CO2 Hit symptom recognition

Steve

This post's intention is to help raise awareness of CO2 hits and specificity the usefulness or lack there of of experience in dealing with CO2 hits.

A bit of background; my initial CCR training was with the Royal Australian Navy. My course (1992) was one of the earlier ones (possibly the first) that did not do a CO2 exposure exercise to show the diver what CO2 symptoms felt like. Up until then each student was given a CO2 hit to show them what the symptoms felt like so that they could look out for them. I will guess that most of you can see the usefulness of this exercise but are justifiably a bit scared of the idea. It was stopped, not for any modern Health and safety reasoning but because it was deemed to be counterproductive.

As we experienced or have learned there are several symptoms that let us know a CO2 hit is about to bite and there is a certain amount of variety in the symptoms from person to person. As far as I am aware they don't strike with no symptoms. Medical Doctors? In the CO2 hit exercise, these symptoms are what RAN divers were taught to look for and remember so that if one was being experienced in the real world (non training) they could react acordingly. Seems like tough but realistic training right?

Here is the rub. The divers were later deemed to be worse off than divers that had not done the CO2 exercise as they were looking for the hit they had the first time. They 'knew' what a hit felt like and were found to work through different symptoms and take serious hits rather than prudently stoping work and dealing with the potential issue. Not a good thing to do when dealing with tools and explosives ;-)

This is why the RAN stopped this training. As far as I know no civilian training agencies have ever done this oficially.

In short, the age old maxim of 'if in doubt, bail out' rings true. Sanity breaths are a winderful thing. Long live the OC/CC DSV as it was called back in the good old days.

<edit> There might even be something in PADI's; STOP, Breathe, Think, Act.

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Drmike

reposted from other thread:

One reason I dont agree with the RAN theory about getting used to CO2 hits makes one push their luck is because Ive noticed that knowing that I have survived co2 hits (your never sure at the time if its retained or inspired) before by calming down, calming my breathing, flushing/bailing and most importantly by NOT panicing, goes a very-very long way to reducing my stress and enabling me to not panic and begin to take control of the situation.

IMO its the panic that is our imediate theat with retained co2 - at least it has been for me. You stop your exersion (or solve the ventilation issues) then fight back thoughts of panic. Knowing that you have sucessfully done that before I found helps a lot to help you do it again as the confidence that gives you aids fighting the feelings panic


...well thats what ive found anypoo

Thought process goes something like "come on mike you know your having co2 issues and you know its panic that will kill you and you know you have handled this situation before - you can handle it again"...I definately think it helps rationalise and deal with the situation and to me that quite an important benefit of having some co2 experience

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PCDiver

I get the "here we go again feeling ..."

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Steve

I may as well keep the cross posting thing happening...

This isn't my theory. IIRC it was John Pennefather

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WARNING: I contain occasional coarse language, extreme sexual references, nudity, and adult themes, which may offend some people - Usually churchy types.

Drmike

lol,

someone once asked me what goes through my mind when the sh1t hits the fan on a dive, and I said my 1st thought is always the same:

"oh no - not again"

my 2nd thought is always the same:

"ah so THIS is how mike finaly manages to kill himself"

my 3rd thought is always:

"boy this is going to be embarising"

__________________
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

Drmike

I agree that getting 'used' to having CO2 hits might enable/encourage one to push our co2 levels to the max limit we think we can tolerate (based on experience) and that 'conditioning may not be good - however given that often the onset of symptoms (for inspired)is very rapid i cant see the diver being able to conciously push the boundry in these more dangerous hits. So all in all I think the benefit (or being able to reduce stress/panic feelings and thus deal with issues ,encouraged by previous experience) outweighs the potential downside that a diver may push his limit on those occasions where theres a slow build up of co2, before reacting (delayed reaction)

I suspect the exact same thing can be said for not using a bov or side reg. the diver often delays reacting to co2 until hes very sure hes having a hit because of the hassle (physical) and mental stress of bailing to offboards. One of the primary reasons I prefer side reg over even a bov. nose breathe at slightest feeling of weirdness

__________________
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

Dave Sutton

And top marks to the first guy who typed "BOV" instead.... typing all of that other stuff was a pain (and who else remembers them being called that?)


Dave

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divetheworld

Having been there, and not further, I'd like to know how close to being in the sh1t were we at that point? If we hadnt dealt with those symptoms there and then, would it have been recoverable?

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Mdemon

I think he's given up diving! Step forward Paul and take your bow.

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jptaylor9

I read a report from a student who took an GUE RB80 course in Florida & they did a shallow dive without any lime in the scrubber to experience a CO2 hit.

Posted on YD & Stuart's "other" web forum.