In-Water Recompression, Revisited

[JohnnyC]

Can't wait to see the paper. I just bought a FFM to add to the "I'm diving in the middle of nowhere" kit as another hedge against the "got bent" bet.

 

[Kay Dee]

I don't know how much Bret dives or posts these days, since I am not generally in the presence of either, but I have a comment on both............

If you note John, I also used the word 'generally' And having also 'spoken' to him recently I hold my stated view, 'generally'. ;-)

 

[Schwob]

...I just bought a FFM to add to the "I'm diving in the middle of nowhere" kit as another hedge against the "got bent" bet

@JohnnyC
or anyone....
(for fast readers, actual question in bold below)
There's a lot of mentiong of using / having / being trained on an FFM in this thread, but somehow, amongst the epic (and while it should be unecessary in the first place, still interesting) "who is right contest" on display here, I seem to be unable to find the post - that likeley is there - that would explain to the uninitiated why and how so an FFM would be of help
....
I could ask some dumber questions yet, like that I assume the FFM (in this context) is to be used during the IWR, not necessarily the regular dive and I might be wrong already... and then wonder if it's for communication purposes or if it somehow is helpful in dealing with convulsions (which seems to make limited sense as the point ought to be to avoid those) .... or possibly, somhow magically aids in avoiding convulsions (but can't seem to see a way that could be the case)...
...
... but having just learned from this thread, I might be dealing with (whoever they may be) "egos for whom the description "epic ego" is an understatement", I better not ask in any such total ignorance confessin way so as to not risk inflating anything of already more than epic proportions...
...
... so best keep it simple:
The FFM, in the IWR context, what exactly does it do for you that a regular regulator does not?
...
... disclaimer: No, I won't go run out and try IWR... won't have a reason to... just working on "getting a general better grasp on health affecting things related to diving" and getting to the point where I can be discerning enough to not follow some real stupid advice some day should that situation occur (sure heard stupid things said...)... ... and I hope to having achieved "non-capitalized-differentiation"

 

[Miyaru]

...
The FFM, in the IWR context, what exactly does it do for you that a regular regulator does not?
...

Prevents losing the regulator from your mouth in case of an oxygen toxicity hit. You will keep breathing while you're seizing, while the support diver brings you up to a shallower depth. The risk is real while you're breathing O2 for prolonged time with a partial pressure exceeding 1.6bar.

 

[boulderjohn]

Prevents losing the regulator from your mouth in case of an oxygen toxicity hit.

It is also possible to pass out as a result of the DCS.

 

[Akimbo]

Prevents losing the regulator from your mouth in case of an oxygen toxicity hit...

More specifically an OxTox convulsion. There are other OxTox symptoms that includes nausea. That is a consideration with FFMs, especially if your are hanging off in a swell (sea sickness and OxTox can upset a tummy). Barfing in a FFM is manageable, but requires some forethought and simulated practice.

See VENTIDC in Post #2: Oxygen Toxicity Limits & Symptoms

 

[Schwob]

Prevents losing the regulator from your mouth in case of an oxygen toxicity hit. You will keep breathing while you're seizing, while the support diver brings you up to a shallower depth. The risk is real while you're breathing O2 for prolonged time with a partial pressure exceeding 1.6bar.

Thanks!

Edit:
Ditto to @boulderjohn & @Akimbo. thanks for link too.

I was aware of what all might happen, not so much about how to combat it or why an FFM would help with that..., so, thanks... "It stays on your face" is easy to understand, why a well managed, necklaced regulator with an attentove buddy nearby would not do that is a bit harder to grasp ... but that may just be because I have no idea how severe (and getting you completely out of control of all??? things ?) real convulsions might be as opposed to "just" getting really sick & throwing up...

 

[Miyaru]

More specifically an OxTox convulsion. There are other OxTox symptoms that includes nausea. That is a consideration with FFMs, especially if your are hanging off in a swell (sea sickness and OxTox can upset a tummy). Barfing in a FFM is manageable, but requires some forethought and simulated practice.

See VENTIDC in Post #2: Oxygen Toxicity Limits & Symptoms

Very good point. While I wrote the post, I did think about nausea and the fact that you wrote earlier about throwing up in a FFM. But I have no experience with that, I just know how to do it through an ordinary reg.

 

[Miyaru]

... but that may just be because I have no idea how severe (and getting you completely out of control of all??? things ?) real convulsions might be as opposed to "just" getting really sick & throwing up...

A convulsion or seizure is simple: lights out, like the flip of a switch. You won't have any memory of it. So yes, you're completely out of control.
Can you feel it coming? Small chance.

 

[boulderjohn]

.
Can you feel it coming? Small chance.

As I understand it, sometimes you get a warning (see VENTID or ConVENTID for the signs). Sometimes you don't. When you do, it may well be like the warning I got when I saw the bicyclist coming at me in my lane in his tuck position as I was riding in a curving underpass--it gave me a chance to scream before impact. On the other hand, that may be all the warning you need. In one famous case, a diver getting such a warning signalled for an air share from a buddy and thus was able to get a safe gas in his mouth with a hand holding it there when he seized.