Talk:Shallow water blackout

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• Original author comment. I have now developed more detailed treatment of Deep Water Blackout and have split this off as new article in its own right. Consequently cut it out of here and interlinked. Better this way. Ex nihil 01:53, 31 January 2006 (UTC)

OK, Night Gyr has put an OR on this. This is pretty common knowledge and I'll put some refs in when next me and my library are in the same place. If anyone else can put some in that would be good. I would have thought that some of the External link references would have been sufficient, US Navy not authoritative enough? PADi or FAUI dive manuals would probably do if anyone knows haoe to cite them. Ex nihil 04:36, 28 February 2006 (UTC)

Well, you include diagrams that you admit have created yourself, and you make numerous specific assertions and recomendations without reference for them. That's why I"m calling it OR. I shouldn't have to read all the external links just to know if anything you're saying is accurate or not, and if something was common knowledge, why have I never heard it before? Also, the advice section, as written, goes against WP:NOT. We're not an instruction manual, so it needs to be written as facts, not advice. Night Gyr 16:29, 28 February 2006 (UTC)

• Ex nihil 00:03, 1 March 2006 (UTC) I have recast the advice to divers to read as facts. I have added section References and I will put in some references when I have some time with my library , which is not where I am typing this. Maybe this weekend. No problems citing references but if you have a good source please put it in. Note that the last time I looked at the PADI open water manual it used the term 'shallow water blackout' to mean a decompression blackout as for deep water blackout and doesn't have a term for the phenomenon here because it doesn't usually affect scuba divers. The terminology is rather confused but I think it is dealt with adequately in the two articles, deep and shallow water blackout.

Contents 1 Brown-out? 2 The breathing drive 3 Deletion of Image:SWB3 temp.jpg 4 Repetition

[edit] Brown-out?

I can find no medical reference for this term, and I am not sure what precisely is meant. Near-blackout? Confusion? Dizzyness? Any of the above? 208.20.251.27 21:51, 7 June 2006 (UTC Ex nihil 01:28, 9 June 2006 (UTC) Yes. Exactly that. Usualy what is noticed is the vision dimming, hence 'brown-out'. You have probably experienced it yourself from time to time on standing up suddenly, probably when you are sick or severely hungover. Is is a common term in flying to describe the experience of pulling heavy Gs, the opposite being red-out for pushing negative Gs. Ask your GP, he'll know immediately what you are talking about.

Could this please be exaplained in the article? I have some knowledge of shallow water blackout, but have never seen anyone speaking of brown-out. Thank you. --hhanke 22:18, 16 June 2006 (UTC)

Ex nihil 09:45, 19 June 2006 (UTC) There is now a link in text to a new brownout stub.

[edit] The breathing drive

This article states that there is no O2 detection in the body. There is in fact O2 detection, and the strongest breathing drive in a person is the O2 level. I'm an EMT-Paramedic student and part of my hospital OR clinical rounds required me to know this for people on ventilators. The CO2 drive to breath triggers first, at approximately 40-45% CO2 level. Severe COPD patients have gone so long with high CO2 levels that their CO2 drive diminishes, sometimes completely, and in that case the drive to breath is triggered by the O2 level in the blood, at approximately 60% O2. This is dangerous, as anything below 85% is severe hypoxia.

Hyperventilation blows off the CO2 level too fast, and the person is unconscious long before their O2 drive kicks in (a person can maintain an O2 saturation in the 90's% for several minutes after they stop breathing, then it falls fairly fast).

Also, I don't know if its universal or not, but both SSI and NAUI SCUBA books stress very highly the importance of not "skip breathing" or not hyperventilating then holding your breath while underwater.

If I can get ahold of the books the Anesthesiologists had me reading this up on, I'll put in some sources.

• That is interesting, 'though I suspect that you have hit upon an exceptional case with your COPD patients. If it is true that they can detect low O2 then is this ability available to anyone else? And if so where in the body is it detected? Not in the carotid sinus. My background in this is flying. In training we were put into a hypobaric chamber and taken up to 20,000' breathing O2 via mask. One of us was on air from groundlevel up but we didn't know which one, we had to guess. Nobody did of course, we had to wait until the person flaked out. Then we were given tasks while our O2 was changed to air. Undetectable. The point of the exercise being to drum into us that if we have a slow depressurisation and we haven't been watching the cabin altitude, unconsciousness is the first symptom and that there is no way to detect low O2. All those sumariners gasping in the sunken sub are gasping because of CO2 buildup, they may or may not have enough O2. This was reinforced when caving in wet limestone. The limestone breaks down to CO2 so we pant. We can tolerate this provided that we know there is still O2 in the air, sometimes there isn't. With no way to tell, panting away, we had to use expensive instruments to tell us we could continue safely. A rather cheap and dodgy way is to carry a candle and check it's still burning well. Having said all that, however, I have always been puzzled why, when climbing at high altitude we pant heavily. In theory the low ppCO2 should suppress panting and the only symptom should be that our muscles don't work, which they don't, and we have brownouts, which I haven't personally, yet here we are gasping, that must indicate that our bodies know something, somehow. Workers in sewers and ship holds have similar training on the undetectability of anoxic conditions. I would love to see this all spelled out, maybe in another article, let us know if you get it sorted but in the meantime I think what is written should stand. Ex nihil 06:05, 5 August 2006 (UTC)

