Article and flowchart about OxTox Convulsion

JonnyB

Ok, now i see,
IN that case, specially since the diver wears FFM or regulator is still in the mouth, then keep him there and try to do as much deco as possible. You would still have to asses the situation when it happends.
Look at what is happening,
1. Diver is unconsious, but breathing. Try to do deco, reasses situation over and over again.
2. Diver is unconsious and not breathing, is there anyway you can provide him with a heartbeat underwater? You whink he will survive if he does not get immediate help, no matter what. Then do deco, otherwise send him to the surface.

Usually a toxed diver with a regulator or dsv will have dropped it, some people say that do not attempt to get the regulator back in, i dont know if it is possible to get it back in but if it is too deep he is going to drown anyway.
All i am saying is that drowing is certain death, while DSC is not. If it is me that is toxing, send me to the surface. I believe i have more chances to survive that way.
Also i would not want the rescuer to endanger his life more than absolutelly necessary.
As a commercial diver i have been doing quite a few surface decompression. It is fully possible to skip alot of deco and get back down to complete them or even do them in dry chamber.

/Jonny

__________________
A quote from Crazyduck - In remembering our own Rob Davies.
"Outbound flight 777 heavy you are cleared for flight
Due west into that warm red Texas sunset
You have angels on your wings and divers memories on your six."

Rest In Peace

http://www.divetekcyprus.com
http://www.diveccr.com

Drmike

really? why do you assume that?


I was under the impression that at depth you have more CO2 are working harder and are thus more susceptible to toxing at ppO2s that resting on deco you can more easily tolerate.

__________________
Cave diving is a sport
Wreck diving is a sport
Diving in general is a sport

'Rebreather diving' is not a sport
its the delusional obsession with a highly dangerous and often inappropriate piece of equipment

Mdemon

Empty your PM box and I'll tell you...

__________________
www.southwestmafia.com



"Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"

cedricverdier

Hi all,

It sounds like the discussion becomes even more interesting with the active participation of Simon and Andrew.

Before working on a new version of the protocol and the flowchart, I need your opinion on some points. Please remember that there is no controversy here. Only reasonnable doubt. The whole idea is not to base the protocol on one man's opinion but to use everybody's experience to end up with a realistic, safe and flexible protocol.

As everyone pointed out, there is no Right Way to deal with this kind of scenario. So I try to doubt about every opinion until further notice and keep on questionning about the relevancy of every single step of a rescue scenario.

So far, we have the following protocol that gains some popularity:

1. If the victim doesn't have a mouthpiece in place, the ascent should start ASAP

1. Do you think it's still important to swim to a shotline nearby in order to have a better control on the ascent (rather than a catastrophic scenario with 2 very buoyant divers...)?
2. Is there any benefit in gently squeezing the air out of the the victim's chest? (I don't use "punching" anymore. Sorry for my mistake in english)

2. If the victim has a mouthpiece secured by an efficient neck strap or wears a FFM, the ascent might be slightly delayed to wait till the end of the convulsion

1. - If the victim resumes breathing, do you think that completing their decompression obligation could avoid DCS or is it useless? How to properly check for breathing with a CCR and a FFM?
2. - Is the Lung Overexpansion really a problem and does anybody know any other case of a Convulsing diver brought to the surface and experiencing bleeding or any other signs/symptoms that could be associated with it?

I hardly believe that the convulsing diver I was talking about in an earlier post could have bitten his tongue. Difficult to do that with a mouthpiece in place.
As pointed by Simon, the US Navy manual protocol is not 100% clear. On the other hand, according to the Royal Navy (thanks to Neil Holden on this forum):
"First, there is a period of body rigidity ... It is dangerous to attempt to surface the casualty at this stage because spasm of the glottis and respiratory muscles may result in inadequate exhalation during the ascent. Inadequate exhalation will result in lung over pressure and pulmonary barotrauma." (INM Report No. R97066 - THE PREVENTION AND MANAGEMENT OF DIVING ACCIDENTS - revised October 1997 - Paragraph 2.3.3)


3. Whatever the problem at the origin of the convulsion, there is no need for a diluent flush

1. - Nevertheless is it important to check the pO2 in the loop? to shut the O2 valve off? to open the CL OPV?

4. And we still have the situation of the significant decompression obligation for the rescuer.

What could be the factors to decide whether to:
- Bring the victim to surface and coordinate with the surface support?
- Send the victim on their own for an uncontrolled buoyant ascent?

