Nitrox: Narcosis myth?

[Alexandros]

Hello,

What I've been taught is that Nitrogen becomes narcotic at a certain partial pressure. So that by reducing the percentage of Nitrogen on the mixture we have less pp at the target depth, thus lower probability of narcosis.

So, could someone explain with simple words (I cannot really interpret the papers linked in this thread) why a Eanx32 mix for a dive at 30m does not reduce the nitrogen narcosis effect?

If nitrox has no relation with nitrogen narcosis, I'm also wondering why nitrogen narcosis is not observed in dives deeper than 40m with trimix, say 18/45 mix. Nitrogen is still present there, isn't it?

Thanks in advance for any explanation.

 

[PfcAJ]

Hello,

What I've been taught is that Nitrogen becomes narcotic at a certain partial pressure. So that by reducing the percentage of Nitrogen on the mixture we have less pp at the target depth, thus lower probability of narcosis.

So, could someone explain with simple words (I cannot really interpret the papers linked in this thread) why a Eanx32 mix for a dive at 30m does not reduce the nitrogen narcosis effect?

If nitrox has no relation with nitrogen narcosis, I'm also wondering why nitrogen narcosis is not observed in dives deeper than 40m with trimix, say 18/45 mix. Nitrogen is still present there, isn't it?

Thanks in advance for any explanation.

Oxygen is likely narcotic and increased po2 affects co2 retention which is for sure narcotic.

 

[northernone]

Hello,

What I've been taught is that Nitrogen becomes narcotic at a certain partial pressure. So that by reducing the percentage of Nitrogen on the mixture we have less pp at the target depth, thus lower probability of narcosis.

So, could someone explain with simple words (I cannot really interpret the papers linked in this thread) why a Eanx32 mix for a dive at 30m does not reduce the nitrogen narcosis effect?

If nitrox has no relation with nitrogen narcosis, I'm also wondering why nitrogen narcosis is not observed in dives deeper than 40m with trimix, say 18/45 mix. Nitrogen is still present there, isn't it?

Thanks in advance for any explanation.

Co2, oxygen AND nitrogen are responsible for narcosis at depth. As you stated, reducing the partial pressures of these gasses (by going shallower or introducing helium into your breathing mix) will reduce the narcotic effect.

 

[KevinNM]

Oxygen is likely narcotic and increased po2 affects co2 retention which is for sure narcotic.

Gasses get denser with depth. Denser gasses increase work of breathing, which can cause CO2 issues too. Deep air is not a great idea for more than one reason.

 

[NAM001]

I have like others taken pictures of stuff at the 130 range and when back on the boat many I don't remember taking and others I don't know why I took them. That lack of clarity is not there when I use nitrox. I am also less fatigued after using nitrox. another point that many say is not true. I can tell when it takes so much effort to climb a ladder to et back on board the boat. I suspect that there is little benefit for those that are joc's or have no lungt issues known or not. Those that do,,, seam to see the same benefits that I do. I cant begin tot comprehend the idea of nitrox does not reduce narcosis. the math is there for the nitrogen portion. less nitrogen less effect from nitrogen. I have no way to determine the effects from O2 but as clarity goes,,,,, to use notrox and have O2 be equal to N2,,,, is a personal non verifiable claim for me. I don't dive trimix often enough to use that as a comparison factor. I'm sure every gas has a narcosis factor to it. What I don't believe is that narcosis,,, for what ever gas,, happens at the same depths. In sure He is narcotic but not at any depths I would ever dive to.

 

[AJ]

I have like others taken pictures of stuff at the 130 range and when back on the boat many I don't remember taking and others I don't know why I took them. That lack of clarity is not there when I use nitrox. I am also less fatigued after using nitrox. another point that many say is not true. I can tell when it takes so much effort to climb a ladder to et back on board the boat.

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

 

[RayfromTX]

There's no academic proof there is an positive effect from using higher percentage of O2. snip

I think there actually is some academic proof but it is not widely distributed yet, perhaps because of the need for further peer review. @Dr Simon Mitchell do I have this right?

 

[AJ]

Ah, that's interesting. I had this debate with many buddy's but was'nt aware of any proof for what I'am sensing.

 

[MaxBottomtime]

I have like others taken pictures of stuff at the 130 range and when back on the boat many I don't remember taking and others I don't know why I took them. That lack of clarity is not there when I use nitrox. I am also less fatigued after using nitrox. another point that many say is not true.

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.

 

[tarponchik]

Nitrox is oversold but on a different premise: that divers get less fatigued diving on Nitrox. I've read this multiple times on Scubaboard and heard again on a boat recently.