Talk:Nitrogen narcosis

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Good article Nitrogen narcosis has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
August 25, 2009 Good article nominee Listed
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I found this good quote:

'The light does not change color as it usually does underneath a turbid surface. I cannot see clearly. Either the sun is going down quickly or my eyes are weak. I reached the hundred foot knot. My body doesn't feel weak by I keep panting. The damn rope doesn't hang straight. It slants off into yellow soup. It slants more and more. I'm anxious about that line, but I really feel wonderful. I have a queer feeling of the beatitude. I am drunk and carefree. My ears buzz and my mouth tastes bitter. The current staggers me as though I had to many drinks. "I forgotten Jacques and the people in the boats. My eyes are tired. I lower on down, trying to think about the bottom, but I can't. I'm going to sleep, but I can't fall asleep in such dizziness. There's a little light around me. I reach for the next knot and miss it. I reach again and tie my belt on it. Coming up is merry as a bubble. Liberated from weights I pull of the rope and bound. The drunken sensation vanishes. I'm sober and infuriated to have missed my goal. I pass Jacques and hurry on up. I am told I was down seven minutes.' Didi's belt was tied off two-hundred and ten feet down. This huisser attested it. No independent diver had been deeper. Yet Dumas's subjective impression was that he had been slightly under one hundred feet.
from The Silent World, by Jacques Cousteau

in this online book. (Presumably it could be found in the original book too). I think it'd be nice to include, as fair use text, but I'm not sure what Wikipedia's policy on that is. I'll leave it here for now. --Andrew 08:23, Apr 10, 2005 (UTC)


" neon at a fixed pressure has a narcotic effect equivalent to nitrogen at 0.23 times the pressure, so in principle it should be usable at four times the depth." This sounds to me like neon is more narcotic than nitrogen, if the intention correct it must be reformulated to make it usefull...—Preceding unsigned comment added by Togo (talkcontribs) 5 May 2006

No, the phrasing is correct. If something is 0.23 times as powerful as something, it is more than four times as weak, or a fourth as strong, which are equivalent statements. - BanyanTree 05:46, 19 November 2007 (UTC)
Perhaps " neon at a given pressure has a narcotic effect equivalent to nitrogen at 0.23 times that pressure ..." would be acceptable to remove the possibility of misinterpretation? RexxS (talk) 17:12, 6 January 2008 (UTC)


I tried to add 2 references in an attempt to improve the section on Effects, but although I think I followed the guide at Wikipedia:Footnotes, some of the references now seem to have gone awry. Can anyone help me to regularise the footnotes? RexxS (talk) 02:46, 6 January 2008 (UTC)

I think your problem is that the first references really aren't footnotes, so the "reference list" tag doesn't pull them up. A simple solution (which I put up, as a suggestion) is to create a separate section for the sited (footnoted) references. See what you think. SBHarris 03:47, 6 January 2008 (UTC)
I highly recommend using DAN as a source for this article, there are some things in it that aren't exactly correct, such as the part about being narced as a toxic syndrome. DarthGriz98 05:36, 13 February 2008 (UTC)
DAN wouldn't disagree about nitrogen at high pressure being toxic. Not only will it kill you, but it's killed many a diver going for the "air" depth limit below 400 ft. So many that the Guiness Book no longer carries that as a record, because everybody who's tried to beat the current record just below 400 fsw, has died. You might want to see Exley's Caverns Measureless to Man for a personal view of how they looked doing it: sitting on the bottom, totally anesthetized, until they ran out of air. With no way to help them because Ex's vision tunnelled in anytime he tried to get to them. And he was unusually resistant to nitrogen's effects. Being generally anesthetized at 300 or 400 ft is fatal, if you have nobody to help you. And often even if you do. SBHarris 06:00, 13 February 2008 (UTC)
References were not matched with PubMed ID's so I corrected those as well as changed the citations from web to journal. I will try to return to this but want to finish references on a couple of other articles first. This one will take a while.Gene Hobbs (talk) 03:17, 8 April 2008 (UTC)
Changing a web cite to a journal is an improvement, I believe, as long as there is still a url available for quick checking, rather than having to find a copy of the journal. So the second reference you updated (Hamilton, Laliberte & Fowler) makes sense. However, the first reference (originally Rogers & Moller, 1989), which was in the context of coping vs adaptation, was provided to highlight its conclusion:

"These results are taken as evidence that there is little or no behavioral adaptation to nitrogen narcosis in response to brief, repetitive exposures to narcosis-inducing hyperbaric air."

To replace that reference with older research (Fowler, Ackles & Porlier, 1985), which is unable to form any conclusion about physiological tolerance, seems to miss the point of the original reference. I will therefore reinstate the Rogers & Moller reference. --RexxS (talk) 17:16, 8 April 2008 (UTC)
Agreed, I missed adding that one back in but the reference you placed there and the abstract it links to do not match! That was my point in the first correction. I will fix that be the paper you link to the abstract of in PubMed.Gene Hobbs (talk) 21:05, 9 April 2008 (UTC)
Reference is correct to be exactly what you wanted. I do have to point out my disagreement with the validity of "older research" being less valid. Key documents for this field are key because of the quality of the work. There have been several references in other articles to poor and sometimes bad research. I have tried hard NOT to replace those out of respect for this medium but at some point, this needs to be considered and addressed by the WikiProject SCUBA team. Just my 2c.Gene Hobbs (talk) 21:20, 9 April 2008 (UTC)
First of all, thanks to you, Gene for your skills in improving the references here. I'm not sure how I managed to dissociate the reference and the abstract that I thought it referred to, but I'm grateful for your diligence in fixing it. I fully accept that research being older does not automatically imply it is less valid, but there is a general point that later researchers are likely to be aware of the limitations of earlier research (in their own field). In this case, the earlier research tried to address four issues, but was unable to distinguish between learning and physiological tolerance; while the later (presumably aware of this) focussed on adaptation and concluded that no physical tolerance occurred over the space of 12 daily exposures. Of course, this doesn't rule out the possibility that future research might find some evidence over a longer time-period, but it's the clearest reported research that I'm aware of that has a direct bearing on the "myth" that divers can physically adapt to narcosis by repeated exposure to it. --RexxS (talk) 00:29, 10 April 2008 (UTC)