I guess this one is very hard to answer (but if everything was simple, we wouldn't be discussing about it!). I think it's better to think about these different parameters while being comfortable in front of a keyboard. At least it's a good starting point to prepare yourself to deal with a real situation with a high level of stress, so many things to do at the same time and so little hands available.

Thanks all for your participation. We all work with the same goal.

Cheers

__________________
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

Drmike

I still keep seeing this word IF apearing. Nowhere has it been shown that victims wouldnt start breathing again.

I think this is very important that we once and for all dispell this myth one way or another. (Especially for those that wear FFM)

IS THERE ANY EVIDENCE THAT A FFM WEARING DIVER WOULD NOT START BREATHING AGAIN UNAIDED? Everything I have read suggests they would.

If I convulse whilst wearing a FFM Id hate to die of AGE or masses of missed deco because someone dragged me to the surface when there was no need to. Sure I may be combative or confused for quiet some time but isnt it worth trying?

I am obviously not talking about blowing a meer 30mins of deco here.


With a FFM diver wouldnt it be best to;

a) wait for the convulsion to stop,
b) ascend slowly and await for the divers breathing response to kick in,
c) try to do as much deco as possible

If this is too difficult due to a combative diver or other factors fine - but surely its worth a try rather than having a blanket - ascend imediately forget deco policy. If we have a buddy take a CO2 hit during a dive we dont just bolt for the surface even if they are uncooperative/unresponsive some effort is made to do deco if possible.

Its very easy for the USN to say bring a toxing FFM diver straight to the surface when they have a staffed chamber on the boat where they can be recompressed!

__________________
Cave diving is a sport
Wreck diving is a sport
Diving in general is a sport

'Rebreather diving' is not a sport
its the delusional obsession with a highly dangerous and often inappropriate piece of equipment

Sutty

1. Unless the line is VERY close I'd probably go for the immediate ascent, I'd still try to re-insert a reg. But you have to think if you will drift much, not be seen quickly by the boat etc, so perhaps different in a significant current.

2. I wouldn't squeeze/punch at all, if the airway is closed (but a source of gas in place) then opening the airway (head tilt/chin lift) is more important. If the airway is open then gas will escape if not then squeezing unlikely to help.

1. Assuming breathing I think holding a stop at least until victim is becoming agitated would be reasonable - if they become difficult/combative then take or send them to the surface. Could watch or feel counterlungs to check breathing.
2. I doubt lung overexpansion is a problem if airway is open.

Checking has got to be a good idea - a convulsion could be due to hypoxia rather than hyperoxia, a shame to ascend with a hypoxic victim when adding O2 or dil could save the day.

This is very difficult, how much deco to miss and what risk is attached for the rescuer! Always going to be up to the individual, you might miss more for someone you knew rather than a stranger for example.

Just my take on some of it.

__________________
Never forget that life is a finite resource.

Drmike

I would propose flushing with dil as a first step. If a diver has gone either hypoxic or Hyperoxic and he/his buddy was not aware of the loop going that way (maybe due to lack of flashing hud or beep beep beep) I would suspect the unit/sensors anyway and not trust the displays (without doing a dil flush)

Of course if the diver is wearing a FFM with a BOV (remind me again why everyone isnt) then Id just turn the BOV after verifying its plumbed in and turned on

__________________
Cave diving is a sport
Wreck diving is a sport
Diving in general is a sport

'Rebreather diving' is not a sport
its the delusional obsession with a highly dangerous and often inappropriate piece of equipment

Mdemon

My thoughts, FWIW...

1. If the victim doesn't have a mouthpiece in place, the ascent should start ASAP

1. Do you think it's still important to swim to a shotline nearby in order to have a better control on the ascent (rather than a catastrophic scenario with 2 very buoyant divers...)? If close, yes, because there may be other divers on the line to assist. I would protect the airway first, if possible.
2. Is there any benefit in gently squeezing the air out of the the victim's chest? (I don't use "punching" anymore. Sorry for my mistake in english)As you ascend, the gas will be forcing it's way out from the inside and the water will be pressing in from the outside. I don't think extra manual pressure will achieve anything and may even damage the already-expanded lungs (caveat: I'm not a doctor...)

