my narcosis experience

[tiggerbiker]

i was just reading a post in the instructors section about narcosis and getting back in and it reminded me of an experience i had recently in lanzarote - was i right or wrong to do it? - read on.

it was the the middle of our weeks trip in lanzarote and the guided dive list mentioned a dive called the cathedral 32-40m, i signed up for it and away we went, all was going fantastic until we went inside the cathedral (its like a small cave) i looked at my gauges- gas was fine, depth was 36m.
then the cave started to feel like it was getting smaller, i could feel myself getting a bit, well, twitchy i suppose. (i do not and have never suffered from claustrophobia)
i signaled to my buddy that i would like to go out of the cave, we went out and hovered at about 30m looking down at the rest of the group, as soon as we came out and up a little, i felt fine (and embarrassed) - the rest of the dive went well.

the next day i lead a dive with my instructor to the cathedral, this time i went right inside the cave- right to the back, without a torch and we leveled out at 40m whilst feeding a huge dusky grouper.
this time, i felt fantastic.
i didn't feel apprehensive or 'twitchy' at all.

for me at least, if i have an issue i like to sit back analyze the problem, talk it through with someone more experienced then go out next day and face it head on - maybe its just my competitive nature and the thought of being beaten makes me try harder?

Grant

[Mal Bridgeman]

An interesting tale.

There are those who believe that narcosis can be adapted to.....

I, though, subscribe to the view that there are two forms of narcosis ....

the "fuzzy" narcosis which makes us slow and a little confused but seems enjoyable... like when you look at your contents gauge but 2 secs later have no idea what it said so you look again

the "panic" narcosis when everything is really scarey and can lead to irrational behaviour like bolting for the surface.

The fuzzy narcosis is caused by higher Nitrogen partial pressures and the panic is caused by raised CO2 partial pressures.

So when worried by something and breathing rate increases so does the CO2partial pressure which leads to that very uncomfortable feeling. It's why the STOP, THINK, BREATHE, ACT mantra is so good....a good lungful of fresh gas can make big difference to this feeling.

Could this be the case with your cave incident? On the second day without the fears your breathing rate remained calm so without the CO2, you didn't get "the willies". No doubt you were still narc'ed but with the fuzzy one instead.

HTH
Mal

[CotoChris]

It happened to me on what was the same spot in Tenerife. I can not remember the name but it was around 36m. Outside the cave I was Ok but when I went inside I felt very aprehensive with the 'fear bolt' feeling. I did the same signalled by buddy and swam out, with this feeling I closed my eyes and controlled my breathing. That helps but I find that it is difficult to get your mind to think of anything other than danger.

In the Azores this summer I went down to 42m, I was fine until my buddy landed o top of me! Suddenly I was very converned and ascended to 30m where I felt fine.

With me I know that I susceptible to narcosis past 30m. It helps to concentrate on something rather than let your mind wonder to the 'dark side'. Before that as Mal rightly said it is important to get the breathing rate back to normal. I do this by closing my eyes and count to ten (in Hungarian).

[malcolm smith]

Competitive nature, diving,-------oh my god, take it easy and enjoy it!

Competitive natures are for those who think depth/cave penetration/land speed records, are important.

Think of your family, and none of it matters one bit.

Have fun, relax, and if 'progression' in this leisure activity is what you want, it will come a whole lot easier if you get rid of this silly competition idea in diving.

This is for fun.

Regards, Malcolm.

[tiggerbiker]

Originally Posted by malcolm smith

Competitive nature, diving,-------oh my god, take it easy and enjoy it!

Competitive natures are for those who think depth/cave penetration/land speed records, are important.

Think of your family, and none of it matters one bit.

Have fun, relax, and if 'progression' in this leisure activity is what you want, it will come a whole lot easier if you get rid of this silly competition idea in diving.

This is for fun.

Regards, Malcolm.

ah, i think i worded it badly,

what i meant was i dont like to have problems, i want to be the best i can at everything i do.
hence i feel that i must overcome any problem i encounter and not let it 'beat' me.
im probably not making that sound right! (those that have dived with me will know what i mean!! )

Mal, thanks for your input - i think you are right,
feeling a bit tense, shallower/faster breathing - we also did a fair surface swim before dropping down to the cave.
co2 buildup is more likely.

