New oxygen narcosis study (May 2017)

[wedivebc]

Which? I first learned with PADI, and it was stated that this was not the case. Having taught NAUI and still teaching SDI/TDI and NASE, I know that this is not a part of their curriculum. An instructor or two might have it wrong, but I don't see this as an agency mantra.

Strangely enough PADI didn't always take a hard line on that because in the PADI semiclosed rebreather manual they stated that one of the effects of lowered PO2 was an increase nitrogen narcosis which surprised me given their position on the issue in the OC realm of diving.

 

[The Chairman]

I don't quite understand what you're trying to say.

 

[wedivebc]

I don't quite understand what you're trying to say.

PADI teaches that O2 has a potential to affect nitrogen narcosis equal to nitrogen in other words O2=narcotic yet they caution that low PO2 in a rebreather loop will cause elevated nitrogen narcosis which strikes me as contradictory.

 

[The Chairman]

PADI teaches that O2 has a potential to affect nitrogen narcosis equal to nitrogen in other words O2=narcotic yet they caution that low PO2 in a rebreather loop will cause elevated nitrogen narcosis which strikes me as contradictory.

Hypoxia is it's own form of stupid. Hypercapnea is yet another form of stupid.

 

[wedivebc]

Hypoxia is it's own form of stupid. Hypercapnea is yet another form of stupid.

I don`t think that was what the statement was referring to since if you are that hypoxic or hypercapnic narcosis is the very least of your worries

 

[The Chairman]

since if you are that hypoxic or hypercapnic narcosis is the very least of your worries

Actually, those are symptoms and are well documented.

 

[wedivebc]

Actually, those are symptoms and are well documented.

Yes I am well aware of that. The premise of low O2 affecting nitrogen narcosis has nothing to do with hypercapnia it has to do with elevated CO2. A completely different animal.
I am saying if your O2 is so low you feel impaired you are in very big trouble as most people experiencing hypoxia report no awareness of symptoms prior to loss of consciousness . That leaves me to assume the intent of the comment by PADI is low O2 will result in high N2 which exacerbates nitrogen narcosis. That to me is a contradiction of their stated position of O2 narcosis.

 

[The Chairman]

The premise of low O2 affecting nitrogen narcosis has nothing to do with hypercapnia it has to do with elevated CO2.

You're too busy trying to be right and not paying attention to what I'm writing. All three conditions can cause you to be stupid. You can experience them separately or together which can be horribly bad. If you won't believe me, then maybe Google or Wikipedia can help...

From Google searches for each condition:

Changes in the color of your skin, ranging from blue to cherry red, Confusion, Cough, Fast heart rate, Rapid breathing, Shortness of breath, Sweating and Wheezing.

According to other sources, symptoms of mild hypercapnia might include headache, confusion and lethargy.

Symptoms of nitrogen narcosis include: wooziness; giddiness; euphoria;disorientation; loss of balance; loss of manual dexterity; slowing of reaction time; fixation of ideas; and impairment of complex reasoning. These effects are exacerbated by cold, stress, and a rapid rate of compression.

Notice "Confusion" or "Impairment of complex reasoning" in each of the list of symptoms. Not to confuse the issues any further, but carbon monoxide poisoning can cause people to be stupid as well. With so many things causing stupidity in divers that gets amplified as you go deeper, it's best to do your best to hardwire the "When in doubt: Bail the eff out!' mantra into your diving protocols. nothing down there worth dying for.

 

[wedivebc]

You're too busy trying to be right and not paying attention to what I'm writing. All three conditions can cause you to be stupid. You can experience them separately or together which can be horribly bad. If you won't believe me, then maybe Google or Wikipedia can help...

From Google searches for each condition:





Notice "Confusion" or "Impairment of complex reasoning" in each of the list of symptoms. Not to confuse the issues any further, but carbon monoxide poisoning can cause people to be stupid as well. With so many things causing stupidity in divers that gets amplified as you go deeper, it's best to do your best to hardwire the "When in doubt: Bail the eff out!' mantra into your diving protocols. nothing down there worth dying for.

I'm not trying to be right about anyt

You're too busy trying to be right and not paying attention to what I'm writing. All three conditions can cause you to be stupid. You can experience them separately or together which can be horribly bad. If you won't believe me, then maybe Google or Wikipedia can help...

From Google searches for each condition:





Notice "Confusion" or "Impairment of complex reasoning" in each of the list of symptoms. Not to confuse the issues any further, but carbon monoxide poisoning can cause people to be stupid as well. With so many things causing stupidity in divers that gets amplified as you go deeper, it's best to do your best to hardwire the "When in doubt: Bail the eff out!' mantra into your diving protocols. nothing down there worth dying for.

You're the one trying to confuse the issue by introducing Co2 and now CO toxicity. Read what I initially posted. The conversation was about low O2 causing symptoms of nitrogen narcosis. I am saying if O2 is so low to cause confusion, unconsciousness is not far behind and that makes the statement in the PADI literature just silly if that was the intent of the statement. This whole discussion is just getting silly.

 

[The Chairman]

You're the one trying to confuse the issue

That was not my intention. You suggested that PADI was wrong in suggesting that hypoxia can result in narcosis like symptoms. You are wrong and I have proof.

I am saying if O2 is so low to cause confusion, unconsciousness is not far behind

Please support your contention. How "far behind"? What oxygen saturation should we be looking for? Let's see what NOAA says about PPO2 levels in atm, shall we? This is the list from NOAA's Diving manual, Chapter Three: Diving Physiology of what to expect with various oxygen levels. Only I reversed it and colorized it. Orange is not good and Red will not support life and is dangerous.

• 3.00 50/50 nitrox recompression treatment gas for use in the chamber at six ata
• 2.80 100% O2 recompression treatment gas at 2.8 ata (60 fsw)
• 2.40 60% N2/40% O2 nitrox recompression treatment gas at six ata (165 fsw)
• 2.20 Commercial/military “Sur-D” chamber surface decompression, 100% O2 at 40 fsw pressure
• 1.60 NOAA limit for maximum exposure for a working diver
• 0.50 Threshold for whole-body effects; maximum saturation dive exposure
• 0.35-0.40 Normal saturation dive PO2 level
• 0.21 Normal environment oxygen (sea level air)
  
• 0.14-0.16 Initial signs/symptoms of hypoxia
  
• 0.09-0.10 Serious signs/symptoms of hypoxia
• <0.08-0.10 Unconsciousness in most people
  
• <0.08 Coma to ultimate death

So, according to NOAA, the symptoms start at 1.6 atm, .5 atms below normal, and unconsciousness sets in .6 atms lower than that. You can further read this:

Hypoxia decreases the ability to think, orient, see properly, or perform tasks. Of all the cells in the body, brain cells are the most vulnerable to hypoxia. Unconsciousness and death can occur in brain cells before the effects of hypoxia are apparent in other cells. The victims of hypoxia do not usually understand what is occurring, and they may even experience a feeling of well-being. Signs and Symptoms:
• Frequently none (the diver may simply lapse into sudden unconsciousness)
• Mental changes similar to those of alcohol intoxication
• Confusion, clumsiness, slowing of response
• Foolish behavior
• Cyanosis (bluish discoloration of the lips, nailbeds, and skin)
• In severe cases, cessation of breathing

Again, some of those symptoms certainly remind me of the symptoms of narcosis, so I can see why PADI would print that. Who knew they would agree with NOAA and me. Must be some sort of conspiracy, I'll tell ya!

Caveat: though I used the figures from NOAA's manual, I thought reversing them from High to Low and then color coding them only made sense to me and might also make more sense to subsequent readers.