My first ever oh sh*t moment. (CO2 hit?)

[johndiver999]

Reverse squeeze can be pretty minor amount of feeling in the ear. The problem is when one ear equalizes and the other does not. It has caused me to have spinning vision, so bad that I have been puking. It can incapacitate you. I have had it when snorkeling in 8 feet of water doing underwater training swims. Hit the surface and one ear has pressure and the other does not. So dizzy I can barely hop out and lay on the pool deck and try to wiggle my jaw, keep my eyes shut and just wait for the pressure to equalize. the discomfort in the ear, does not have to be significant.

It is not the degree of unequalization, but rather the fact that the brain is getting wacky signals that differ from each ear and it can throw you for a loop, and very quickly.

It can be mild and just make you a little dizzy for 10 seconds all the way to total incapacitation and your eyes are spinning in your head.

Also, this is weird and I don't understand why - you can be descending and have one ear equalize and the other not, really that is a very common problem or situation. So in this condition, one ear is equalized and the other is not. But I have NEVER felt any noticable dizzyness or any of the other horrible effects that are common when you get a reverse squeeze when comming up? It seems like if one ear is equalized and one is not, it should not make a big difference if it occurs on the descent or the ascent, BUT IT DOES. I don't know why the two situations are so drastically different?

If the OP had a very rapid onset of very significant symptoms and it was just after the ascent started, I just does not sound like CO2; definitely not narcosis and also NOT oxygen tox at 1.3 after a relatively short exposure. None of these other causes should come on super fast or at all.

 

[Beau Holden]

Reverse squeeze can be pretty minor amount of feeling in the ear. The problem is when one ear equalizes and the other does not. It has caused me to have spinning vision, so bad that I have been puking. It can incapacitate you.

I have pretty much zero feeling in the ear until after the onset and if I did not know what to be looking for I would not even notice that. Now I notice it before the spinning vision and the feces hits the fan. Like you imply, it is bad and can scare the hell out of you.

 

[KevinNM]

There was a cave fatality where a woman was on a ppO2 of 1.4 using Triox.

According the person who posted that case, there has never been oxtox death at 1.3 or below, and 1.4 seems very rare. He mentioned that being female was a risk factor. My impression is that most oxtox incidents are not from 1.4 to 1.6, they are 2.x or even much higher from totally inappropriate gasses used. Not saying this wasn’t incipient oxtox, but it seems a bit like hearing hoofbeats and thinking zebras.

 

[UofMI_Divegeek]

CO2 is a particularly insidious gas creating all sorts of at-depth issues. I suspect your analysis is spot on ... great job in post dive review.

Incidentally, a number of years ago, the Israeli military reported in Undersea Biomed Research that the slightly (and it is really small) increase in gas density associated with breathing oxygen enriched air (Nitrox) exacerbated CO2 retention.

So, I advise divers using any oxygen enriched air mix to carefully monitor their breathing rate and CO2 symptoms (feeling air starved, excessive perspiration, sharp head ache between the eyes above the nose, etc )

Since the excess CO2 situation can rapidly escalate, I advise divers when they first sense / suspect CO2 that they close their eyes and imagine a stop sign. For most, this visualization has a calming effect to mitigate the CO2 increase.

My similar experience is described at

A Little Knowledge

 

[berndo]

My questions to you:

• Do you agree in my assessment that it was a CO2 buildup/hit?
  • I wasn't overexerting myself when it started, and I'm in pretty good shape, but my breathing had been restricted.
  • The headache also seems to support this...
• Any comments on what happened, the way it was dealt with, my thoughts about it?

I don't think this was related to CO2. It sounds very much like you just got narced and maybe a bit of a light panic attack and than you were shook from the scary experience.
When you get super stressed out that feeling can linger.
CO2 would have been caused by either exerting yourself too much or by trying safe air by breathing too little. I don't see that in your story.
Narcoses can go from feeling high and gitty to getting scared and panicky depending in the situation.
I've seen some people being really hammered at 30m and being stressed thoughout the rest of the dive. It's not super common but not super unusual either. The headache could have been easily caused by you being really stressed out and tense.

