Type 2 vs. Type 1 hit

[JeffG]

I thought nearass was done with ScubaBoard?

 

[texdiveguy]

I thought nearass was done with ScubaBoard?

Naaa..... he appeared again to bless us all here at Christmas time with his diving knowledge.

I am still saving $5 on not purchasing argon and and using airgon instead....this money I am going to use to get nearass a gift. :mooner:

!!!!OK--- back to business........good thread OP.....interesting reading and replies so far!

 

[ianr33]

Nereas: Any chance you could remove that post? As others have pointed out it is just flat out wrong. Misleading people about DCS is not a smart thing to do.

 

[hobodiver]

Shorter than this and you are exceeding the 2:1 decompression gradient tolerance of body fluids and tissues.

Can anyone clarify what this 2:1 decompression gradient is? I've seen it referred to in several places, but don't understand what it is.

 

[wedivebc]

Nereas: Any chance you could remove that post? As others have pointed out it is just flat out wrong. Misleading people about DCS is not a smart thing to do.

What about all his other posts?

 

[pengwe]

Thanks for the explanations. I'm still a bit confused. Is it sort of something like this:

Nitrogen gets off-gassed into the blood as we ascend. Some areas of the body have lots of blood vessels, so they will also get lots of nitrogen bubbles (not proportionately more, but more because there is more blood flowing through). Doing deep stops gives bubbles a chance to get exhaled before they grow. It will have the most effect wherever there is the most bubbles to be gotten rid of. That may be in the heart/lungs/CNS, or it may not, all depending on many different factors, but it could sorta maybe likely help to clear those tissues.

How's that?

 

[wedivebc]

Thanks for the explanations. I'm still a bit confused. Is it sort of something like this:

Nitrogen gets off-gassed into the blood as we ascend. Some areas of the body have lots of blood vessels, so they will also get lots of nitrogen bubbles (not proportionately more, but more because there is more blood flowing through). Doing deep stops gives bubbles a chance to get exhaled before they grow. It will have the most effect wherever there is the most bubbles to be gotten rid of. That may be in the heart/lungs/CNS, or it may not, all depending on many different factors, but it could sorta maybe likely help to clear those tissues.

How's that?

I think this question may be answered by a similar question in another thread http://www.scubaboard.com/forums/4046011-post7.html

As far as the type1 type2 thing, they are just terms to differentiate groups of symptoms and are not hard or fast rules. The cause and treatment of DCS does not differentiate between those groups other than faster tissue compartments often involve central nervous system (type 2) type symptoms such as nerve involvement and even paralysis but no matter what its called it is still DCS.

BTW, Ian
nearass's reply, while ignorant and incorrect is unlikely to cause anyone to come to harm.

 

[pengwe]

That's very clearly explained, the clearest I've read. Thank you.

But what I don't understand is: are these tissues or compartments actual tissues in the body such as brain, bone, muscle etc, or are they 'theoretical' tissues, which would mean what exactly?

I think people are saying that the tissues are real, but the compartments are theoretical.

 

[wedivebc]

That's very clearly explained, the clearest I've read. Thank you.

But what I don't understand is: are these tissues or compartments actual tissues in the body such as brain, bone, muscle etc, or are they 'theoretical' tissues, which would mean what exactly?

I think people are saying that the tissues are real, but the compartments are theoretical.

Not exactly. Compartments are groups of certain types of tissues that share similar ongassing and offgassing properties. This is all thoretical and as mentioned above is only really a mathmatical representation of something that may or may not occur in real life. Since it seems to work in a vast majority of divers many people incorrectly assume it is a real life condition of tissue but it is not.

 

[TSandM]

"Tissues" are mathematical constructs. Although Thalassamania has informed me that the Navy has actually done some gas tension measurements in body tissues under pressure, those results are not generally available. It is a inference that well-perfused tissues correspond to faster compartments, but an inference that is given some weight by the tendency of certain kinds of ascent violations to produce neurologic symptoms, and others (typically the multiple day/multiple dive sort) to produce muscle and joint symptoms.

People making decisions about what KIND of deco violations they'll choose based on this type of inference are making some very large leaps of faith.