Better references on hyperbaric exposure and marijuana in animals are available. BEHAVIORAL EFFECTS OF THE INTERACTION OF MARIJUANA AND INCREASING PARTIAL PRESSURES OF N2 AND O2. Walsh and Burch. UHMS Abstract 1978. RRR 4320 and Reduction of the Behavioral Effects of Δ9-Tetrahydrocannabinol by Hyperbaric Pressure. Walsh and Burch. Pharmacology Biochemistry and Behavior, v7 p111-116 1977. RRR 4226 Gene Hobbs (talk) 03:28, 8 April 2008 (UTC)

The reference you provide would be useful in the context of the article statement "Nitrogen narcosis is known to be additive..." but not as a replacement for the NIDA reference used to verify the article statement "...which is more likely than alcohol to have effects which last into a day of abstinence from use". The NIDA reference specifically contains the statement "Moreover, research has shown that marijuana’s adverse impact on memory and learning can last for days or weeks after the acute effects of the drug wear off" with three references to verify it. --RexxS (talk) 17:34, 8 April 2008 (UTC)
I was not comfortable enough making stronger comment than those provided, hence my placement of these articles here and not in the main article. Due to pressure reversal of anesthetic actions, I question the direct assumptions made in the article. It will be impossible to know for sure what happens and no answer will ever truly be known.Gene Hobbs (talk) 21:27, 9 April 2008 (UTC)
If you mean the assumption behind

Nitrogen narcosis is known to be additive to even minimal alcohol intoxication, and also to the effects of other drugs such as marijuana...

then we both know it's true for alcohol (e.g. effects of hyperbaric air in combination with ethyl alcohol and dextroamphetamine on serial choice-reaction time) and false for marijuana (as your reference clearly shows). However, given the "political" sensitivity of suggesting that diving reduces the effects of marijuana, I would prefer to see some discussion here before amending the latter part of that sentence. I know about WP:BOLD - what do others think? --RexxS (talk) 01:00, 10 April 2008 (UTC)
I think it calls for more research... But seriously, I'm not convinced of the science behind the proposition. --Legis (talk - contribs) 01:34, 15 November 2008 (UTC)

Is it just me, or is the claim about marijuana's additive effects to nitrogen narcosis completely unfounded? The cited study has nothing to do with nitrogen narcosis, it's just a general study about marijuana's cognitive effects. If there is a relationship between marijuana and narcosis, it should be clearly and explicitly stated on the Wikipedia page with citations, because it is currently unsubstantiated. —Preceding unsigned comment added by (talk) 05:55, 23 December 2009 (UTC)

External Links[edit]

I just removed an EL as the article it linked to contained nothing new. I checked WP:ELNO to be sure I could justify the removal (WP:ELNO #1) and looked at WP:ELNO #13:

Sites that are only indirectly related to the article's subject: the link should be directly related to the subject of the article. A general site that has information about a variety of subjects should usually not be linked to from an article on a more specific subject. Similarly, a website on a specific subject should usually not be linked from an article about a general subject. If a section of a general website is devoted to the subject of the article, and meets the other criteria for linking, then that part of the site could be deep-linked.

On that basis, I would question all of the ELs in this article. I know those are useful resources but as they don't seem to meet the criteria for EL in Nitrogen narcosis, can we justify keeping them here? --RexxS (talk) 01:12, 5 August 2008 (UTC)

Re-write to conform with WP:MOSMED?[edit]

I've done an overhaul of Nitrogen narcosis at User talk:RexxS/Narcosis (diving) by taking the content of the article and re-arranging it to conform with WP:MOSMED as we did with Oxygen toxicity. I'm now adding references (slowly) and think it's capable of becoming a good article. I'd like to know if anyone has any comments, suggestions or objections before I consider replacing the current article. Thanks --RexxS (talk) 23:28, 3 November 2008 (UTC)

Avoidance and cure[edit]

At present the articles states that some agencies will certify you to 130 feet on air, but some Tec diving agencies will certify you much deeper. TDI's extended range certification is good for up to 180 feet on air, and I think the PADI/DSAT course is very close to that. Do we need to amplify? --Legis (talk - contribs) 18:12, 4 November 2008 (UTC)

Yes, of course - and if you don't mind, I'll copy any info you insert into User:RexxS/Narcosis (diving) in the hope that we'll get agreement to replace the article here. It's worth noting as well that the UK agencies (SAA and BSAC) both certify recreational divers to 50 metres (160 ft) at CMAS** level. Having been there (and beyond!) in the days before we could get helium, I'm sure there's a lot more we could add about what is recommended as best practice nowadays. --RexxS (talk) 18:43, 4 November 2008 (UTC)

Effects of Narcosis (table)[edit]

The following table was published on message board that I frequent (see post #33 on this page). It is said to be lifted from NOAA diving manual, but I don't have a copy of the NOAA manual myself. If correct, I think it would be a useful addition to the article, but it really needs to be checked by somebody (I am sure the NOAA manual is a reliable source, but somebody needs to check that it is in fact in the manual!). I also think something must have been lost in the "translation", as they seem to have key single depths alternating with ranges, so it would be good if we could tidy that up. --Legis (talk - contribs) 17:34, 8 December 2008 (UTC)

