Saw-tooth dive profile

[Mdemon]

You actually need several large syringes full of air in your heart to stop it (acording to my doctor friend).

The danger is as you pointed out - if blood flow is stopped "downstream".  Clots usually do this better though...

My friend, martial arts instructor, aerobics instructor, fit as fcuk, ended up in hospital with multiple clots on his lung - for no reason.  He's damaged a large part of his lung as a result, and I don't think it grows back.  Poor sod.  

I don't know if the same damage can happen from sawtooth or reverse profile, but if it could, I expect we'd all be a bit more careful...

[Ian W]

Originally Posted by [b

Quote[/b] ]Microbubbles form on all ascents.

As I said, categorical answers are not possible. There have been dives with no bubbles detected. They may have been there, but with the limitations in detection technology we will never know.

Originally Posted by [b

Quote[/b] ](although "trap" isn't a word I've seen used, in this respect before).

Really? That's surprising. Most explanations of the risks of PFO refer to the lungs "filtering" or "trapping" bubbles.

"The lungs can trap and excrete venous bubbles. Without this capability, compressed gas diving would be associated with a much higher arterial bubble load."

" ... it has been demonstrated in vivo that venous bubbles trapped in the pulmonary capillaries after diving may redistribute to the arterial circulation during a subsequent compression."

From: Francis and Mitchell in Bennett and Elliott 5th Ed.

HTH,
Ian W.

[Andy G]

Originally Posted by [b

Quote[/b] (Ian W @ Feb. 10 2004,08:36)]

As I said, categorical answers are not possible. There have been dives with no bubbles detected. They may have been there, but with the limitations in detection technology we will never know.

Really? That's surprising. Most explanations of the risks of PFO refer to the lungs "filtering" or "trapping" bubbles.

"The lungs can trap and excrete venous bubbles. Without this capability, compressed gas diving would be associated with a much higher arterial bubble load."

" ... it has been demonstrated in vivo that venous bubbles trapped in the pulmonary capillaries after diving may redistribute to the arterial circulation during a subsequent compression."

From: Francis and Mitchell in Bennett and Elliott 5th Ed.

Granny and Sucking Eggs spings to mind