[TerryH]

Originally Posted by tiggerbiker

i was just reading a post in the instructors section about narcosis and getting back in and it reminded me of an experience i had recently in lanzarote - was i right or wrong to do it? - read on.

it was the the middle of our weeks trip in lanzarote and the guided dive list mentioned a dive called the cathedral 32-40m, i signed up for it and away we went, all was going fantastic until we went inside the cathedral (its like a small cave) i looked at my gauges- gas was fine, depth was 36m.
then the cave started to feel like it was getting smaller, i could feel myself getting a bit, well, twitchy i suppose. (i do not and have never suffered from claustrophobia)
i signaled to my buddy that i would like to go out of the cave, we went out and hovered at about 30m looking down at the rest of the group, as soon as we came out and up a little, i felt fine (and embarrassed) - the rest of the dive went well.

the next day i lead a dive with my instructor to the cathedral, this time i went right inside the cave- right to the back, without a torch and we leveled out at 40m whilst feeding a huge dusky grouper.
this time, i felt fantastic.
i didn't feel apprehensive or 'twitchy' at all.

for me at least, if i have an issue i like to sit back analyze the problem, talk it through with someone more experienced then go out next day and face it head on - maybe its just my competitive nature and the thought of being beaten makes me try harder?

Grant

Hi Grant,

Of all the places you could get narced this is one that I would say you
would have the highest chance.

Ok so you drop down on the sand out of the bay and head for the gully.
You then skirt round to the left, over the dropoff and head for a gap in the
reef where it forms a penisular. Soon as you are through you swing left again
and drop down to the start of the cave.

Now if you think about it you are over the dropoff with 40m below you
and as you go over that ridge its even more. Dropping down the wall you
enter the cave onto a slope. So it's a funnel from a bright slope into the
darkness.

So we have potential vertigo, clastrophobia and even perception/balance
issues.

But TBH the prime cause of narcs on this site is dropping down too fast
into the mouth of the cave from that top ridge.

Second time you were fine cause you knew what to expect and your brain
was already prepared.

I wouldnt worry, I've been narced there at least 3 times to my memory
and once at night, now that was fun

Rgds
Tel.

[MattS]

FWIW

I had a Narcosis event quite early after I started diving which was serious enough that in my typical style I got a bit obsessed with reading up. It is one of those subjects where there has not been a great deal of specific research so you have to pick through lots of unrelated research and try to make sense of it.

I don't think it is quite as simple as Mal makes out but his is as good an explanation as any.

All the evidence suggests that you can not adapt to Nitrogen narcosis. However the anecdotes from divers make it clear that some are able to become more comfortable with it than others. Personally I would say that there are two somewhat separate things going on which divers happen to lump under the narcs catch all.

There is an old maxim from the days when deep air meant diving air deeper than what is now regarded as a sensible PO2;

You can do anything when narced, you just need to do it slowly.

Raised PN2 interferes with the less complicated parts of the brain that control sensory input, cognition, motor function and reaction. There has been specific diving research in this area which all reaches the same conclusion; that it just happens and nothing can be done to influence the effects particularly. This is the fuzzy feeling which is generally detectable from about 20m down. It is unlikely to kill you of itself, because oxtox will get you long before you get deep enough that PN2 interference causes parts of your body to start shutting down.

Clearly there is something else going on. We can get a clue from the well documented side effect of the anaesthetic gas NO2 (Nitrous Oxide). NO2 is commonly known as Laughing Gas because it causes people to burst out laughing uncontrollably for no good reason. Put another way, the patients emotional response is not appropriate to the stimulus. The increased PN2 is obviously interfering with higher brain functions which control emotions.

Raised PN2 is known to be a CNS depressant, as are alcohol, Valium, Prozac and any number of other uppers and downers. What they all do is alter our state of emotional control. You could call it the office party effect. You go to work sober (hopefully) all year and some imaginary friend, (lets call him Nigel) keeps reminding you not to tell the boss what you really think of him, and the secretary is a moose. But at the Christmas party, you end up calling the boss a t0$$er, and copping off with the secretary. Looks like Nigel got lost on the way to the bar. So thanks to Nigel not being around to help control your emotions on the night, you feel very, very embarrassed the morning after.

At this point I should mention that Nitrogen is not alcohol and divers have a nasty habit of pushing the comparison way further than is sensible. I believe it is a useful comparison only in sofar as alcohol is an example of a CNS depressant that most people are familiar with.

Underwater it is quite important that emotional responses are appropriate to the stimulus. When you get a little water in your eyes it is quite natural to want to bolt to the surface because your emotions are telling you the surface is a safe place. But if you think about it bolting to the surface could hurt a great deal more than a bit of water in your eyes, so the response is not really appropriate. Nigel provides a little emotional detachment and reminds us that clearing water from our masks is a far more appropriate response. Unfortunately Nigel is a little slow when it comes to learning to dive. On the day you pass Deco Procedures, Nigel's still struggling with the Open Water class.

On the 30m+ dive where everything is going well you may find yourself smiling at odd things. Becoming euphoric about how nice everything seems to be. There are no obvious threats and Nigel is not there to tell you that you are acting a bit of a fool.

When you are at 30m+ in a small cave for the first time your best buddy is not there with you. You know that 30m+ of water above your head is a bit of a threat. Dark enclosed spaces are also a bit of a threat. Another word for threat is stress of course. Without Nigel around to tell you not to be so stupid, your emotions react inappropriately blowing the combined stress out of all proportion to the stimulus. There are hundreds of stories of divers narc events being triggered by the addition of one small additional stressor which on it's own would get little reaction. Even something like a change in the direction of current.