I don't think the weight belt had anything to do with it.
What I don't understand about the story is why you got into a strong current at the end of the dive and why you were worried to lose sight of your buddy on the surface.

Next time just tell your buddy you want to go shallower as soon as you feel uncomfortable. If you feel you need to breath more do it. Just make sure you don't breath too shallow.

Have you experienced something similar on OC? Was it caused by CO2 or do you suspect something else?

I have had CO2 build up. I was swimming against a pretty strong current into a cave I didn't know about same depth and with the same gas from your story. I the time I had only done one other cave diving in current and didn't have a guide and basically clueless. When I turned around and basically stopped paddling I noticed that my body really needed gas. A lot of gas. Apparently I had been working to hard and breathing too little for about 40 min or so. I didn't feel uneasy I just kept breathing very deeply at a higher rate than normal for a while on the way even though I was hardly moving. I was pumping through a lot gas. By the time I was out I was fine.

 

[crofrog]

I’ve observed in new divers who are working to maintain bouyancy primarily with breathing a tendency to stay at the top (full) or bottom (empty) lung for a while when they’re either heavy or light.

So when they’re diving it looks something like “fast inhale -> long pause -> fast exhale -> repeat” when they’re a bit negative and “fast inhale -> fast exhale -> long pause -> repeat” when they’re slightly positive. Because it is still inside the range they can control with their breathing they don’t adjust their wing, but eventually this leads to co2 retention and the feelings you’ve described.

 

[berndo]

Because it is still inside the range they can control with their breathing they don’t adjust their wing, but eventually this leads to co2 retention and the feelings you’ve described.

What makes you think that leads to co2 retention and causes narcosis?
His story sounds like text book dark narcosis to me.

 

[crofrog]

What makes you think that leads to co2 retention and causes narcosis?
His story sounds like text book dark narcosis to me.

Because they’re basically holding their breath between breaths. I invite you try either of those breathing patterns while engaged in moderate cardio and you’ll feel the co2 build up.

Oddly enough I can’t find any textbook or other academic publication that supports something called “dark narcosis,” however the literature does support that CO2 is significantly more narcotic than nitrogen.

 

[steinbil]

I don't think the weight belt had anything to do with it.
What I don't understand about the story is why you got into a strong current at the end of the dive and why you were worried to lose sight of your buddy on the surface.

It's an area of medium strong tidal current that accelerates through narrow channels between islands. I think we mistimed the tide a bit, and that the specific area we were in accelerated the water. I was worried because I'm not familiar with diving in strong currents and didn't think straight...

Next time just tell your buddy you want to go shallower as soon as you feel uncomfortable. If you feel you need to breath more do it. Just make sure you don't breath too shallow.

Good advice.

 

[berndo]

Because they’re basically holding their breath between breaths. I invite you try either of those breathing patterns while engaged in moderate cardio and you’ll feel the co2 build up.

CO2 build up is a thing but I don't know how you can be so sure it's that when it just looks like normal narcosis. You know, walks like a duck, quacks like a duck.

Oddly enough I can’t find any textbook or other academic publication that supports something called “dark narcosis,” however the literature does support that CO2 is significantly more narcotic than nitrogen.

Dark narcosis is what people call it when you don't get high and gitty but you get scared and your mind takes you to a dark place. Surprised you never heard of this. Instead of 'text book example' I could have said 'perfect example'. It's an idiomatic expression. a textbook example

CO2 is more narcotic, yes, so what? I gave an example. If I can swim againg strong flow for 40 min like a maniac and clearly be CO2 overloaded without any narcosis. How would somebody, who says he has a good fitness level, be completely hammered from CO2 on a benign dive?
As I said, it's not super uncommon for people to be hammered at 100', especially when you're not used to it.

What big studies have been done on different types of nitrogen narcosis and CO2 in hobby OC divers and how did they measure it?

Some of you newer guys really seem to really under value actual experience and over value random stuff you find on the internet. If any 'academic' publication told me there is no such thing as dark narcosis I wouldn't take it seriously.