Breathing up with pure O2

[lowviz]

So you read the Baker's Dozen post and still don't think 80/20 is the wrong mix for final deco on a tech dive? I won't argue it here, but I felt that post was dramtically effective in explaining why the benefits of 100% for deco made this the only real choice.

Regards,
DanV

Did you read the Baker's Dozen? I prefer physics and physiology to an emotional rant. Other than #13, it is all opinion. Er, with the exception of #5 which is just plain wrong. To each his own, but you could have come up with a much better justification for using 100%. Such examples exist. -I remain a stroke in the eyes of the Great One.

 

[Thalassamania]

Thal,
My ideas of O2 toxicity are really from tech diving, where lots of research has been done. The freediving applications are only guesses..at least as far as I am concerned.
This is the kind of thing where if I was to be guessing wrong, I would want it to be on the safe side, not the blacking out side...

Better safe than sorry, but I'm curious anyway about what the actual science is.

As to the specifics of your first point to me, there has been some research on pinnipeds and whales, where air is exhaled prior to the huge descents into deep ocean depths, and scientists postulated this was effective in both decreasing DCS potential and O2 tox....which would relate to your point. And there are human freedivers who are using a technique where after breathing up for a few minutes on the surface, they exhale most air from their lungs, and then do drops to 80 feet deep and far beyond....

Poulter suggested this back in the 1960s. Diving on exhalation was originally thought to be a buoyancy thing, but could easily serve multiple purposes as adaptations like that rarely serve a single purpose.

In the study of Sperm Whales, they found that after the 3500 foot or so big drops these whales would do, after surfacing for a minute or so ( less time than required for hypersaturation/bubbling) they would drop back down to 40 feet or so and languish their for 10 minutes or so....essentially a deco stop !!!!

Regards,
DanV

I've observed that behavior, that's an interesting and reasonable hypothesis. Got to slap a Doppler sensor on one of them some time.

 

[danvolker]

Did you read the Baker's Dozen? I prefer physics and physiology to an emotional rant. Other than #13, it is all opinion. Er, with the exception of #5 which is just plain wrong. To each his own, but you could have come up with a much better justification for using 100%. Such examples exist. -I remain a stroke in the eyes of the Great One.

While George had something of a WWF Wrestling personna in his internet tirades, the science was from the best minds in diving pysiology....WKPP had its own tables, contributed to by George, Jarrod, Bill Mee, and Dr Bill Hamilton...their deco proceedures and results after 6 hour bottom times at 280 feet, were so impressive in vastly reduced time and vastly reduced incidence of injury, the Navy Spec Warfare used to attend major dives for the knowledge and science they could glean from this, and the enormous strides JJ and GUE have made since, using this understanding of deco ( and the correct use of Oxygen) , speak for themselves.
DanV

 

[Thalassamania]

Well ... let's be honest. George and Jarrod, et.al. were willing to be lab rats in a lash up that did not require human subjects approval by any organization. Billy Bob and his buddies from the dark side of Key West were more than happy to make use of this opportunity; and made some great advances.

 

[wrybosome]

I once watched Dr. Christian Lambertson breathe up on pure oxygen and hold his breath for 15 minutes.

You know it's the brain that uses the most oxygen. My standard response to people who brag about their sac...

Seriously, how is that possible? 15 minutes seems like 8 minutes past believable.

 

[lowviz]

Better safe than sorry, but I'm curious anyway about what the actual science is.
Poulter suggested this back in the 1960s. Diving on exhalation was originally thought to be a buoyancy thing, but could easily serve multiple purposes as adaptations like that rarely serve a single purpose.

I've observed that behavior, that's an interesting and reasonable hypothesis. Got to slap a Doppler sensor on one of them some time.

Fascinating post.

While George had something of a WWF Wrestling personna in his internet tirades, the science was from the best minds in diving pysiology....WKPP had its own tables, contributed to by George, Jarrod, Bill Mee, and Dr Bill Hamilton...their deco proceedures and results after 6 hour bottom times at 280 feet, were so impressive in vastly reduced time and vastly reduced incidence of injury, the Navy Spec Warfare used to attend major dives for the knowledge and science they could glean from this, and the enormous strides JJ and GUE have made since, using this understanding of deco ( and the correct use of Oxygen) , speak for themselves.
DanV

If some mod will be so kind as to pick this apart and start a new thread, I'll continue. If not, let's stop walking all over Hank49's post. He deserves better.

Well ... let's be honest. George and Jarrod, et.al. were willing to be lab rats in a lash up that did not require human subjects approval by any organization. Billy Bob and his buddies from the dark side of Key West were more than happy to make use of this opportunity; and made some great advances.

I'm quite impressed by your post. (FWIW) Yes, and from this careful self experimentation came a lot of solid (truly scientific) data that became the basis of an extremely safe way to dive, delicious irony. Kinda funny that the mere passage of time turned it into elitist dogma.

 

[dumpsterDiver]

I would guess that in breathing up on pure O2 that you do decrease the CO2 dramatically. You do that hyperventilating on just air, which is dangerous also before a free dive. (remember, I wasn't free diving after this and PLEASE, DON'T ANYONE TRY THIS FOR FREE DIVING.. I was just experimenting to see if it would really lengthen my breath hold time....out of....boredom on a bad weather day)

But even though you breathed in pure O2, your body cells would still be producing and releasing CO2 back into your bloodstream, wouldn't they?
This is why I THINK my diaphragm began to spasm. I was experiencing the build up of CO2 telling me to breath, but I had enough O2 left in my blood and countered that demand which negated the urgent feeling of needing to breath.

I had a commercial airline pilot tell me that he knew of other comm pilots that used to experiment when board with flying. They would take turns (thank God) breathing up on oxygen and then seei how long they could hold their breath while at altitude.

 

[Hank49]

Which begs the question, how much is your breath hold reduced by breathing up at say....15,000 feet altitude? Would you be more prone to pass out from lack of O2, since that would happen before the buildup of CO2?
It is interesting though. Breathing up on pure O2 does seem to "trick" our natural mechanisms for telling us to breath. It seems that the CO2 alarm is very strong but normally coincides with the strong urge to breath as you O2 level drops. It was weird having strong diaphragm spasms but not feeling much need to breath at all.

 

[Arubandi07]

You know it's the brain that uses the most oxygen. My standard response to people who brag about their sac...

Seriously, how is that possible? 15 minutes seems like 8 minutes past believable.

Check out the most current record for static apnea, I believe it's actually 17+ min.

 

[Thalassamania]

Which begs the question, how much is your breath hold reduced by breathing up at say....15,000 feet altitude? Would you be more prone to pass out from lack of O2, since that would happen before the buildup of CO2?
It is interesting though. Breathing up on pure O2 does seem to "trick" our natural mechanisms for telling us to breath. It seems that the CO2 alarm is very strong but normally coincides with the strong urge to breath as you O2 level drops. It was weird having strong diaphragm spasms but not feeling much need to breath at all.

Interesting question, I'll have to try it next time I'm up at the telescope.