Tissue stress associated with bubble formation; potential benefits of diving enriched air

[tarponchik]

EAN decreases nitrogen uptake during dives. You can use that fact to increase bottom times or decrease decompression stress. I'm not sure how decreasing inert gas loading and decompression stress has a downside?

The downside is that you have to pay for this. In this case, I paid for nothing, just like everybody else on this dive. I forgot to mention that 2 divers went up with DM #2 5 min earlier than the rest of the group. If you dive like that, diving NITROX makes no sense because your bottom time is limited by gas consumption, not by N2 intake.

Also, I've mentioned already that I do not believe that breathing excessive O2 is a freebie. We probably pay for that with extra DNA and tissue damage. Please read here The Oxygen Dilemma: Can Too Much O 2 Kill? for example.

 

[Storker]

excessive O2

...is a non-issue for rec divers. There's no way you'll reach pulmonary oxtox limits if you dive normal rec profiles and do fewer than ~five dives per day. Even on EAN36.

 

[packrat12]

Also, I've mentioned already that I do not believe that breathing excessive O2 is a freebie. We probably pay for that with extra DNA and tissue damage. Please read here The Oxygen Dilemma: Can Too Much O 2 Kill? for example.

You know that Victoria Stern, the author of the 2008 (fairly old) article in Scientific American is a science and health author. She is not a researcher nor is the article a research based article. Notice that any scientific studies and references are missing from it. This article is popcorn at best. Show some peer reviewed studies showing permanent damage with limited exposure on an otherwise healthy individual.

Without serious research, I would find it difficult to say where limits are etc. Nitrox reduces tissue stress for divers. This is a benefit. It further buffers us from the NDL limits regardless of depths. Divers are generally on 21% for most of their live so I doubt we build many hours a week on average, save a few professional divers.

On the whole, I seriously doubt there is any negative trade off on the human body by using nitrox, other than ones wallet.

 

[uncfnp]

The downside is that you have to pay for this. In this case, I paid for nothing, just like everybody else on this dive. I forgot to mention that 2 divers went up with DM #2 5 min earlier than the rest of the group. If you dive like that, diving NITROX makes no sense because your bottom time is limited by gas consumption, not by N2 intake.

Also, I've mentioned already that I do not believe that breathing excessive O2 is a freebie. We probably pay for that with extra DNA and tissue damage. Please read here The Oxygen Dilemma: Can Too Much O 2 Kill? for example.

And yet there is the counter view that has seen a dramatic increase in the number of conditions successfully treated with hyperbaric oxygen therapy by, among others, Johns Hopkins, Mayo Clinic and yes Duke.

 

[Diver-Drex]

The article doesn't really explain the studies or their application in medicine. The concern with 100% O2 resuscitation is limitted to infants, primarily premature newborns. They limit O2 to 60% during initial resuscitation and don't worry about pushing O2 saturation up too quickly because thier cells aren't able to handle it. In NICUs they try to keep O2 administration to bare minimum and high flow room air is preferred. Eye damage, to include blindness, and cerebral palsy like conditions can be the result. Beyond that 100% O2 is the standard for resuscitation. Long term exposure can cause lung tissue damage, but you all learned that in your EAN class.
The studies do not in anyway question administration of 100% O2 for resuscitation to anyone other than premies and possibly newborns. The studies have no application to either breathing EAN, using high PP deco gases or treating decompression injuries with 100% O2.

 

[tarponchik]

You know that Victoria Stern, the author of the 2008 (fairly old) article in Scientific American is a science and health author. She is not a researcher nor is the article a research based article. Notice that any scientific studies and references are missing from it. This article is popcorn at best. Show some peer reviewed studies showing permanent damage with limited exposure on an otherwise healthy individual.

Without serious research, I would find it difficult to say where limits are etc. Nitrox reduces tissue stress for divers. This is a benefit. It further buffers us from the NDL limits regardless of depths. Divers are generally on 21% for most of their live so I doubt we build many hours a week on average, save a few professional divers.

On the whole, I seriously doubt there is any negative trade off on the human body by using nitrox, other than ones wallet.

Whoa, you require a peer reviewed paper from me but give me this BS about "tissue stress" w/o any reference whatsoever? As far as I know, tissue stress is nothing but a theory. I do know, however, what oxidative stress is. Here is a peer reviewed paper on simulated diving with air and NITROX. They show that FMD response was significantly reduced in EAN divers only. This is a sign of oxidative stress. I do not know how bad this actually is but I do not want it because it is still bad.

As for the NDL, no question that NITROX is beneficial here but for me this benefit is obvious only in, say, Bonaire where I can dive myself off to the limit. There diving on NITROX pays off.

 

[tridacna]

For those of you trying to figure out what Tarponchick meant by her post, let me just say that she has views about diving with nitrox that are very much out of mainstream thinking. Don't be too quick to judge what was meant by one past alone.

Understatement of the decade. Wow.

 

[uncfnp]

For those of you trying to figure out what Tarponchick meant by her post, let me just say that she has views about diving with nitrox that are very much out of mainstream thinking. Don't be too quick to judge what was meant by one past alone.

And just for the record tarponchik's profile lists gender as male?

 

[tarponchik]

And yet there is the counter view that has seen a dramatic increase in the number of conditions successfully treated with hyperbaric oxygen therapy by, among others, Johns Hopkins, Mayo Clinic and yes Duke.

Well, if you think of O2 as a drug, any drug has side effects. This is why healthy people do not take them.

 

[uncfnp]

Well, if you think of O2 as a drug, any drug has side effects. This is why healthy people do not take them.

Yes, I think of O2 as a drug and as with any drug used indiscriminately or inappropriately it can cause harm. But in this thread we are not actually talking about O2 as a medical treatment for illness but as a well recognized and extensively used gas for diving, used for the prevention of injury or illness. And prevention will always top treatment.