200' on air for 5 min bottom time?

[Tigerman]

Although they ARENT the same, they can LOOK the same..

 

[DCBC]

Although they ARENT the same, they can LOOK the same..

Yes, appearances can be deceiving.

 

[danvolker]

Perhaps someone could describe the difference/relationship between being asleep and unconsciousness. I don't think that they're the same thing...

Among the issues to discuss with this:

• How does the mental state initiate? Suddenly without warning, gradually, etc.
• How long does the state typically last once the person goes out.....seconds, minutes, etc.
• When they come back to awareness, are there any other issues that occurred outside of what we would usually associate with sleep? ( emptying of bowels, etc)
• Is there a functional state worth discussing like a drug induced sleep--like a Drunk that passes out and has different sleep patterns than they would if sober---with deep air could many other issues occur, even some more closely resembling an epileptic seizure? Narcolepsy?

 

[DCBC]

Among the issues to discuss with this:

• How does the mental state initiate? Suddenly without warning, gradually, etc.
• How long does the state typically last once the person goes out.....seconds, minutes, etc.
• When they come back to awareness, are there any other issues that occurred outside of what we would usually associate with sleep? ( emptying of bowels, etc)
• Is there a functional state worth discussing like a drug induced sleep--like a Drunk that passes out and has different sleep patterns than they would if sober---with deep air could many other issues occur, even some more closely resembling an epileptic seizure? Narcolepsy?

I suppose that we could start by examining the different properties of sleep as oppose to an anesthesia. My formal training is as a Hyperbaric Physiologist and not as a Physician or Anesthetist. I do know that sedatives (like Nitrous Oxide) are a type of anesthesia that are used for minor medical procedures. As far as I'm aware, it induces what's called twilight anesthesia, which depresses the CNS.

To the best of my knowledge "sleep" doesn't occur; however the Patient is relaxed and "Sleepy." A drug induced depression of consciousness occurs, but the Patient can respond to verbal commands.

I suppose it would be reasonable to believe that if such a depressed consciousness occurs with Nitrous Oxide, that similar reactions would occur during Nitrogen Narcosis. It might be pointed-out that Nitrous Oxide is a chemical compound with the formula N2O. Medical N2O is man-made. Nitrogen Narcosis is related to Nitrogen (N2) Gas at a higher PPN2 than normal. N2O and N2 are two different gases.

The next thing that's worth mentioning is that there are no studies that indicate that IGN contributes to "Sleep" that I'm aware of. In thousands of wet and chamber dives involving thousands of test subjects at DCIEM, I haven't experienced anyone going to sleep.

Although this may be unrelated, during Saturation Diving the sleep patterns of Divers (myself included) generally deteriorates, as exposure time increases. This is a concern to the Commercial Diving industry. As sleep decreases, fatigue increases, thus affecting Diver performance.

 

[GrimSleeper]

I suppose that we could start by examining the different properties of sleep as oppose to an anesthesia. My formal training is as a Hyperbaric Physiologist and not as a Physician or Anesthetist. I do know that sedatives (like Nitrous Oxide) are a type of anesthesia that are used for minor medical procedures. As far as I'm aware, it induces what's called twilight anesthesia, which depresses the CNS.

To the best of my knowledge "sleep" doesn't occur; however the Patient is relaxed and "Sleepy." A drug induced depression of consciousness occurs, but the Patient can respond to verbal commands.

I suppose it would be reasonable to believe that if such a depressed consciousness occurs with Nitrous Oxide, that similar reactions would occur during Nitrogen Narcosis. It might be pointed-out that Nitrous Oxide is a chemical compound with the formula N2O. Medical N2O is man-made. Nitrogen Narcosis is related to Nitrogen (N2) Gas at a higher PPN2 than normal. N2O and N2 are two different gases.

A zillion posts in, and it gets interesting...

What you describe sounds exactly like what I had in mind with the phrase 'going on the nod' (I've heard it used to describe heroin addicts who've taken a slightly higher or purer dose than usual, and are in exactly that semi-conscious state you describe. They can still hear you and mumble a response, but will stare blankly at a single spot for hours and struggle to keep their heads up. Don't ask...), and also sounds like a reasonable fit for the anecdotes posters have offered about altered states of consciousness that might be attributable to narcosis. I've always taken it as a given that, given a high enough ppN2, one would depress the CNS enough that basic functions like breathing would cease, although obviously in the case of deep air diving an OxTox event would likely occur long before that point.

