Sounds like there was another dive incident this weekend.

From what I hear a diver entered the water with too much weight and sunk like a stone. He then fully inflated his BC but still couldnt surface so dropped his weight belt. This caused him to rocket to the surface resulting in a lung overexpansion injury.

Im guessing this type of incident would not require recompression treatment since the time at depth would have been very limited????

Yeah, speaking as someone without a clue and in search of the same answer myself, my own thoughts on the matter are that I would say a collapsed lung would be classed as a decompression related injury, however I have heard of air bubbles being forced into blood vessels due to lung over-expansion as opposed to being metabolised through gas exchange in the lungs.

If this is the case I have several questions :

a) Would one introduce the patient to a re compression chamber to shrink / dissolve the bubble(s) and if so:-

b) If the above is true, would this significantly increase the risk of having that shrunk bubble travel to other extremities / narrower vessels / the brain only to (potentially) re-expand later.

c) If the bubble is left alone, would the patient run the risk of that bubble blocking blood supply to other vital organs / tissue.

I have absolutely no idea. But I would think that the damage to the lung would need to be addressed ASAP and this may not be able to be done in a chamber.

spacekat - remember that the pulmonary veins from the lungs are being routed back to the heart then through the arteries and eventually capillaries - it is here that any small bubbles would get 'trapped'. Anyways all gas exchange is done at the capillary level in the lungs blood vessel hierarchy, so provided it didn't get stuck in the capillaries of the lung, it would end up in the pulmonary vein , on route to the heart and then the body. Assuming it remains small, there would be little major damage except at maybe the capillary networks around the body, which (i think) is how a skin bend happens.

Worst case scenario - the bubble(s) expand in an artery, even with blood flow blocked to the brain, there is a failsafe called the Circle of Willis, which is a loop in the brain where the bloodflow from both carotid arties (2 of 3 main arteries to brain) merge and then supply the brain with blood. So if blockage occurs in an artery of the brain or even the capillary network associated with that artery, it is likely that blood (and thus O2) can get to the starved area via another route. In my opinion, the 'easiest' place to cut off blood supply with a bubble would be the extremities and some organs which have only one major artery (like the spleen i believe).

Of course with the lung over-expansion, you will possibly rupture a load of blood vessels, and would be in the shit - even if you somehow got away with no major vascular damage, there would be cellular damage from the excess force experienced when the lungs were expanded and you would probably be in severe pain as there is a hell of a lot of nerves in your lungs to sense when the lung is inflated/deflated in a normal breathing cycle.

Anyways, thats the end of the lecture for today guys hope you found it interesting (and i hope i got it right lol would be embarrassing if someone spots a mistake and im actually supposed to have learnt this kinda stuff over the past 2 years . . )