Effects of Nitrogen Narcosis
Depth Comments
0-100 fsw Mild impairment, mild euphoria
100 fsw Reasoning and immediate memory affected, delayed reaction
100-165 fsw Laughter, idea fixation, overconfidence
165 fsw Hallucinations, sleepiness, impaired judgement
165-230 fsw Terror, talkative, dizziness, uncontrolled laughter
230 fsw Severe impairment of intellectual performance
230-300 fsw Mental confusion, sounds seem louder, gross delay to stimuli
300 fsw Hallucinations (similar to drug induced) impairment of memory, judgement, loss of intelligence
Source: NOAA Diving Manual
It's interesting as an idea of the sort of symptoms that may occur. It's surely worth including, but we would have to ensure that we're not suggesting that every diver will experience all of those as they reach a particular depth <grin>! Anecdotally, in the days before we could get helium easily, I was involved in a number of projects using deep air. I never experienced laughter (uncontrolled or otherwise), hallucinations, terror, or talkativeness. At extreme depth, I could hear my blood in my temples; I often had to re-read my gauges as I immediately forgot what I had read; and my peripheral vision shrank down dramatically. This was generally repeatable but not always at the same depths. So, as you can see, narcosis would appear to affect different divers very differently and the same diver somewhat differently on different dives. Of course, I'm not a WP:RS, so it's not much help to the article. Gene's probably got an up-to-date copy of the NOAA manual somewhere. There's a similar, but more detailed table in:
  • Lippmann, John; Mitchell, Simon (2005). "6". Deeper into Diving (2 ed.). Victoria, Australia: J.L. Publications. p. 105. ISBN 097522901X. OCLC 66524750.  Unknown parameter |month= ignored (help)
but I'm a little wary of quoting a whole page because of WP:copyvio. Bennett & Elliott give a much more detailed analysis and it would be difficult to collate that into a table. I'll drop Gene a line and see if he can conform the NOAA table.
That is not the complete table, the "Effect" section is shortened somewhat. I can send it to you guys if you want to continue with that version. If you are happy with the Lippmann/ Mitchell version, use it. Any table used would have copyright concerns but all that needs to be done is proper referencing of the source. The NOAA Manual is not copyrighted by NOAA but rather Best Publishing. If you want one with a US Government copyright, try looking over the one in the USN Manual rev 3 (There is not a similar table in the current Rev 6). If I were picking one to use, it would be the Lippmann/ Mitchell version. I can write or call Simon if that would make you guys happier but his answer will be give the credit through a proper reference. Hope this helps! --Gene Hobbs (talk) 15:17, 9 December 2008 (UTC)

RE: marijuana use; Under "Prevention" Section[edit]


"Abstinence time needed for marijuana is unknown, but due to the much longer half-life of the active agent of this drug in the body, it is likely to be longer than for alcohol.[17]"

Marijuana's most commonly cited active ingredient has a half life shorter than ethanol's. The refrence given only shows that cognitive impairment is correlated with marijuana use even after the drug is removed from the body.

Since no similar data is available for ethanol, the conclusion really can't be drawn that marijuana is different. At most it should mention the correlation and state what that may indicate if other factors are presumed.

Objections to removing refrence to relative halflives? —Preceding unsigned comment added by Δζ (talkcontribs) 21:56, 30 December 2008 (UTC)

No objection whatsoever; let's not have inaccurate info in our articles. I wasn't aware of the relative half-lives of THC and ethanol, so the time taken for effects of marijuana to wear off remains a bit of a mystery. Perhaps something along the lines of "Abstinence time needed for marijuana is unknown, but it is likely to be several days.<ref>... etc.", preserving the ref, but not giving the false information? Anyway, please feel free to make the changes you think best.
The original statement was supported by this article: "NIDA InfoFacts: Marijuana (see references 19,20,25)". Retrieved 2 March 2008.  - particularly the references quoted, but that was merely to contrast with the advice of abstinence from alcohol for 24 hours before a dive. Gene Hobbs also provided good refs on the talk page in the section # Marijuana above. They might be worth checking when you rewrite that statement. --RexxS (talk) 02:42, 31 December 2008 (UTC)

Wrong value for Kr in table?[edit]

This reference: gives a narcotic value of 7.14 for krypton as compared with nitrogen (obviously calculated from partion in oil/water), which is about what would be expected, as an intermediate between Ar at 2.3 and Xe at 25.6. I think the table is probably wrong and should be checked. Incidentally this makes a difference, since it means that breathing Kr at 80% would be about like breathing air at 200 ft depth in seawater. That's significantly narcotic, and would mean krypton has additional dangers beyond a simple asphyxiant. Even 40% krypton might make a person feel more dizzy than just getting 60% of normal oxygen would by itself (what you'd get with 40% argon, say). SBHarris 03:48, 4 March 2009 (UTC)

Thanks for bringing that up. The table was derived from Brubakk, Alf O.; Neuman, Tom S. (2003). Bennett and Elliott's physiology and medicine of diving, 5th Rev ed. United States: Saunders Ltd. p. 304. ISBN 0702025712.  which is generally considered as reliable a source for diving physiology as exists. The summary table at Techdiver is claimed to be derived from the 4th Edition (1993), which I don't have. However, Bennett does cite multiple sources for his figures and points out that "By far the most satisfactory correlation is afforded by lipid solubility" - which of course is not the same as saying there is a direct relationship. (As an aside, it's worth noting that relative oil-water solubility ratio differs from relative lipid solubility - for example, argon has almost the same oil-water solubility ratio as nitrogen, but twice its lipid solubility.) I do agree though that krypton's relative narcotic potency as quoted by Bennett is anomalous. It is possible that the figure of 2.5 is a mistake; or that krypton as a breathing gas has been so little studied that its measured narcotic potency is inaccurate; or that it actually is anomalous in its correlation with lipid solubility. At the moment, I don't know the answer and still prefer a direct quote from Bennett & Elliott to an indirect one from a website, but I'll see if Gene Hobbs can comment - or if he can ask Peter Bennett what the answer is! --RexxS (talk) 13:21, 4 March 2009 (UTC)
Gene tells me that the fourth edition quotes the relative narcotic potency of Kr as 0.14 - i.e. as N2/Kr which is 7.14 if calculated as Kr/N2, so there is a difference between editions, but Peter Bennett is out of town this week. Hopefully we can get some clarification soon. Good catch, Steven! --RexxS (talk) 21:33, 4 March 2009 (UTC)
Thanks. Nice to know the universe makes sense. I'll mess with the "precautions" section of the krypton article when we get it sorted out and a decent reference. There are questions on that element's talk page which are related. SBHarris 23:14, 4 March 2009 (UTC)
Having checked all the sources I can, I'm convinced the value in the table in Bennett & Elliott 5th Edition is erroneous. I've uploaded a new table derived from the values given in the 4th and 5th editions using the value for Krypton given in the 4th edition. Hope you can sort out the Krypton precautions section now. With the revised value, it certainly implies some anesthetic properties even at normobaric pressures. --RexxS (talk) 19:27, 22 March 2009 (UTC)

YouTube video[edit]

There is a video on YouTube, illustrating several points in the article, that I thought might make a useful external link. Unfortunately, it looks like it may be copyright and may be being used without permission, so it would be unusable as an external link. Does anybody recognise it? If so, it's possible that we could then determine whether it is on YouTube with permission and make the link. --RexxS (talk) 15:35, 27 March 2009 (UTC)

Thumbs test[edit]

Since the paragraph in "Prevention" about the "Thumbs test" has remained uncited since March, and I can find no WP:RS for it, I've cut it and pasted it here, in the hope that someone can find a ref for it.

