DAN says you get one or the other.Maybe its just because I'm "old" but my old bones really prefer the added safety and added bottom time of nitrox...
http://www.daneurope.org/web/guest/...ategories=&p_r_p_-1523133153_commaTags=doctor
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DAN says you get one or the other.Maybe its just because I'm "old" but my old bones really prefer the added safety and added bottom time of nitrox...
Here is one study
Evaluation of critical flicker fusion freq... [Diving Hyperb Med. 2010] - PubMed - NCBI
This thread discusses this and another study if anyone is interested
http://www.scubaboard.com/forums/diving-medicine/460403-silent-bubbles-fatigue-tiredness.html
I don't think these studies address what Skittles' instructor was talking about. These relate to fatigue caused by sub-clinical bubbles, not to the idea that taking a full-blown DCS hit can be made stastically less likely by diving Nitrox on air tables. If I understood correctly, her instructor believed that the statistical likelihood of taking a DCS hit on air is already so low that any reduction in the likelihood that might be achieved by diving Nitrox on air tables is statistically insignificant. My guess is that gathering data to study this in a controlled way would be exceedingly difficult. But I suggested posting over on the Diving Medicine branch to see if anyone from DAN or Duke Dive Medicine might weigh in.
I agree with her instructor fully, and that statement is included in the training materials for at least some of the certifying agencies.
Let's look at the statistics. The statistical likelihood of you getting bent on a recreational dive while breathing air is something like 0.001%. How much safer can you make that by using nitrox on an air profile? Even if you make it twice as safe, you are changing the likelihood of getting it by 0.0005%. Congratulations.
I don't think these studies address what Skittles' instructor was talking about. These relate to fatigue caused by sub-clinical bubbles, not to the idea that taking a full-blown DCS hit can be made stastically less likely by diving Nitrox on air tables. If I understood correctly, her instructor believed that the statistical likelihood of taking a DCS hit on air is already so low that any reduction in the likelihood that might be achieved by diving Nitrox on air tables is statistically insignificant. My guess is that gathering data to study this in a controlled way would be exceedingly difficult. But I suggested posting over on the Diving Medicine branch to see if anyone from DAN or Duke Dive Medicine might weigh in.
I agree with her instructor fully, and that statement is included in the training materials for at least some of the certifying agencies.
Let's look at the statistics. The statistical likelihood of you getting bent on a recreational dive while breathing air is something like 0.001%. How much safer can you make that by using nitrox on an air profile? Even if you make it twice as safe, you are changing the likelihood of getting it by 0.0005%. Congratulations.
If you are that person in the 0.0005% it becomes very important.
For me it doesn't matter that much, for my wife, perhaps essential to allow her to continue to dive
That's too bad that an instructor says something like that.The longer I'm in diving, the more I've been around people who've experience DCS. Maybe its just because I'm meeting more serious divers but, I'm beginning to think that my earlier thinking was far too cavalier. Because, I thought like your instructor-DCS is really rare so it will never happen to me. Guess what, DCS has happened to lots of my friends and I think it may have happened to myself and I don't even know it.Whether there have been studies of the benefits of diving Nitrox on air tables would be a good question to post over in the Diving Medicine branch. It's sound logic that there would be benefits, but whether the difference has actually been found to be statistically significant in a study is a good question.
Sorry Lorenzoid, I thought you meant studies showing any ​benefit.
---------- Post added July 23rd, 2013 at 07:48 PM ----------
I have to agree with Peter69_56 on this. If you are one of the majority of divers with no known increased risk of DCS the reduced DCS with nitrox is not significant and if you are using it solely for that benefit it's probably overkill.
But for those of us at known increased risk, I feel the statistics are skewed. The more relevant statistic would be a study with a subgroup of divers with known risk factors for DCS that compared nitrox vs air. I'm not aware of such a study but I am suspicious that it would indeed show a greater statistical significance.
The fact that DAN recommends nitrox on air tables to such divers also leads me to believe that would be the case as well.
My wife took a small hit while in PNG. She thought it was just a rash, and I argued it was DCS. She wouldn't have it. I managed to talk her into using Nx if she was going to continue diving and she did have a half day break during the period too. She showed no indications of another hit during that period. that on its own is not conclusive.
We then went to Brunei and did deco diving over 10 days, after day 4 she took a hit, but once again it was not obvious that it clearly was a hit. Day 6 saw a clear and obvious hit with associated pain. Looking back, it became clearly obvious that 2 days previous it was DCS and in PNG as well (same skin symptoms just larger area). I believe the PNG incident was caused due to continual diving and nitrogen build up with no break days. The half day break and Nx usage allowed her body to clear the nitrogen loading and thus no additional hit at that time.
This is actually pretty text book! And so many people dismiss the "skin bends" the fact is that skin bends often become more serious in nature with neurological symptoms presenting hours or even days later!