Air Embolism In Shallow Water

[scwdive]

It is theoretically possible to rupture the alveolius with as little as a 2psi pressure differential, so a little over four feet of travel holding a full breath if air could result in a lung overexpansion injury. Here's a good article for reference.

http://www.dtmag.com/Stories/Dive Physiology/04-99-feature-2.htm

Practically, there are several instances that have occurred in swimming pools during training with depths of about 10 feet.

Here are the details on Diver Medics:

http://www.nbdhmt.org/dmt.asp

Be Safe.

 

[drrich2]

Egovenatus:

Do you recall whether you had a full breath at the time you were yanked up and had the injury?

Richard.

 

[egovenatus]

I was hovering below the ladder breathing in and of at a slow rate, I grabbed the ladder on exhale and I was inhaling as the boat went to the peak of the wave. So not holding per sea but

---------- Post added October 5th, 2013 at 02:12 PM ----------

But on my way to a full set of lungs if you will. My reasoning in holding on was I didn't want to get brained as the boat came back down. Now I always surface and swim over... Lesson learned I guess!

---------- Post added October 5th, 2013 at 02:14 PM ----------

Sorry I phone auto corrects... That was breathing in and out slowly, not holding my breath, and holding on to the ladder....

 

[mtngoat2674]

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.

I can't contribute anything more than what has been mentioned, but I did want to say that what you propose could certainly save lives if used properly. I know an individual who had become entrapped in an inflatable kayak when it collapsed after a puncture and became hung up on a downed tree. Literally inches from the surface, but drowned anyway. Granted, any type of spare air in this case would have had to be immediately within reach, but such is the case with a lot of rescue equipment.

 

[Steve_C]

I find the ladder incident interesting. In getting on a dive boat in rough water you need to grab it and hold or you may get a boat on your head. You also are supposed to keep your reg in your mouth. So the message is to breath around the reg but not to inhale off the tank when you are submerged by the down motion of the rear end?

 

[egovenatus]

For me, I always surface and time my approach to the ladder, as best I can, given surface conditions now. Then, I did exactly as I was trained and the result was a lung overexpansion injury. My point to the OP was that I would not use a source of pressurized air/gas to breathe from in a situation where your depth and if you can maintain it is not certain. The OP was thinking about using a "Spare Air" or some such device in white water rafting and wondered how shallow you can be and still experience a lung over expansion injury. I was simply offering my experience with a shallow water lung injury.

 

[flots am]

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,

If the kayaker keeps breathing, everything should be fine. However for a non diver dumped into an emergency, that's a big "if."

I've never heard of anybody getting an compressed gas injury without having any dissolved nitrogen or breath holding.

flots.

 

[egovenatus]

Good practice sure, but say you are being tumbled in class 5 rapids while struggling to place a Spare Air in your mouth while being bounced all over. People get stressed, hold their breath, etc... traveling through rapids at a high rate of speed with you moving at a varying depth... It just seems like adding a piece to the puzzle that you don't need that might have more of a chance of causing injury than preventing it. I would not do it, but hey I don't participate in whitewater rafting, just the much safer sport of SCUBA!

 

[g1138]

It's not really the depth you have to worry about, but the pressure changes. White water is similar to wave actions. There's erratic pressure changes as you're pounded by different forces of water from different angles. So even if you're at 3 feet, you may be experiencing pressure forces equal to 4 feet or more. And keep in mind these are rapid changes in pressure both increasing and decreasing. So I would say risk is even greater.

 

[egovenatus]

Makes perfect sense, like I said I wouldn't do it, seems like a risk that is not needed.