Diving Deeper

[rstone]

Originally posted by uwsince79
And the next time some diver tells you he built up a tolerance to N2 you can laugh and know he is narc-ed on the surface and you know to swim the other way.

And next time some diver on some message board tells you that nitrogen narcosis affects us ALL the SAME you can know he is narc-ed and go the other way.

Now for your info..

"Nitrogen narcosis can become a very serious adversary on deep air dives. Although we can acclimatize ourselves to the affects of narcosis to some extent by regular exposure to depth."

And for Walter.. ac·cli·ma·tize - To adapt (oneself), especially to environmental changes.

"Nitrogen narcosis affects every diver differently, but a test conducted in the 1970s found that at 100 feet, 100 percent of divers were narced to some degree."

"Nitrogen narcosis is a highly variable sensation but always depth-related. Some divers experience no narcotic effect at depths up to 130 fsw, whereas others feel some effect at around 80 fsw. One thing is certain: once begun, the narcotic effect increases with increasing depth."

"Beginning at a depth of about 100 feet, most air-breathing divers experience a slight feeling of euphoria that progresses upon descent. This condition is termed nitrogen narcosis. At depth, nitrogen produces the same effect on the central nervous system that nitrous oxide, a gaseous surgical anesthetic, does at sea level. The degree of euphoria experienced from either gas depends only on the gas's partial pressure and responds immediately to changes in partial pressure"

"Training your body by diving deep repeatedly can create a specific tolerance to nitrogen narcosis. If you build up to a deep dive over a week by making the first dive of each day progressively deeper, you'll be far less likely to become narced. That tolerance dissipates within a week or so, however. But even on a single dive you may be able to achieve some tolerance. If you become narced, you can ascend 10 feet or so and the narcosis will likely go away in a few moments. Then, many divers can return to the original depth with no narcosis.

Discipline may be your best antidote to nitrogen narcosis. If you concentrate and stay focused, you can probably overcome the worst of its effects. For example, in studies of nitrogen narcosis where divers are required to perform arithmetic problems at various depths, highly motivated divers can concentrate so intensely that they perform nearly as well at depth as at the surface - despite their narcosis. Discipline also means planning your dive and being determined about following your plan. It means watching your buddy and watching your instruments. It means staying alert to signs of narcosis and immediately ascending until they go away. And if you have repeated trouble with nitrogen narcosis, discipline means accepting the fact that you are unusually sensitive to it and that your personal depth limit must be 60 feet, 90 feet or whatever."



Organizations

American College of Hyperbaric Medicine. P.O. Box 25914-130, Houston, TX 77265. (713) 528-5931. http://www.hyperbaricmedicine.org.

Divers Alert Network. The Peter B. Bennett Center, 6 West Colony Place, Durham, NC 27705. (919) 684-8111. (919) 684-4326 (diving emergencies). (919) 684-2948 (general information). http://www.diversalertnetwork.org.

Undersea and Hyperbaric Medical Society. 10531 Metropolitan Avenue, Kensington, MD 20895. (301) 942-2980. http://www.uhms.org

REFERENCES AND BIBLIOGRAPHY

See references Sections b-e, plus the following (*Especially recommended).

*Edmunds C, McKenzie B, Thomas R. Diving Medicine for Scuba Divers. J.L.
Publications, Melbourne, 1992.

*Gilliam B, Von Maier R. Deep Diving. An Advanced Guide to Physiology,
Procedures and Systems. Watersport Publishing, Inc. San Diego; 1992.

Lanphier EH. Carbon dioxide poisoning, in Waite CL, ed., Case Histories of
Diving and Hyperbaric Accidents, pages 199-213.

Lanphier EH, Rahn H. Alveolar gas exchange during breath hold diving.
J Appl Physiol 1963;18:471-477.

Lanphier EH, Rahn H. Alveolar gas exchange during breath holding with air.
J Appl Physiol 1963;18:478-482.

Lanphier EH. Breath-hold and ascent blackout. In The Physiology of Breath-hold Diving,
UHMS Pub. No. 72(WS/BH) 4/15/87, pages 32-43.

Leitch DR. A study of unusual incidents in a well-documented series of dives.
Aviation, Space, and Environ Med 1981;52:618-624.

*Lippmann J. Deeper into Diving Aqua Quest Publications, Inc., New York, 1992.

*Lippmann J. The Essentials of Deeper Sport Diving. Aqua Quest Publications,
Inc., New York, 1992.

Martin L. Hypercapnia Revisited. Sources, Journal of the National Association
of Underwater Instructors. November/December 1994, pages 52-54.

Alberts, Bruce, et al. Molecular Biology of the Cell. 4th ed. New York: Garland, 1994.

Alliance Pharmaceutical Corporation. "Current Therapies for Acute Respiratory Failure." http://www.allp.com/lv_sum.htm (29 March 1999).

