Oxygen poisoning seizure > how to react ?

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Doc Harry

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I've read it multiple times. It's also about as good of a retrospective study on LOC, seizures, and drowning risk as you are ever going to get. Do you even dive a rebreather?
Are you a physician?

Just to be sure that I didn't miss anything, I read the paper again.
"About as good," doesn't mean that it's very good at all.
I found the paper "interesting," but it lacked enough detail to draw very many intelligent conclusions.
And, again, the paper was addressing a different matter than this thread, so it's apples and oranges.
 

Dr Simon Mitchell

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The study you provided is flawed in regards to question being asked, i.e., the survival of a seizure underwater. The study you provided included all forms of loss of consciousness, not just seizures, which means you're comparing apples to oranges. Furthermore, the study you quoted did not break down the survival rate for the hyperoxia/seizure group, which means that study is irrelevant to this discussion. Furthermore, the study size is so small that their guess is as good as mine.
Harry,

Let's start with your original statement:

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

I offered the French study as evidence that your statement was not correct. You call the study flawed. I would be interested in your plan for a non-flawed, ethically acceptable, human study of whether mouthpiece retainers protect the airway in an underwater seizure.

I suspect that commentators with experience in this area would unanimously agree that 54 underwater loss of consciousness events would be expected to result in more than 3 drownings unless some protective strategies are in play. In the latter regard, the ubiquitous use of a Drager mouthpiece retainer in the French study is very plausible contributor to this unexpectedly good outcome. Yet you seem prepared to ignore this possibility on the tenuous basis that not all the loss of consciousness events in the study were seizures, and the outcome data were not stratified to isolate that group. There may be some relevant differences among the 3-H events (hypoxia, hyperoxia, hypercapnia), but unconsciousness with an unprotected airway in a non-respirable liquid environment is the final common pathway and I therefore don't agree with your apples and oranges metaphor. Your methodologic criticisms would be more compelling if a gold standard study were doable, but clearly it is not. As rjack321 said, we are unlikely to ever have better evidence than observational studies like this.

Going back to your original statement and with the above in mind, I believe you do the community a disservice with such a dogmatic proclamation on a critically important safety issue, and where you ignore expert opinion (and some compelling evidence) that there actually is an alternative strategy to a full face mask that seems likely to enhance survivability if you have a seizure at depth. You should be careful about the accuracy of authoritative statements on such important issues, especially when you imply expertise with the title "Doc". I'm not sure what to make of your "I've intubated lots of people" statement. Are you an anesthesiologist or a CRNA or a paramedic?

I have attached another paper which discusses this issue and which you might find interesting.

Simon M
 

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wetb4igetinthewater

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OT: Anyone got a link for the Draeger mouthpiece restraining strap (Is that the correct name)? I'd like to buy one for my Prism2.
 

rjack321

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wetb4igetinthewater

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Doc Harry

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I suspect that commentators with experience in this area would unanimously agree that 54 underwater loss of consciousness events would be expected to result in more than 3 drownings unless some protective strategies are in play.

Simon M

You are drawing false conclusions that are not supported by that article
This thread is about surviving a seizure underwater.

In regards to you article:

How many subjects had an underwater seizure?
The answer is 26

How many survived the underwater seizure?
The article makes no mention of the survival rate of those who had a seizure.

I agree that even if all 3 deaths were from seizures, an 89% survival rate is not horrible (unless you're one of the 11% who die). But also note in the article that these are professional divers who have good mutual support, and who were rescued as quickly as possible by other professional divers. I expect the death rate for rec divers would be much higher because of lack of proper buddy skills.

The article that you provided above looks promising, and I will get to it within the next week.
 

Dr Simon Mitchell

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You are drawing false conclusions that are not supported by that article
This thread is about surviving a seizure underwater.

In regards to you article:

How many subjects had an underwater seizure?
The answer is 26

How many survived the underwater seizure?
The article makes no mention of the survival rate of those who had a seizure.

I agree that even if all 3 deaths were from seizures, an 89% survival rate is not horrible (unless you're one of the 11% who die). But also note in the article that these are professional divers who have good mutual support, and who were rescued as quickly as possible by other professional divers. I expect the death rate for rec divers would be much higher because of lack of proper buddy skills.

The article that you provided above looks promising, and I will get to it within the next week.
Let's go back to your original statement that sparked this discussion again:

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

Now you are admitting that we have a published scientific journal report of 26 underwater seizures with only 3 deaths, and none of them were wearing a full face mask. Right there your original statement is proven incorrect.

You're choosing to interpret that high survival rate as a result of close buddy contact. I agree (and previously stated) that "prompt rescue" arising from close buddy contact was probably influential in this result. However, I put it to you that close buddy contact is indisputably something that divers can "plan" for and execute if they choose. Thus, your interpretation is incompatible with your own original statement where you said that planning "however you want" is unlikely to make any difference unless you are wearing a full face mask. .

And in all of this you are choosing to ignore that all these divers were wearing a device explicitly designed to retain and seal the gas supply in the airway instead of it inevitably falling out with the almost equally inevitable inhalation of water in the first post-seizure breaths. I really am at a loss to explain your strange intransigence on this point.

Finally, it still escapes me why you think a high survivability in loss of consciousness due to events other than seizures (such as hypoxia or hypercapnia) is not relevant to this discussion. Nevertheless, I am happy to limit the conversation to the 26 cases you seem happy with, and even to assume that all three reported deaths occurred in that cohort. It still proves that your original statement was completely wrong.

I stand by my previously stated conclusion (which you characterise as "false") that a mouthpiece retainer device "seems likely to enhance survivability if you have a seizure at depth". It is a view supported by the only available evidence, and multiple experts have come to the same conclusion.

Simon M
 

doctormike

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You have the patience of Job sometimes Simon, bless you

This ^

There are very few people in this world who are not only at the top of their field, but who are also willing to take the time to help others on a personal level.

:clapping:
 
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