Deep diving advice that goes against conventional thought?

[danvolker]

According to George...who did work closely with Dr Bill Hamilton in the creation of the special WKPP tables George had made for he and JJ's exploration dives....
The 250 foot air dives actually cause your red blood cells to become rigid and to NOT slide through the blood vessels properly, without causing inflammation....Inflammation being one of the most prominent causes of many human diseases, you really DONT want to be causing inflammation or to be damaging your red blood cells.... And according to George, the Helium was much better at not interacting in this manner..in not making the blood cells rigid or causing inflammation.

 

[PfcAJ]

On narcosis 'adaptation' (or lack there of)
Effect of brief, repeated hyperbaric exposures on susceptibility to nitrogen narcosis

On subjective 'adaptation', but lack of objective 'adaptation'
Dissociation of the behavioral and subjective components of nitrogen narcosis and diver adaptation

Performance at 30m on air
[abstract] NITROGEN NARCOSIS - EVIDENCE FOR A CHANGE IN STRATEGY.

On RBCs
[abstract] EFFECT OF HYDROSTATIC PRESSURE ON RED BLOOD CELL MEMBRANE AND RHEOLOGY.

Still waiting for all the low END accidents, DCBC.

 

[100days-a-year]

Dan,I've remember seen studies that suggest high PO2 is behind most of the damage but in capillaries it seems feasible the larger N molecules could obstruct flow.

 

[danvolker]

On narcosis 'adaptation' (or lack there of)
Effect of brief, repeated hyperbaric exposures on susceptibility to nitrogen narcosis

On subjective 'adaptation', but lack of objective 'adaptation'
Dissociation of the behavioral and subjective components of nitrogen narcosis and diver adaptation

Performance at 30m on air
[abstract] NITROGEN NARCOSIS - EVIDENCE FOR A CHANGE IN STRATEGY.

On RBCs
[abstract] EFFECT OF HYDROSTATIC PRESSURE ON RED BLOOD CELL MEMBRANE AND RHEOLOGY.

Still waiting for all the low END accidents, DCBC.

PfcAJ, I would have liked to read the HYdrostatic Pressure on Red Blood Cell article, but the links don't work for me....perhaps you have to join/be a member?

 

[Storker]

in capillaries it seems feasible the larger N molecules could obstruct flow.

No, it doesn't.

Sorry, but if you've got an inkling of an idea of the size of an O2 molecule, an N2 molecule and a human capillary, that idea is a lot closer to "seriously far-fetched bovine manure" than "feasible".


--
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Typos are a feature, not a bug

 

[John C. Ratliff]

On narcosis 'adaptation' (or lack there of)
Effect of brief, repeated hyperbaric exposures on susceptibility to nitrogen narcosis

On subjective 'adaptation', but lack of objective 'adaptation'
Dissociation of the behavioral and subjective components of nitrogen narcosis and diver adaptation

Performance at 30m on air
[abstract] NITROGEN NARCOSIS - EVIDENCE FOR A CHANGE IN STRATEGY.

On RBCs
[abstract] EFFECT OF HYDROSTATIC PRESSURE ON RED BLOOD CELL MEMBRANE AND RHEOLOGY.

Still waiting for all the low END accidents, DCBC.

pfcAJ,

You realize that you are depending upon a 22 year-old study, which was a laboratory simulation. Try:

Home - PubMed - NCBI

and search for saturation diving and diving and red blood cell. Here is one result:
Scuba diving increases erythrocyte and ... [Med Sci Sports Exerc. 2009] - PubMed - NCBI
There has been a lot of research since that study. 'Not saying it's wrong, just out-dated.

Dan, there is no such medical term of "rigid" red blood cells. There is greater aggregation under pressure, but I have not looked up the research to see whether breathing gases or the pressure itself influences this situation.
Enhanced aggregability of human red bloo... [Undersea Hyperb Med. 1998] - PubMed - NCBI

Dan, if you want to search in the Rubicon Foundation, go here and do a search:
Rubicon Foundation

http://rubicon-foundation.org/underwater-physiology-symposiums/

http://archive.rubicon-foundation.org/xmlui/handle/123456789/3988

SeaRat

 

[PfcAJ]

I'm not depending on the study at all, and age of a study doesn't really make it valid or not. Studies aren't potato chips, its not like they go stale if they're old. I'm merely linking to a article about RBCs under pressure. Draw your own conclusions.

Sorry about the links not working for some of you. try these (same order)

Effect of brief, repeated hyperbaric exposures on susceptibility to nitrogen narcosis
Dissociation of the behavioral and subjective components of nitrogen narcosis and diver adaptation
[abstract] NITROGEN NARCOSIS - EVIDENCE FOR A CHANGE IN STRATEGY.
[abstract] EFFECT OF HYDROSTATIC PRESSURE ON RED BLOOD CELL MEMBRANE AND RHEOLOGY.

Let me know if those don't work.

 

[John C. Ratliff]

pfcAJ,

You have to be careful about conclusions from abstracts. These studies are available, but for a price, from the publishers. Here's the abstract:

EFFECT OF HYDROSTATIC PRESSURE ON RED BLOOD CELL MEMBRANE AND RHEOLOGY.
Yedgar, S; Halle, D; Chen, S
It has been previously shown that high pressure, in the range of thousands, hundreds or tens of atmospheres, affect various cell and protein functions. Such high pressure is far from physiological conditions. We have examined the effect of mild hydrostatic pressure of up to several atmospheres on red blood cell (RBC) membrane. To differentiate the pressure as a mechanical force per se from partial gas pressure, RBC were subjected to pressure in three ways: (a) centrifuging the cells and changing the rotation velocity, or (b) the height of the water column above the spinning cells; (c) applying direct argon pressure on the cell suspension. It was found that using all three methods application of pressure, from 1 to 5 atm. modifies the membrane composition, inducing resistance to hemolysis. The changes in the membrane composition is associated with changes in the rheological properties (aggregability and shape) of the RBC. It has been generally assumed that mild pressure, in the range of several atmospheres, does not affect cell function. Our findings refute this notion, as they demonstrate that mild pressure may alter cell membrane properties and function.
______________
Abstract of the Undersea and Hyperbaric Medical Society, Inc. Annual Scientific Meeting held June 23-27, 1992. Hyatt Regency Bethesda Hotel, Bethesda, Maryland (Undersea and Hyperbaric Medical Society)

If you'll look at the simulations, one was by centrifuge. This would indicate that the effect is by pressure itself, and not by the gas being breathed.

SeaRat

 

[PfcAJ]

100% agreed.

I'm not posting that to agree with Dan (or George) that nitrogen is the cause.

 

[100days-a-year]

Storker,I kill things for a living Plz forgive my lack of judgement.I assumed N bubbles could come out of suspension blocking flow.

What mechanism do you propose N or O would take to cause the necrosis?I'd seen claims of acidification of the blood but I think it would be easier for oxygen to react at increased partial pressure than a relatively inert gas.

Pubmed is the best way to find out much of this stuff.Mostly free and easily searchable.