omitted decompression after a VERY long exposure time at 2,57 bars

[Papyone]

Hi, I’ve a question for the hyperbaric doctors of this forum which concerns omitted decompression after a VERY long exposure time under pressure.

I suppose that a person that was submitted during 14 hours to an absolute pressure of 2,57 bars and is then decompressed within less of an hour to the atmospheric pressure has very little chance to survive. But what I would like to know is how long it would take to that person to pass away. Is it a question of hours or minutes?

Thanks in advance for your reply.

 

[jborg]

I'm certainly not a doctor, hyperbaric medicine or otherwise. Partly this depends on what they were breathing. I threw it into Subsurface and it says that 14 hours at 16m and then surfacing immediately gives a gradient factor of 169%. That's not great and I can't say I'm sure but my highly uninformed gut feeling says that might well be survivable, given treatment. That's after breathing 32% though. If they were breathing air instead, they'd have a GF of 239% which is decidedly worse.

 

[scubadada]

That's a lot of missed deco on air, 32%, or 36%

 

[tursiops]

Hi, I’ve a question for the hyperbaric doctors of this forum which concerns omitted decompression after a VERY long exposure time under pressure.

I suppose that a person that was submitted during 14 hours to an absolute pressure of 2,57 bars and is then decompressed within less of an hour to the atmospheric pressure has very little chance to survive. But what I would like to know is how long it would take to that person to pass away. Is it a question of hours or minutes?

Thanks in advance for your reply.

Why do you ask? It sounds,like you are writing a novel...

 

[Papyone]

I'm certainly not a doctor, hyperbaric medicine or otherwise. Partly this depends on what they were breathing. I threw it into Subsurface and it says that 14 hours at 16m and then surfacing immediately gives a gradient factor of 169%. That's not great and I can't say I'm sure but my highly uninformed gut feeling says that might well be survivable, given treatment. That's after breathing 32% though. If they were breathing air instead, they'd have a GF of 239% which is decidedly worse.

No recompression treatment possible at that time.

The surrounding atmosphere was air contaminated by hydrocarbon gasses and the theoretical PPCO2 was around 25,6 mb.

 

[Papyone]

Why do you ask? It sounds,like you are writing a novel...

Unfortunately no, it’s a real case.

 

[tursiops]

Unfortunately no, it’s a real case.

OMG. You mean this actually happened to someone? When did it happen? Sounds coarse, but are you currently waiting for someone to die?

 

[scubaozy]

Maybe you want to research the history of caisson workers building Brooklyn bridge, they have probably been working long hours at comparable depths.

 

[Jonn]

All this stuff is probabilistic. You can get bent after strictly following a conservative algorithm, you can exceed the limits a lot and be just fine. Your example exceeds the limits a lot though. He’s not going to explode and die instantly or anything, he’ll probably survive, but he’ll be lucky to avoid permanent brain damage.

 

[Papyone]

All this stuff is probabilistic. You can get bent after strictly following a conservative algorithm, you can exceed the limits a lot and be just fine. Your example exceeds the limits a lot though. He’s not going to explode and die instantly or anything, he’ll probably survive, but he’ll be lucky to avoid permanent brain damage.

Of course he won’t explode. This only happened once in 1983, but it was under very specific circumstances and during an explosive decompression at great depth. But when you say he could probably survive it seems a bit surreal to me because after spending all this time at this pressure, the victim had to be practically saturated with inert gas. As a comparison, it could be said that this person was about in the same physiological conditions as a commercial diver who had done air saturation at 16 m depth. This also means that if he wanted to return safely and healthily to the surface this diver would have had to undergo a decompression of about 33 hours. So I really have my doubts that the poor victim survived a long time after they decompressed the place into which he was confined.