Does Type I DCS go away?

[mccabejc]

Does Type I DCS, if untreated, eventually go away as the nitrogen bubbles are absorbed? I would think that time would do the same as a chamber ride, assuming there is no physical damage.

By the way, I found an excellent article explaining the basics of DCI:

http://www.deeperblue.net/article.php/391/29/0

It also explains where the term "bends" comes from, what partial pressures are, etc. Pretty cool.

 

[Dr Deco]

Hello jim:

DCS Remission

In general, joint pain DCS will remit on its own. HOWEVER, it is never clear that neurological DCS will not develop as joint pain is vanishing. Thus it is not a good idea to treat DCS with “tincture of time” and simply wait it out without a treatment plan. Quaffing down beer and aspirin under the mistaken notion that one has “the flu” is bad medicine. One should have a definite plan following a dive if pains and such are not attributable to another cause.

Web Reference

That is an interesting article. I would like to point out, however, that most barophysiologists today DO NOT believe that specific tissues have the definite halftimes listed. Most attribute variations to blood flow.

Dr Deco :doctor:

 

[MikeFerrara]

I'll let Dr. Deco give the technical details but the excess inert gas..."the bubbles" will go away. Gas comming out of solution and trying to leave is what's forming the bubbles and causing the problem in the first place. Recompression and oxygen treatment is meant to control the speed at which you off gas. Without treatment you stand a greater chance of having those "unceontrolled" bubbles do damage and that damage may be permenant. It all depends what gets damaged.

In the specific case of type 1 (as in no CNS envolvement) I don't know what the likelyhood of permenant damage is.

 

[Charlie99]

My layman's understanding (or perhaps, oversimplification) of recompression is that there are at least 2 things going on --- preventing further damage, and helping to heal existing damage.

Immediate, timely recompression will help control the bubble formation and recompress existing bubbles, thereby reducing damage.

If the damage is already done, or well in progress, the value of the treatment ends up more like hyperbaric oxygen therapy. The high PPO2 gets oxygen to damaged sites and helps healing --- much like high pressure O2 therapy is used to help healing in diabetics.

 

[Dr Deco]

Recompression indeed does recompress gas bubbles.

1. This can reduce/eliminate pain in many cases.

2. Reduction in bubble size will often restore the flow of blood where it previously was blocked.

3. Reduction in bubble diameter will cause a great increase in internal pressure from surface tension and increase the outflow of inert gas into the tissue (to be eliminated by the capillaries).

4. Addition of oxygen to some tissues will restore metabolic function.

5. Reduction of inert gas in the breathing mix will promote elimination of inert gas from bubbles and tissues.

 

[Scubakevdm]

3. Reduction in bubble diameter will cause a great increase in internal pressure from surface tension and increase the outflow of inert gas into the tissue (to be eliminated by the capillaries).

Hey, I don't get it. The bubble shrinks. I get it. Internal pressure (in the bubble?) increases. I get it, (if it's in the bubble). But how does this cause the outflow of inert gas to be increased into the tissue? Isn't the tissue subjected to the same pressure that is reducing the diameter of the bubble? Sorry to bug you about it, I just wonder about stuff alot. (I don't have many friends)
Hey! Is it a partial pressure thing, and the disolved gas in the tissue has less nitrogen in it from breathing the chamber mix, and raising the bubble pressure magnifies the gradient? Or perhaps the tissue has a lower N2pp regardless becuse the bubble is pure nitrogen. Hmm. It's a good thing I'm not a doctor.

 

[DepartureDiver]

But how does this cause the outflow of inert gas to be increased into the tissue?

I think Dr. Deco is simply saying that when the bubble gets smaller, it's internal pressure keeps getting greater due to the skin pressure trying to collapse the bubble and this squeezing effect is pushing gasses out. The simple example is a balloon. Everyone knows a balloon is hardest to blow up in the beginning as it resists more ... i.e. it's internal pressure is greater when it is small as compared to when it is big ... and thus it is driving the gas inside of it out more. i.e into the tissues.

 

[Dr Deco]

As the hydrostatic pressure is increased (very often with an oxygen mix) the pressure in the bubbles will increase faster than the inert nitrogen partial pressure will increase in the tissue. Thus, nitrogen will leave the bubbles, and enter the tissue. It will then leave the tissues and enter the capillaries and be carried off in the blood stream to the lungs.

 

[Scubakevdm]

As the hydrostatic pressure is increased (very often with an oxygen mix) the pressure in the bubbles will increase faster than the inert nitrogen partial pressure will increase in the tissue. Thus, nitrogen will leave the bubbles, and enter the tissue. It will then leave the tissues and enter the capillaries and be carried off in the blood stream to the lungs.

Hmmm, 'cause the bubbles just get instantly squished, but the pressure has to kinda soak into the tissues? If I get it, just say "You got it", if I don't just say "Shut-up". I won't pester you anymore. Thanks for helping me!

 

[liberato]

By the way, I found an excellent article explaining the basics of DCI:
http://www.deeperblue.net/article.php/391/29/0

Author states it is OK to drink after diving but "...drinking copiously before a dive may allow more inert gas to be absorbed which will increase the risk of DCS if the extra fluid is then lost prior to surfacing."