Oxygen Toxicity Discussion

[tracydr]

I was amazed at the amount of lung irritation and sinus irritation that I had after a 4.5 hour chamber treatment. I almost felt like I was getting the flu. My sinuses were terribly congested and I was coughing like crazy. The symptoms started before the chamber was even over, despite 5 minute O2 breaks very 15-20 minutes.
I also ended up feeling twitchy by the end and had a migraine.

 

[Tortuga68]

2 bars are definitely toxic, the diver maybe has 90% chance to blackout in a couple of minutes

This guy must be totally dead then

 

[vladimir]

This guy must be totally dead then

View attachment 155777

That's a pretty orderly, well-controlled ascent for a floating stiff. I guess he got the decomposition just right.

 

[iluvcozumel]

Hey, grey hair doesn't make us all morons........plenty of morons in the 20-30 age range, too.....

---------- Post added May 26th, 2013 at 08:41 PM ----------

I had the same symptoms, attributed it to dry air and 100% oxygen for the "energy buzz"......I got out at midnight on a Friday from the Cozumel Chamber and had to walk past all of the partiers and abstain. Went back to my hotel room and had some pretty weird dreams. Felt great after the ride, but was advisd not to dive for 6 months, which I followed.

 

[tamas970]

This guy must be totally dead then

He spent around 2 minutes above ppO2=2bar, which is certainly not enough to saturate the tissues with O2. How high is the CNS peak?

 

[Tortuga68]

He spent around 2 minutes above ppO2=2bar, which is certainly not enough to saturate the tissues with O2

2bars are definitely toxic, the diver maybe has 90% chance to blackout in a couple of minutes

A couple of minutes & two minutes are the same thing, right?

How high is the CNS peak?

255%

 

[tamas970]

You're right, I should've written like 10 minutes.

A couple of minutes & two minutes are the same thing, right?

Omgg. Does the CNS clock ticks soo fast at 2bars??

255%

It's a bit difficult to believe, since at 1.6bar you still have a 45min to reach 100%.

 

[Firefyter]

research

DAN | Medical Articles

Sent from my SAMSUNG-SGH-I747 using Tapatalk 2

This, at least to me, is the most relevant part of that article:

"The reality is that adverse reactions to pseudoephedrine are rare in healthy people when it is used as directed. That is not to say that certain individuals may have an idiosyncratic reaction to the drug and experience undesirable reactions to a drug while most others do not. For this reason, one should never use a drug for the first time just before diving and should make sure to use it long enough to determine that no hypersensitivity to the drug exists."

I've been using it for years, and most likely will continue to do so. We all have to weigh our own risks and make our own decisions....

 

[Tortuga68]

Does the CNS clock ticks soo fast at 2bars??

It's a bit difficult to believe, since at 1.6bar you still have a 45min to reach 100%.

If you don't understand how the CNS clock works, why do you make bold statements like you did?

The CNS clock isn't linear. at 1.6 it loads 4x as fast at at 1.4 and above 1.6 it's much faster again. At 1.8 and above you're heavily penalised and each minute of time will add 100% plus to your loading.

It's quite possible (and not uncommon, in deep air technical diving) to have a CNS exposure of >1000.00% for a single dive (the total loading for the dive I posted would be around 1500%, peak was 255%).

There's a lot of debate about the CNS clock (and OTUs) and their relevance to high PPO2 dives. Anyway if you have an OxTox event you're probably going to seize and drown, not blackout.

 

[tamas970]

If you don't understand how the CNS clock works, why do you make bold statements like you did?

I do understand exponential functions, holding an engineering phd... However, not all non-linears are the same, some accelerate "faster" some "slower".

It's quite possible (and not uncommon, in deep air technical diving) to have a CNS exposure of >1000.00% for a single dive (the total loading for the dive I posted would be around 1500%, peak was 255%).

I am not an expert on hyperbaric medicine, but these numbers seem to be on a different units...
(OTU's maybe?) And I am sceptical that a tec diver can take 10x more CNS oxygen just because of training.