Unpleasant Experience

[Uncle Pug]

I said supposedly because that is what I have read concerning the narcotic potential of CO2.

If the lipid solubility of a gas is an indicator of its narcotic potential then CO2 would be 25x more narcotic than nitrogen according to the Bunsen Solubility coefficient of each gas. (nitrogen 0.052 vs CO2 1.340 btw O2 is 0.110)

This may or may not be the case... but CO2 buildup (hypercapnia) certainly seems to exacerbate nitrogen narcosis and of course causes shortness of breath (SOB) as well as anxiety.

 

[mrobinson]

(I invested a siginificant amount of time and money on the trip)Anybody ever have a similar experience or think they can shed some light on the situtation?

I've been on artifical reefs, with nitrox and had some similar experiences too. Now I take it easy on dives. If I can't take it easy through the dive, I should call it. But I know the dilemma you face on a trip - sounds stupid here at home while typing on a computer but when you're out there on a dive boat, your gear waiting, everyone's paid, it's very hard to call a dive. It really sounds like the advice you're receiving on the posts previous to this one sums up all the physical issues. It might take some time to feel confident you analized that situation thoroughly. Talking about it in places like here will help! Good luck and thank you for sharing because it will likely prevent someone else going through a similar situation.

 

[DeepSeaDan]

What the heck, I guess I'll share an experience that has concerned me for a while.

While diving on a wreck in about 130 foot of water with NITROX 30% I started to feel as if I was going to pass out. The current was strong and I had to swim pretty hard for a few moments. I felt a sensation through my whole body and could feel my heart beat. I felt slightly starved for air and adjusted my second stage a bit. After a few minutes of feeling like I was going to pass out and die, I acsended to about 70 feet. I hung on the anchor line for a minute or two and the feeling went away. For some reason (Yes, I know this was stupid) I went back down to the bottom. Immeadiately the feeling returned. This time I ascended and got back on the boat. During the safety stop I felt as if I was sweating in my wet suit. The water was about 80F and I had a 3mm on, no gloves or hood.

Back on the boat I felt light headed and clumsy. After about 2 hours I still didn't feel right so I sat out the second dive. In hind sight this was obviously the right choice but at the time it was a difficult desicion. (I invested a siginificant amount of time and money on the trip)

It was very rough that day and I might have been slightly sea sick. I didn't puke or come close to puking. After sleeping the whole ride back I felt fine. After taking several months off, I have been back diving a bunch with no problems. I've even returned to the same site. I still do not understand what was wroung with me on that dive

I had performed many similar dives, and conditions that day were fantastic, so I do not think I was nervous or stressed out. And I typically do not have any significant problems with narcosis. It was my first dive that week and I was well within the no deco limits. I'm young and I wasn't exerting myself that hard so I do not think I was having a heart attack.

My max depth was 128 feet. Maybe I pushed the PO2 too far? Was it a C02 build up?
Did I get a bad tank fill? Anybody ever have a similar experience or think they can shed some light on the situtation?

(Is there a Spell Check on this board?)

Thanks

...I would suggest you check out Scubadoc's papers on Co2 issues here http:// www.scuba-doc.com

...I would also encourage you to be more aware of your physical condition post-dive after every dive, but especially more aware after a dive such as the one you have described. Never hesitate to discuss how you're feeling with your buddy, the Divemaster, the vessel operator &/or any other person who may be of assistance. A call to D.A.N. in such circumstances is a very prudent thing to do. If 100% medical O2 was part of the vessel operator's emergency equipment, it would have been wise to partake of it. Vital statistics, dive history & a rapid neurological exam would have assisted the physician @ D.A.N. to assess your situation.

...Any abnormal physical experience(s) u/w &/or post-dive should be treated with suspicion until ruled otherwise by professional medical opinion.

Regards,
D.S.D.

 

[Mako Mark]

CO2 is becomming more and more recognised as a potential fly in the ointment while diving, particularly in deeper diving, and by the sounds of it you were not putzing around in the shallows.

I like the term Dark Narc though, kinda catchy.. Good one Pug.

.

 

[H2Andy]

If the lipid solubility of a gas is an indicator of its narcotic potentila then CO2 would be 25x more narcotic than nitrogen according to the Bunsen Solubility coefficient of each gas. (nitrogen 0.052 vs CO2 1.340 btw O2 is 0.110)

actually, i have read about this a lot, and i haven't really seen anything that shows
the the bunsen solubility coefficient is not a good indicator of narcotic effect.
from what i've read, helium is not be very narcotic at all (.015) and xenon is
extremely narcotic (1.900)

nitrogen is really not that narcotic (.052) compared to oxygen (.110), argon (.150),
carbon dioxide, as you state (1.340) and nitrous oxyde (1.560)

both hydrogen (.042) and helium (.015) are less narcotic than nitrogen (.052)

of course, as you say, this is all assuming the Meyer-Overton rule is correct and the anasthetic potency of a gas is inversely related to its lipid solubility.

i do have a question, though:

since oxygen is more narcotic than nitrogen, how come trimix (which is hyperoxic air)
doesn't narc you as bad?

maybe because since the body metabolizes (is that the right word?) oxygen, its
narcotic effects are different or experienced less dramatically than nitrogen's?

also... could oxygen toxicity really be "oxygen narcosis" and its side effects?

just thinking out loud

 

[Ayisha]

i do have a question, though:

since oxygen is more narcotic than nitrogen, how come trimix (which is hyperoxic air)
doesn't narc you as bad?

Isn't it because of the helium in Trimix?

 

[H2Andy]

yeah, which takes the place of nitrogen, so you don't get narced from nitrogen
as bad

but in terms of oxygen (which is more narcotic than nitrogen) how come when you
have more oxygen in a gas (such as nitrox or trimix) the oxygen doesn't narc you?

 

[wedivebc]

yeah, which takes the place of nitrogen, so you don't get narced from nitrogen
as bad

but in terms of oxygen (which is more narcotic than nitrogen) how come when you
have more oxygen in a gas (such as nitrox or trimix) the oxygen doesn't narc you?

Maybe because Meyer - Overton deals with inert gas narcosis and O2 isn't inert. Therefore does not follow the M-O theory.

 

[Uncle Pug]

AFAIK that actual mechanism of narcosis is still not completely clear. It is possible that different gases affect narcosis in ways not totally dependent on their solubility coeffcient. Certainly one must at least consider that O2 is metabolized where as the other gases are more or less biologically inert.

That said, my subjective opinion is that nitrox has a greater narcotic effect than air. Something that bears this out, at least in my mind, is the narc that I've experience at 70' going from trimix to EAN50.

 

[scubafool]

AFAIK that actual mechanism of narcosis is still not completely clear. It is possible that different gases affect narcosis in ways not totally dependent on their solubility coeffcient. Certainly one must at least consider that O2 is metabolized where as the other gases are more or less biologically inert.

That said, my subjective opinion is that nitrox has a greater narcotic effect than air. Something that bears this out, at least in my mind, is the narc that I've experience at 70' going from trimix to EAN50.

This is sort of an answer to a question that has been bouncing around in my pea brain as of late, which is " Is enriched air(nitrox) less or more narcotic than regular air at deeper depths?". My thought was that the lower nitrogen levels would make nitrox slightly less narcotic than air, considering that O2 takes the place of nitrogen. Considering all of this, however, possibly the reverse is actually true?