How To Experience Narcosis With Minimal Risk?

[lowviz]

Yeah, I know.

But I secretly like Kev, consider it a rolled up newspaper to the nose. I might get away with it, I might get bitten. We shall see...

 

[kr2y5]

Thanks for all the replies! To respond to a couple of the comments about the futility of such an endeavor: I did not mean to suggest that an experience of narcosis should be somehow used as a valid method of dive planning, or that having experienced it, one could somehow rely on that experience to recognize when narcosis hits. I realize it can be unpredictable, tolerance can change from day to day and depends on a lot of factors (and that according to some, the concept of narcosis tolerance is mistaken to begin with). As to whether this experience is predictable, I guess that's a whole another discussion, I know there are plenty of folks with strong opinions on either side of the fence. I guess I thought it would be useful as a way to get to know yourself, how your body might possibly react, and how it feels, regardless of the operational utility of such knowledge (on the matter of which, opinions apparently differ a lot).

 

[Bob DBF]

Yeah, I know.

But I secretly like Kev, consider it a rolled up newspaper to the nose. I might get away with it, I might get bitten. We shall see...

I'm betting on bitten.

I didn't chime in because I started looking up definitions and it was clear as mud.
Overbreathing means both hyperventilating which lowers CO2 levels in the body and shallow breathing which raises CO2 level. On top of that, hyperventilating also can mean shallow breathing. I couldn't figure what side of the argument to get on.

It is clear to me that any modern reg, and a lot of old ones, can deliver enough air to the diver if he can get it together to breathe properly. Of course my limited experience is not a scientific study.


Bob

 

[lowviz]

Yeah, Bob. You could demand more from some old-style primary regs than they could deliver without effort, thus the mechanical take on this. Overbreathing also has a physiological meaning. So the term remains ambiguous and both sides are defensible.

I'll fess up, maybe just a teensy bit of busting on Kev...

I'll also man-up and take the bite, worth it.

 

[TheHuth]

So where does one go for a chamber dive in Southern California?

 

[Kevrumbo]

So where does one go for a chamber dive in Southern California?

Better yet, volunteer to be part of the Chamber Operations Crew, on one of only two Recompression Chambers in the US dedicated only for Dive Accidents & Casualties 24/7 365. . .

Becoming a Chamber Volunteer > USC Catalina Hyperbaric Chamber > USC Dana and David Dornsife College of Letters, Arts and Sciences

 

[Kevrumbo]

I'm betting on bitten.

I didn't chime in because I started looking up definitions and it was clear as mud.
Overbreathing means both hyperventilating which lowers CO2 levels in the body and shallow breathing which raises CO2 level. On top of that, hyperventilating also can mean shallow breathing. I couldn't figure what side of the argument to get on.

It is clear to me that any modern reg, and a lot of old ones, can deliver enough air to the diver if he can get it together to breathe properly. Of course my limited experience is not a scientific study.


Bob

CO2 retention and its spiraling vicious cycle is the danger along with the sudden debilitating narcosis that can occur:

Carbon dioxide acts as a respiratory stimulant and can cause depression of the central nervous system (CNS). The effect depends on the level of carbon dioxide in the blood. Deep diving produces elevated blood carbon dioxide levels for several reasons, which include:

1. the resistance to breathing caused by breathing denser gas [especially Deep Air] through a regulator and against a higher ambient pressure;
2. reduced ventilation efficiency due to the denser breathing gas; and
3. reduced transport, and, hence, elimination of carbon dioxide. . .

Hypercapnia increases narcosis and the likelihood of CNS oxygen toxicity. In addition, it may increase heat loss, alter heart rhythm and predispose to decompression illness. If the carbon dioxide level gets too high, and it can on deep scuba dives -- especially if a diver is very anxious and / or exerting him/herself -- the diver may go unconscious without warning. Certain divers are more susceptible to severe hypercapnia for a variety of reasons and are therefore more at risk.