2. If the victim has a mouthpiece secured by an efficient neck strap or wears a FFM, the ascent might be slightly delayed to wait till the end of the convulsion

1. - If the victim resumes breathing, do you think that completing their decompression obligation could avoid DCS or is it useless? How to properly check for breathing with a CCR and a FFM? If the diver is breathing and the Rebreather is functioning OK then there is no need to add DCS to the diver's problems. What's the rush if the airway and loop is OK? The high PO2 may make their deco more efficient than the rescuer's, ironically. A hand on the counterlungs (or abdomen for BM CL) would show movement if breathing.
2. - Is the Lung Overexpansion really a problem and does anybody know any other case of a Convulsing diver brought to the surface and experiencing bleeding or any other signs/symptoms that could be associated with it? People have died from it, including a child who rose from the bottom of a swimming pool with a bucket on his head! If your lungs are screwed, then it's not looking good for you... And yet, the Docs don't rate it as risky as we do, and they should know... Tough one.

3. Whatever the problem at the origin of the convulsion, there is no need for a diluent flush

1. - Nevertheless is it important to check the pO2 in the loop? to shut the O2 valve off? to open the CL OPV? Checking the PO2 would be important if wearing FFM/gag and deco is being attempted, for obvious reasons. CL OPV would be essential to help control buoyancy on the ascent - and breathing against a fully inflated CL would be impossible so just as dangerous for the diver as not breathing. Shutting O2 off would be bad - maybe for the off-effect but also ultimately for hypoxia. Contraversial, but if the PO2 remains high, the deco will be better allowing more leeway if a rapid ascent occurs. If another fit happens, well you are still managing the airway and buoyancy so is this actually changing anything?

4. And we still have the situation of the significant decompression obligation for the rescuer.

What could be the factors to decide whether to:
- Bring the victim to surface and coordinate with the surface support?
- Send the victim on their own for an uncontrolled buoyant ascent?
Are they breathing? Definitely no? If not breathing for a long time then airway might be compromised. Would a lung-crush on the CLs force enough gas into the diver to re-start breathing? Would ascending a few metres purge any water from the lungs? Time to consider sending them up, unless you have a black belt in Underwater CPR... At least the body will be recovered for the relatives.
Is their Rebreather functioning OK? If they are breathing and their Rebreather is working then there seems to be no reason to avoid deco. They will be doing your schedule though, unless theirs is longer...
Is there any other reason not to do the deco? The victim/you may have another problem which is unresolveable, but if they are breathing and the Rebreather is working then I can't see a reason to skip deco.
Is the surface support capable of rescuing the diver in a timely fashion? In the UK, the skipper may be shepherding a long line of DSMS spread over a large area. I'd suggest it is unlikely that they would appreciate the problem immediately without you telling them and when they do, it may be too late. It's a big gamble hoping that the diver will be found in time, especially "mouthpiece out". A great way to discharge your responsibility as a rescuer, but maybe not the best thing for the diver. So the only way to co-ordinate will be do what you can with the airway, to ascend with them, manage the situation and return to depth for missed deco. That's a personal call I think is best made on the ground, on the day.
Is the missed deco serious enough to kill/severely injure the diver? What state will someone be in having missed lots of deco, victim or rescuer? I don't know the answer, but I suspect it is "not good" at best. IWR would seem to be the only solution - but doing it to an unconscious tox victim? For preference, doing the deco would seem to give the best long term outcome.

More questions than answers, but I think you see where I'm coming from.

__________________
www.southwestmafia.com



"Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"

Mdemon

Exactly. That's how I hope anyone with an intact loop, FFM/gag or otherwise, would be treated.

I phoned our local chamber and they had never heard of breathing not re-starting. I have never heard of any cases at all where breathing hadn't restarted except the two that Dave T mentioned, and who's to say whether or not that was as a result of inhaled water rather than the tox itself?

I have got a mantabite/gag combo. I am assuming that if I tox, I will at some stage recover. If I can't self-rescue, I am hoping that some kind soul will come and find me (I have 3 hours guaranteed by AP for you to do this, so please do try... ) and bring me up, breathing, and doing my deco for me. I am assuming that my PO2 will have remained very high, so although I may multi-tox, my actual deco will be less than my VR£ says.

Please don't screw up all my hard work by launching me like a Polaris at the boat! Adding concussion and DCS to my problems won't help...

__________________
www.southwestmafia.com



"Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"

dave t

the two cases I witnessed May have started breathing again on their own, to be honest in our ignorance we didnt give them a chance, we just did it for them. When you are taught "resuss as soon as possible", thats what you do.