Can Narcosis be managed?

[SUB ZERO]

I ask a sensitive question. There may be people in the closet with insightful answers and there may be loud voices who repeat popular rhetoric. Yet I ask.


Can Narcosis be managed? It seemed like before Trimix came, there were certain things that were agreed upon until they became politically incorrect. Bret Gilliam, the founder of TDI still states on his personal website that there are factors that effect it such as

cold
fatigue
rate of descent
effects of sea sickness medication
even increasing PPO2.
exertion and WOB

Almost all of these are under YOUR control. Then there are factors that are outside your control but when you put them together then Narcosis becomes manageable upto certain parameters. He also suggests building tolerance in progressive segments.

Dive Day 1: Dive to 150 feet
Dive Day 2: Dive to 175 feet

Second dives on both days would be shallower than the first. He said he had no significant impairment at 452 feet during experiments.

Modern research shows that 100 - 130 is the safe range due to gas density and CO2 concerns but before Trimix came, tens of thousands of dives had already been made specially in the 130 to 200 ft. Not enough people had died especially in the open water technical dive environment to suggest that it is that suicidal.

Hal Watts and PSAI also held similar views. They used to have a course in Narc Management, but it is not very popular anymore. So my question is can Narcosis be managed where open water technical dives from 130 - 187 feet will become easier and more manageable as we learn to control those factors that are within our control?

Id love to hear from all sides of this argument. I thank you.

[FW]

If you dive deep often, you eventually build up a tolerance, but it never really goes away.

[bletso]

Yep, it's called helium!

[divingabe]

Yep, it's called helium!

Ditto
It has been called the martini effect so the so called control is only in the imagination of the individual. One can get used to feel in control of a familiar situation
But if you throw in an unforeseen variable the odds of probably doing the right and safe thing is a crapshoot. Of course this is just my opinion, safe deeper than 100’ diving should include normoxic trimix.
Gabe

[SUB ZERO]

Ditto
It has been called the martini effect so the so called control is only in the imagination of the individual. One can get used to feel in control of a familiar situation
But if you throw in an unforeseen variable the odds of probably doing the right and safe thing is a crapshoot. Of course this is just my opinion, safe deeper than 100’ diving should include normoxic trimix.
Gabe

Sure but Helium is a finite resource, and the world is running very low. Our ability to extract it is also limited. Medical use will obviously get prioritized for whatever helium is available for consumption. So yes Helium is a prescribed solution that is very cost prohibitive unless you are Bill Gates. Realistically for most people the choice is

a) Stop doing technical dives
b) Start doing technical dives on CCR. I know a lot of people who dive deep air to 180 and do not know anyone who died due to that in open water. I know very few people who dive CCR and four are dead.
c) Start to look at Narcosis. Pull out PSAI Narc Management notes and see what is real and what is not. Dive within parameters in which Narc can be managed, if there are any.

In a world where helium has become a very rare commodity those are what you would have to choose from right?

[DogDiver]

We did a lot of deep air diving on wrecks in the Great Lakes. We always took a camera with us so we could remember what we saw on the wreck.


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[billb]

Sure but Helium is a finite resource, and the world is running very low. Our ability to extract it is also limited. Medical use will obviously get prioritized for whatever helium is available for consumption. So yes Helium is a prescribed solution that is very cost prohibitive unless you are Bill Gates. Realistically for most people the choice is

a) Stop doing technical dives
b) Start doing technical dives on CCR. I know a lot of people who dive deep air to 180 and do not know anyone who died due to that in open water. I know very few people who dive CCR and four are dead.
c) Start to look at Narcosis. Pull out PSAI Narc Management notes and see what is real and what is not. Dive within parameters in which Narc can be managed, if there are any.

In a world where helium has become a very rare commodity those are what you would have to choose from right?

Well said

[gschaut]

Like alcohol, you build up a tolerance to nitrogen. BUT... also like alcohol, building up your tolerance to high partial pressure nitrogen usually results in addiction to diving.

[kensuf]

This is a cave diving forum, let's ask "can narcosis be managed in a cave environment".

In the context of cave diving, back in 1996 I was the accident analysis committee chair for the NACD and someone asked about the number of deep air cave diving fatalities. The records that I had indicated that between the 1960s and 1994, approximately 55 people that had some level of cave training died while deep air diving. This happened to align with what I was taught by my cave instructor, deep diving was the #1 cause of fatalities of trained cave divers.

Of those, 2/3rd of them died on dives at depths between 150-180'. This result surprised me, I was personally expecting most of the fatalities to have been at much deeper deaths (over 200'), 150' on air didn't seem that extreme of a depth to me at the time.

Best I could figure at the time is that the likely chain of events for many of these, which I still believe as the most likely scenario today, was:

1. Primary light dies - remember the period we're talking about was when halogen bulbs and wet cell nicads were common, primary lights were not nearly as reliable as they are today
2. In the process of deploying a backup light, something happened (silt out, turned around, or off the line)
3. Stress caused increased gas consumption
4. Between being at 6ATA and increased gas consumption from stress as well as the delayed reaction time from slight narcosis impairment, there was a reduced amount of time for problem solving - diver runs out of air at some point near the exit.

Life has risks, driving along US27 to Peacock Springs on a foggy morning can be one of the most hair raising experiences a person can ever have. Some risks can be managed, some can't. When figuring out a personal risk / reward tolerance for deep air cave diving, I would hope the person contemplating it would also consider the impact to the community in the event something goes wrong. In the last five years we've lost access to several amazing sites, I'd hate to be the one to cause other places to get shut down simply because I didn't want to buy some helium.

[Draker]

This is a cave diving forum, let's ask "can narcosis be managed in a cave environment".

In the context of cave diving, back in 1996 I was the accident analysis committee chair for the NACD and someone asked about the number of deep air cave diving fatalities. The records that I had indicated that between the 1960s and 1994, approximately 55 people that had some level of cave training died while deep air diving. This happened to align with what I was taught by my cave instructor, deep diving was the #1 cause of fatalities of trained cave divers.

Of those, 2/3rd of them died on dives at depths between 150-180'. This result surprised me, I was personally expecting most of the fatalities to have been at much deeper deaths (over 200'), 150' on air didn't seem that extreme of a depth to me at the time.

Best I could figure at the time is that the likely chain of events for many of these, which I still believe as the most likely scenario today, was:

1. Primary light dies - remember the period we're talking about was when halogen bulbs and wet cell nicads were common, primary lights were not nearly as reliable as they are today
2. In the process of deploying a backup light, something happened (silt out, turned around, or off the line)
3. Stress caused increased gas consumption
4. Between being at 6ATA and increased gas consumption from stress as well as the delayed reaction time from slight narcosis impairment, there was a reduced amount of time for problem solving - diver runs out of air at some point near the exit.

Life has risks, driving along US27 to Peacock Springs on a foggy morning can be one of the most hair raising experiences a person can ever have. Some risks can be managed, some can't. When figuring out a personal risk / reward tolerance for deep air cave diving, I would hope the person contemplating it would also consider the impact to the community in the event something goes wrong. In the last five years we've lost access to several amazing sites, I'd hate to be the one to cause other places to get shut down simply because I didn't want to buy some helium.

Ken, I read through this very carefully, and my best take away is that since my primary light is much better now vs then, I?m ok to dive deep air and save the cash by not wasting it on helium. Thanks for this!!!

We need to plan a return visit to the bottom of the Black Abyss as soon as conditions allow.
Merry Christmas!


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