Brylske, Alex, et al. The Encyclopedia of Recreational Diving. 2nd ed. Santa Ana: PADI, 1996.

Campbell, Ernest S. "Arterial Gas Embolism." Diving Medicine Online. http://www.scuba-doc.com/artgsemb.htm (28 March 1999).

"Inert Gas Summary." http://www.cisatlantic.com/trimix/aquacorps/mix/MixBox.htm

Rudge, Frederick W. "Effects of Decreased Pressure: Decompression Sickness." Southern Medical Journal, Volume 38, No. 2, pages 228-9, February 1995.

United States. National Oceanic and Atmospheric Administration. Department of Commerce. "Inert Gas Narcosis." http://uwsports.ycg.com/reference_library/noaa/section_03 (9 March 1999).

 

[Walter]

rstone, thanks for the defination, but when you come across a word you haven't learned yet, don't post the defination on my account. I do sometimes stumble over the big words, but I did already know that one and I can look them up myself. I tend to have more difficulty following meanings when the wrong word is used. Examples would be "of" instead of "have" or "there" instead of "their" or even "then" instead of "than." I can usually puzzle them out as well, but if there are too many substitutions it can be a chore.

WWW™

 

[rstone]

Originally posted by Walter
rstone, thanks for the defination, but when you come across a word you haven't learned yet, don't post the defination on my account. I do sometimes stumble over the big words, but I did already know that one and I can look them up myself.

I probably should in your case walter, I wouldn't want to give you the wrong defination.

def·i·ni·tion - a statement expressing the essential nature of something.

 

[uwsince79]

Since you like to foot note I shall give you mine.
1. EB Smith on the science of deep-sea diving, observations on the respirations of different kinds of mediums.
2.jj. meyers Hand book of ocean & underwater engineering
3. Shilling: The underwater handbook
4.NOAA Manual 4th edition
5.US Navy Manual
Bennett's :The Physiology and medicine of diving
6.Gortan's Deep diving hydrogenated breathing mixtures
7. Minimum breathing gas requirments London Ass. of Offshore Diving Contractors. & Heinz's Mixed Gas Diving
8.SUT's Developments on Diving Technology
9.Use of Inhert Gasses by Offshore diving contrors LAODC
10. Professional Divers Handbook
11.Commercial diver Training Manual College of Oceaneering
12.Royal Navy Diving Manual
13.Oxy-helium diving tables from the UEG Group Report of 78
14.Vann's Decompression theory and application
15. Heine's Scientific Diving Techniques
16.Kaster's Ocean Salvage
17. Exploring Ocean Frontiers
18.Darby's Conquering the Deep Sea
19. Lippmann's Deeper into Diving
20.The Principles of Safe Diving practice UEG report UR23
21.Rafis's Technical Gude to Gas Blending
22. Gentile's Technical Diving Handbook
23. Diving Supervisors Manual ODC 1986
24. Imbert's Safe deep sea diving using hydrogen. MTS Journal vol. 23 # 4 dated 1989
25. last but not lleast which really did not add much to anything but I'll post it any was was Brylske's Beating the bends
So here you have some reference to the material.

 

[miked]

I realize that any endeavor as complex and varied as diving creates many areas where strong, and conflicting opinions can arise, but can we just "cool it"?

Perhaps I'm too new at this web thing, but the tone of this thread, and a few others, seems to be sliding downhill, towards what some would consider personal attacks, p***ing contests, or (God help us) flame wars.
I don't know "who actually knows who" , in real life , and I may be coming late to an ongoing battle of wits(?) , but it is neither fun nor informative to read these type BS contests.{Yeah I know, "if you don't like it-don't look",but that is precisely the reason I like this dive related Board and don't spend much (any?) time looking at others.}

I also wonder if anybody who reads these type exchanges is reluctant to post, fearing that a typo, spelling or grammar error will be ripped to shreds, instead of the content being addressed. As a Board that seems to take pride in the growing number of members, should we not consider how to not scare people away- or intimidate new members?

I would assume that the first step is self control, and lacking that, then "imposed control", and lacking that.."just another trash talking board"....??
Admittedly, the level is far from that last description, but as the first domino falls....
Am I alone in this feeling, or do others agree?

