WKPP - Dealing with O2 tox protocols

cedricverdier

[quote=db8us;64682
@Cedric,
where can i find your protocol ?[/quote]

In the Rebreather World library!
http://www.rebreatherworld.com/gener...her-diver.html

and it's not MY protocol but a protocol based on 2 very long threads on Rebreather World (just do a search): a lot of interesting information from several Hyperbaric doctors.

cheers

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Cedric Verdier
PADI Course Director, ANDI-IANTD-PSAI-TDI-DSAT-DAN-NAUI-CMAS Instructor Trainer
Trimix (CCR and OC) and Cave Diving Instructor Trainer

www.CedricVerdier.com
DIRrebreather member

Simon Mitchell

Hello Jim,

No, we don't all agree that this is not a good time for depth changes. This has been thrashed around quite a lot in the threads that Cedric refers to and if you are interested you will find the relevant information there. The glottis is not closed during a grand mal seizure - particularly the clonic bit which is the phase that may last a "long" time. Some risk of pulmonary barotrauma associated with an ascent during this period is undeniable (as it would be in any unconscious ascent) but the increment in risk implied by the seizure has almost certainly been overcalled. Holding a diver underwater during a seizure in the expectation that you will somehow be able to manage and protect his or her airway during the post ictal period will very likely result in drowning and should be avoided in my view.

The WKPP advice to get the diver to a habitat immediately is fine because it gets them out of the water, and quite frankly, I would not give a rats about what position they are in, whether the reg is in or out in my efforts to achieve this. This sort of detail just complicates thinking at a time when the focus should be on one thing and one thing only..... get their head out of water. If I had a habitat or bell 5m above me when my buddy started convulsing, I would have them in that bell long before the clonic phase of the convulsion ceased.

However, this is hardly likely to be relevant to 99.99% of technical divers who don't decompress in habitats. For those divers, getting to the surface is the priority, even if it means omitted decompression. How you get them there without compromising your own safety is the tricky bit and it will vary according to circumstance.

Regards,

Simon M

Drmike

Thanks Dave thats good info to have

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Steve

This is one of the most constructive threads I have ever read on Rebreather World. We have what apears to be a well constructed procedure that has being commented on by leading professionals. It is important to listen to people like Dave and Simon. In my life I have literally worked with true rocket scientists, global intelectuals by any measure. That being noted, Dave and Simon are amongst the brightest people I have ever met and whilst this isn't a guarantee that they are correct, it is worth noting that they should be listened to and if we are to develop quality information that is useful, we should use their and their peir's) tallents to build a useful procedures.

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Jim Brown

Greetings Simon:

Concur that drowning is greatest risk and prevention should be first priority.

I would advocate a more methodical response than I think you suggest, unless I'm reading it wrong... take the time to make the right decision then act aggressively. Omit the right decision and result could be keystone cops.

All: I did hijack the thread away from it's original context. Made classic mistake of re-hashing a recently discussed topic. Sorry 'bout that.

Regards, Jim Brown

Sutty

A few things occur to me reading through this thread, firstly this is a BAD situation and death is likely whatever is attempted, so huge risks to the rescuer should not be undertaken.
Also if you are the "hero" type, even if it all goes well(ish) underwater getting a victim to the surface (unconscious or obtunded) and then both drowning because DCS has paralysed you is not a good outcome.

Having said that if you can get my airway out of the water without risk of very serious DCS to you, then feel free to ascend even whilst I convulse to get to surface/habitat/whatever. (I'm not a cave diver)

On the protocol given I see no reason to check for a pulse, the protocol doesn't change whether or not you find one so why waste time checking. It is worth noting that a high proportion of trained healthcare professionals cannot detect a pulse or its absence within a reasonably short time (on the surface, not in an exposure suit), I doubt divers will do better.

Agreed it is possible to cause barotrauma with excessively vigourous ventilation, but at some point attempting ventilation must be better than certain death.

Lastly, I believe that one of the greatest benefits of any of these "protocols" is to get people to think through various options in various circumstances, thereby giving them a "repertoire" of behaviours to choose from in an emergency. Making it all up on the spot in an extremely stressful situation is even less likely to succeed, and more likely to have the rescuer feeling even worse about it afterwards when it goes badly.

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dteubner

For me the whole issue is about emphasis. I entirely agree with Simon that the first and most important thing is to get an unconscious diver's head out of the water - where you can usefully intervene.

Then you have some small print about what you do when you can't get them out of the water. Attempting to provide them with something to breathe seems not unreasonable - if they have spontaneous respiration.

So what do you do if they are not breathing? For mine the answer is to get them out of the water as quickly as you can hoping that the (presumably large) amount of oxygen in their lungs will keep them alive. Attempting to ventilate them from a very high high flow Ambient+10ATA gas source is, IMHO, much more likely to cause harm than good.

Well, what if you are 30 minutes back in a cave with an apnoeic diver? I guess that there are 3 options. Firstly you might just say "they're dead" and do nothing. Secondly you might attempt to exit while providing a regulator or whatever so that if they wake up enough to use it they can. Thirdly you could try to ventilate them. The outcome is pretty likely to be the same no matter which option you choose so it probably doesn't matter much.

I guess, at the end of the day, that I find it very difficult to imagine a situation where trying to ventilate someone with a second stage will save someone's life. I don't find it difficlut to imagine a situation where trying to ventilate someone with a second stage will kill them.

Dave T