 

[Bob DBF]

CO2 retention and its spiraling vicious cycle is the danger along with the sudden debilitating narcosis that can occur:

Carbon dioxide acts as a respiratory stimulant and can cause depression of the central nervous system (CNS). The effect depends on the level of carbon dioxide in the blood. Deep diving produces elevated blood carbon dioxide levels for several reasons, which include:

1. the resistance to breathing caused by breathing denser gas [especially Deep Air] through a regulator and against a higher ambient pressure;
2. reduced ventilation efficiency due to the denser breathing gas; and
3. reduced transport, and, hence, elimination of carbon dioxide. . .

Hypercapnia increases narcosis and the likelihood of CNS oxygen toxicity. In addition, it may increase heat loss, alter heart rhythm and predispose to decompression illness. If the carbon dioxide level gets too high, and it can on deep scuba dives -- especially if a diver is very anxious and / or exerting him/herself -- the diver may go unconscious without warning. Certain divers are more susceptible to severe hypercapnia for a variety of reasons and are therefore more at risk.

My problem is not with understanding the concepts, but using words with multiple and conflicting definitions.


Bob

 

[lowviz]

Exactly, nice job of untangling the semantics problem.

I'll take on the mechanical meaning: The Mother of All Reg Reviews Search on "Consumer alert". Yes, there are regs that can't deliver without undue effort. -"Overbreathing the reg".

This is just for background: http://vintagescuba.proboards.com/thread/1827

So, who wants to take on and define the three (more?) physiological meanings? Doing so could add some serious value to this thread...

(edit) Explicitly, the top physiological contenders are (at this point in time):

... I started looking up definitions and it was clear as mud.
Overbreathing means both hyperventilating which lowers CO2 levels in the body and shallow breathing which raises CO2 level. On top of that, hyperventilating also can mean shallow breathing. ...

That is three more meanings in my book...

 

[Kevrumbo]

I'm betting on bitten.

I didn't chime in because I started looking up definitions and it was clear as mud.
Overbreathing means both hyperventilating which lowers CO2 levels in the body and shallow breathing which raises CO2 level. On top of that, hyperventilating also can mean shallow breathing. I couldn't figure what side of the argument to get on.

It is clear to me that any modern reg, and a lot of old ones, can deliver enough air to the diver if he can get it together to breathe properly. Of course my limited experience is not a scientific study.


Bob

Exactly, nice job of untangling the semantics problem.

I'll take on the mechanical meaning: The Mother of All Reg Reviews Search on "Consumer alert". Yes, there are regs that can't deliver without undue effort. -"Overbreathing the reg".

This is just for background: http://vintagescuba.proboards.com/thread/1827

So, who wants to take on and define the three (more?) physiological meanings? Doing so could add some serious value to this thread...

(edit) Explicitly, the top physiological contenders are (at this point in time):
That is three more meanings in my book...

Semantically, overbreathing the reg caused by physical exertion is what starts the whole "vicious cycle" --a pathophysiological feedback loop and concept that's clearly understood within a medical/pathological context:

CO2 retention and its spiraling vicious cycle is the danger along with the sudden debilitating narcosis that can occur:

Carbon dioxide acts as a respiratory stimulant and can cause depression of the central nervous system (CNS). The effect depends on the level of carbon dioxide in the blood. Deep diving produces elevated blood carbon dioxide levels for several reasons, which include:

1. the resistance to breathing caused by breathing denser gas [especially Deep Air] through a regulator and against a higher ambient pressure;
2. reduced ventilation efficiency due to the denser breathing gas; and
3. reduced transport, and, hence, elimination of carbon dioxide.
4. (GoTo #1 above and repeat). . .

Hypercapnia increases narcosis and the likelihood of CNS oxygen toxicity. In addition, it may increase heat loss, alter heart rhythm and predispose to decompression illness. If the carbon dioxide level gets too high, and it can on deep scuba dives -- especially if a diver is very anxious and / or exerting him/herself -- the diver may go unconscious without warning. Certain divers are more susceptible to severe hypercapnia for a variety of reasons and are therefore more at risk.