Some diving organizations teach their divers to frequently check their mental state while immersed using the "thumbs test". The two companions regularly show each other their fingers. One shows a number of fingers (e.g. 2), and then the other must respond by showing back one more or one less (i.e. 3 or 1), depending on previous agreement. If either of them botches the arithmetic, they should suspect narcosis.[citation needed]

--RexxS (talk) 22:50, 2 July 2009 (UTC)

Name of this article[edit]

This topic has been known as "Nitrogen narcosis" since the beginning of the last century. Nevertheless, it was demonstrated in 1939 that many other inert gases also cause the effect; therefore "Inert gas narcosis" is likely to be more appropriate. However, following work in the 1970's it became clear that oxygen could exert the same narcotic effect as well, so I suggest "Narcosis (diving)" is the most accurate title for this article. All of these are contained within the lead, and the single word "narcosis" has been used throughout, without any loss of clarity.

I suggest a "straw poll" of preferences be taken now for the most appropriate title for the article. Please indicate your preference as first/second/third or support/oppose as you see fit and sign each preference. Any additional brief comments to explain your preference would be valuable. Please use the "Discussion" subsection for any threaded debate. --RexxS (talk) 01:03, 8 July 2009 (UTC)

1. Narcosis (diving)

  • First choice - most accurately represents the topic. --RexxS (talk) 01:03, 8 July 2009 (UTC)
  • First choice - Gene Hobbs (talk) 03:05, 8 July 2009 (UTC)
  • No way - Why rename to a disambigue name when unique name is free. --Stefan talk 06:03, 8 July 2009 (UTC)
  • Second choice - most accurate, but wouold be a less commonly recognised title. --Legis (talk - contribs) 11:24, 8 July 2009 (UTC)

2. Inert gas narcosis

  • Second choice - common in the literature. --RexxS (talk) 01:03, 8 July 2009 (UTC)
  • Second choice - Gene Hobbs (talk) 03:05, 8 July 2009 (UTC)
  • Second choise - See no reson to change, nitrogen narcosis is more common and more used by laymen (i.e. our readers) --Stefan talk 06:03, 8 July 2009 (UTC)
  • Third choice - although this term is used, only really in scientific/technical liternature. Also misleading: non-inert gases are narcotic too. --Legis (talk - contribs) 11:24, 8 July 2009 (UTC)

3. Nitrogen narcosis

  • Third choice - still commonly used. --RexxS (talk) 01:03, 8 July 2009 (UTC)
  • Third choice - Gene Hobbs (talk) 03:05, 8 July 2009 (UTC)
  • First choice - See why change below. --Stefan talk
  • First choice - in common parlance, this is the most common title for the subject even though in reality we know it is not just nitrogen. --Legis (talk - contribs) 11:24, 8 July 2009 (UTC)


BTW, what exactly is the best evidence that oxygen is narcotic? SBHarris 02:02, 8 July 2009 (UTC)

Well, for easy access: Work by Paton showed that oxygen works as an anesthetic at "around 11 atmospheres". At the 2008 DAN Technical Diving Conference, Peter B. Bennett described work performed by the Royal Navy Physiological Laboratory. He showed video of rats being rapidly compressed (32 seconds) to 1,000 fsw on 100% oxygen and falling asleep around 800 fsw. The hard thing to figure out is what this might mean to divers but I like Bennett's conclusions and well, its hard to find another expert with his experience on this topic.
Hope this helps... --Gene Hobbs (talk) 03:23, 8 July 2009 (UTC)
There's a good write-up in Bennett & Elliott (5th Ed) p.304, citing Frankenhaeuser et al. (1963) who used choice reaction times and mirror drawing to "study the narcotic effect of varying oxygen partial pressures at constant nitrogen partial pressure of 30 msw" and several other subsequent studies, which eliminated the possibility of the effect being an indirect effect due to CO2 action. So it's been pretty conclusive for some time. However, for oxygen it's not a simple relationship between ppO2 and narcotic potency, since much of the oxygen will be metabolised and you can't just assign a relative narcotic potency of 1.7 (as I've done in the table, copying from Bennett & Elliott!). It seems the safest course is to assume oxygen has, on average, about the same narcotic effect effect as nitrogen (and hence as air), and plan your END relative to air, treating O2 & N2 as 1 and He as 0. That's what NOAA recommends now anyway. --RexxS (talk) 04:28, 8 July 2009 (UTC)
  • Legis - I'd keep it as nitrogen narcosis, because frankly that is what I think most people would "Google" when looking for information on the subject. It is the same as calling the article Pelé instead of Edison Arantes do Nascimento. Technically less accurate, but much more commonly recognised. --Legis (talk - contribs) 11:24, 8 July 2009 (UTC)

Why change[edit]

As stated above there are 3 options, lets see at the wikipedia policy NAME says:

Generally, article naming should prefer what the greatest number of English speakers would most easily recognize, with a reasonable minimum of ambiguity, while at the same time making linking to those articles easy and second nature.

That should mean that Nitrogen narcosis is the right name (remeber we do not have the most correct scientific name) but the 'most easily recognizes' name. Reading on, NAME states

Wikipedia determines the recognizability of a name by seeing what verifiable reliable sources in English call the subject.

So by that I would grade the three choises like this:

Nitrogen narcosis: Is best at two of three of the considerations, easily recognize, linking and maybe second comes to reliable sources

Inert gas narcosis: Maybe best for reliable sources, same for linking and second for easily recognize

Narcosis (diving): Very bad for easily recognize, linking and reliable sources So I can not understand why we want to change the name?? --Stefan talk 06:03, 8 July 2009 (UTC)

It is interesting that WP:NAME does not documentCheck the consensus at WP:MEDMOS#Naming conventions, which states:

The article title should be the scientific or recognised medical name rather than the lay term (common, unscientific, and/or slang name)[wc 1] or a historical eponym that has been superseded.[wc 2] These alternative names may be specified in the lead. Create redirects to the article to help those searching with alternative names. For example, heart attack redirects to myocardial infarction.

