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?

 

[dumpsterDiver]

Arguing over some of this stuff is probably not that productive. High Co2 levels are very dangerous to divers, they can cause mental impairment and panic.

For open circuit scuba divers, the take home message should probably be to not over- exert yourself, don’t make having a low SAC a competition, and concentrate on exhaling fully, if they feel like they are getting behind with respiration.

At depth, the diver has more oxygen in each inhalation than they can use, so the biggest challenge is to expel Co2- and that is best accomplished by a more complete exhalation. The problem is that when the diver has Co2 build up it feels bad and they may try to pant and breathe quickly and shallowly, and this is BAD.

If we take Puffer's idea to the extreme, a diver using pure oxygen at 20 feet would be creating carbon dioxide at a huge rate. When in fact, the production of carbon dioxide is simply a function of the divers metabolic rate. Yes they may be consuming more oxygen if their work load goes up, but you don't consume double the amount of oxygen at 33 feet than you do at the surface..- this is the whole idea of rebreathers.. they are most beneficial because you continue to consume the same small amount of oxygen - regardless of your depth.

 

[Puffer Fish]

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.....

I don't know how this became about free diving, but it is not the subject and no one was talking about free divers.. however they can get all the things you said...well maybe not the Tox hit (but don't study it)

---------- Post added May 12th, 2015 at 07:32 PM ----------

To my surprise, there are free divers that are using straight O2.. who knew? So yea, they can get a Tox hit.

 

[cerich]

I don't know how this became about free diving, but it is not the subject and no one was talking about free divers.. however they can get all the things you said...well maybe not the Tox hit (but don't study it)

---------- Post added May 12th, 2015 at 07:32 PM ----------

To my surprise, there are free divers that are using straight O2.. who knew? So yea, they can get a Tox hit.

I quoted you where you were talking about freedivers... so your "I don't know how this became about free diving" reply to me is weird, go read your own posts.

 

[Basking Ridge Diver]

Not to belabor the point but free-diving came in as an example of you saying breathing at surface level - holding your breath and then going down to 3 ATA... that is when I said what about free-divers - thinking your point was not valid... Post 290

Humor me and buy the book "Deco for Divers" it will help.

 

[Puffer Fish]

Arguing over some of this stuff is probably not that productive. High Co2 levels are very dangerous to divers, they can cause mental impairment and panic.

For open circuit scuba divers, the take home message should probably be to not over- exert yourself, don’t make having a low SAC a competition, and concentrate on exhaling fully, if they feel like they are getting behind with respiration.

At depth, the diver has more oxygen in each inhalation than they can use, so the biggest challenge is to expel Co2- and that is best accomplished by a more complete exhalation. The problem is that when the diver has Co2 build up it feels bad and they may try to pant and breathe quickly and shallowly, and this is BAD.

If we take Puffer's idea to the extreme, a diver using pure oxygen at 20 feet would be creating carbon dioxide at a huge rate. When in fact, the production of carbon dioxide is simply a function of the divers metabolic rate. Yes they may be consuming more oxygen if their work load goes up, but you don't consume double the amount of oxygen at 33 feet than you do at the surface..

It is not that under normal conditions one is making more CO2 (which was not the point of all this), it is that there are things that can stop your lungs from working, and as you have lots of O2 available, but no way to get rid of all the CO2, one is headed for a very ugly event. In the case I had, it was a trachea spasm for just over 3.5 minutes (throat closed more than 90%). The much more common one is a Larynx spasm (there is a third form, but have already forgotten it's name). Trying to exhale with any of them will cause you to attempt to suck air out of your lungs.. and that will cause a pressure differential and that causes an adema event (pink frothy blood filling your lungs).

This actually happens several time a day in hospitals from removing breathing tubes after an operation..and scratching the throat. But there it is a know issue and they are looking for it. (another who knew?) On the surface, it used to be called "dry drowning".

As I have now had two different doctors explain to me, that higher, unused O2 now becomes a problem that cannot happen on the surface, as you are exchanging that O2, turning it into CO2, and there is no way to get rid of that.

