Watching Coast Guard Florida : Diver rescued with collapsed lung - Possible Causes?

[00wabbit]

I was just watching coast guard Florida and there was a case where they rescued a diver with a collapsed lung. They didn't give a lot of details about the cause of the accident. Here is what I heard from the show:
Diver was a 50+ female. Appears to be a fairly active diver but wasn't said on the show
Just started a dive down to a shipwreck (did not say if she dove previously this trip)
Said she got to the bottom but just didn't feel comfortable and then she decided to return to the surface. As she was getting on the boat her major symptoms started and I presume this is where the lung collapsed.

My first thought was that maybe it was a lung over expansion injury that abused the collapsed lung but nothing was said about holding her breath or panicked ascent or anything.

What could potential causes be?

 

[TSandM]

It doesn't take much breath-holding to cause a lung overexpansion injury. I have seen one, and as best we could reconstruct it, it was probably due to breath-holding for a brief period while ascending inside of a wreck, where the diver involved was unaware he was ascending, because the wreck was peculiarly oriented and up and down weren't obvious.

If this diver was stressed during ascent, and for even a short period held her breath, she could have caused a pneumothorax. It is much less likely that it occurred at depth, although that is also possible -- pneumothoraces can be spontaneous, if there is underlying pathology in the lung.

 

[psiborg1812]

^ agreed. Is this a TV show? If so then it's not surprise that there's not a lot of information. I think something like 4 feet of water pressure change can injure alveoli, it doesn't take much to get a lung overexpansion injury. Did the sow say if she was smoker? That would increase the risk of spontaneous pneumothorax.

 

[00wabbit]

It didn't say she was a smoker, but she looked like should could be.

 

[Ken Kurtis]

I think something like 4 feet of water pressure change can injure alveoli, it doesn't take much to get a lung overexpansion injury.

Yes, but it depends on where that four-foot breath-holding ascent is occuring.

If you hold your breath from 99 FSW to 95 FSW, the pressure changes from 4.00ATM to 3.88ATM, a change of 3% where there's likely little chance of causing an over-expansion injury (embolism). However . . .

If you hold your breath from 4FSW to 0FSW (the surface), you go from 1.12ATM to 1.00ATM, a 12% change. Better chance of injury (though still possibly small, and probably requiring a REALLY full lung to do it).

The point is that it's not the raw number depth change that does it to you, it's the rate of change, which is depth-dependent.

Perhaps a better example is 10-foot breath-holding ascent. From 99 to 89 feet, there would be an 8% increase in lung volume. But from 10 feet to the surface, that same 10-foot depth change produces a lung volume change of 30%. Ouch.

- Ken

 

[tyrerubber]

It didn't say she was a smoker, but she looked like should could be.

What does a smoker look like?

 

[00wabbit]

 

[dadediver]

I was just watching coast guard Florida and there was a case where they rescued a diver with a collapsed lung. They didn't give a lot of details about the cause of the accident. Here is what I heard from the show:
Diver was a 50+ female. Appears to be a fairly active diver but wasn't said on the show
Just started a dive down to a shipwreck (did not say if she dove previously this trip)
Said she got to the bottom but just didn't feel comfortable and then she decided to return to the surface. As she was getting on the boat her major symptoms started and I presume this is where the lung collapsed.

My first thought was that maybe it was a lung over expansion injury that abused the collapsed lung but nothing was said about holding her breath or panicked ascent or anything.

What could potential causes be?

I was thinking more like why were the AST's diving off a boat without anybody left aboard.