With cognitive function reduced by narcosis, in response to the gathering threats the body prepares for the good old fall back response of fight or flight. Adrenaline is dumped into the blood stream, the heart speeds up, the rate CO2 arrives in the lungs increases with the increased blood-flow, causing breathing to become rapid and shallow. Regulators do not work efficiently when breathing is short and shallow. CO2 levels in the lungs rise causing your brain to believe the regulator is stopping you from breathing, increasing the stress further. Emotional response and chemical reactions to it becomes one big feedback loop. The situation will continue to get worse unless either you die, you reah safety or something elsse breaks the loop. It is about this time the cognitive part of your brain catches up and reminds you what you have been taught, this is narcosis and you need to calm down and ascend a little. At the shallower depth and with less interference the cognitive part of your brain works out the emotional reponse was out of proportion and could have killed you. Embarrassment follows as the adrenaline and CO2 levels slowly subside back to normal.

On the way to the surface Nigel shows up trotting out "You don't want to do it like that. You want to do it like this." Your brain is also very good at recognising patterns such as; 30m of water + dark confined space + scuba + panic = death. Next time around your brain will try to avoid doing what almost killed you last time giving your cognitive functions a little longer to rationalise the threats, recall Nigel's nagging and provide an alternative response.

To summarise. There is a bit of narcosis that is unavoidable, slows you down but is unlikely to be fatal. The emotional part is far more dangerous and far more unpredictable between individuals. It can be tamed with progressive experience, rational thought and basic stress management.

You might want to think about curbing the competitive streak. It is generally another emotion that is not conducive to surviving underwater. It's another common report from narced divers that they were so busy trying not to be beaten by a small problem, they kept trying harder and failed to spot a much more significant problem (like running out of gas). Another example of inappropriate emotional response. There is also the number crunching problem to contend with. Divers usually compete by going deeper, faster because depth is a very simple thing to measure and understand. It is the complete opposite to the progressive experience which has been proven time and time again to work. Divers keep doing it because they want to be better than someone else or they want to be accepted by a group they believe to be better. Personally I try to remember the competition is merely to survive and enjoy the experience.

It could all be b@lls but diver anecdote, the psychology books, physiology, chemistry and my own experiences seem to support it.

[Woz]

Interesting. With my own diving I tend to notice it in stages- at 20m I get the heebie jeebies, usually cos that's when the PPCO2 is high enough from the surface swim/long walk/kitting up breathlessness. I also get some spinny vertigo too. However because I'm expecting it, coping with it is relatively trivial and it's quite enjoyable once you know it's coming. The down to 30+ and there's the warm fuzzy feeling and past 40 things at that stage depend largely on the viz. Good viz then it's still warm and fuzzy, 2 ft viz it's uncomfortable.

It's all about working up to dives. I've already done a whole week's relatively deep repetitive diving in Scapa so the Salsette tomorrow is a dive to really look forward to. However what I've found works well (for me) is once kitted up, have a minute or 2 to relax, do a sanity check on your kit, then jump in to the 6m bubble check, then another pause at 30m to check everything's still ok, then down to the bottom of the shot. At this point I take a minute or 2 to acclimatise, make sure the backup reg is working and let things settle down before heading off for the bottom part of the dive. Works really well rather than bolting off as soon as you hit the bottom of the shot.

[Garf]

we have a standard procedure (there's a shocker) which means we pause at the bottom of the shotline to...

--kick off the bottom time so we can calculate the deco
--check the gas so we know what our min gas plan / turn pressure is
--do a flow check of the valves to sure you have missed anything or rolled a valve off on the shotline.

This takes about 30-45 seconds. It gives you that time to get yourself calmed down and ready to go, and focuses your brain.

Oh and Helium. Helium is nice.

[Bardo]

Originally Posted by tiggerbiker

i was just reading a post in the instructors section about narcosis and getting back in and it reminded me of an experience i had recently in lanzarote - was i right or wrong to do it? - read on.

it was the the middle of our weeks trip in lanzarote and the guided dive list mentioned a dive called the cathedral 32-40m, i signed up for it and away we went, all was going fantastic until we went inside the cathedral (its like a small cave) i looked at my gauges- gas was fine, depth was 36m.
then the cave started to feel like it was getting smaller, i could feel myself getting a bit, well, twitchy i suppose. (i do not and have never suffered from claustrophobia)

I dived the Cathedral in Lanzarote about three years ago with MA Diving - it's a good little dive! To be fair, the cavern does actually get smaller as you go inside it so it probably wasn't all down to the narcosis you were feeling! As Woz hinted at, my money would be on CO2 being the main cause of the narcosis you were feeling - take things a bit slower, lower your breathing rate and generally chill out and you should find that narcosis won't hit you quite as bad...

...or use helium. Helium is your friend