It is possible. I have read DAN's article on IPE, linked below, as well as a few others.
http://www.diversalertnetwork.org/medic ... ticleid=82
I will start by mentioning that I have none of the common cardiogenic risk factors listed for IPE. I'm 30, I sprint at a sub 5 minute mile pace, my blood pressure is normal, I do not smoke, and I am in exceptional cardiovascular health with a low body fat percentage. I also completed a pulmonary function test last month. It would have to have been a transient variable that induce IPE in me, as I have never experienced it before. I would be willing to talk to a physician at Duke or DAN via phone or email, and I would also participate in any of the famous underwater exercise bike tests too, provided that I could do it on a weekend. If Duke wants DNA or blood to examine it for whether I have any sort of predisposition to IPE that I could have inherited genetically, then they are welcome to it provided they pay for it or do it on site.
One thing of note is that I did swim for a bit before I went diving, and my heart rate was slightly elevated. The water was pretty cold as well, at about 69 degrees. I was wearing a 7mm wetsuit. That is at least anecdotal evidence of it being IPE, but it sounds like the majority of research is limited so I am not going to get too wound up about it. I know that IPE has presented in combat swimmers in cold water according to the Rubicon Foundation as well. Their abstract is posted here:
http://archive.rubicon-foundation.org/d ... tem+record
I have made about ten dives since the one in which I exhibited symptoms of pulmonary edema with no return of signs or symptoms. Interestingly, if there is a correlation between IPE and exercise, then maybe it is dependent somehow on an additional factor. I swam for a good hour today before diving, and I then did a 53 minute dive. The water was 83 degrees and everything went great. I was using similar equipment to what I was using when the edema happened. The only other appreciable difference to my knowledge is that the dives in which I experienced edema were fresh water, and all of my dives since then have been salt water. Also, the last thing that may be relevant is that I recall drinking a very large energy drink before my dive in which I experienced pulmonary edema. I know caffeine causes vasoconstriction, as does immersion in cold water and exercise. Temporary increases in blood pressure could lead to increased pulmonary hydrostatic pressures, which have been known to cause IPE in combat swimmers. Plus, I have never met a military guy who does not drink a lot of caffeine, even when cold and exercising, so that could be something common to combat swimmers in particular. That could be why most younger guys who present with IPE typically have normal blood pressures, as the effects of caffeine on blood pressure are transient. Maybe the temporary vasoconstriction from caffeine coupled with that of immersion in cold water is what does it. I can tell you that I have not drank an energy drink that size (320 mg of caffeine, which is quite a large amount) and gone diving in water that cold simultaneously to my recollection before. As a matter of fact, when I boat dive I do not drink caffeine at all to help avoid potential seasickness. I also drank a large gatorade before swimming, as I wanted to make sure I was hydrated. I know that temporary overhydration can cause capillary seepage due to increased volume if the kidneys have not had time to remove the extra fluids, so that may have contributed as well. As an aside, this sounds strikingly similar to high altitude pulmonary edema with the exception of the increased partial pressures in lieu of the decreased ones experienced at altitudes. Just a few thoughts.
I look forward to hearing from you, and I appreciate the information and your help.
The impossible missions are the only ones which succeed. -JYC