[edit] Deletion of Image:SWB3 temp.jpg

There have been several attempts to delete this image. If you feel the image is inappropriate please discuss it here first. Let me explain why it was created:

It was created originally to illustrate shallow water blackout and it was later appropriated by others for drowning, which is fine. The purpose was to illustrate how such drownings really appear. The traditional image of drowning involves the splashing, waving and shouting that one has come to expect from the movies; in reality victims usually go silently and without visible struggle to attract attention and in pools are discovered exactly like in this picture. The pool that hosted the picture actually had a shallow water blackout incident two years before this staged picture and the photograph shows exactly how it was discovered. The person in the picture and myself have an interest in explaining shallow water blackout, the picture is unpleasant, perhaps even shocking but it is very accurate; if you are unfortunate enough to discover a drowning in a pool this is how you will find it and this is what you should look for, the pool lifesavers look for this. The picture was also taken to contrast it with the mechanism for deep water blackout, see the partner image in that article. The picture is not added to be macabre, it is there to illustrate and explain. If you do have reason to object to it please disuss the matter first before deleting it. Ex nihil 12:24, 7 August 2006 (UTC)

For some reason I remember when you added that picture o_O you posted it on the misc help desk or something. Anyway I think the image isn't overly "shocking" and that the moribund girl is even appropriate to the somewhat ghastly topic of the article, and of course the water looks very cool =) In fact, call me weird but I think I have this photo in My Pictures o_o Very good article by the way- esp the diagrams. It's definately on its way for featured! --Froth 21:04, 29 August 2006 (UTC)

I think the picture is certainly a good one. However, consider the audience of this page. They might, perhaps, have known someone who recently suffered from a shallow water blackout and died. They may wish to find out more about the phenomonon. However, they find this picture and it could have a damaging effect on them.

Then again, if they're looking up this article in the first place, they should probably expect to find some shocking information. Psychade 15:09, 11 September 2006 (UTC)

I don't have an ongoing interest in the article - just happened by while learning about increasing your lung capacity, but the picture struck me as odd and at first I honestly thought it was a really poor-taste act of vandalism. The picture could be useful in illustrating the lack of any kind of panic or struggle (although a dead body looks lifeless whether the cause was panic in the water or blacking out) but the caption "Victims go quietly, often unnoticed." sounds a bit too much like a horror movie tagline. Reworking the caption and locating the block "below the fold" where the article mentions that there is little warning before the victim blacks out may make the illustration more useful and appear less intended for shock value. Jzerocsk 15:19, 5 January 2007 (UTC)

Jzerocsk, actually the caption was a quote from a child safety advertising campaign either by the Autralian RSLSA or my the Northern Territory Childsafe. Anyway it's changed now. Ex nihil 02:14, 3 February 2007 (UTC)

The image has been reversed by me and the old image is orphaned. This may not completely help, but the old view is now ready to be deleted, with the new version completed. Catherine Woods 00:39, 3 February 2007 (UTC)

[edit] Repetition

There is a lot of material in common with deep water blackout, particular with the explanation about hyperventilation. Why not just combine the two into one article? Stevage 05:38, 5 March 2007 (UTC)

• It is true that SWB and DWB are closely linked but I would counsel against combining them into one because they describe two quite different events even though they both end in unconsciousness. The two pictures were meant to try to illustrate the different nature of each one. Articles don't need to be mutually exclusive, better that they make sense in themselves without too much linking out to tell the story. DWB can occur without any hypocapnia at all, SWB is dependent on it. DWB started out as a subset of SWB and this caused a lot of confusion, which seperating them solved, they work quite well as a linked pair. The only repeated element in DWB is item 3 Self Induced Hypocapnia. If they were to be combined what would the article be called? The two terms are used quite independently and people search for them independently. Ex nihil 07:08, 6 March 2007 (UTC)

Well, to be honest, the two articles as they stand confused me quite a lot. Merging two articles doesn't mean that they are synonymous - it simply means that they are best explained as a pair. In this case, something is obviously badly structured: there is a section on "deep water blackout" in the SWB article, and a section called "DWB vs SWB" in the DWB article. That's an awful lot of repetition. Perhaps you want to create one article called "Underwater blackout" which contains the general material and brief discussion of the difference of the two types, and then have separate articles which purely concentrate on the phenomena specific to each type? Stevage 11:30, 6 March 2007 (UTC)