I also know that CO2 forms an acid in water, but how fast and how fast the CO2 gas comes off is not something I know anything about.

But there are other events that can also cause this.. just a straight edema (which seems to be showing up more and more) will do it. There are equipment issues.. and several other human factors. It is when these happen that no one can plan for.

 

[Basking Ridge Diver]

As I have now had two different doctors explain to me, that higher, unused O2 now becomes a problem that cannot happen on the surface, as you are exchanging that O2, turning it into CO2, and there is no way to get rid of that.

This is simply not true... Seriously - I believe you misunderstood.

 

[dumpsterDiver]

The term is a lyarnx spasm.. don't know the spelling larengiospasm or something.. I can't spell it. The answer to that problem is to simply SWALLOW. I was taught this and I make a big deal about it when teaching my kids about scuba.. If you suck in water and are choaking and cant seem to get air in or out... you must not panic.. you must STOP trying to breath... and then you need to swallow the small amount of water that is causing the problem. This will resolve the spasm.. I guess they don't teach this in scuba anymore..

 

[Puffer Fish]

I quoted you where you were talking about freedivers... so your "I don't know how this became about free diving" reply to me is weird, go read your own posts.

I was assuming when you said free divers, that you were talking about people just breathing surface air. The maximum amount of O2 in your blood from that is the 21%. Free diving is filled with guessing as to exactly what is happening...is it Nitrogen Tox, is it O2 Tox....is it CO2 Tox? Because we are are balanced between running out of O2 and CO2 tox...and their big issue is shallow water blackout, it could be some are running out of O2 and some are having a CO2 issue..but as it is shallow, and they are coming up, the most likely issue is just O2. But if they are now using O2 to get over this, then they will run into CO2..but I have zero knowledge. What I was talking about is that take a breath on the surface and that is all the O2 you have...your fluid is fixed, the amount of gas is fixed...it is not possible for the % to change. Breath gas at depth and all bets are off on that issue. How much we use, how much gets attached is one of those things I sure don't know for a fact.

---------- Post added May 12th, 2015 at 08:18 PM ----------

The term is a lyarnx spasm.. don't know the spelling larengiospasm or something.. I can't spell it. The answer to that problem is to simply SWALLOW. I was taught this and I make a big deal about it when teaching my kids about scuba.. If you suck in water and are choaking and cant seem to get air in or out... you must not panic.. you must STOP trying to breath... and then you need to swallow the small amount of water that is causing the problem. This will resolve the spasm.. I guess they don't teach this in scuba anymore..

I was taught that, but as it turns out, it is not effective. For a very long time it has been thought that this was rare (it is not that rare),and that just swallowing would make it go away (it does in a few cases) It does not take water either. as they have found out in hospitals. But mine (from a cut in my trachea) lasted 3.5 minutes (give or take 10 seconds, as my computer records my breathing, or lack of it). I'm at 50 feet with closed lungs, and keep in mind I don't know how long this is going to last..could have been 10 minutes..or 20 for all I know at the time. My second stage flooded on my exhale.. so I have no air, and got a very tiny amount of salt water on a cut (there are pain nerves there so one cannot feel it). I'n in a heavy surge, pushing up and down...not breathing was not an option, unless one wanted a major lung event. So I pulled air out and slowly surfaced.. but that then caused fluid in the lungs. To date, with DAN, I am the only one who has lived thru this (but there are lots of suspected events, but dead people do not tell). As it turned out, my slow ascent (taking over 5.5 minutes) was just below the maximum safe speed I could do (based on the amount of air I could get in and out), which was 25 fpm or less.

I've know of a shallow water case where the person lived, and two cases where they died...but until one actually has an event, understand what someone is going thru is not easy to understand. Thankfully I was able to get in touch with a doctor that had actually been thru it.

---------- Post added May 12th, 2015 at 08:31 PM ----------

and it's laryngospasm or larynx spasm (your choice) and I had the spelling correct. I did not have that, mine was a trachea spasm.. similar, but different area.

