Take a pill to find off the bends

[Saturation]

Dear Readers:

Bubble Reduction :inlove:

As Dr Brubakk states, this medication might reduce the bubbles in the blood stream. Arterialization (other than from barotrauma) results from bubbles in the venous return, either through a PFO or pulmonary shunts. With fewer venous bubbles, the risk of arterialization is reduced. Certainly any problems, e.g. neurological DCS from embolization, would be reduced.

It is very possible that this compound could aid divers and astronauts during EVA as well. Whether exercise immediately prior to or during the dive negates the effect of the medication remains to be seen. It certainly indicates that some degree of chemical manipulation of bubble concentration appears to be possible.

Dr Deco :doctor:

Yes, certainly options for additional funding from the military or NASA.

There is much to be examined and done: optimal dosing for effects versus side effects; other available drugs; combinations of drugs +/- exercise .. but we have a promising tool that seems more beneficial than just taking aspirin or NSAID, both of which have questionable benefits.

 

[DivemasterUK]

:11:
This is an article that appeared recently on the BBC...
Pill 'could prevent the bends'


The bends can be fatal
Scientists believe a pill could be developed to prevent divers getting the bends.
Combining exercise prior to diving with a pill releasing nitric oxide (NO) would allow longer or deeper dives.

New Scientist magazine reports the Norwegian researchers are confident the drug would reduce the number of harmful bubbles that form in the blood.

However, sub-aqua experts warned the side-effects of any drug would have to be carefully examined.

The research team at the Norwegian University of Science and Technology in Trondheim previously carried out tests on rats, which found
intense exercise around 20 hours before a simulated dive in a pressure chamber significantly reduced nitrogen bubble formation.

Appropriately timed exercise and a nitric oxide-releasing agent may form the basis of a new approach to preventing serious decompression sickness

Ulrik Wisloff, Norwegian University of Science and Technology
Nitrogen dissolves in the blood during dives, but comes out of solution if divers return to normal pressure too rapidly and this can cause the bends, or
decompression sickness.

It is thought exercise works by eliminating microbubbles, or nuclei, that lead to the formation of larger bubbles in the blood.

Other studies have suggested the microbubbles attach to the walls of blood vessels, and exercise is known to stimulate the release of nitric oxide,
dilating the blood vessels and changing their surface properties.

The Norwegian team therefore carried out further research on rats, published in the Journal of Physiology, which combined exercise with nitric oxide-releasing
agents given for five days and then 20 hours prior to diving.

This significantly reduced bubble formation and prevented death.

Ulrik Wisloff and fellow researchers concluded: "The findings of a protective effect against the bubble formation and death by
appropriately timed exercise and an NO-releasing agent may form the basis of a new approach to preventing serious decompression sickness."

Methods

Mike Clack, techinical adviser at the British Sub-Aqua Club, said anything that added to the methods available to deal with decompression sickness
was to be welcomed.

But he added: "The diver should ensure that any drug used while diving would have no effect on them while breathing under pressure."

Dr Rachel Broadley, a hyerbaric physician at the Diving Diseases and Research Centre in Plymouth, described the research as "very exciting".

She said: "If you inhibit the synthesis of nitric oxide, it appears to predispose to more bubbles being formed. By opposing that, you can prevent it.
But how it would be done is very difficult to say."

She warned that nitric oxide can alter how the cardiovascular system works under diving conditions.

There were also problems associated with the use of exercise because of the precise timing needed.

(Now don't go critisising me for any of the above, I just copied & pasted it!!)

 

[crispos]

Note, however, that some pharmaceuticals do not make it off the drawing board due to the inability to formulate clinical trials and get approval. Any "reducing DCS risk" diver pill sanctioned in the Western World would have to be approved by regulatory authorities if it were legally marketed as such, necessitating several phases of statistically valid clinical trials. Unless of course the unapproved pills became subject to diver folklore, and were sold similar to steroids.

I would think a chamber study could be developed to determine whether such a nitric oxide pill was safe and had any prophylactic effect. But why take the pill when there are simpler ways to get rid of DCS? That's all we need, teach divers to take a pill and ignore NDL's.

 

[BigJetDriver]

Hello jhnsndn:

The “Tablet Approach”

This is reminiscent of the news flash that appeared a couple of years ago that indicated that bacteria could prevent the bends. We certainly a folks that love drugs – while at the same time looking for “all natural.”

The study refers to a finding from the laboratory of Dr Alf Brubakk in Norway concerning exercise one day prior to decompression. There was a reduction in DCS in the rats that exercise compared to those who rested. This has been repeated (with Doppler bubbles as the biomarker) in humans. It is truly fascinating work if nitric oxide------------------------------( not nitrous oxide)---------------------------------is implicated, as the authors suggest.

The “Exercise Approach” :sprite10:

The truth is, if you have exercised one day prior to diving, you are doing what is suggested by the authors. Far be it from me to say that I also found this (earlier), but for those interested, the Reference is below.

What is of more importance is to avoid strenuous activity during and after the dive, since that will produce micronuclei and DCS could well result.

Dr Deco :doctor:

References :book3:
MR Powell. Exercise and physical fitness decrease gas phase formation during hypobaric decompression. Undersea Biomed. Res., 18 (Suppl.), 61, (1991).

BUT DOC, THINK HOW MUCH MORE FUN IT WOULD BE IF IT WERE NITROUS OXIDE THAT WE ARE TALKING ABOUT!!


(Just a little joke, folks!) BJD :anakinpod

 

[DivemasterUK]

Well, yes, that's IS all we need. A pill to stop the bends and so trainees need never fear the bends, and ignore NDL's. Right?

 

[Dr Deco]

Hello Readers:

Curiously Enough

Nitrous oxide is a gas that has a very short (fast) diffusion time. It can enter into a gas bubble much faster than nitrogen can exit. Thus tissue bubbles will grow rapidly, at least initially. This gas stitch technique was employed by researchers to demonstrate the presence of “silent bubbles” in tissues of rats.

While NITROUS OXIDE might be fun (laughing gas), it certainly would be a pain in the neck (really) for divers. :11:

Dr Deco :doctor: