[cedricverdier]

Hi all,

Just to let you know that, based on all the very interesting comments made about the proper protocol to follow in case of convulsion, I updated the article and the flowchart.
(not updated, completely changed!!)


It's still far from perfect and I don't expect everybody to fully agree with this protocol, even if tried to implement all the good ideas...
So as usual all your comments are welcomed.

For the time being, the article can be downloaded here:
http://www.cedricverdier.com/articles.html

...but very soon, Louby Lou should update the RBW Library (Thanks Lou)

cheers

[ERIK_A]

Im not sure if I am the only one but I cant download your seven deadly sins article off your web site.

Erik

[cedricverdier]

Quote: (Originally Posted by ERIK_A)

Im not sure if I am the only one but I cant download your seven deadly sins article off your web site.

Erik

Not finished yet....
Just too many dives and not enough time to write articles...

cheers

[Sutty]

Nice work Cedric, much improved, it looks a bit complex - but that is
because we are dealing with a complex situation! I still think there are a few changes needed though.

Following the chart doesn't allow for the possibility of a mouthpiece being in place without there being a FFM or strap, surely the 1st question is "is the mouthpiece or FFM in place" how it is being held there is secondary.

I still can't agree with not inserting a reg if mouthpiece out. Unless you get to the victim during the clonic or tonic phase they are unlikely to have much muscle tone if unconscious, the mouth is likely to be already open and full of water (this doesn't mean the lungs are). The victim has obviously lost sufficient muscle tone to lose the mouthpiece, they are unlikely to have sealed the lips after this.

Inserting a reg (purge during insertion) may occasionally introduce small volumes of water but is more likely to displace water from the mouth. It then helps you to keep the airway open (easier with something in the mouth like the reg mouthpiece because it keeps the jaws slightly apart), allows expiration of expanding gas, and prevents further water aspiration.

In the event the victim has convulsed but not yet re-started breathing then we want to provide for when they do. This would be possibly the most rescuable unconscious-mouthpiece-out scenario and without some gas supply they will probably drown.

As i understand it most agencies for open-circuit rescue also teach to replace a reg in a victims mouth before ascent, why should it be different if you were on a rebreather before the incident?


On the water in mask part: following the chart gets us to "water in mask?" which if "yes" leads to pinch nose and the ascent section without addressing the mouth, if "no" then you ask if mouthpiece is in - you shouldn't need to ask if mouthpiece is in here as you have already determined the airway is protected by FFM or strap.

Although not a route on your flow-chart but is in the article, if you seal the mouth and pinch the nose during significant ascent there is no-where for expanding gas to go and barotrauma will occur. It is important to allow gas out somewhere!

Thanks for keeping going on this!

Neil

[cedricverdier]

Quote: (Originally Posted by Sutty)

Nice work Cedric, much improved.

Following the chart doesn't allow for the possibility of a mouthpiece being in place without there being a FFM or strap, surely the 1st question is "is the mouthpiece or FFM in place" how it is being held there is secondary.

Just because, if the mouthpiece is in place but not well maintained (eventually by a higly stressed rescuer who has many other things to do), the risk of drowning is high and the best thing to do is to ascent ASAP anyway.

Quote: (Originally Posted by Sutty)

I still can't agree with not inserting a reg if mouthpiece out. Unless you get to the victim during the clonic or tonic phase they are unlikely to have much muscle tone if unconscious, the mouth is likely to be already open and full of water (this doesn't mean the lungs are). The victim has obviously lost sufficient muscle tone to lose the mouthpiece, they are unlikely to have sealed the lips after this.

I tried several times with students or friends (not anymore after that!) and wasn't impress by the result. Some of them coughed or ingested some water.
I'm quite sure it's a matter of practise and if you feel comfortable with this technique, do it.

Quote: (Originally Posted by Sutty)

Inserting a reg (purge during insertion) may occasionally introduce small volumes of water but is more likely to displace water from the mouth. It then helps you to keep the airway open (easier with something in the mouth like the reg mouthpiece because it keeps the jaws slightly apart), allows expiration of expanding gas, and prevents further water aspiration.

You can't reinsert the DSV, as there is no positive pressure (except with a BOV), so you have to insert an OC second stage.
In this case it means:
- deciding which tank to use (rescuer's or victim's). Also make sure that the mix will be breathable all the way to the surface (MOD, hypoxic mix, etc)
- opening the valve
- checking if the reg works
- checking if there's enough pressure in the tank
- inserting the reg

Quite a lot of things to do instead of ascending. But again, if you feel confident enough to do that, fine.

Quote: (Originally Posted by Sutty)

As i understand it most agencies for open-circuit rescue also teach to replace a reg in a victims mouth before ascent, why should it be different if you were on a rebreather before the incident?

Please could you be more specific? Which rescue diver course are you referring to?

Quote: (Originally Posted by Sutty)

On the water in mask part: following the chart gets us to "water in mask?" which if "yes" leads to pinch nose and the ascent section without addressing the mouth, if "no" then you ask if mouthpiece is in - you shouldn't need to ask if mouthpiece is in here as you have already determined the airway is protected by FFM or strap.

Good point. I'll try to change that.

Thanks for all the comments

Cheers

[Sutty]

Quote: (Originally Posted by cedricverdier)

Just because, if the mouthpiece is in place but not well maintained (eventually by a higly stressed rescuer who has many other things to do), the risk of drowning is high and the best thing to do is to ascent ASAP anyway.

I'd agree ascend - but hold the mouthpiece in and flush if you can.

Quote:

I tried several times with students or friends (not anymore after that!) and wasn't impress by the result. Some of them coughed or ingested some water.
I'm quite sure it's a matter of practise and if you feel comfortable with this technique, do it.

There's a big difference between a conscious friend and an unconscious victim with a mouthfull of water, it only takes a drop to provoke a cough. We're trying to prevent aspirating large volumes, if they aspirate a small volume so be it.

Quote:

You can't reinsert the DSV, as there is no positive pressure (except with a BOV), so you have to insert an OC second stage.
In this case it means:
- deciding which tank to use (rescuer's or victim's). Also make sure that the mix will be breathable all the way to the surface (MOD, hypoxic mix, etc)
- opening the valve
- checking if the reg works
- checking if there's enough pressure in the tank
- inserting the reg

Quite a lot of things to do instead of ascending. But again, if you feel confident enough to do that, fine.

Agreed its hard, but if you have a stage of gas you know is OK just use that (its not even too critical what gas it is, anything you carry will be better than a lungful of water, ideally breatheable to surface,) Part of the benefit is the one-way valve effect to allow gas out without letting water in.

Quote:

Please could you be more specific? Which rescue diver course are you referring to?

I remember being taught this at BSAC Sport diver level but understood PADI had similar - I may be wrong about either or both.

Quote:

Thanks for all the comments

Cheers

You are welcome, thanks for your efforts.

[cedricverdier]

Quote: (Originally Posted by Sutty)

On the water in mask part: following the chart gets us to "water in mask?" which if "yes" leads to pinch nose and the ascent section without addressing the mouth, if "no" then you ask if mouthpiece is in - you shouldn't need to ask if mouthpiece is in here as you have already determined the airway is protected by FFM or strap.
Neil

Hi Neil,

I just changed the flowchart based on your comment. Please download the new one (you should read version 2.1 on the bottom).

I also included some names I forgot to mention in the article (like Dave T).

Cheers

[Sutty]

Looks much better now

We can agree to disagree about reg insertion.

The only thing I'd change is where "is the mouthpiece in place" is "yes", I'd add "Add O2 if loop PO2 low" in case hypoxia causing unconsciousness.

Nice work!

Neil

[Louby Lou]

Quote: (Originally Posted by cedricverdier)

...but very soon, Louby Lou should update the RBW Library (Thanks Lou)

Hia Everyone

Cedric's "How to Deal with an Unconscious Rebreather Diver?" article has now been updated in the Rebreathworld library and can be found HERE

Just got to add the new flowchart to it

Cheers

Miss Lou

[Louby Lou]

Just to let you all know that the flowchart "How to deal with an unconsciousness rebreather divern underwater (convulsing or not)" has now been added to Cedric's article and also into the Rebreatherworld gallery

The article can be found HERE

The flowchart can be found HERE (Click image to see full-size)

Cheers

Miss Lou