  1. ^ This convention was documented at the now-defunct WikiProject Clinical medicine,[1] and was the result of several discussions in 2004.[2][3][4]
  2. ^ Arguments for and against eponyms, plus background information, can be read at the List of eponymous diseases.
Just as the consensus is have heart attack redirect to myocardial infarction, I would expect Nitrogen narcosis (common unscientific name) to redirect to either Inert gas narcosis or Narcosis (accurate/sourced/medical name) - but since Narcosis has ambiguous uses (the article is a dab page), I have suggested adding the (diving) disambiguation for this article. The redirect would ensure anyone searching for "Nitrogen narcosis" would arrive here (whatever this article is called), as would the link Nitrogen narcosis; while "narcosis" as used in diving, when linked or searched for, would lead to the expected disambiguation, i.e. the "(diving)" qualifier. I don't count these as overwhelmingly convincing arguments against "Nitrogen narcosis" as the article title, I just felt it useful to point out that WP:NAME really doesn't tell the whole story for medical-related articles. --RexxS (talk) 20:17, 8 July 2009 (UTC)
Update: After raising the issue, WP:NAME now contains a link to WP:MEDMOS#Naming conventions. Also, the word "common" has now been removed from the guidelines at MOSMED. --RexxS (talk) 22:53, 8 July 2009 (UTC)
I'm confused, we have a POLICY that states use the most common and most easily recognized name, then the policy redirects to a GUIDELINE that states use the scientific term (the policy should copy the text from the guideline ...). Nevermind that is not the topic here, but I still do not agree, I think that common name should be used in this case (does this page really fall under the scope of MOSMED?? :-) Nitrogen narcosis is not a disease, is it? It is a reversible alteration. To see what is the correct scientific name I tried google schoolar "Inert+gas+narcosis"&btnG=Search Inert Gas Narcosis 823 hits and "Nitrogen+narcosis"&hl=en&btnG=Search Nitrogen Narcosis 1550, for google books the result is 702 vs 847, this obvioulsy is not a good test since it uses lots of old texts, but I found books from 18?? using Inert Gas Narcosis and scientific papers from 200? using nitrogen narcosis. --Stefan talk 02:59, 9 July 2009 (UTC)
Policies (apart from WP:5P) and guidelines on wikipedia do no more than document consensus that has been reached on a particular issue over many edits to many articles. They tell us how our editors do things. In that sense, they are rather more descriptive than prescriptive. If an editor edits against a policy, they are not editing contrary to a rule, but contrary to an established consensus. I hope that helps in putting WP:NAME and WP:MOSMED into context. In other words, MOSMED documents the agreed exceptions to NAME, where naming medical articles is concerned.
I believe that nitrogen narcosis falls under MOSMED. Referring to WP:MEDMOS#Diseases.2Fdisorders.2Fsyndromes, there is an assumption that all articles about medical conditions will fall under MOSMED. In addition, the scope of WP:WikiProject Medicine extends to "medical conditions, diagnosis and treatment". Isn't a "reversible alteration in consciousness" a medical condition? Anesthesia (to which narcosis is compared) is a reversible alteration in consciousness, but who would deny it is medically-related?
Having said all that, the best name for this article is by no means clear-cut, and I believe compelling arguments exist both for and against each of the three choices I suggested. Having this discussion (and the straw poll) is very valuable, imho. Eventually, we may be able to discern a consensus for one of the three; if not, the name will stay as it is. But at least the issues will be well-documented for the future. My thanks to all who are taking part. --RexxS (talk) 18:59, 9 July 2009 (UTC)
Good points, and I tend to agree that it does fall under MOSMED, but that does not mean that it have to be followed 100%. Falling under WP:WikiProject Medicine does not mean that MOSMED must be followed. When I wrote the previous comment I only checked the first part which specifically talks about naming which includes diseases, drugs and anatomy, these are the types of articles that this exception to COMMONNAME refers to, and which the exception to the naming policy was made. I do not want to put nitrogen narcosis as a disease. Also just because it is under MOSMED does not mean that MOSMED naming is applicable, say that MOSSCUBA existed and stated always use common name, which would then be used?
I also agree that this is not a clear cut case either way, and I must admit that I had never read MOSMED or the exception to NAME when I cast my !vote. I can understand the reason for MOSMED naming, but I do not think that is applicable to this case. I also think Legis had a very interesting point above, non-inert gases are narcotic too, if this is true it make things even more complicated :-) --Stefan talk 00:52, 10 July 2009 (UTC)
This is completely off-topic for the name of the article, but there is a sub-text here that needs to be considered. I'm hoping that this article will be able to be nominated for Wp:Good Article status sometime soon. Take a look at the last scuba/medical-related article which was nominated: Talk:Oxygen toxicity/GA2. OxTox is probably more obvious, but these sort of articles actually need MOSMED - it really helps meeting GA criterion 1, 2, 3. --RexxS (talk) 01:14, 10 July 2009 (UTC)

One more reason to use "common" Wiki article names[edit]

You may not know that Google page ranks by exact article name (or whatever links they've set as equal to the name), and does not see any hits based on internal wiki-redirects, if those aren't obvious. Thus, flu shot redirects to influenza vaccination on Wikipedia, but not on Google, because Google hasn't performed it's own redirect. Thus, a google search on "Flu shot" will NOT get you the wikipedia article, or any redirected article, for many pages (and this article hardly gets any pageviews, showing that most Wikipedia hits still come from Google). In effect, the Wikipedia article doesn't exist for Google, and this cannot be helped at the Wikipedia end except by naming it "Flu shot."

However, in another case, where Google itself has done the redirect, typing "Flu" into Google will get indeed get you the Wikipedia Influenza article, as your second hit. But that's because Google has redirected the search.

My point is that if you're not careful, you'll end up naming your Wiki technically "correctly" but if Google doesn't follow you in the redirect, nobody will ever see the Wiki article on the Google search, no matter how you re-direct things on Wikipedia. It's well to remember that. If you want this stuff to be read, keep the titles as something Google users will search on.

