Nitrox: Narcosis myth?

[tarponchik]

while simultaneously demonstrating a... let's say "rather unconventional" outlook on things that the majority regard as pretty well established.

The majority being you and...she/he/it the @RainPilot? Or I forgot someone?

 

[tursiops]

The majority being you and...she/he/it the @RainPilot? Or I forgot someone?

You forgot me. I disagree with you on nearly everything,

 

[tarponchik]

You forgot me. I disagree with you on nearly everything,

Oh right, the marine scientist! How could I forget. Now 3 is already a crowd. You guys can get courage from your numbers.

 

[BRT]

But in his case it was a sale, not an oversale. Nitrox did exactly what it is supposed to do: increased bottom times safely.

Wookie would have to say, but I didn't understand from what he said that it increased bottom time, just reduced DCS to nothing. Once again, less DCS stress MIGHT make people feel less fatigued.

 

[NAM001]

There's no academic proof there is an positive effect from using higher percentage of O2. That does not mean it is not there, just there no academic prove either positive or negative, yet.

What could be is that you're a 'CO2 retainer'. Which means your body is absorbing CO2 easy or is not efficient in releasing CO2. I know, because I'am on the same boat. I have a very very slow breathing rhythm while diving (very low gas usage). Higher O2 percentage probably helps me to reduce CO2 build up, and therefore I feel better after the dive. Nitrox works for me too. Scientifically proof or not, I don't care

The point you make is a good one. because what is heard or read too often are statements that speak as if they are gospel. "This applies to all". Any one that thinks they get benefits are just that.... ones that THINK they get benefits. I too often hear that its the CO2 that drives breathing. I believe that also. the question needs to be move to what drives the CO2 buildup. After all body metababolic process generates the CO2 and the resparatory system flushes it out in exchange for non CO2 gas. Not Oxygenated gas but Non CO2 gas. If that exchange is done is not done efficiently (having say reduced lung capacity) then the CO2 build up removal is lacking and you breath more to increase the flushing cycles and consume more gas. All too many IMO speak from the metobolic side of the equation and not the others. Very much like a plane will get you form NYC to LA faster than a car ,,,,,,,,,Unless the plane only makes that flight once a month, in which case you can get there driving faster if driving between scheduled flights (that are not taken into consideration) when these blanket rules are made or passed along.. Its all a point of reference i guess. So those that say a tank of nitrox lasts longer than a tank of air may not only be founded but may be a symptom of a health or technique issue. To many times we hear on posts that your sac will improve with comfort. And it should,,,,,, Our health has to be a limiting factor to just how low that sac can go and the body still remain ballanced as in a rest condition.. Not every thing can be blamed on trim, technique, current, and comfort. The very items that everyone wants to point fingers at. I wonder what the difference would be if one did equal dives being a smoker and then not being a smoker. what tank would last longer.

 

[tarponchik]

So those that say a tank of nitrox lasts longer than a tank of air may not only be founded but may be a symptom of a health or technique issue. To many times we hear on posts that your sac will improve with comfort. And it should,,,,,, Our health has to be a limiting factor to just how low that sac can go and the body still remain ballanced as in a rest condition.. Not every thing can be blamed on trim, technique, current, and comfort. The very items that everyone wants to point fingers at. I wonder what the difference would be if one did equal dives being a smoker and then not being a smoker. what tank would last longer.

I believe the efficiency bottleneck is not in the lung volume and not in the oxygen %% in the tank. I am a very slow breather myself, but I am also borderline polycythemic. I live as if I'm using blood doping. So for every breath I take my blood absorbs more O2 per cubic inch than the blood of an average guy and I need to inhale less frequently.

 

[tarponchik]

Wookie would have to say, but I didn't understand from what he said that it increased bottom time, just reduced DCS to nothing. Once again, less DCS stress MIGHT make people feel less fatigued.

Nitrox increased safe bottom times.

 

[BRT]

Nitrox increased safe bottom times.

Fair enough. But people were diving close to the line. Seems that close to the line nitrox might give less stress and less fatigue. Do you think this is unlikely?

 

[NAM001]

I believe the efficiency bottleneck is not in the lung volume and not in the oxygen %% in the tank. I am a very slow breather myself, but I am also borderline polycythemic. I live as if I'm using blood doping. So for every breath I take my blood absorbs more O2 per cubic inch than the blood of an average guy and I need to inhale less frequently.

Interesting,, hard to reconcile the aspect of CO2 driven breathing with your situation.

 

[beester]

I would run, not walk to the nearest neurologist if I were you. Not remembering taking photos when you get back on the boat is probably not because you were breathing air at 130 feet. There is no secret ingredient in nitrox that relieves fatigue nor narcosis, but if it feels good to you then go for it.

Obviously one persons experiences have no relevance to science, they don't proof anything but here goes. I have done deeper air dives (max about 200ft/60m), and some even with reasonable bottom times (no where near what I'm doing now but still no bounce dives). After an episode which in fact wasn't so deep but put the fear of god into me, I moved into team based tech diving (GUE). Some of my experiences:

- Doing a 150ft air dive my buddy at the bottom signs to me to take over the lead of the dive. I do but put out a questionmark because I don't understand why... and he shows me his computer (a galileo sol with a bunch of information on). I'm making a real effort to check his computer for at least 20-30 seconds but I can't make out why he wants to hand over the lead of the dive to me. So we continue the dive and during deco at 30ft I ask him to show me his computer again. Immediately I notice that his current depth is fixed at 96ft. So I was fine doing a normal dive but whenever my "computing power" (ie brain) was needed at depth I just couldn't compute that his computer had crashed and the depht was fixed at 96ft while we were at 150ft. Something I noticed immediately at 30ft. I might be a dumb **** but not that dumb.

- I've had the opportunity to revisit some of the deeper wrecks that I dove on air in the past (150-200ft) but now with trimix. Of course memory is impacted not just by narcosis but also by time. I tend to have a very visual memory and my memory of those wrecks were in detailed shots of those wrecks but not a full wide angle view of the wreck. I also thought the wrecks to be in very good condition. Re-diving them on trimix I noticed that they were much more broken down than I remembered and funny enough I 'm now remembering these wrecks in wide angle (full view) and less the details. Meaning my recollection after a trimix dive is very different then after an air dive.