First of all I want to thank Eric Hexdall who has been tremendously helpful with his questions and correspondence to my wife. Secondly, to all on this board...I'm obviously a newbie but it is clear that the diving community (like the pilot community) is full of folks who help each other out
I got a response from DAN, and here it is. It was helpful, although I must admit it makes me rather hesitant to dive ever again. I've always believed that if you followed the rules and kept your diving conservative, the likelihood of you getting hit with something was vanishingly low. As DAN points out, 1 severe hit in 106 dives is a pretty terrible ratio.
In aviation, we train and practice constantly in order to avoid accidents, but this is something different; this is something that no training or preparation could possibly have avoided. So tell me -- if this had happened to you, what would your future course of action be? Would you dive again?
Anyhow, here's the DAN response:
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We are very sorry to hear what you've both been through. What a nightmare! So glad she had a full recovery!
Ok, let’s start by saying that unfortunately, we can't tell you exactly what happened. As a matter of fact, no one can. All we or anybody can do is merely speculation, surmise.
First -
Based on what you are describing, she was not "bent", for she did not have "DCS". What you are describing is in fact very consistent with an AGE (arterial gas embolism). Onset time and the dramatic nature of her symptoms makes a strong argument to assume such cases are AGE until proven not. Why? that's another story.
Why? -
Hard to tell for sure. PFO is possible, but whether she has a PFO or she hasn't, the reality is that though it would be very tempting to connect the dots, and fairly easy; even by proving she has a PFO that does not prove it caused this incident. Chances of her having a PFO are relatively high (about 1:3), but it wouldn't be the first time someone develops a case like your wife's and there is no PFO to blame. There may be other shunts or short-circuits that could cause the same paradoxical embolism we so strongly like to suspect, like intrapulmonary AV malformations.
What if she has a PFO? -
Well, what if she has one? Is she going to need surgical closure? I would say probably not, if she never had any issues before. Watch out here, you might actually hear "Oh... she needs surgery!". Keep in mind that if she never had any issues whatsoever for 36+ years, going through cardiac surgery just for diving? Even when we can't really prove that her PFO actually caused it? I would say it is absolutely not worth the risk, for surgery is not risk free either. And even if she goes through surgery, a successful surgery does not eliminate DCI risks, and the recommendation after surgery would still be to dive very conservatively.
What if she doesn't have a PFO? -
Well, it might be worth looking for other shunts, because her only dive was not that provocative, and her symptoms and symptom onset was very compatible and suspicious of an embolism. Classic AGE cannot be ruled out either, by no means. She could have had a bronchospasm and caused pulmonary barotrauma leading to AGE. The absence of any form or signs of extra-alveolar air does not rule out pulmonary barotrauma and AGE, this is not a sine qua non finding.
What about future diving? -
That is the toughest question. 106 uneventful dives lifetime, and 1 major hit. 1:100 . Not bad for the casino, but woefully high for diving. At least, that's what we think over here.
Now it is strange that the chamber staff decided she did not need treatment. Normally most facilities, when facing such a case, they would treat anyway.
Anyway, we hope this helps, and please do let us know if you think we could be of any further help. Same if your doctors would like to consult with DAN, we are here to help.
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