BTW, feel free to test what I say. Look at the number of page hits for this article using then do the same after you've renamed it and redirected to it. You'll find to your shock that it doesn't work. It's not the same. You have to write a letter to Google to "fix" it. SBHarris 23:18, 8 July 2009 (UTC)

Good point, Steve. It was raised at Talk:Myocardial infarction#Name of the article when there was discussion about "heart attack" vs. "myocardial infarction", so I guess that the medics are aware, but prefer the guidance at MOSMED as it stands. I see that google has fixed that particular problem since a gsearch for "heart attack" now shows wikipedia's article Myocardial infarction at number 1. In this case, a gsearch for "narcosis" has our dab page at number 1, with "nitrogen narcosis" showing in the first line of its description. That would still be true, whatever we called this article. As you rightly point out though, the gsearch for "nitrogen narcosis" could be affected - to what extent I can't speculate, but I suspect it would be just as fixable as the heart attack case. --RexxS (talk) 00:23, 9 July 2009 (UTC)
Actually that may NOT be true if you name an article to something rarely searched for. However, if it's already made the top under a common name, I suppose the redirect will keep it there, as people will still link to it under its old name. Be interesting to see. But for a new article you have name the article commonly and then wait till it hits the top of searches, before renaming to something uncommon. Again, even though flu shot redirects to influenza vaccination, Google is unaware of the redirect and will not give you the second when you search for the first. So Google does not necessarily track WP's redirects. SBHarris 03:14, 9 July 2009 (UTC)
Thanks again, Steve. That's excellent advice and I'll do my best to remember it when creating new articles in the future. --RexxS (talk) 19:01, 9 July 2009 (UTC)

Preparation for GA Review[edit]

To do list

  1. Find source for:
    • "An early effect may be loss of near-visual accommodation, causing increased difficulty in close-accommodation reading of small numbers in middle-aged or older divers who already have any degree of presbyopia" removed until source found --RexxS (talk) 18:31, 19 August 2009 (UTC)
      Added with this diff by User:Sbharris
    • "Paradoxically, badly affected divers may panic, sometimes remaining on the bottom, too exhausted to ascend" removed until source found --RexxS (talk) 18:31, 19 August 2009 (UTC)
      Original text added with this diff by
    • "Excellent cardiovascular health is no protection and poor health is not necessarily a predictor" removed until source found --RexxS (talk) 18:31, 19 August 2009 (UTC)
      This diff was added probably by User:Robert Dolan as
    • "Experts recommend total abstinence from alcohol at least 24 hours before diving, and longer for heavy drinking"
  2. Copyedit:
    • Check each paragraph has a common theme
    • Try to amalgamate small paragraphs
    • Check if large paragraphs can be split
    • Consistency of date format, units format
    • Look for possible wikilinks for uncommon words
    • Consistency of spelling per WP:ENGVAR
  3. Check references for:
    • Consistency of format, dates, punctuation
    • full text availablility
    • dead links, accessdate if not stable link
  4. Check images for:
    • Licence
    • Caption
    • Placement
    • Alt text

Strike when done. --RexxS (talk) 20:55, 23 July 2009 (UTC)

Also check this autogenerated peerreview. --Stefan talk 01:34, 29 July 2009 (UTC)

Text size is 20 kB. Dablinks check; as do external links. --RexxS (talk) 03:47, 29 July 2009 (UTC)

GA Review[edit]

This review is transcluded from Talk:Nitrogen narcosis/GA1. The edit link for this section can be used to add comments to the review.

The article is an interesting, well-researched, and well-written article. It should be worthy of the GA rating pending a few minor adjustments. Here's how it stacks up against the six Good Article criteria:

GA review (see here for criteria)
  1. It is reasonably well written.
    a (prose): b (MoS):
    Article text is good. Lead section is a good summary. The article meets the manual of style.
  2. It is factually accurate and verifiable.
    a (references): b (citations to reliable sources): c (OR):
    The article is well-cited by sources that meet reliability guidelines. There are a couple of citation needed tags in the article that do need to be addressed prior to GA status, however.
  3. It is broad in its coverage.
    a (major aspects): b (focused):
    The article appears to cover the important aspects of the topic well. A minor concern is with the relatively short length of the management, prognosis, and epidemiology sections. With just a few sentences in each section, it seems like the information could be expanded here. The management section seems to repeat information already given in the diagnosis section, so perhaps those two sections could be combined?
  4. It follows the neutral point of view policy.
    Fair representation without bias:
    The article is written in a neutral tone.
  5. It is stable.
    No edit wars etc.:
    Most edits are by one editor. There are no major edit wars.
  6. It is illustrated by images, where possible and appropriate.
    a (images are tagged and non-free images have fair use rationales): b (appropriate use with suitable captions):
    The images are all tagged appropriately and meet copyright requirements. The Meyer-Overton correlation graph is good, but appears to simply be added on to the history section, and isn't connected to the text of that section. It would help if the text of the section connected with the image.
  7. Overall:
    Overall, the article is very good. Once the issues are addressed sufficiently, the article can be promoted to GA status. I'll put it on hold for now. Dr. Cash (talk) 15:09, 12 August 2009 (UTC)

First response[edit]

Thank you for offering to review Nitrogen narcosis. I'll give my detailed responses below:

2. The article existed for over six years before I made my first edit to it, and it was largely unsourced. Working with Gene Hobbs, we were eventually able to cite sources for most of the content. What could not be immediately sourced, I tagged, to encourage other editors to help with refs. Those four statements are what is left and I've highlighted them on the Talk page. I'll ask my collaborator, Gene Hobbs, who is the expert on sourcing, if he can make another attempt to find decent sources supporting those statements. If they can't be sourced within a few days, I'll remove them until such time as they can be verified. --RexxS (talk) 18:27, 12 August 2009 (UTC)
3. I wish I could expand diagnosis, management, prognosis and epidemiology, but the condition has its diagnosis confirmed by its management (which is trivial: ascending); it affects everyone; and has no long-term effects if managed. That's it, really. The interesting bits are the symptoms, causes and prevention and so sources concentrate on those. Anyway, I've merged diagnosis and management - as they are inextricably related - as well as prognosis and epidemiology since they may be described so simply. I'll re-read later to see if I can remove redundancy in the diagnosis and management section.
6. The Meyer-Overton graph was intended to refer to this paragraph in History: The first report of anesthetic potency being related to lipid solubility was published by Hans H. Meyer in 1899, entitled Zur Theorie der Alkoholnarkose. Two years later a similar theory was published independently by Charles Ernest Overton. I can now see that I didn't make that clear enough, so I've added a sentence explaining that became the Meyer-Overton Hypothesis and the graph illustrates it.

