Student got Narced at 25' - cause?

[wavetrain75]

Hope this thread is ok here, tried it once before in a different part of the forum that was deemed incorrect.

I was conducting checkout dives for two students after they completed their pool sessions a few days earlier.

What happened: Second day of checkouts. The student in question was with the divemaster doing a very slow descent. The student was uneasy about the dive, saying that the night before he had dreams of drowning and did not sleep well. He wanted to do an orientation dive before doing any skills. I did not witness the event but I trust the divemaster completely (otherwise I wouldn't have paried them up). At 25' the divemaster said that the student's behavior matched nitrogen narcossis. The student said "It was like someone was giving me a drug and I had to just keep taking it." He said he was dizzy and disoriented. No injuries resulted. Computer indicated the minimum possible nitrogen loading at the end of the dive.

What happened the day before: First day he had been unable to complete the checkout dive after saying he was unable to breathe. Maximum depth was 11'. This was attributed to a heavy wetsuit and tight BCD. The BCD was the same one he had been using in the pool, but he did not use a wetsuit in the pool. A larger suit and BCD were used for the second day. He tried them on before the dive and said he no longer felt constricted.

The Diver: Male, ~50 years old, medical release for shoulder surgery 18 months ago. Active and in good health.

The Lake: Fresh water, 70*, 20' visibility, 3500' above sea level.

In the Pool: Did well with the skills in the pool class but never "settled in" to the water. At times said he felt claustrophobic, he would blame this on a fogged mask or the heavy humid air in the indoor pool. He would occasionally stop on the surface to rest. At no time do he want to abort the class. We moved to an outdoor pool and he said he felt much more comfortable and his behavior in the water was much more relaxed.

I sent him a general "how was the trip home" email after the class but we have not talked specifally about the dive since we left the lake. I'm wondering if anyone else has seen this and what if anything can be done. I'd like to have some ideas for him the next time we get together.

 

[Tortuga68]

CO2 retention through improper breathing due to nervousness would be my guess

 

[farsidefan1]

Guy is simply not comfortable underwater. Don't let him go on. Make him do a LOT more pool time till he is relaxed and comfortable. Do him the favor of not moving him into situations in which he is not comfortable. You have seen all the posts in here critisizing certifying agencies for "graduating" unprepared divers. This is your chance to prevent this diver from being another excuse for banging on one agency or another.

 

[koyote1111]

Between expressing feelings of claustrophobia, having a nightmare of sorts, and stating that he felt "unable to breathe" at various times during the training, it seems obvious that stress was a factor. Dizziness and disorientation can also be symptoms of anxiety/stress. So, I'm not totally convinced that what may have appeared as nitrogen narcosis was indeed the issue.
It might be worth asking the student if he has had some challenges with anxiety in situations other than diving. An anxiety disorder can present in various fashions. Also, I imagine that many students do NOT list anxiety on their medical forms even if diagnosed with/or taking medication for anxiety. Approximately 18% of the U.S. population is diagnosed with an anxiety disorder.
You may already understand this...but just for the record, feeling anxious is different that having an anxiety disorder. Also, many people have anxiety disorders yet experience no anxiety with regard to diving. I am one of those people...absolutely no anxiety related to physical activities/adventure, etc. ... yet more intense anxiety in other situations. So...my opinion is a bit based on personal experience.

 

[BUGBAGGER]

Just wrote about a scary situation that I had early in my career as an instructor but got kicked offline and it all got lost. Here is a new version...

I had a student who did Ok in the shallow end of the pool but it was a whole different story in the deep end. On the second night of pool, after a brief review of the shallow end skills and all the preliminaries we started to descend in the deep end. As luck would have it, I had a DM and a co-instructor. They proceeded to the bottom with the other students while I stayed by one who had stopped descending at 3 feet below the surface.

