Bringing an unconscious Rebreather diver up from depth

Dave Sutton

Not really. There's a huge gap between time of useful conciousness (TUC) and time to suffering permanent physiological disability. You will pass out *lots* sooner than you will suffer brain damage. Aviation stuff: TUC at 35,000 feet is about 1 minute. Takes hours there to suffer brain damage. Convert that to PP02 and see what it works out to.


In any case, I'll again beat the "use a reasonable diluent" drum one more time.


Dave

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"All animals are equal, but some animals are more equal than others"


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Divechick

Are there any circumstances where the best option would be just to hit the unconcious diver's wing inflate button and send them up? (Assuming there is surface support). For example, if it appears they had stopped breathing and a controlled ascent to the surface would simply delay getting help to them? Or is it too difficult to tell reliably at depth whether they have stopped breathing?

decoweenie

Just my own thoughts...

If you send the unconscious diver by him/herself up by injecting the BCD without bringing the person up yourself, there is a chance that the diver will be floating face down in the water at surface - and the mouthpiece could have been dislodged along the way (from overpressure of fast ascend, as example).

With OTS-CL, it is fairly easy to tell the diver is still breathing by looking/feeling the CL inflating and deflating.

All-enclosed BMCL would be more difficult. And compound with thick wetsuit/drysuit, it could be difficult to feel the chest moving up/down with each breath.

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Divechick

I absolutely agree that this would be a risk. However, if it appears from the lack of movement of the (OTS) counterlungs that there is no breathing, isn't there a risk that a controlled ascent to the surface will simply extend the time the diver is not breathing and is not getting help? This is not a personal opinion - more an enquiry...

decoweenie

Perhaps someone with medical background could give their opinion.

__________________
"...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..."

- Rebreather World PM

fireman

My thoughts: I haven't had to rescue anyone underwater, but I have in other toxic atmospheres. First thought what can I do without killing myself. Two dead is worse than one. Second--A CPR instructor once said what is the worst thing that can happen if your doing CPR--Nothing because if your doing CPR they are already dead. So if the only thing you can do is zip somebody to the surface...Of course there are usually better alternatives. In my experience it is tremendously difficult to handle uncontious people. So getting somebody out of the water in bad conditions will require lots of help. Lastly, with cudos to WKPP preplanning is invaluable, and having resources in place including manpower when one is taking high risks is essential. So back up divers, Medical equipement, what are we going to do if xyz happens.
So:
What is the situation--how risky is it for me.
What is happening with the diver.
Airway, Breathing and Circulation.
How can I get help and what is available.

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Heres to you Capt. Bill
Never Forget, and stay safe everyone.

Tom Mount

Good risk evaluation

You need to get the diver off the loop and personally bring them to the surface if poossible -ttreating drowing is much safer than keeping a diver on a hypoxic-hyperoxic or hypercapnia loop

Try to get the diver to exhale- do not screw around trying to get a reg in the mouth - this process has save lives - unfortunately using OC thinking and keeping on loop has cost lives

But when ffaced with the challenge you will have to make that decision at the time
Tom

Gilles

Assuming I could remain calm in such a situation (and that's a big assumption), victim still breathing, no BOV;

I would try to make his loop breath-able. If it's hypoxic, a few squirts of O2 might be needed. Hyperox then maybe shut-off the O2 and hope a slow and controlled ascent brings down the PO2 sufficiently. Anything needing a loop flush might be the most complex to do, and should maybe not even be attempted unless there is some help.

Hope it never happens, and if it does, the victim has a BOV.

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Gilles
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Drmike

'I think'

the words 'I think' have no place in a discussion regarding life saving protocols.

'I think' any 'published' articles that people are likely (and do) refer to, should be subjected to peer review.

'I think' we should look at the specific credentials of those who offer their opinion or submit such articles and see if they are qualified to do so. What real medical training have they had? What real rescue training have they had (and I don't talk about dive course training I mean professional medical/rescue training)

Peer review is whets keeps uneducated dangerous or just outright incorrect tosh out of the public domain.

I sit on the board of review for two international conferences and journals. As such I/we vet through submitted papers and review them for content. These papers are subjected to peer review. The trouble with the net is its all too easy for self proclaimed 'experts' to make up an article and publish it - get it out there in the public domain most often with no review at all and often these people have insufficient knowledge.

I'm not saying all such 'net' threads/discussions or articles are rubbish - but people DO believe what they read. We can (and probably are) moving towards a time when the net is clogged up with un-reviewed 'opinion' expressed as fact and any poor sod who's trying to get to real info would have a hard time.

There are places to go for real data, real results, real qualified opinion. I think we are better off availing ourselves of that than we are 'winging it' ourselves and referencing papers that mainly are just reformatted internet forum discussions and consensus mostly created by unqualified people.

Hey if enough forum people (unqualified) agree it must be a correct protocol yes???........er NO.


Bitter experience has taught me people never get the point so Ill spell out my point clearly so there's no confusion:

-I am not saying discussions are not useful.

-What I am saying is in the interest of the very safety we are trying to promote we should at all times when having such discussions clearly differentiate between educated opinion and uneducated opinion.

Rant over - I'm going diving!!! yey!!! :P

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rdmmdr

Mike
i supported you on the meg question, but where did this anger come from for this post. while most of us have decided that our families come first, and therefore don't do the kind of extreme dives that you do. Our contributions and concerns are still valid, and this is the place to air those concerns and voice our opinion. while i have not dove to the depths that you have, i still have 36 years of experience. that experience i think, allows me to express an opinion. During those 36 years of diving i have been involved with 7 body recoveries, 2 of which where scuba related. and god knows heard about how many other deaths. The first duty any diver has during a rescue is to his family. IE stay alive. a dead rescuer is just one more victim to deal with. the second duty of a rescuer is to assist the victim without violating rule number one. This is a subjective call but if you are in a situation with a large deco obligation, a far transport distance and limited support, the victim is most probably dead, just not now. I personally would not blow a stop deeper than thirty ft. during a rescue. if i was on the line with a thirty ft stop ahead of me then yes i would blow it and surface. followed by a panic decent to 90 for a slow ride back. But what did that action give us, one bent and possible dead diver on the boat, one bent diver doing in the water re-compression. no recuse scenarios are good, except in Hollywood, the best we can hope for is the least bad.

so since there is no good way to rescue an unconscious diver, how do we avoid being the unconscious diver.

1. check cells for current limiting
2. don't push the scrubbers.
3. if the tank is marked 232 bar fill it to that.
4. can you say bov.
5. carry enough bail out.
6. don't dive with broken gear.
7. annual services are not a recommendation they are a requirement.
8. And to quote the safety officer from a Confederate air force fly in
" all right everybody, nobody do anything stupid." If you will not tell your wife or your parents exactly what you are doing you are probably doing something stupid.

rick