I'm most grateful for your comments and hope that this initial response goes some way to meeting them. Please let me know if you feel I'm moving in the right direction, and if there are any other issues that I can address. --RexxS (talk) 18:27, 12 August 2009 (UTC)

The changes so far look good. Thanks. The citation needed tags do need to be addressed prior to GA, as they're red flags. Specifically, the GA criteria states: "it provides in-line citations from reliable sources for direct quotations, statistics, published opinion, counter-intuitive or controversial statements that are challenged or likely to be challenged, and contentious material relating to living persons—science-based articles should follow the scientific citation guidelines". The presence of 'citation needed' tags indicates that the material is being "challenged", which goes directly against that criterion. Dr. Cash (talk) 13:40, 14 August 2009 (UTC)
Second response
Well, I'm the one doing the challenging as I placed the tags (the material was added by other editors). But I hope you would agree that those four statements need to be substantiated, so I usually place those tags to attract any other editors who might be able to find a source that I can't. Since they have been there for a month now, I'm ready to remove the statements - they are not crucial to an understanding of nitrogen narcosis. If it's ok with you, I'll give it another couple of days (in case Gene can find something, although I know he's been busy at work recently). By Monday 17 August, either I'll have sources or I'll take out the four statements. I hope that timeframe is acceptable to you. If you get a chance, I appreciate it if you could indicate any other issues you may have, or if I haven't sufficiently addressed the other points you raised above. Thanks again. --RexxS (talk) 22:51, 15 August 2009 (UTC)
I've now sourced one of the four statements and removed the other three. The text still reads just as well, and if sources can be found in the future, they can be put back. Is there any other issue still outstanding? --RexxS (talk) 18:56, 17 August 2009 (UTC)

GA passed[edit]

The article meets the GA Criteria and will be listed. Nice work. Dr. Cash (talk) 03:41, 25 August 2009 (UTC)

General comments[edit]

Just finished reading through the DAN Tec Diving conference report (free download here), and it had some interesting things to say about lots of things, including Narcosis. Before I start hacking away at what is presently a very good article, I wanted to push them out onto the talk page for discussion:

  • Conference cites studies showing that, despite its higher lipid solubility, oxygen is only 0.27 times as narcotic as nitrogen, thus suggesting that nitrox does in fact reduce narcosis, albeit only slightly (page 75).
  • Suggests that cognative skills are affected disproportionaly greater than manual dexterity.
  • It also cites a number of studies suggesting that one can acclimatise to the effects of narcosis (contrary to what the article presently indicates).
  • It further suggests that rapid descent potentiates narcosis, but time at depth ameliorates it as the body comes to accommodate the chemical change.

I think some or all of these might properly be included in the article, but I don't want to trample on the excellent work of RexxS and Gene Hobbs (Gene, I think you were listed as a key participant at the conference, weren't you?). The nice thing about the report is that it is heavily footnoted, so we have good sourcing on hand. --Legis (talk - contribs) 20:45, 20 November 2009 (UTC)

Thanks very much for the link to that report. I'm just working through it now, but so far I don't think there's anything new, as Gene provided most of the refs for this article, and those are pretty much the same as the report makes use of. I'll just make a quick response to your four points above, but I'll come back to them when I've had more chance to digest the report.
  • The study cited by the conference to support "oxygen was found to be only 0.26 as potent as nitrogen " (Hesser CM, Adolfson J, Fagraeus L (1971). Role of CO2 in compressed air narcosis. Aerospace Med 42:163-168) is an early study and recognises that the metabolism of oxygen lowers its apparent narcotic effect. The report fails to acknowledge the later study by the same authors (Hesser CM, Fagraeus L, Adolfson J (1978). Roles of nitrogen, oxygen and carbon dioxide in compressed air narcosis. Undersea Biomed Res 5:391-400) which concentrated more specifically on the role of oxygen and concludes "This suggests that for producing equivalent degrees of decrement in mental function, the rise in nitrogen pressure has to be 3 to 4 times greater than that in oxygen pressure and, hence, that oxygen is 3 to 4 times as potent a narcotic as nitrogen." (p. 398). I was aware of both of these when I wrote that part of the article, but have cited only the latter in the article, as I believe it to better reflect the wider literature.
  • The difference in effect between mental and motor skills is well-known and mentioned in the article (with the same sources as the report uses), but I'd be happy to see the distinction clarified and expanded if anyone can come up with better wording.
  • The ability to acclimatise is still controversial and evidence consists mainly of anecdotal experiences of a few deep-record divers, as the report shows. I really don't see this as more than a selection of individuals who naturally have better than normal tolerance, and who have "learned to cope". I was already aware of the adaptation studies on saturation diving and the opposing results at different depths, but dives lasting for 4–6 days don't seem to me to be very relevant to a general article on narcosis. Is this worth including? I do agree that the final sentence of para 3 in Prevention should be expanded and clarified though.
  • The report agrees with what the article states in the first paragraph of Causes, so I don't see any contradiction there.
Gene's been away for a while, but when he's able to return to editing more regularly, I'd suggest that the three of us (plus anyone else interested?) could collaborate to push this article to FA. The report is an excellent overview of current knowledge and will be valuable in improving the article. --RexxS (talk) 03:33, 21 November 2009 (UTC)

Helium narcosis[edit]

Edited a couple of references to make it clear that Helium is narcotic, just less so than Nitrogen, using an existing reference. —Preceding unsigned comment added by (talk) 21:36, 20 March 2010 (UTC)

Thanks for trying to improve the article, but the reference you give (techdiver) is wrong on this point. They took their table from Bennett & Elliott's Physiology and Medicine of Diving, but obviously didn't read the text. If you look here:
  • Bennett, Peter; Rostain, Jean Claude (2003). "Inert Gas Narcosis". In Brubakk, Alf O; Neuman, Tom S. Bennett and Elliott's physiology and medicine of diving (5th ed.). United States: Saunders Ltd. p. 305. ISBN 0702025712. OCLC 51607923. 
You can read what Peter Bennett actually says:
He then goes on to discuss mood changes and other effects that may be a helium narcotic effect at pressures of 40–80+ bar, but is unable to be certain of that diagnosis.
I do feel that the results for neon should be mentioned, however, so I'll rewrite the sections to reflect more accurately what Doctor Bennet wrote. --RexxS (talk) 03:22, 21 March 2010 (UTC)

Gilding the lilly[edit]

To the extent that it is really true that narcosis is totally reversed in every last person upon ascent, it is redundant to then add that there are no lasting effects. By logic it goes without saying, so why bother to say it? SBHarris 04:38, 27 February 2012 (UTC)