The reason not much is public, is because the initial Navy work was taken by the CIA to develop waterboarding..you strap someone down, tilt them back, put a cloth over their face and pour water over it. You cannot avoid inhaling some water, and you get a larynx spasm...and sometimes you die from it. If you do some reading on it...it always works and it is not uncommon for people to go thru some of the other CO2 toxic aspects.

Dr Chimiak has been thru it, and seems to believe it is the worst torture one can go thru..and asking someone to behave the right way while that is happening seems a bit of a stretch.

 

[gcarter]

I was taught that, but as it turns out, it is not effective. For a very long time it has been thought that this was rare (it is not that rare),and that just swallowing would make it go away (it does in a few cases) It does not take water either. as they have found out in hospitals. But mine (from a cut in my trachea) lasted 3.5 minutes (give or take 10 seconds, as my computer records my breathing, or lack of it). I'm at 50 feet with closed lungs, and keep in mind I don't know how long this is going to last..could have been 10 minutes..or 20 for all I know at the time. My second stage flooded on my exhale.. so I have no air, and got a very tiny amount of salt water on a cut (there are pain nerves there so one cannot feel it). I'n in a heavy surge, pushing up and down...not breathing was not an option, unless one wanted a major lung event. So I pulled air out and slowly surfaced.. but that then caused fluid in the lungs. To date, with DAN, I am the only one who has lived thru this (but there are lots of suspected events, but dead people do not tell). As it turned out, my slow ascent (taking over 5.5 minutes) was just below the maximum safe speed I could do (based on the amount of air I could get in and out), which was 25 fpm or less.

My math puts that ~ 9 fpm.

 

[Puffer Fish]

This is simply not true... Seriously - I believe you misunderstood.

Ok, I am not saying it correctly, using the correct terms and in the correct way (sorry).. it is the partial pressure that is the issue, and this gets really complex an I don't have a clue as to how to explain it. We obviously don't breath the 21% on the surface...we only absorb some of it and it gets transported into cells.

But here is where it gets really difficult..we only normally use a small amount of that O2, but O2 Tox is from having too high of partial pressure...on one hand it is not really more o2, but the effect is as if there was. And how all of the transport chemistry works with changing pressure is seriously complex.

So me bad, but everyone else seems to be avoiding it.

Trying to be correct here.. if you would pass out with say 8% serium O2, then at 99 ft, you would pass out at 2%.. which means you can make more CO2 than you can at the surface. On the other hand, the toxicity is also a partial pressure issue, so if 10% causes you to pass out, then at that same depth, you would effectively have 40% + that extra 6%, or a total of 64%.. which you would be dead at.

Looking at it in reverse, if you pass out at 10%.. you would pass out at 2.5% at 99 ft.

But none of that is true either.. as the response on both sides is not perfectly linear, and gas to fluid effect changes with pressure, and soluble gasses act different in the complex organic chemistry (and yes I was trained as an organic chemist, but worked as an engineer, so am not up to speed)

So all I can, for sure say, is that at depth, one has more available O2 to make CO2 and CO2 has a much stronger effect at depth...how much..I cannot find a hard answer to that.

While I cannot get the research the Navy did, I do know they actually tested the effect in a chamber at different depths, and the effect follows what was expected.

---------- Post added May 12th, 2015 at 09:12 PM ----------

My math puts that ~ 9 fpm.

You would be correct..but there was a lot of surge, so when you look at the jagged profile it was the up motion that had to be slower. At no point did I actually know what I was supped to do.. and at the very start (the up and down motion was stronger deeper (thankfully)), I had a small section where it exceeded 30 ft per minute, but the swell decrease as I went up, so it was only around 4 to 5 ft at around 46 ft, after that no issue. I tried to use my BP/W to hold me down, and so was putting air in and dumping it, so DAN used the low reading and every jump assumed it was from that, to get the 25 ft number...it also assumed that all the air I inhaled was actually pushed into my lungs.. guess that could be true.. don't know.