I'm with Lynne here, it actually sounds pretty cut and dry like a CO2 retention event.
High CO2 will have a very vivid effect on the diver if left unchecked (AKA exertion continues) it can start with just a general sense of unease, to hearing your heart pounding, to feeling 'too warm', not being able to get control of your breathing, all the way to "get me the F*%$ out of here, i want to go home".
if you've experienced it, you can even logically _know_ whats going on, but all that does is give you something to hold on to that can prevent it from becoming a full blown oblivious to the world around you panic episode.
CO2 causes this much more often that divers realize or admit to.
My buddy Lamont and i are almost sure that its a High CO2 that contributes to what we refer to as a "Dark Narc" (that narcosis thats worse than plain narcosis and makes you wanna go home) most commonly caused by bombing your way down depth with effort (swimming, pulling arm and arm, fighting current on surface, etc...) or exertion once at the bottom.
The more aware you become of your "self" underwater, the more you will see/recognize the subtly different nuances of the physiology going on, on the inside. People can then recognize the tendrils of a CO2 loading issue coming on, wrapping its clammy fingers around your brain stem, and work on stopping the cycle (reduce effort, blow off some CO2, etc...)
here is an interesting non diving example that i relate in these discussions....
my real job is as a surgical tech, and one of the operations i've been a part of many many times is an awake carotid endarterectomy. To make sure the patient has adequate collateral flow from the other side, and isn't showering their brain with plaque or clots, some surgeons keep them awake and talk to them, and have them squeeze a rubber ducky during the critical part of the procedure. It sounds a bit barbaric, but the fancy gadgets designed to monitor this stuff have a delay, supposedly (as it was explained to me) if something is going bad, you can tell much faster when the squeaking stops or the patients starts slurring than waiting for it to show up on the monitor.
okay, so when we put a clamp on the carotid bulb to start the actual endarterectomy part, we actually put pressure on the carotid bodies, little chemo receptors near the bifurcation. When the clamp goes on, the patients will sometimes get super agitated and uneasy, "i can't breath" "the drapes are smothering me" "I don't feel right" "I'm dying". Nothing else has changed except for the stimulation of the receptors. If we release the clamp, or move it slightly, almost immediately the patient will settle down. (interestingly enough, one of my very first instructors referred to the carotid bodies and compression of them as to why some people just can't tolerate a snug drysuit neckseal)
The clamp is simulating a sudden increase in CO2 (the receptors don't know the difference). If someone can be perfectly fine with moderate sedation (as fine as you can be if you are on the OR table) one minute and whacked out the next, it seems to me quite logical that if we as divers drive up our retained CO2 rapidly (fighting current, gear, sucking through a straw or a ****ty reg) that we too will encounter some of those same feelings..
anyhow, sorry this was so long... and since i'm not a doctor and don't even play one on TV, its essentially worth what you paid for it... It is a theory based 20 years of diving/diving instruction, and 15 years in surgery watching the same things happen again and again and again....
High CO2 will have a very vivid effect on the diver if left unchecked (AKA exertion continues) it can start with just a general sense of unease, to hearing your heart pounding, to feeling 'too warm', not being able to get control of your breathing, all the way to "get me the F*%$ out of here, i want to go home".
if you've experienced it, you can even logically _know_ whats going on, but all that does is give you something to hold on to that can prevent it from becoming a full blown oblivious to the world around you panic episode.
CO2 causes this much more often that divers realize or admit to.
My buddy Lamont and i are almost sure that its a High CO2 that contributes to what we refer to as a "Dark Narc" (that narcosis thats worse than plain narcosis and makes you wanna go home) most commonly caused by bombing your way down depth with effort (swimming, pulling arm and arm, fighting current on surface, etc...) or exertion once at the bottom.
The more aware you become of your "self" underwater, the more you will see/recognize the subtly different nuances of the physiology going on, on the inside. People can then recognize the tendrils of a CO2 loading issue coming on, wrapping its clammy fingers around your brain stem, and work on stopping the cycle (reduce effort, blow off some CO2, etc...)
here is an interesting non diving example that i relate in these discussions....
my real job is as a surgical tech, and one of the operations i've been a part of many many times is an awake carotid endarterectomy. To make sure the patient has adequate collateral flow from the other side, and isn't showering their brain with plaque or clots, some surgeons keep them awake and talk to them, and have them squeeze a rubber ducky during the critical part of the procedure. It sounds a bit barbaric, but the fancy gadgets designed to monitor this stuff have a delay, supposedly (as it was explained to me) if something is going bad, you can tell much faster when the squeaking stops or the patients starts slurring than waiting for it to show up on the monitor.
okay, so when we put a clamp on the carotid bulb to start the actual endarterectomy part, we actually put pressure on the carotid bodies, little chemo receptors near the bifurcation. When the clamp goes on, the patients will sometimes get super agitated and uneasy, "i can't breath" "the drapes are smothering me" "I don't feel right" "I'm dying". Nothing else has changed except for the stimulation of the receptors. If we release the clamp, or move it slightly, almost immediately the patient will settle down. (interestingly enough, one of my very first instructors referred to the carotid bodies and compression of them as to why some people just can't tolerate a snug drysuit neckseal)
The clamp is simulating a sudden increase in CO2 (the receptors don't know the difference). If someone can be perfectly fine with moderate sedation (as fine as you can be if you are on the OR table) one minute and whacked out the next, it seems to me quite logical that if we as divers drive up our retained CO2 rapidly (fighting current, gear, sucking through a straw or a ****ty reg) that we too will encounter some of those same feelings..
anyhow, sorry this was so long... and since i'm not a doctor and don't even play one on TV, its essentially worth what you paid for it... It is a theory based 20 years of diving/diving instruction, and 15 years in surgery watching the same things happen again and again and again....