Getting bent again...what's the story

[DiverBuoy]

Hey, I've read that once you get bent you have a highter tendancy to get bent again. Then I've read once you've "cleaned out your system" the slate is washed clean and all returns to normal again. Any thoughts?

 

[Spectre]

DiverBuoy once bubbled...
Hey, I've read that once you get bent you have a highter tendancy to get bent again. Then I've read once you've "cleaned out your system" the slate is washed clean and all returns to normal again. Any thoughts?

I actually originally thought that, and I believe I was corrected in that it's a confusion of cause and effect. everyone's susceptability to DCS is different, and some are more susceptible than others... hense the 'undeserved hits'. It's more likely that you are just more susceptable, than that you have a higher tendancy.

Search through the Dr. Deco archives. There are plenty of discussions on the theory of increased susceptibility, as well as plenty of discussions about "what's done is done... go dive again"

 

[WreckWriter]

You'll find lots of opinion, even scientific opinion, for both. Personally I've always believed that once bent, more easily bent again.

Tom

 

[DiverBuoy]

But what Spectre says is very interesting, with all that I've read it may just be that after a person gets bent - and lives of course - they have now been flagged as one of the more susceptable individuals. Therefore, subsequent hits are really further proof they were more susceptable during that part of their life - and NOT necessarily that their chances were worsened by the event itself.

Because age is a factor, in those cases where persons dove for decades but never got bent, then perhaps due to age, weight (that comes with age), injuries (as bones become more frail, and other bodily problems occur more frequently) , these factors and others cause them to get that first hit. After that as long as none of those susceptablity factors change (improve or go away) - they will remain susceptable.

IMO - getting bent flags you being susceptible to take another hit.

 

[Spectre]

DiverBuoy once bubbled...
But what Spectre says is very interesting,

Please understand my comments were pure parrotting of what I understand of what I've seen here, and have absolutely no basis in my personal knowledge... I just threw it in to sum up what I believe you'll find when searching the Dr. Deco archives.

... "spectre wanna cracker!"

 

[DiverBuoy]

I've moved this thread to Dr. Decompression since it is better served in this forum.

 

[DiverBuoy]

Spectre, be careful too many crackers can lead to dehydration which is another factor in DCI <lol>

 

[Dr Deco]

Dear Diver Buoy:

Preselection

During the Second World War, it was demonstrated that an effective countermeasure to altitude decompression sickness (“flyers’ bends”) was preselection of susceptible individuals . This was done by putting the candidates for high altitude bomber crews in an altitude chamber and exposing them to reduced pressure for a period of time. Those who were able to pass this test were deemed to be resistant to DCS.

DCS Susceptibility – Is It Real?

Extensive test programs at various centers around the United States demonstrated that

• some individuals were definitely more susceptible to the effects of pressure reduction,
• this susceptibility was constant over days to weeks to months, and
• it could be altered by physical exercise.

I bet that no one who reads this FORUM would have guessed all of those – “Right!” [The references for this work are not easy to obtain since was performed fifty years ago and requires a university library.]

“Once Bent – Twice Shy”

It is a possibility that you are a “susceptible.” It is also possible that you encountered some of Dr Deco’s “Trouble Spots.” :nono:

These would be

• excessive exercise at depth and too much inactivity at the surface (bad gas load/unloading characteristics,
• climbed ladders onto the boat with heavy gear and [excessively] nucleated yourself,
• performed too much strenuous activity during the surface interval [nucleation],
• were under hydrated and thereby lower the surface tension of your body’s fluids.

Conservative decompression is required in the future – and I do not mean just staying within the table “limits.” There are not really any “limits” in a biophysical sense.

Dr Deco :doctor:

 

[DiverBuoy]

I understand this premise "some individuals are more susceptible."

I understand this premise "susceptible individuals who encountered some of Dr Deco’s “Trouble Spots” are more likely to get bent."

What isn't clear is whether a person who gets bent a second time was merely susceptible and encountered a "trouble spot" a second time. Or whether an individual who gets bent a second time got bent directly because they were bent before and repeated the same circumstances (maybe even within table limits).

If nothing changes for an individual, that is they don't work-out and stay fit, don't improve their health, or work to reduce susceptibilty factors and avoid "trouble spots". Then ... how can we positively prove that getting bent means you are more susceptible to getting bent again. Or in other words, getting bent the first time could just be proof of your susceptibilty, much like the chamber tests of the 50's.

The fact that a susceptible person avoided getting bent for decades and suddenly gets bent twice in short order doesn't in and of itself bear witness to the theory that getting bent once in and of itself increases your chances to get bent again. What it may prove is that you could likely be susceptible now in ways that you previously were not susceptible, such as growing older, putting on more weight, sustaining more bone injury, joint problems, etc.

Any thoughts?

 

[DiverBuoy]

This really was a thorough response from Dr. Deco. But I felt I never got closure ... so after searching around and not finding a thread that really nailed this down I'm going to try rephrasing the question:

Does getting bent once increase susceptiblity even in the absence of all other "Trouble Spots"?

Is there a case where a non-susceptible diver who was bent previously for hitting a "Trouble Spot", later got bent again but no "Trouble Spot" or susceptibility could be identfied?