EAN, Air and a propensity towards bubble formation

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Also, we do advise divers in the OP's situation to dive nitrox and set their computers to the air setting. This adds an additional safety factor if the diver can make the gas last long enough to approach the computer's no-stop limit, as the OP apparently can.

Best regards,
DDM
How much safety can it possibly add when the rate of DCS is already so low?
 
If you suspect a PFO, it might also be a condition in which the flap opens briefly causing a shunt. In addition to previous advice, you may want to try to restrain from exertion when getting out of the water such as climbing boat ladders or walking up hill. When possible, spend a few extra minutes on the tag line or surface resting before exiting. This might give you time to take advantage of the "surface deco stop," hand up or remove any additional heavy gear like cameras, goody bags, fins, even your tank, and climb out strong and light. If your condition worsens and you consider giving up scuba, freediving is a healthy and relaxing way to enjoy the underwater world and many people enjoy it far more than when using scuba.
 
This incident resulted in DCSII (doc says it was probably an AGE based on symptoms but I did not do a rapid ascent or hold breath...we suspect PFO).
I am very confused by this. Could you tell me what I am not understanding?

You said it was DCS, but the doctor said it was probably AGE. If it was AGE, then it was not DCS. If it was not DCS, then what you are saying about your history is that you had skin bends once.
 
How much safety can it possibly add when the rate of DCS is already so low?

If you are one of the few divers with a predisposition towards DCS, then it can add a lot of safety.

Whilst the statistical rate of DCS is predicted to be low, there are still divers who are unlucky to suffer repeated hits.
 
How much safety can it possibly add when the rate of DCS is already so low?

What Andy said. If they suspect PFO in the OP's case, and considering his history of multiple DCS hits (i.e. his individual risk is much higher than that of the general diving population), it may reduce the formation of venous gas emboli which could then be shunted.

Best regards,
DDM
 
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I am very confused by this. Could you tell me what I am not understanding?

You said it was DCS, but the doctor said it was probably AGE. If it was AGE, then it was not DCS. If it was not DCS, then what you are saying about your history is that you had skin bends once.

John,

Venous gas emboli that shunt through an intracardiac defect like a PFO become arterialized. It's possible that the practitioner used the term arterial gas embolism in that context, though AGE as classically defined in a diving setting results from pulmonary barotrauma. Maybe the OP can clarify.

Best regards,
DDM
 
John,

Venous gas emboli that shunt through an intracardiac defect like a PFO become arterialized. It's possible that the practitioner used the term arterial gas embolism in that context, though AGE as classically defined in a diving setting results from pulmonary barotrauma. Maybe the OP can clarify.

Best regards,
DDM


This is my understanding. I believe he drew this conclusion based on the nature of my symptoms, which were skin and cognitive. We both poured over the profile details in my computer and couldn’t really find anything that would have confirmed that.

As for diving Nitrox on an air profile- after much tinkering, I've discovered that a P2 factor with 32% Nitrox basically gives me an air profile. I'd love to get my hands on some 34%+ but it's not always available.

I've been milking my safety stops. Fortunately, I seldom surface with under 1000 PSIs so have the luxury of putting them to good use.
 
How much safety can it possibly add when the rate of DCS is already so low?
That is the problem with statistics. If you are, like it appears the OP is, on the outside of the bell curve, you have to take more conservative measures to accomodate your unique situation.
 
Perhaps you folks have heard? There's no such thing as "No decompression Limits". There are NDL recommendations, by and for specific groups and allowing for specific numbers of hits even within those limits, but no absolute limits. Anyone have a copy of the old Navy tables? 60/60, NDL, right? Except, it is 60/50 now and has been for some years. The research is ongoing and the "acceptable" percentage of hits is no longer acceptable outside of combat.

There's also no reason that the OP should "suspect" a PFO for more than 30 days. That's how long it takes to find a cardiologist and do the tests that will say if he does or doesn't have a PFO. If he does...things have to be considered or changed. If he doesn't?

He still has to simply accept that, assuming his math for his dives has been right, HE is more susceptible than "average" and HE needs to bump his safety factors up two steps, or else accept the fact that he WILL get hit if he keeps using NDLs that work for *other* people.

Really, there shouldn't be any mystery here. He just needs to make the choices.
 
we suspect PFO

Go & get tested so you know whether you have a PFO or not, & how problematic it is/could be.

I have a PFO albeit a small one & I have never had DCS. My tests, a discussion with my cardiologist, a discussion between my cardiologist & a DAN-recommended dive medicine cardiologist, & heavy duty research into the current standards for PFO treatment helped me personally determine that I didn't need surgery, could continue to dive, but needed to become extremely conservative.

However, another diver I know determined that their PFO was large & was the cause of their 3 DCS episodes so decided to get the PFO surgically closed...& is now diving symptom-free.

If you get tested, you can make an informed decision. Insurance covers this testing & since you're in nyc like me, I know you have access to fantastic cardiologists here. :)
 
https://www.shearwater.com/products/peregrine/

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