Is DCS possible under 20fsw, or 100% impossible?

[scubadada]

Even at 33 feet/10 meters, I had to use a dive time of 6 hours to exceed the NDL and get minimal deco time at a GF high of 95. That would be a long dive . I could not exceed the NDL by running ten 1 hour dives with half hour surface intervals

 

[tursiops]

Even at 33 feet/10 meters, I had to use a dive time of 6 hours to exceed the NDL and get minimal deco time at a GF high of 95. That would be a long dive . I could not exceed the NDL by running ten 1 hour dives with half hour surface intervals

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I haven't dug into the details of the previously reported info that DCS occurred on a 4m dive, but I can only assume it was due to repeated violations of yo-yo profiles and rapid ascents, i.e. NOT due to exceeding NDL limits.

 

[ginti]

In the article one case is reported to be bend at 4m.which is about 12 ft.

So the answer is yes. There is at least one reported case, where this happened.

It is speaking less than 10m, not 10m dives. Like Raphus wrote there is one DCS case from 4m dive.

Sorry guys, but maybe the link I open is not working well... I cannot find any information about this accident at 4m.

When I click on the link, a very short article speaking only about dives in less than 10m appears, nothing more.

Is there any pdf file available? Could you update the link?

EDIT: sorry, I am blind - it was clearly stated forget my request

 

[ginti]

I tried to find the original transcripts/articles of the Australian and New Zealand College of Anaesthetists conference in Brisbane. I couldn't find them.

Frankly speaking, the article speaking of a 4m dive ended up with bends is not scientific neither peer-reviewed. We know knothing about that dive: was it done at sea level or at high altitude? Did the guy who got the bends have any medical conditions? There could even be a misintepretation/error of the writer (in case you are wondering, very often journalists make serious mistakes about science).

Anyone is free to believe in whatever wants. I choose to believe in peer reviewed science, and the only reviewed article in this thread was speaking of no DCS at all in dives shallower than 6m.

I would really appreciate if anyone can provide a peer-reviewed source that describes an accident at depths shallower than 6m, but until that moment, for me the 6m constituite a pretty reasonable limit.

 

[boulderjohn]

I heared about cases, where people got skin bends in a 3m pool.
Drinking alcohol the night before. Dehydrated and going up and down to fast. I spoke with the person, who claims to saw multiple skin bends of this kind.

I have heard lots of things in lots of contexts that turn out not to be true.

Frankly speaking, the article speaking of a 4m dive ended up with bends is not scientific neither peer-reviewed.

One of the problems with this is not just that the article was not peer reviewed and we don't know if it is true. The real problem is that we often do not have a good way of being certain that an afflicted diver is bent. We use the term "DCI" to cover both the bends and lung overexpansion because it can be so difficult to tell the difference between the two, and the treatment is the same for both. In many cases, the diagnosis is made after treatment--the patient responded to recompression treatment, so it must have been DCS.

A few years ago we had a thread about DAN's rules regarding payment for recompression treatments, and that thread included information from DAN about the frequency with which unqualified doctors recommend DCS treatment for people who do not have any sort of dive-related injury. IIRC, they specifically cited spinal stenosis as a condition that can cause DCS-like symptoms after a physical activity like scuba, symptoms that go away after roughly the amount of time the person would have spent in a chamber.

In another thread, I talked about my own situation a few years ago. I go on weekend technical diving trips in New Mexico, and for a while, as I was driving home, I would develop DCS symptoms--especially hand numbness. The symptoms would get worse for a day, and then they would get better over the next couple of days--just as if I had had 3 days of recompression treatment. Well, to cut to the chase, my problem was 100% cured with carpal tunnel surgery. It was the handling of all those tanks that was causing the problem. When I mentioned this in the thread, Dr. Simon Mitchell, who regularly treats DCS patients in a chamber, gave a LOL response, saying many people with carpal tunnel syndrome are regularly treated for DCS.

So we have one anecdote of one unknown person getting DCS at 4m? Sorry. Not believing it until I see something more definitive.

 

[dmaziuk]

10 m is Haldane's original 2 atm. Given that it comes from observing caisson workers doing hard labour for >6 hr shifts at those pressures, I'll take it over 7.8, 6, or 4 metres any day. As for rumours of someone getting bent on a 4-meter dive: the plural of "anecdote" is not "data". That is, sh*t happens an' all that, but under normal circumstances I wouldn't worry about DCS at 10 msw or shallower.

 

[tursiops]

In another thread, I talked about my own situation a few years ago. I go on weekend technical diving trips in New Mexico, and for a while, as I was driving home, I would develop DCS symptoms--especially hand numbness. The symptoms would get worse for a day, and then they would get better over the next couple of days--just as if I had had 3 days of recompression treatment. Well, to cut to the chase, my problem was 100% cured with carpal tunnel surgery. It was the handling of all those tanks that was causing the problem. When I mentioned this in the thread, Dr. Simon Mitchell, who regularly treats DCS patients in a chamber, gave a LOL response, saying many people with carpal tunnel syndrome are regularly treated for DCS.

My wife returned from a dive trip with an achy hand/wrist. She called DAN, went to the local chamber, started treatment, they asked her if the pain went away, she said no, they brought her back up and proclaimed carpal tunnel.

So we have one anecdote of one unknown person getting DCS at 4m? Sorry. Not believing it until I see something more definitive.

Concur.

 

[boulderjohn]

Given that it comes from observing caisson workers doing hard labour for >6 hr shifts at those pressures,

I believe he was more into watching goats get bent.

 

[ginti]

So we have one anecdote of one unknown person getting DCS at 4m? Sorry. Not believing it until I see something more definitive.

Exactly my point. Ready to change my mind, but only with something more definitive.

 

[lowwall]

NASA uses Nitrox to set a maximum equivalent air depth of 7m (23 feet) in their astronaut training pool. Dives are up to 6.5 hours long. They published a paper on their experience which I uploaded to the most recent shallow water thread: Nitrox for shallow water artifact diving??

From the introduction:

Since the facility opened in 1997, over 30,000 hours of suited training has been completed with no occurrence of decompression sickness (DCS) or oxygen toxicity.