Did you have any test subjects showing the kind of significant disconnect from their situation we're talking about when you were doing the chamber rides?

 

[DCBC]

Did you have any test subjects showing the kind of significant disconnect from their situation we're talking about when you were doing the chamber rides?

Narcosis causes a slowing down of reactions and a decrease in problem solving ability. So in this way, there is a disconnect. What is significant is dependent upon the situation.

One factor that's noteworthy is the Subject's attitude. Are they trying to resist the affects, or do they want to "go with it." Those caught unawares have a tendency to do the latter in a chamber environment. I believe that this is one factor in experienced Divers performing better at depth than the inexperienced. Concentration reduces problem solving time.

I don't buy the Narcosis Sleep possibility as something that's probable. Narcosis is not like OxTox in that it provides the Diver with indicators of its oncoming affects. No one automatically gets so blasted that they lose control, or becomes lethargic.

If during a dive, my mask leaks, I clear it. I don't go through the dive watching the water steadily increase until my mask is full of sea water. If I find myself negatively buoyant and I want to be neutral, I don't wake up to this fact 200' deeper than I want to be; I correct the problem immediately. Such is the case with Narcosis.

Where the problem really exists is that the Diver must be aware of the level of impairment and operate within the margin where he is still within his safe diving envelope. This may change daily. Some may be upset that I promote diving impaired. DCIEM testing has confirmed the fact that a Diver at a depth of 50 FSW is impaired (when compared with reaction times and problem solving scores at the surface). It's all a matter of degrees of impairment. At what depth are you unsafe? This is of course subjective and will vary from one individual to the next.

So the answer is a personal one. The easy way around this is to dive a different mixture. I'll go along with that, if that's the diver's choice. It isn't however the only answer. Deep-Air is an alternative for some depths, as long as the person is trained, monitors his/her performance and knowns and is willing to abort the dive when required.

The commercial industry routinely has divers working at depths of up to 200' on air. They are paying to have a job done properly. The diver has to be able to utilize tools such as a torch in a construction setting (governed by government regulations for a job site). Governments don't condone Narced divers wielding torches. Divers are covered by Worker's Compensation and other insured benefits. There is a long history of Divers working in this way for hundreds of thousands of hours without incident.

As far as recreational diving is concerned, know that depth increases danger, regardless of the mixture. The diver should dive within his safe diving envelope and should be properly trained and experienced before this can be expanded.

 

[danvolker]

Narcosis causes a slowing down of reactions and a decrease in problem solving ability. So in this way, there is a disconnect. What is significant is dependent upon the situation.

One factor that's noteworthy is the Subject's attitude. Are they trying to resist the affects, or do they want to "go with it." Those caught unawares have a tendency to do the latter in a chamber environment. I believe that this is one factor in experienced Divers performing better at depth than the inexperienced. Concentration reduces problem solving time.

I don't buy the Narcosis Sleep possibility as something that's probable. Narcosis is not like OxTox in that it provides the Diver with indicators of its oncoming affects. No one automatically gets so blasted that they lose control, or becomes lethargic.

If during a dive, my mask leaks, I clear it. I don't go through the dive watching the water steadily increase until my mask is full of sea water. If I find myself negatively buoyant and I want to be neutral, I don't wake up to this fact 200' deeper than I want to be; I correct the problem immediately. Such is the case with Narcosis.

Where the problem really exists is that the Diver must be aware of the level of impairment and operate within the margin where he is still within his safe diving envelope. This may change daily. Some may be upset that I promote diving impaired. DCIEM testing has confirmed the fact that a Diver at a depth of 50 FSW is impaired (when compared with reaction times and problem solving scores at the surface). It's all a matter of degrees of impairment. At what depth are you unsafe? This is of course subjective and will vary from one individual to the next.

So the answer is a personal one. The easy way around this is to dive a different mixture. I'll go along with that, if that's the diver's choice. It isn't however the only answer. Deep-Air is an alternative for some depths, as long as the person is trained, monitors his/her performance and knowns and is willing to abort the dive when required.