I don't want to draw this out, so, I will simply say that the student was breathing evenly but looking straight through me and not responding to hand signals or physical contact. I took her to the surface. Long story made short, we talked and tried to descend 2 or 3 times. I even tried to get her to see a question on my slate underwater, no luck. She would not respond at all underwater and had no memory of the ways I tried to communicate with her underwater once we would surface. She was catatonic underwater. She would become completely immobile and unaware of any external stimuli including being lightly shaken , tapped, or pinched on the arm.

I tried counseling her and she thought I was unjustly holding her back. A third instructor at the pool tried to explain what he had seen, as well, which was exactly as I described and she refused to believe that she was becoming unresponsive underwater. She complained to the store owners who offered her private instruction at no additional cost but explained that she would still have to demonstrate water comfort and mastery of skills at each level before she would progress to the next. She never returned. I am hopeful that she found another leisure pursuit as I do not believe that she would have safely overcome a phobia that caused her such dire effects of which she was not aware.

Basically, I agree that your student is exhibiting signs and describing symptoms congruent with anxiety. In his case, it is likely that he is not breathing properly which is exacerbating the physical symptoms. The psychological symptoms of anxiety and lack of water comfort and ensuing physical symptoms are usually incompatible with safe diving. His anxiety alone could create the feeling of being drugged but that may not be the entire cause of the physical symptoms. They may be secondary to the anxiety or other underlying medical conditions.

I will say that mild cases of anxiety may be overcome with a lot of water experience resulting in mastery and comfort at each level before progressing, but, it has to be said that diving just isn't for everyone.

Since your student's symptoms could be anxiety and/or an underlying medical condition, it might be prudent to recommend a physical examination before he proceeds with training. His age would suggest that it is not unreasonable to consider that he may have undiagnosed heart, respiratory, or endocrine issues which may be contributing to his issues and might also be contraindicated with diving.

Best wishes for you and your student.

 

[Thalassamania]

A classic case of a student who is woefully unprepared being taken out into open water long before he's ready.

 

[BUGBAGGER]

A few more thoughts...

Setting aside all the indications of claustrophobia and anxiety for a moment, dizziness and disorientation are also common when a student suffers barotrauma either from failing to equalize, forceful equalization, or a reverse block.
It would be a good idea to find out if he had any pain or feeling of fullness in his ears during or following the dive. Sometimes the full extent of the barotrauma may not present until several hours to a full day after the dive. If a student reports feeling dizzy and disoriented underwater you often have to ask if he/she had any ear pain or sensation of water going into the ear during the dive. Also ask if they have any ear pain or feeling of fullness in the ears following the dive. They are often reluctant to offer this info up.

It is also possible for some to experience vertigo in poor visibility (even 20ft visibility) with no barotrauma.

 

[Tortuga68]

Some people always look for complex solutions to simple problems

 

[bletso]

it has to be said that diving just isn't for everyone.

Since your student's symptoms could be anxiety and/or an underlying medical condition, it might be prudent to recommend a physical examination before he proceeds with training. His age would suggest that it is not unreasonable to consider that he may have undiagnosed heart, respiratory, or endocrine issues which may be contributing to his issues and might also be contraindicated with diving.

Well stated. I have sent prospective students packing and given them money back. Diving isn't for everyone. Don't ever feel pressured to continue on to certify someone you feel could be a danger to themselves or others. Your name is on that card and it could well come back to haunt you.


Dale

 

[wavetrain75]

Obviously the checkouts were aborted and he is not certified (just to clarify). We did a nearly 4 hour pool session in an outdoor pool a few days before checkouts and he was clearly much more comfortable than at the indoor pool and he did the skills very well.

We've both had some time to think about it, I'll see if I can get ahold of him today to see what his impressions are. Of all the above explanations I cannot say that any one in particular is unlikely.

Medical releases are an issue in this area simply because there are very few doctors who understand diving. I have personal experience with a doctor simply asking "Do you know of any reason you shouldn't be diving?" and then sigining off on the release.