Question Panic in the experienced diver?

It would seem to me that, as we gain experience and go through some minor glitches on dives, we should increase our capacity to tolerate issues underwater. I'm wondering what could cause an experienced (say, more than 200 lifetime dives) diver to become distressed enough to lose rational thought. Has anyone here (who meets those criteria) been through a panic event? What caused it, and what did you do?

 

[cerich]

cerich, there is not getting used to this, nor stopping it. As was pointed out to me, in my case I waterboarded myself, in a form several times worse that one can do on the surface. The doctor I talked to who had gone thru it over 30 years ago, still was terrified by it. We really need to stop putting this reaction in with water or the face or claustrophobia..they have nothing to do with each other.

I do believe that different folks have a different predisposition to handling it or not, in fact many navy type selections weed folks out by testing their reactions to being underwater and suddenly without air/gas to breath. I can say with confidence of experience that having grown up on a lake, swimming every day with a big brother, then swim team, ad experiences as a young adult that I in fact did get better at dealing with it with practice.

I believe that if divers who wish to pursue in particular tech, leadership, psd type diving they owe it to themselves to take a freediving course so they start to develop less dependence on immediate gas delivery when underwater.

 

[Puffer Fish]

I bolded for effect - so how do we account for freedivers that breath hold well below 3ATA? Or am I missing the point?

A bit, they are effected by it (just not for very long), but they only have the amount of O2 they got on the surface. So yea, they will still have the toxic effects, but for a much shorter time and from a limited amount of O2. The gradual onset is also much easier to withstand, as is the short time involved. Waterboard someone, and compare to holding your breath..not the same effect.

Here is what you can expect from various levels of CO2, and they can easily happen if you cannot exhale:

http://www.blm.gov/style/medialib/b...A/cfodocs/howell.Par.2800.File.dat/25apxC.pdf

As you can see, this is not just being scared because you are not comfortable...this is a chemical issue effect.

---------- Post added May 12th, 2015 at 04:43 PM ----------

And 10% is roughly the maximum one can get on the surface with normal air...that Nitrox example would allow a maximum of almost 50% (but you would be very dead way before then. Also the panic effect is not listed in that document, but it is very well known

 

[dumpsterDiver]

Sorry, would be happy to expand. On the surface, we have around 21% O2, and seems we can survive (not well) down to about 6%. And we can live up to around 6% CO2 (which is actually from 12% O2 because half of the CO2 goes into solution as an acid). So, if you hold your breath on the surface, when you get down to 6 -8% O2, your CO2 is just reaching the toxic level...so it a tie between panic and passing out (how long one holds their breath has no effect here, it is just concentrations).

Lets go down to 66 ft...or 3 atm's. We now have 3 times the amount of O2 (pressure effect), but that does not change how we react to CO2. In effect, we have lots more O2 to make CO2, and over the short term, we can now make huge amounts of CO2...and the system is no longer limited by the starting amount of O2.

Then, lets add 32% Nitrox into the equation...at 66 ft, we now have (32 x 3, or 96% O2, or 4.5 times the O2.. which can make a huge amount of CO@ before it gets down to the 6% level. The effect is you will not initially pass out (like on the surface) and you will go thru a terror massively worst than any waterboarding has ever caused.

cerich, there is not getting used to this, nor stopping it. As was pointed out to me, in my case I waterboarded myself, in a form several times worse that one can do on the surface. The doctor I talked to who had gone thru it over 30 years ago, still was terrified by it. We really need to stop putting this reaction in with water or the face or claustrophobia..they have nothing to do with each other.

It should be noted that this is not just about the panic, a bunch of very real, very deadly effects are taking place... remember this is a toxic compound and just because you don't pass out, does not mean it is not effecting your brain function.

I'm doubting A LOT of what you are saying in this post and your previous one..

---------- Post added May 12th, 2015 at 06:59 PM ----------

I bolded for effect - so how do we account for freedivers that breath hold well below 3ATA? Or am I missing the point?

Freedivers work very hard to acclimate to high levels of Carbon dioxide, it is a load of crap that you can not acclimate to it. Freedivers are susceptible to high Co2 levels, but they train to be able to withstand it, without freaking out and expending all kind of energy clawing their way to the surface in a panic.

The high Co2 level will not kill a freediver, what will kill a freediver is too low of an oxygen level which results in diminished mental capacity, reduced sensory input (vision being affected or loss early on) and loss of motor control and then finally loss of consciousness - although someone may or may not progress through all those symptoms in a sequential manner.

You CAN acclimate (to some degree) to higher levels of CO2. However, the point about high Co2 levels feeling dreadful is correct.

A very simple experiment is to walk briskly for a minute or two and then exhale Completely and forcibly, blowing out all you can from your lungs, then hold and don't inhale. You blood is still saturated with oxygen and you really don't need to breathe right away, but without the full lung volume to dilute the Co2 your body puts out, the concentration of CO2 will rise rapidly in the partially collapsed lungs. In just 20 seconds, I am on the verge of panic.. Try it.. When you recover you will just take several deep breaths and you will recover quickly - because you really did not build up any significant oxygen debt in this short time.

