Air Embolism In Shallow Water

I am a certified recreational diver that is exploring the use of emergency air for whitewater kayaking, including extreme, big water conditions. There are a variety of hazards in whitewater that may cause the need for emergency air. It would be rare for a kayaker to ever breathe emergency air at a depth of ten feet, and most hazards would be in three feet of water or less. However, there are some situations where a kayaker ends up swimming in huge whitewater where the hydraulic forces would make his depth vary, but again, probably not more than ten feet. The theory being explored is that if a kayaker can increase the time between respirations (hold his breath or very slow breathing), his emergency air will last longer, increasing his chance for self-rescue, or rescue by others.

Are there any MD's, or other knowledgeable divers, that can comment on the chance of air embolism in 3-5 feet of water. My layman's thinking tells me that unless your lungs are completely full, the chance of air expansion sufficient to cause an embolism is pretty low in 3-5 feet of water. How about ten feet of water?

Thanks in advance for any constructive comments.

It beats drowning, I guess, but I've heard of at least one incident in about 5' water during helicopter crew training. I don't currently have a link, but I'll look around.

Try posting this question in this section:

Marine Science and Physiology

There are MD's who frequently answer there.

I don't have the stats with me...but do have a PDF at home. I believe there is even a known case of death caused from the shallow end of a swimming pool. I'll post the exact info later.

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Thanks to each of you. I'll be interested if you can find your data, and that is a good suggestion to post on the other forum.

One of my instructor buddies is also a dive medic. A while back she taught me that it is possible to get an embolism in as shallow as 6 feet.

On a side note, what is a dive medic? I'm a medic in the army, have been a flight medic previously (add altitude physiology and common barotrauma), and I'm curious about this. Is it a PADI thing? What are the qualifications or criteria? F you could snag some info from your friend, that would be great!

Back on subject, yes, you should breath carefully at any depth. Keep in mind, people can earn themselves an embolism on dry land... It happens.

I have been present for one instance of an over-expansion injury from about 7 feet of depth. Constant, even if slow, breathing is preferable to a breath hold when breathing compressed air at any depth. Not preferable, essential.
DivemasterDennis

You can have a lung expansion injury in 4 feet of water. I would think that the most dangerous situation for this would be in white water, where the person can be thrown from 10 feet to the surface in seconds, with no control over it.

As others have pointed out, it probably is not a good idea to use pressurized air in this case . I myself received a lung over expansion injury in shallow water. In 1992 I was diving off the coast of Spain in rough seas. The dive was over and I was waiting my turn to enter the boat on a rear ladder while trying to avoid being brained by it. I had just removed my fins and grabbed the ladder at the bottom of a trough in the water when I was yanked upward by the ladder as the boat traveled to the peak of a wave. I was pulled up from about 3 to 4 feet fsw to the surface rapidly. It felt like a million pin pricks all over my lungs and thankfully never developed into anything more than a nagging cough for several weeks. In short, if you can't control your depth don't use pressurized gas to breath. I was a fairly new diver then, but I learned my lesson on boarding boats in the open ocean.