advise on a bend and diving after a bend

Mike

I keep hearing this, but still don't really believe it. Is there a medical reference for it, or is it just recieved wisdom?
Mammalian reflex and all that is going to mean that we have fluid pooling in our core and our extremities are going to be dehydrated on every dive, throw in some cold water dieuresis and it looks worse.

Rehydration is part of the treatment for DCS, but saying it's the cause seems to be following the logic "I have a headache because I didn't take enough asprin yesterday."

Mike

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Simon Mitchell

Gidday Mike,

Perfectly reasonable to be sceptical about the strength with which this belief is held. Its more received wisdom than proven fact; though it does make biological sense and its fair to say that you are probably better off being well hydrated than dehydrated.

There are only a couple of relevant animal studies, and no human data. The animal studies drew opposite conclusions, though the best one by Dave Dromsky favoured the notion that dehydration was an important risk factor (see the abstract below).

Dehydration effects on the risk of severe decompre...[Aviat Space Environ Med. 2006] - PubMed Result

The other study by Jon Broome, which did not find any disadvantage in "underhydration", was only ever published as an abstract to the best of my knowledge. The difference in results between the two studies may result from the degree of dehydration (the pigs were actively dehydrated using diuretics in the Dromsky study).

As you point out, serious DCS can result in loss of fluid from the vascular system, to the point of cardiovascular collapse in serious cases. In that setting, aggressive intravenous rehydration is lifesaving.

Warm regards,

Simon M

intotec

Jaymos2004,

I was just wondering if the skin bends was just on your right arm or did it appear anyplace else? Where you hammering with your right hand?

Curtis,