Hey Kurt!
I'm a triathlete from Montreal and have experienced what I believe was SIPE - Swimming Induced Pulmonary Edema... I think there might be a common link between what is happening to both you, and I.
Wow...That was the most comprehensive article on activity-induced pulmonary edema (AIPE) I've ever read. Thank you very much for sharing it. It's interesting that it's difficult to find any other comprehensive, scientific reviews on AIPE out there. I was also surprised that my search through the vast message base of Deeperblue didn't turn up anything specific to PE, although the more familiar issue of lung squeeze is probably closely related. I think it's because PE occurs in a very small minority of individuals, so my fellow divers and the researchers haven't had much impetus to consider the issue seriously. Those of us that have been afflicted by it feel very strongly about it, though, because it's so horrible to experience.
I experience SIPE usually in the first 750m of a competitive triathlon swim - cold water - in a wetsuit. Rapid start with no warm-up, so the lungs seem to be getting overloaded and flood as a result.
I have probably experienced freediving-induced PE to varying degrees at least two dozen times now,
but I've never experienced it while swimming. And I have done plenty of swimming in cold pools/open water to the point of shivering, including very hard swim workout sets. Weird, huh?
I've competed in numerous triathlons, including a few involving wetsuits swims. Never noticed PE in these either. The stories in your article are scary. The interesting thing in several of those stories is that you guys wouldn't experience any SIPE in your training swims in the exact same circumstances as your races (i.e., wearing wetsuits in open water), but succumb to it very quickly in your races. I guess your blood pressure may be higher during the races due to higher cardiac output,
but I think your blood pressure could possibly be higher for another reason that hasn't been mentioned...Stress from the race.
I mention this because I'm starting to believe that stress has been a consistent factor in my cases. I have done some very deep dives lately (for my ability, that is...down to 58m/192ft), and I didn't really even notice any PE, even though it might be expected, not as abnormal AIPE, but the more expectable "thoracic filling" that occurs in deep freedivers. This diving was done in a
Performance Freediving course, where our warm-ups were very thorough, dive conditions were favorable, etc...Essentially, doing the utmost to minimize stress in hopes of pushing our limits and doing personal-best dives. Then, in some spearfishing dives just this past weekend, to a max depth of 25m/80ft, I experienced some light PE. In these dives, conditions were not that great (strong current, kayaking beforehand, etc.), so my stress level was high. And I can recall in nearly all of my past experiences with PE that I was highly-stressed, usually from trying to dive in strong current. Of course, diving in current would coincide with higher cardiac output and thus higher blood pressure from working harder, but I still think that stress is a linking factor in our cases.
Perhaps the stress, itself, temporarily increases our blood pressure significantly.
Another interesting thing in some of the cases in your article was that some individuals actually coughed up blood. I always made a distinction between my PE and the condition of
lung squeeze that is more familiar to freedivers on the basis that I never coughed up blood...Just yellow blood plasma without the RBCs. I thought the blood could only result if alveoli were ruptured, which is what is believed to happen in lung squeeze; I believed I was not rupturing alveoli in my incidents of PE since it appeared that only plasma was crossing over, through its permeability. But since you've identified some victims of SIPE that coughed up blood, the fundamental difference between lung squeeze and PE that I reasoned may no longer be valid. A possibility, though, is that the blood is not coming from the lungs, but instead the trachea. The very hard coughing accompanying a bad bout with PE may cause trauma to the trachea. There is some belief, though, that the blood emitted in a bout with lung squeeze could also be coming from the trachea instead of the lungs, due, essentially, to tearing the trachea by stretching it under high negative pressure when deep.
I was recently diagnosed with high BP, so have been taking meds to see if that will eliminate high BP as one of the trigger mechanisms.
I will make it a point to get a physical examination soon to check on my BP. I seriously doubt that I have BP though.
I was also intrigued when I read that you are a triathlete as well.
Since abnormal PE doesn't seem to happen in many freedivers, I've tried to think of what unique characteristics I have as a freediver. I don't know of many who are serious endurance athletes, so I've suspected that my training as a triathlete is possibly a factor, and that the idea of having thinner alveolar walls as an adaptation from training is plausible (never found a reference to this yet though). Of course many freedivers undoubtedly practice endurance activities too, especially the most competitive ones, many of which have demonstrated that they do most of their training "dry" (i.e., lots of cardiovascular training on land), then enter the ocean to do dive-specific training only a few weeks before their performances (e.g., Pipin, Tanya Streeter, Mandy-Rae Cruickshank). But I've never seen in their training programs the really intense, above lactate-threshold training that many serious endurance athletes perform (e.g., 10 x 400m intervals at the track). Perhaps this highest level of cardiovascular training is required to develop the adaptation of thinner alveolar walls. I'm curious to find out if Topi Lintukangas (former professional Ironman triathlete) or Stephane Mifsud (very active athlete, judging from his promotional videos), two successful professional freedivers, ever experienced PE, considering their high levels of cardiovascular training.
Ultimately, though, I think this will all be attributable to some characteristic(s), perhaps genetically-derived, that are unique to the few of us that do experience AIPE...Something like the "diastolic dysfunction" mentioned in your article. There are so many other divers and athletes out there that can tolerate the possible contributing factors of PE we've noted without pathology; e.g., plenty of freedivers get cold (or even intentionally allow themselves to get cold for enhanced peripheral vasoconstriction) without experiencing PE; in triathlons plenty of other swimmers are working at high cardiac workload without having to stop midway to clutch a kayak and cough up blood; etc. There's got to be something fundamentally different about us. It definitely doesn't occur randomly; we are at risk of it happening repeatedly. I'm confident that I could fill my lungs with plenty of fluid by going out and diving with no wetsuit, in case any researcher wanted to observe it.
I'll keep in touch with you.