Although the management or treatment of a given medical condition may fully relieve the symptoms, it is not always the case that there are no long term consequences. For example, you only need to think about chicken pox which is normally resolved without difficulty in childhood, but which sometimes resurfaces as shingles much later in life.
The lead is meant to summarise the rest of the article, and the Diagnosis and management section contains "The management of narcosis is simply to ascend to shallower depths; the effects then disappear within minutes", while the Prognosis and epidemiology section states "Except for occasional amnesia of events at depth, the effects of narcosis are entirely reversible by ascending and therefore pose no problem in themselves, even for repeated, chronic or acute exposure". I believe that it is important to summarise explicitly both points and that is why I chose the original formulation. I don't agree that removing the phrase 'with no long-term effects' from the lead adequately conveys the prognosis indicated by the two sources. --RexxS (talk) 19:59, 27 February 2012 (UTC)
While there is no long term damage from the narcosis itself upon recompression, should there be a link to decompression sickness, since rapid recompression will cause that?Mzmadmike (talk) 15:50, 25 August 2014 (UTC)
The narcosis is alleviated by ascending to a shallower depth, i.e. a lower pressure. Although DCI is caused by rapid decompression (not recompression, which is the opposite), any effect of narcosis will have disappeared before reaching a depth of around 20 metres (66 ft). Anybody who has done such an extreme dive that they have accumulated enough dissolved gas to require a decompression stop that deep will have noticed narcosis a lot earlier in the dive. With modern diving planning there's no sensible scenario where ascending to alleviate narcosis can trigger DCI. --RexxS (talk) 17:26, 25 August 2014 (UTC)

Helium narcosis part 2[edit]

Reading the sources given (Bennett & Elliott), it can be seen that no narcotic effect has ever been observed in either helium or neon, although there has not been much research done into neon because its higher density makes it less useful than helium. There is a quote from Peter Bennett two sections above #Helium narcosis that makes this point clear. It seems that I ought to quote the exact text from page 305 of the source:

  • Helium: "Helium is not narcotic ..."
  • Neon: "The first performance tests on man were made by Hamilton et al (1966) at 183 msw (600 fsw) using a standard pursuit rotor which demonstrated no deterioration. ... Lambertsen studied the effects of breathing neon at 366 msw (1200 fsw) and found no narcosis."

I don't think it can be any clearer than that. I've restored the previous text. --RexxS (talk) 15:06, 24 January 2013 (UTC)

Reader feedback: more easy-to-understand writ...[edit] posted this comment on 12 December 2012 (view all feedback).

more easy-to-understand writing for young people

I fear this may be a cry in the darkness. Link to an article on Simple English? (I have just started one for the purpose) Any thoughts?

• • • Peter (Southwood) (talk): 15:46, 19 July 2013 (UTC)

Explanation of graph[edit]

graph with logarithmic scales showing a close inverse correlation between "Potency of anesthetic drug" and "Olive oil:gas partition coefficient" for 17 different agents
Both Meyer and Overton discovered that the narcotic potency of an anesthetic can generally be predicted from its solubility in oil

The graph needs clarification. Superficial reading suggests that N2 with a potency of around 50 or 60 is the strongest anaesthetic of the compounds measured. The meaning of the term gas partition coefficient is not explained in the text, which makes the data in the graph inaccessible to anyone without this knowledge. I will try to look it up, but if anyone has a good reference please go ahead and explain. • • • Peter (Southwood) (talk): 10:06, 28 July 2015 (UTC)

It seems that the Y-axis is actually MAC (Minimum alveolar concentration) to prevent movement in 50% of patients in response to a noxious stimulus. And MAC is inversely proportional to anaesthetic potency, indicating that much higher concentration of nitrogen is required in the alveolar gas that the compounds lower on the graph. So as it stands the graph is misleading.• • • Peter (Southwood) (talk): 10:22, 28 July 2015 (UTC)

I have modified the graph to provide the correct information. • • • Peter (Southwood) (talk): 11:14, 28 July 2015 (UTC)

Thanks, Peter. Good job. --Legis (talk - contribs) 13:16, 28 July 2015 (UTC)


So the chart reads, in the lowest row, that at 90+ meters, a diver will experience levitation (it even hotlinks). I find this highly unlikely, especially since it is stated earlier in the article that helium is non-narcotic. Looking at older versions of the chart say "sense of levitation". I think this is clearer, and that the article should be reverted to this wording. Mykal (talk) 13:53, 6 October 2016 (UTC)

What it actually says is Sense of impending blackout, euphoria, dizziness, levitation, manic or depressive states. It depends how you read it - It could mean: Sense of impending blackout, sense of euphoria, sense of dizziness, sense of levitation, sense of manic or depressive states, but I agree that it is ambiguous and could be improved. • • • Peter (Southwood) (talk): 18:52, 6 October 2016 (UTC)
I've changed the table in Signs and symptoms to read "Sense of impending blackout or of levitation". Does that remove the ambiguity? The table, by the way, is reporting symptoms when breathing air, not a helium mixture. For most people breathing air at 90+ metres, narcosis will be a crippling impairment and I have little doubt that the source [1] accurately reports that divers have felt a sense of levitation. --RexxS (talk) 22:00, 6 October 2016 (UTC)


  1. ^ Lippmann, John; Mitchell, Simon J (2005). "Nitrogen narcosis". Deeper into Diving (2nd ed.). Victoria, Australia: J L Publications. p. 105. ISBN 0-9752290-1-X. OCLC 66524750. 
Now less ambiguous. I assume these are symptoms reported from a chamber, as in water I would have difficulty distinguishing between a sense of levitation and the completely normal sensation of floating at neutral buoyancy. I would also consider Mitchell a reliable source. • • • Peter (Southwood) (talk): 08:36, 7 October 2016 (UTC)


Narcosis results from breathing gases under elevated pressure. This is a gross oversimplification, as there are several anaesthetic gases which are effective at normal atmospheric pressure when mixed with sufficient oxygen to sustain life. Nitrous oxide and Xenon are just two of them. I am not sure whether this was intended to refer to gases which are not generally considered narcotic at atmospheric pressure, or to the proportionality of narcotic effect to partial pressure of the gas. Either way it should be clarified. I would do so myself except not sure what was intended. • • • Peter (Southwood) (talk): 09:18, 26 December 2016 (UTC)