Nitrox the Wonder Gas

[Thalassamania]

All that Bennett was saying was the small decrease in narcosis is not a good reason to use NITROX. But you need to take that statement in the context of the time and the NITROX controversy. I don't know how many of you remember when NITROX was "devil gas" and was seen by many as a "gateway drug" to such evils as deep diving and (gasp) decompression diving.

Let's remember that Bennett rarely seemed to put the interests of the diving public in front of his own, and this was his way of trying to save face finding himself on the wrong side of the issue. If I recall Bennett was one of the people who initially opposed the introduction of NITROX to the recreational community (lining up behind PADI, who also vehemently opposed NITROX, as was his usual style) and even went so far as to back up the folks who ran the Cayman Chamber when they erroneously claimed that would not know how to treat someone who'd been diving NITROX.

It turned out that the Cayman Chamber had made this claim at the behest of the Cayman Watersportsman's Association (the dive operators and dive resports) who first banned computers, and then banned NITROX making rather bizarre claims in the process that included the now famous, "you're 'gonna die." The CWA's problem with computers and NITROX turned out to have nothing to do with diving safety, it was that the increased bottom time meant longer trip's, slightly increased costs and, worst of all, interfered with the meal schedules.

Not everything about the "good old days" was good.

 

[Charlie99]

I am not Nitrox certified and I know little about it other then the basics(just from reading here). A question I have is this. If your body can not absorb more O2 then it already does on air how does one get ox-tox? Thanks ahead of time.

Hopefully some medical types will come along if my simplified version isn't right -----

Hemoglobin in the red blood cells is the main way of transferring oxygen. When people say "the body can not absorb more O2" they are referring to the fact that in a normal person, even at 1ata of air / 0.21ata ppO2, something like 98 or 99% of all hemoglobin molecules leaving the lungs have O2 chemically attached to them. In other words, the hemoglobin sat value is in high 90% range. Going to higher ppO2 won't add much more ability to transfer O2 via the hemoglobin.

Going to higher ppO2 WILL change the ppO2 of the O2 dissolved into the plasma/water portion of the blood, and also the ppO2 in water throughout the body. While the amount of O2 is much less (at normal pressures at least) than what is in the hemoglobin, this high ppO2 of dissolved O2 appears to be what interferes with the nervous system.

 

[TSandM]

Precisely right, Charlie.

 

[DandyDon]

I am surprised that the experienced Thal feels that way, as DCS is so rare anyway that Nitrox to reduce the chance of a hit is generally considered not applicable, but like Kraken suggests - it is going to help some.

On the other hand, I'll go along with String's position. It can be too costly in some places as well as limiting for some dive possibilities. $10/tank upgrade in Cozumel is discouraging so I'll generally include a tank on those multilevel dives only on a 4 dive day, but - when the cost is not discouraging, even a 28% mix would be helpful for recreational limits of 130 ft. For common recreational dive plans, it is a very helpful option to have, and I would also suggest a new diver spend the $100 to get the card & training so they'll have that option.

Can we agree to discount this one as mostly wrong? "Nitrox reduces narcosis," since the Oxygen that replaces it also has narcotic effects?

 

[RoyN]

Could never go back to Air. Yay Nitrox!

 

[String]

I am surprised that the experienced Thal feels that way, as DCS is so rare anyway that Nitrox to reduce the chance of a hit is generally considered not applicable, but like Kraken suggests - it is going to help some.

I dont think you can claim that. Statistically insignificant. In short, it may not help anyone at all, it could actually have no effect at all. *IF* there is any effect its absolutely tiny.

Can we agree to discount this one as mostly wrong? "Nitrox reduces narcosis," since the Oxygen that replaces it also has narcotic effects?

I'd have thought so. General consensus is (i) oxygen is as narcotic as nitrogen or (ii) oxygen is more narcotic than nitrogen depending who you follow. Its also generally accepted that narcisis is the cumulative effect of the partial pressures of gases in a mix so removing nitrogen but increasing oxygen will have little or no effect, possible make it slightly worse.

 

[Teufelhunden]

As a newly certified Nitorx diver (who hasn't used it yet) I took the class for two reasons:
1) I am planning a 7-day liveaboard trip and wanted longer bottom times with shorter SI.
2) I am a control freak, and would rather know about something, and decide not to use it, than simply be told I can't use it.

if nothing else, taking the class and learnign about why Nitrox leads to longer NDL, led to a better understanding of how and why nitrogen can cause the bends and the whole process of off-gassing.

 

[ianw2]

As a newly certified Nitorx diver (who hasn't used it yet) I took the class for two reasons:
1) I am planning a 7-day liveaboard trip and wanted longer bottom times with shorter SI.
2) I am a control freak, and would rather know about something, and decide not to use it, than simply be told I can't use it.

if nothing else, taking the class and learnign about why Nitrox leads to longer NDL, led to a better understanding of how and why nitrogen can cause the bends and the whole process of off-gassing.

Thank you for speaking for me!

Laura and I are Nitrox certified. We'll be diving on Nitrox in Cozumel in 21 days. We plan to do 15 divces over 5 days. Nitrox will help us reduce the nitrogen loading. It is NOT a wonder gas that will regrow hair, make my teeth whiter or imrove our sex life.

Ian

 

[Tigerman]

...
It is NOT a wonder gas that will regrow hair, make my teeth whiter or imrove our sex life.
...

Well forget it then! Im not signing up for nitrox class if its that crappy!

 

[Charlie99]

Laura and I are Nitrox certified...... It is NOT a wonder gas that will regrow hair, make my teeth whiter or imrove our sex life.

Don't know about the hair or teeth, but

Another Benefit of Nitrox? Feb 2006
In a recent issue we noted that there doesn't seem to be scientific evidence that Nitrox makes you less tired, but then we heard from a reader. "My husband and I had been diving for seven years. Each day of diving was usually the same. An awesome morning of two tank dives, back to the room for a hard 30 minute nap, on to more diving and more napping. Then we got Nitrox certified and something amazing happened. After two dives, we went back to the room and had sex. Yep, that's right, sex. Something that had never happened before the nap before that day. This wasn't just a one time thing. We actually had the energy to engage in this extracurricular activity each day after diving. We've been enjoying Nitrox ever since!" And, guess what? More readers have chimed in. Care to share your experiences?

http://www.undercurrent.org/UCnow/upwellings20060321.shtml