Miked

 

[uwsince79]

With everything I have read and studied on Narcosis I feel you are incorrect. (I am very opinionated) You cannot build a tolerance to it period, What you can do is to be able to function with LEARNED TASKS quite effectively while under the “rapture of the deep.” Yes EVERY diver is under the effects of narcosis at 2 bars or better. It is a law of physics. The question is how you handle it. My wife has two glasses of wine and she cannot function. I drink 2 glasses of wine and since I have been drinking wine since I was a little boy it does not have the same effect. Are we both under the same amount of alcohol? Yes. Would we on a BAC test be considered impaired? Depending on the state, Yes. The same holds true of N2, just because you don’t feel it you cannot say you are not under its effects. Remember the currently accepted hypotheses explain that effects of nitrogen are based on the swelling of nerve cells by the gas under pressure. It is believed that there is a correlation between the narcotic effects and the solubility of the gasses in question with in the tissues of the nerve cells. If this is the case how on earth do you build tolerance to it? Plus varying conditions in the body will give varying effects of narcosis at different times. Knowing that it is believed to be liquids that affect the range and effect of the gas, what if you were dehydrated, would this not change your levels of “feeling” the narcosis? Diving with the notion that you are in control of narcosis is not smart. (I am not calling anyone on this board “not smart” I am making a general observation.) Understanding it’s effects just helps you in better dive planning. After recent events that I have personally have had I will not dive deep on air ever again, you do not know the level of narcosis you are under until you dive the same dive you have dove quite a few times on air with a clear head, it is a wake up call. I too once in my life swore I built up a tolerance to it, but after much research and actually physically seeing the difference, I can attest you do not build any tolerance to it at all even after 20+ years and thousands of dives. (I know this statement is going to light the board on fire but so be it.) What I feel we all must be opened to is that technology is allowing us a great understanding of the effects of pressure on the diver, and we must readily adapt and accept change, for it will just make the dives safer and more enjoyable.

 

[uwsince79]

All, I am not mad or upset nor arguning with anyone. R posted some of his reference and I thought I would do the same. Although I am not as will written as he, I still do my homework and do quite a bit of studying on diving and releated topics. Please do not read my words with anger in any way it is not how I wrote them. For some reason when I post pepole seem to think I am angrey witch is not the case at all. I don't even know any of you on this board except for one diver, how could I get angrey unless what was written could harm someone or is an outright attack. Which this is neither. Just two point of views from to different divers.

Have a great day...

 

[Liquid]

Originally posted by NetDoc

Secondly, Liquid, inert means just that... not reactive. While our bodies do not seem to react with nitrogen many chemicals will. Look at all the nitrides and such. I don't think you can name one compound using helium or argon... they just don't combine with other elements. They stay the same, while nitrogen does not! Only the noble gasses are considered truly inert!

It's more or less what I said netdoc.

Narcosis is a fact for EVERY air and NitrOx diver, especially below 90ft!

Ill have to check on this, but I dont think it is true for several reasons. The toxic affects of oxigen are different than those of niterogen, and in any case, they are not cumulative. I'm quite sure about it, but I will check with more knowlegable people than me.

 

[rstone]

Originally posted by miked
I realize that any endeavor as complex and varied as diving creates many areas where strong, and conflicting opinions can arise, but can we just "cool it"?

Perhaps I'm too new at this web thing, but the tone of this thread, and a few others, seems to be sliding downhill, towards what some would consider personal attacks, p***ing contests, or (God help us) flame wars.
I don't know "who actually knows who" , in real life , and I may be coming late to an ongoing battle of wits(?) , but it is neither fun nor informative to read these type BS contests.{Yeah I know, "if you don't like it-don't look",but that is precisely the reason I like this dive related Board and don't spend much (any?) time looking at others.}

Normally i would never engage in a p***ing contest with anyone on this board. I do not claim to be a expert or know it all, and I was more then content just engaging in a healthy debate on the effects of narcosis, however some felt it necessary to engage in a battle of wits with there sly, and obscure comments.

However It is a common theme on this board that several of the people on here who are very opinionated, must thrust there views down peoples throats while belittling other peoples opinions in the process because they may not be as well versed on a subject as they are. While it may not be to provoke another, it is often taken that way. While it may be fun to some to make jest of anothers lack of knowledge on a subject, it is neither productive or healthy.

With all that being said. I will drop it, and I apologize to those who have had to partake in this unnecessary event.

 

[Lost Yooper]

I'm not too sure I want to get into this, but in response to the nitrox and narcosis thing, based on everything I've seen, no one seems to know anything for sure. Yes, O2 is narcotic, but at what PPO2 and to what degree? Most evidence seems to point to PPO2's greater than 1.6 and even then it's not entirely cummulative. There have been studies showing nitrox being no less narcotic than air at the same depth, but likewise there are studies and interviews of divers that claim significant reduction of narcosis (which is my experience).

IMO, narcosis can't be dealt with RELIABLY, and there's enough research and dead bodies to support this. The entire idea of "just ascend and it will go away" is utter madness I think. What if you have a problem and can't just go up? Just use your imagination. The entire "deep air is safe" arguement seems to stem from a dive going perfectly.

Helium disadvantages: cost and availability. You can handle the deco by utilizing the right programs, and the cold with argon (again cost).

Mike