How to measure sensitivity to oxygen

[mdax]

Cora and i have both been tested for PFO's through our local doctors.
We're wondering how to test for sensitivity to oxygen, either duration or ppo2 exposure as it seems to be something that is difficult to determine but will kill you quickly in a cave.

Has anyone outside a military member requested a test using a chamber and o2 for periods of time to determine whether you have elevated sensitivity?

What type of test does the military put candidates through? depth/time and ppo2.

It'd be interesting dealing with our HMO regarding approval for this test but they've always been really good about our other requests...
Thanks

[Sharky1948]

From what I understand, a test of O2 sensitivity would be of little value. The body's sensitivity to elevated PO2 varies from dive to dive, day to day, etc. I'm not sure you would learn anything valuable even if such a test were available to you.

[Greenwood_60]

I think you would be better off being concerned that you might be sensitive, than "knowing" you are not.

[adam0321]

There used to be what's called aott. Or oxygen toxicity test for all seal and recon marines. What we did was put divers in a chamber at 60 feet and put them on oxygen. I believe the time was around 20-40 minutes. This was stoped because it was implemented at the end of training and of someone failed it was 2 years of training wasted. And I think only about 2% actually had problems.

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[mdax]

I was also searching for any studies done on the degree of oxygen sensitivity but couldn't find any so far....for example could folks that previously handled 60 min of pure o2 on one day seize on 20 minutes another day? Still searching the universities online databases but it's looking grim.

[adam0321]

Look for a book by bove and Davis on dive medicine.

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[adam0321]

google.com/m/url?ei=wu8DTrmHL-2xsQe0z8L5Aw&q=http://www.sciencedirect.com/science/book/9780721694245&ved=0CBcQFjAB&usg=AFQjCNHQu_QvYrxRE1 qPyA1nYYM_T7hnKA

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[gasdiver]

There used to be what's called aott. Or oxygen toxicity test for all seal and recon marines. What we did was put divers in a chamber at 60 feet and put them on oxygen. I believe the time was around 20-40 minutes. This was stoped because it was implemented at the end of training and of someone failed it was 2 years of training wasted. And I think only about 2% actually had problems.

Sent from my Eris

When I went through commercial diving school in 1980, we did a PO2 test in the can at 60' for 30 min. I never heard of anyone failing the test, but it was given about 30 days into the 5 month program. I guess if you failed, they'd refund some of your money. During my 4 years working in the Gulf, I never saw anyone get an O2 hit in the water or in the can. I have no idea if the commercial diving schools still do this.

[FW]

When I went through commercial diving school in 1980, we did a PO2 test in the can at 60' for 30 min. I never heard of anyone failing the test, but it was given about 30 days into the 5 month program. I guess if you failed, they'd refund some of your money. During my 4 years working in the Gulf, I never saw anyone get an O2 hit in the water or in the can. I have no idea if the commercial diving schools still do this.

Herein lies the problem. We used data similar to this back in the '70s and determined that 50' would be safe for O2. Then Lewis Holtzendorff toxed on O2 at 50'. We adjusted the depth several times over the next 40 years as more accidents happened (not all in caves), to the current 20'. The bottom line, NO TEST in a chamber will tell you how you will react in the water.

[Kelly Jessop]

. The bottom line, NO TEST in a chamber will tell you how you will react in the water.

That is what I understand,why this paradox exists,but people can breathe ppo2 of 2.5 of oxygen at rest in a chamber at rest and be fine,and replicate the same thing in the water,and show symptoms.