The commercial industry routinely has divers working at depths of up to 200' on air. They are paying to have a job done properly. The diver has to be able to utilize tools such as a torch in a construction setting (governed by government regulations for a job site). Governments don't condone Narced divers wielding torches. Divers are covered by Worker's Compensation and other insured benefits. There is a long history of Divers working in this way for hundreds of thousands of hours without incident.

As far as recreational diving is concerned, know that depth increases danger, regardless of the mixture. The diver should dive within his safe diving envelope and should be properly trained and experienced before this can be expanded.

Maybe the narcosis at 200 feet and deeper, causes susceptibility to Hypnosis ( for lack of a better description of a major change in mental and conscious state).... Each of us that had done deep dives on air, will remember various things that were FASCINATING, and I mean FASCINATING in a way indicating that some things you really have to "pull" your self away from, because it is "counter" to mission objectives--whatever the dive plan indicated you would be doing.... With hypnosis, you "CAN" resist hypnosis, or most people can, usually....failure to try and resist hypnosis, and the person can be rapidly hynotized.

Stopping and seeing a wall of 10,000 amberjack coming by you has a hypnotic effect on you--you just want to watch it...... focusing on the bottom, just ahead of you, trying to reach an object way up in the distance---the visual tunnel of sight could create a pattern under the narcosis that could also lead to hypnosis if it was certain repetitive shapes and colors....

Just spitballing here
What do you think DC?

 

[Tigerman]

I wont say much about the mind alteration from n2 narcosis, but Ill say something about hypnosis and trance states..
You go in and out of different trance states all day. Hypnosis is all about making use of those states.
A good example is the stage shows where people forget numbers, dont see stuff thats right infront of them and such. Ever forgotten a phone number? Ever not found the keys thats right there on the table? Thats whats tapped into when you count 11 fingers or the ball just disappear..
The states used to induce those effects is what people generally consider "hypnosis" and they have NOTHING to do with lack of control, lack of focus or "sleep". Infact you are more alert than normal in these states, you just allow your brain to work in ways you normally filter out because its not useful, although entertaining. You will not be able to make people do things they normally wouldnt in these states either btw.
What people dont normally CALL hypnosis but in reality very much IS, is something athletes do on a daily basis. They call it "mental training" but it is really a form of self hypnosis and quite often anchoring of mental states..

 

[DCBC]

What do you think DC?

As I understand it, Hypnotherapists use various exercises to bring about deep relaxation to achieve an "altered state of consciousness." I believe that IGN creates a similar state (to a much lesser extent); the affects of which can be mitigated to some degree by the individual. It would be unreasonable to believe that the Diver couldn't increase these affects as well through a lack of concentration and a desire to go with it...

During chamber exposures to 200 FSW, I've experienced as much as a 30% decrease in reasoning ability and a decrease in dexterity of 7%. Reaction time (RT) was consistently reduced with higher PPN2. I don't believe however, that I've personally experienced any behavior to-date that would place me in any operational danger at this depth. As a Diver becomes more experienced they largely operate on muscle memory, whereby tasks are performed without conscious effort. I've been tested in a wet-chamber under IGN with only slightly higher times when compared to the same drills undertaken on the surface. Training and preparation can minimize the decision process.

I believe that Divers run into problems with Narcosis because they go too deep on air, before they're prepared. They lack good buoyancy control and end-up descending too fast (a failure in procedure before IGN is a factor), or fail to recognize that they are being adversely affected (lack of training, or inability to follow deep-diving procedure). It's a bit like a teenager driving at 140 mph on a wet road, getting into an accident and blaming the rain. It went wrong because of how the Driver approached driving and not the fact that it was raining. Go slowly and don't exceed your training and experience.

 

[DaleC]

Something I've considered (because of previous unrelated experiences) is the way risk mitigation can be a double edged sword.

One method to avoid narcosis is by using a different gas, which at first glance appears sound. The second method is acclimation. Which appears less sound. However, following the first course leaves one with no experience in dealing with narcosis when it occurs.

Ok perhaps, as long as one can definitely avoid narcosis but I suspect many people who might want to use trimix would occasionally find themselves in dive situations where they either do not have access or the dive is borderline and they decide to forgo it's use. In that case, they may be under prepared for narcosis effects.

Deciding on the regime to avoid narcosis by using mix requires a high degree of commitment to that regime on the part of the diver that might not initially be recognized.