Also the bit about a diver making more Co2 at depth if they are breathing nitrox is baloney too.

 

[Puffer Fish]

I'm doubting A LOT of what you are saying in this post and your previous one..

Really, so you don't believe in MOD's then? Or the effects of any toxic gas under pressure.. or Navy research, or physics or all those limits due to gas effects under pressure? Or how about the toxicity effect in this link?

Carbon dioxide - Wikipedia, the free encyclopedia

If you just did some research (not opinion) on say CO and how people can die when diving from levels on the surface that are not harmful, it would be easy to understand that diving or rather breathing any toxic gas under pressure has much stronger effects.

But if all that is too complex, please call Dr Jim Chimiak at DAN (head of their research) and ask him. He is the one that explained it to me.

 

[dumpsterDiver]

CO is very different from Carbon dioxide...

also some very advanced freedivers will breath up on nitrox before freediving to extend their breathhold dive times..

 

[Puffer Fish]

Free divers only take with them, the gas from the surface, so they only experience what happens at the surface. Does not matter how deep they go, it does not change how much O2, and how much CO2 they can make...which is pretty much a tie between the two.

So if there is no more O2 in you at depth, then why is there a MOD.. if it never changed, then it would not matter how deep you go.. and why as the amount of O2 percent goes up, does the MOD change? If you understand that, then understanding with more O2, you can make more CO2 is easy. If you don't then it is all magic. I am shocked that any instructor would not have had to pass a test on this.. amazing.

---------- Post added May 12th, 2015 at 07:17 PM ----------

CO is very different from Carbon dioxide...

Yes it is, but gas laws are gas laws.. if any gas is more toxic at depth, then all toxic gasses are more toxic at depth..that physics thing. Don't suppose you have ever had any hypoxic gas training? Any deep diving? In order to dive deeper than the mod for air, you have to use a gas that has O2 lower than you can breath on the surface...humm that must be fake also.

 

[cerich]

Free divers only take with them, the gas from the surface, so they only experience what happens at the surface. Does not matter how deep they go, it does not change how much O2, and how much CO2 they can make...which is pretty much a tie between the two.

So if there is no more O2 in you at depth, then why is there a MOD.. if it never changed, then it would not matter how deep you go.. and why as the amount of O2 percent goes up, does the MOD change? If you understand that, then understanding with more O2, you can make more CO2 is easy. If you don't then it is all magic. I am shocked that any instructor would not have had to pass a test on this.. amazing.

---------- Post added May 12th, 2015 at 07:17 PM ----------




Yes it is, but gas laws are gas laws.. if any gas is more toxic at depth, then all toxic gasses are more toxic at depth..that physics thing. Don't suppose you have ever had any hypoxic gas training? Any deep diving? In order to dive deeper than the mod for air, you have to use a gas that has O2 lower than you can breath on the surface...humm that much be fake also.

HUH??? A freediver metabolizes some of the oxygen oxygen. They experience narcosis, can get bent, take a O2 tox hit etc. I don't know where you are getting the idea they can only experience what they happens at the surface.....

 

[Akimbo]

Free divers only take with them, the gas from the surface, so they only experience what happens at the surface. Does not matter how deep they go, it does not change how much O2, and how much CO2 they can make...which is pretty much a tie between the two...

The point you are missing is that depth has a profound effect on the PPO2 and PPCO2. That is the fundamental cause of Shallow Water Blackout. A good freediving course teaches you exercises to increase your tolerance to Anoxia and Hypercarbia. There is a surprisingly long time between that horrible CO2 induced feeling that you must breathe and actually passing out. Understanding that margin and developing a tolerance is very helpful in managing panic in divers.

 

[Basking Ridge Diver]

Fun Fact #328 - When we breath air on the surface 1 ATA we are breathing air with 21% oxygen and our hemoglobin is already 97% saturated with oxygen. At this saturation level the blood has an oxygen content of about 19.8 ml of oxygen per dl blood. As the hemoglobin is already 97% saturated with oxygen it only takes a slight increase in in the partial pressure of oxygen for the hemoglobin to become completely saturated. - taken in parts from Deco for Divers...

So - Oxygen does not behave like Nitrogen or CO or CO2...

"Then, lets add 32% Nitrox into the equation...at 66 ft, we now have (32 x 3, or 96% O2, or 4.5 times the O2.. which can make a huge amount of CO@ before it gets down to the 6% level. The effect is you will not initially pass out (like on the surface) and you will go thru a terror massively worst than any waterboarding has ever caused." Is nonsense or baloney...

Carbon Monoxide CO are like fumes from exhaust...
Carbon Dioxide CO2 is from breathing...

 

[Puffer Fish]

An instructor that does not understand gas laws and partial pressures means there are students that also don't understand, even though there is a ton of information and detail from every agency, but guess I should not be surprised that it is no longer important... way too complex I suppose. Oh, ask Pete, I know he understands it.