Scuba Nitrox Incident for Analysis

[OTF]

Spontaneous PFOs are most commonly seen in novice spearfishermen

 

[VikingDives]

Kind of like spontaneous human combustion?

 

[wetb4igetinthewater]

Spontaneous PFOs are most commonly seen in novice spearfishermen

any supporting evidence of that? Just asked a doctor with some hyperbaric training who had never heard of it. So I'm a little skeptical.

 

[JohnN]

No to get too far off topic but this is a very common myth about nitrox and I would argue that oxygen is even more narcotic that nitrogen.
molecular weight Oxygen 15.999 g/mol
molecular weight Nitrogen 14.0067 g/mol
molecular weight Helium 4.002602 g/mol

I've heard that theory, but riddle me this, a rebreather dive can be at a PPO2 of 1.4 in 15 feet of water. If the concentration of O2 in what your huffing can be linked to narcosis, then why are rebreather divers not always loopy? I know, I know, hold off on the cheap and obvious joke. . .

 

[VikingDives]

I've heard that theory, but riddle me this, a rebreather dive can be at a PPO2 of 1.4 in 15 feet of water. If the concentration of O2 in what your huffing can be linked to narcosis, then why are rebreather divers not always loopy? I know, I know, hold off on the cheap and obvious joke. . .

Edited out, because well, I didn't say what I meant to say

 

[Wibble]

I've heard that theory, but riddle me this, a rebreather dive can be at a PPO2 of 1.4 in 15 feet of water. If the concentration of O2 in what your huffing can be linked to narcosis, then why are rebreather divers not always loopy? I know, I know, hold off on the cheap and obvious joke. . .

Assume 15' = 5m

Dose / pressure = mix = PPO2 1.4 / 1.5bar = 0.93 = 93% O2

Oxygen clock at 1.4 is 150 mins = 2.5 hours.

No narcosis at 5m/15'

 

[tursiops]

Oxygen's narcotic effect is oxygen toxicity.

Did you say what you meant to say? Those are quite different things. One is sedational, the other is the opposite.

 

[VikingDives]

Did you say what you meant to say? Those are quite different things. One is sedational, the other is the opposite.

No, you're quite correct.

 

[kammel78]

I've heard that theory, but riddle me this, a rebreather dive can be at a PPO2 of 1.4 in 15 feet of water. If the concentration of O2 in what your huffing can be linked to narcosis, then why are rebreather divers not always loopy? I know, I know, hold off on the cheap and obvious joke. . .

Please don't confuse partial pressure with FG.

Once more; a PFO causes circulation problems which would mean low oxygen levels, being out of breath?

PFOs can spontaneously happen. Lots of experienced divers suffer, typically a bend (which is caused through inefficient off-gassing), and discover they've a PFO and can't dive until it's fixed.

In the case of this hypothetical, the diver is out of breath underwater when they've been stressed and working hard. It's an NDL dive, with a rich mix, so no ceilings breached. After calming down and relaxing, the oxygen levels rise.

All I'm saying is that a PFO could fit these symptoms, but it's unlikely to be "the answer".

I'm confused as to why if you are admitting it's unlikely the answer that you would bring it up in the first place? Again, one of his lungs spontaneously disappearing and then reappearing could fit these symptoms but it's unlikely to be "the answer".

 

[Wibble]

On the first post in the video, the guy sets a hypothetical scenario. There’s lots of possibilities for causes, one could be a PFO. That’s all.