Oxygen poisoning seizure > how to react ?

[Searcaigh]

I don’t think much evolved since you left Jeddah; the technical community in KSA is still exceptionally small and lining up skilled folks to be on the same dive is a challenge.

I guess that doesn't surprise me to be honest. When I left Jeddah in '97 Nitrox wasn't even available, although on subsequent trips mid 2000s I did manage to obtain some.

Also back in the 90s, the only chamber was at the GNP Clinic where I was a volunteer helping run the chamber on a few occasions (I'm a qualified chamber operator). The person in charge at the time was a Swedish guy (Hans Sjoeholm), but that was 20 years ago.

The issue we have here is that most of the tech diving in UAE is on the east coast and the two available chambers are two to three hour drive on the west coast with a 600m highest point to cross very close to the east coast, which was one of the reasons the tech group I belong to decided to run an IWR course several years ago.

 

[rjack321]

The issue we have here is that most of the tech diving in UAE is on the east coast and the two available chambers are two to three hour drive on the west coast with a 600m highest point to cross very close to the east coast, which was one of the reasons the tech group I belong to decided to run an IWR course several years ago.

We should be so lucky here. From many dive sites in the Washington/Oregon/British Columbia region you're looking at 6 to 12 hours of travel time to a chamber. And the water is 4 to 12C so IWR is less & less attractive

 

[Doc Harry]

Plan however you want, a seizure at depth is likely not survivable unless the person is wearing a full face mask.

In this case, an ounce of prevention is worth a pound of cure. Dive conservatively and keep your pO2 low.

 

[Dr Simon Mitchell]

Plan however you want, a seizure at depth is likely not survivable unless the person is wearing a full face mask.

Hello Harry,

This is not quite true. The other mitigation (which I personally use) that is much less complicated and expensive than a FFM is a mouthpiece retainer device. The Drager gag strap is the best designed one in my opinion. Unlike many things in diving medicine there is actually some evidence for their efficacy. I have uploaded a paper by the French Navy group reporting rebreather accidents among which there were 54 loss of consciousness events with only 3 drownings. I would have expected many more drownings in 54 divers who lost consciousness underwater, but I believe all of them were wearing a gag strap, and most had buddies close by. To be objective, most of these probably occurred in shallow rebreather operations typical of operational attack swimming training, but the point still remains that they had high survivability after losing consciousness with the use of mouthpiece retainers and prompt rescue, which could easily apply in many technical diving situations if we chose to make it so.

Simon M

 

[rjack321]

Hello Harry,

This is not quite true. The other mitigation (which I personally use) that is much less complicated and expensive than a FFM is a mouthpiece retainer device. The Drager gag strap is the best designed one in my opinion. Unlike many things in diving medicine there is actually some evidence for their efficacy. I have uploaded a paper by the French Navy group reporting rebreather accidents among which there were 54 loss of consciousness events with only 3 drownings. I would have expected many more drownings in 54 divers who lost consciousness underwater, but I believe all of them were wearing a gag strap, and most had buddies close by. To be objective, most of these probably occurred in shallow rebreather operations typical of operational attack swimming training, but the point still remains that they had high survivability after losing consciousness with the use of mouthpiece retainers and prompt rescue, which could easily apply in many technical diving situations if we chose to make it so.

Simon M

I use a Drager gag strap, combined with a BOV that any buddy can use to switch me to a breathable gas. I don't know why this combination is touted more by both by agencies and manufacturers

 

[beester]

Me and a close budy once had to help up a teammember from an 90m dive (25min BT), mind you not unconscious, just very disoriented (needing to sandwich him, do the gasswitches for him, keep him down, etc). This was really a workload, and in the end we had to bring him up to the surface from the 6m stop missing about 45min of O² deco. Luckily we had surface support (and a team of JJ divers who were still on the surface in the water who could immediately assist, while we went back down to complete deco).

I can't imagine having to do this with an unconscious diver, on the other hand sending someone up from let's say 60m would be a death sentence or at least this was my assumption until Dr. Mitchells comments. I do know a GUE instructor personally who assisted in a oxtox event with long deco and managed to bring the victum up completing a part of the deco, however I don't remember the details so can't comment on that.

I'm going to rethink, what to do in these scenarios, and also will check gag straps. I know they are standard on some models (revo I believe). But it's not really a GUE (jj) thing, so need to check on this and how it work with our current procedures (probably won't in gas sharing events).

Thanks all who commented, it's been interesting and I learned new things.

 

[Etmutt]

Interesting, though difficult to apply to an OC long hose & stages configuration (over here rebreather are forbidden, so never got to use one).
My buddy used to dive for the French navy and he mentioned this gag system but putting it on the stages it seems like a double edge sword to me : if you switch to the wrong stage and gag it then...

 

[nickbutcher]

Or just hang tight and let them regain consciousness.

Ones “action” can simply be patience.

I had a tox in 2010. Fortunately for me, I was at 6m and recognised the symptoms so I hit the up button on my wing. On the surface I shouted at the boat that I was toxing and the crew guy dived in and hauled me out onto the deck.

Once I knew I was safe, I relaxed and instantly started fitting. It was 25 minutes before I came around and was faced with the winchman from the helicopter that the Coastguard had scrambled.

I doubt that I'd have been so lucky if I'd toxed underwater and been kept there whilst I was undergoing a grand-mal seizure.

 

[nickbutcher]

Dunno. I have seen postictal patients being very disoriented with discoordinated movements, even though conscious. My point is that sitting around at depth with a postictal, unconscious or impaired diver and hoping to keep their airway secure has very specific risks - both to the rescuer and to the victim.

After I came around from my tox (see above post), I was taken by helicopter to the local A&E before being transferred to the chamber at DDRC in Plymouth.

I have no recollection of being on the chopper and only vague memories of everything else that day, including many hours in the chamber being treated for a suspected brain bend that was diagnosed due to my ongoing confusion. I wasn't bent.

If I'd come round underwater after a 25 minute seizure, the outcome would probably not been positive.

 

[nickbutcher]

Hello Harry,

This is not quite true. The other mitigation (which I personally use) that is much less complicated and expensive than a FFM is a mouthpiece retainer device. The Drager gag strap is the best designed one in my opinion...

THIS ^^^

It was after a discussion with Simon in Bikini 2014 that I was convinced of the efficacy of using a gag strap, specifically the Drager one.

I've used one ever since and would hate to be without it now.