrqCq4fGRE&t=73s
        
         | gorkish wrote:
         | Although it's clear you are being facetious, let's see where it
         | goes. I would surmise the best and most economical gas mix to
         | breathe long term at ambient pressure would be somewhere
         | between 80/20 and 75/25 mix of Argon/Oxygen.
        
           | FreeFull wrote:
           | Argon wouldn't work, it has a stronger narcotic effect than
           | Nitrogen
        
         | [deleted]
        
         | cwillu wrote:
         | I expect that the cost of the helium would dwarf the cost of of
         | a fancy voice-shifting mic.
        
       | [deleted]
        
       | qwertyA wrote:
       | Should I move to the mountains to finish my phd?
        
         | ejdanderson wrote:
         | Does your PhD require increased reaction time?
        
       | bottlepalm wrote:
       | Sometimes I feel like the increasing carbon dioxide in the air is
       | making us collectively dumber over time..
        
         | anamexis wrote:
         | Well, it is.
         | 
         | https://www.sciencedaily.com/releases/2020/04/200421090556.h...
        
       | LoganDark wrote:
       | Just curious, is this responsible for any of the effects of
       | hyperventilation?
        
       | [deleted]
        
       | gumby wrote:
       | While anesthesia isn't particularly well understood, the thing
       | that weirds me out is not the neurological mysteries, but that
       | noble gasses like Xenon are anesthetics!
        
       | RedShift1 wrote:
       | What about the soothing effect of air at room temperature in the
       | room temperature room?
        
       | sideshowb wrote:
       | Anecdotally, as a mountaineer, I love the effect of a little less
       | atmospheric pressure.
       | 
       | Not loads less, above 3000m it starts getting inconvenient. But
       | 1000-2000m my mind feels more clear and focused than at sea
       | level.
       | 
       | I wonder if this is related?
        
         | pdc56 wrote:
         | I've found this too, but assumed it was placebo.
         | 
         | I lived at 6500' for a while - that was too high.
         | 
         | The sweet spot for me is a particular mountain I go to which
         | starts at 1200m and goes to 2000 (although I don't spend time
         | at the peak - it's a ski field).
         | 
         | Thanks for your anecdote, now I feel I can take my observations
         | more seriously
        
           | thehappypm wrote:
           | Mount Washington?
        
           | eastbound wrote:
           | It could also be the sheer concentration of CO2. I work in a
           | forest: 400ppm in the office every morning. Back at home, in
           | the city, 5km away: 580ppm minimum all day long. Maybe cities
           | make people stupid :D
        
             | sideshowb wrote:
             | Probably not in my case, haven't measured co2 but I am
             | lucky to live in a small village.
        
         | gojomo wrote:
         | My understanding from the lit, & experience, is that there's a
         | natural high/mild-euphoria from moving to higher-altitude
         | (despite slight cognitive impairment) for the 1st 24-48 hours.
         | That can then give way to crankiness, until slower adaptation
         | progresses.
         | 
         | And: theres some evidence depression/suicide rates higher even
         | at the mild elevations of places of like Reno NV (~4500'), Bend
         | OR (3500'), or Boulder CO (5500').
        
       | Luc wrote:
       | [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"
        
       | FriedPickles wrote:
       | I wonder if there's a cheaper filler gas we could use besides He.
       | Perhaps methane, hydrogen, or acetylene, though they're quite
       | flammable.
        
         | mmanfrin wrote:
         | My partner deeply disliked when I attempted a study of the
         | effects of methane in our bed.
        
         | [deleted]
        
         | mrob wrote:
         | I wonder how pure oxygen (at low pressure to avoid toxicity)
         | would work. There's still a substantial fire risk, as the
         | Apollo 1 fire demonstrated, but unlike flammable filler gases
         | it won't immediately kill you with a single spark. With a
         | sufficiently fire-proof environment, and a full body fire-proof
         | suit, maybe it could be done.
         | 
         | EDIT: Although it seems the Apollo 1 fire happened with a
         | pressurized oxygen atmosphere, not reduced pressure. Still,
         | reduced pressure has its own dangers, because there could be
         | sudden re-compression if the vacuum chamber failed. Re-
         | compression barotrauma appears to be poorly studied (people
         | don't usually work in partial vacuum). Or you could get crushed
         | to death by the vacuum chamber imploding.
        
           | ambicapter wrote:
           | Apollo 1 was high pressure oxygen, since the capsule was
           | still on earth, and they wanted to simulate the positive
           | pressure difference between the inside of the capsule and
           | space. In space it would have been low-pressure oxygen, just
           | enough to satisfy human breathing requirements (so 0.19 atm).
        
         | convolvatron wrote:
         | I don't know if you've ever taken a good whiff of acetylene,
         | but I would hate to have to live off it (maybe is it truly
         | odorless, and its just common contamination?)
        
           | dragonwriter wrote:
           | My understanding is that the characteristc smell of
           | industrial acetylene is a result of sulfur compounds added as
           | odorants (a common practice with odorless gases that create
           | hazards, to make them noticeable.)
        
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