In Water Recompression vs Missed Deco

[eluzgin]

I was reading in US Navy Diving Manual about such thing as water recompression. When a diver gets bad bends and there is no chance to get a rescue helicopter in time, he can be taken back to depth to decrease the bubbles forming in his tissues. Because it can take several minutes for bubble to form after diver's quick surfacing, it's essential to take him down to the depth as soon as possible. This practice resonated with the conclusion I have made for myself when learning about decompression sickness while taking open water class. That if for some reason, I have to do emergency surfacing from the depth and the bend is unavoidable, I would like to try to do a quick tank switch on a boat and then take myself down as soon as possible and then do proper decompression ascent. I realize that a really sick diver may not be able to do such trick but with someone's help it just may work. I know there is no such practice in recreational diving community and instructors avoided commenting on this idea. But can anyone familiar with decompression sickness tell me if it's a crazy idea or what?

 

[Diver0001]

It's not a crazy idea. In water recompression will work as you suspect it does *if you do it right* and there have been cases of divers who have probably saved their own lives using this technique--Richard Pyle comes to mind. He still got badly bent but he didn't die.

However, having said that, the logistics involved and the risk of the victim drowning or becoming hypothermic make it very impractical for all but the most well prepared dive teams who are diving in ideal conditions. Immediate evacuation to a hospital is generally thought to be a far superior response.

R..

 

[M_Bipartitus]

Disclaimer: I a stupid, unqualified, diver and anyone who thinks I know anything is at their own risk...

It's just a bad idea. While it could be helpful, there are far more complications that could occur, and the amount of time that you would be able to be underwater wouldn't likely help much if it was that bad. You still will be traveling at the surface to get to a chamber and that will take a long time relative to how fast bubbles form. I'm not an expert, but I imagine that if it is obvious that the diver will be bent that bad, it's likely to late for this to help very much.

That being said there are times that it could be helpful to have a spare tank and stay at a safety stop as long as you can. Say you are in clear water and you decide to follow a fish. You don't pay much attention, and now you are deeper than you planned and over a NDL. This type of situation happens too often. You decide you must ascend now. There is a good chance there would be DCS, so you may want to stay at a safety stop for a good long time. Probably even best is a different diver brings a bottle to you. Research seams to indicate, once bubbles start it's a lot harder to get them to go away.

 

[darkstar]

I think the Navy manual was talking about a diver with a helmet and surface supplied gas. Attempting the same thing with recreational scuba gear and the risk is much greater. If the diver becomes unconcious (from AGE) it would be much more difficult to keep them from drowning. Then you have the logistics of very quickly providing enough breathing gas for both the stricken diver and the support team.

Administering O2 and rushing to a chamber provides a better chance of survival for most DCI cases. I agree with Diver0001 that the exception would probably be with teams of divers who practiced in-water recompression. How many divers do you know who even bother practicing basic scuba skills and rescues.

 

[dherbman]

It's not a crazy idea. In water recompression will work as you suspect it does *if you do it right* and there have been cases of divers who have probably saved their own lives using this technique--Richard Pyle comes to mind.
R..

And some who didn't, like Mia Tegner.....


According to the decedent's husband, also her dive partner, the decedent
was a marine biologist, and while this was a recreational dive, she was
noting marine organisms associated with the wreck off the shore of Mission
Beach for her own interest. A party of five divers were using a privately
owned 22' boat as their dive platform. The first dive of the day was on a
wreck located in 100 feet of water. She made a single dive in this location
without incident. After a surface interval of approximately 1 1/2 hours,
the decedent began her second dive on another wreck which sat in 85 feet of
water. The decedent began the dive with her husband but after about 20
minutes her husband became low on air and surfaced. The decedent continued
to dive until she became low on air then began an ascent. Since there are
no witnesses to this event, it can not be determined whether or not the
decedent made a safety stop. She was seen reaching the surface and made a
statement to the effect that her computer was telling her she need
additional decompression time and she needed a different tank in order to
submerge again. One of the other divers directed her to his tank, regulator
and buoyancy compensator vest which was hanging from a line over the side
of the boat. The decedent detached the tank system, held it under her arm
and descended. After approximately four minutes, the system rapidly floated
to the surface with the buoyancy compensator almost full of air. The
decent's husband immediately geared up and entered the water. He descended
to the bottom and searched for the decedent and could not find her. He
surfaced again to see if she made it safely to the surface. When he did not
find her, he descended to the bottom again until he ran out of air. He
surfaced once again and summoned help.

 

[Diver0001]

And some who didn't, like Mia Tegner.....

Good point.

R..

 

[nkydiver]

I was reading in US Navy Diving Manual about such thing as water recompression. When a diver gets bad bends and there is no chance to get a rescue helicopter in time, he can be taken back to depth to decrease the bubbles forming in his tissues. Because it can take several minutes for bubble to form after diver's quick surfacing, it's essential to take him down to the depth as soon as possible. This practice resonated with the conclusion I have made for myself when learning about decompression sickness while taking open water class. That if for some reason, I have to do emergency surfacing from the depth and the bend is unavoidable, I would like to try to do a quick tank switch on a boat and then take myself down as soon as possible and then do proper decompression ascent. I realize that a really sick diver may not be able to do such trick but with someone's help it just may work. I know there is no such practice in recreational diving community and instructors avoided commenting on this idea. But can anyone familiar with decompression sickness tell me if it's a crazy idea or what?

As I was going through DiveCon classes, this subject was brought up by our instructor. The articles we read and discussed basically came to the conclusion that this was a personal choice and highly dependent on your level of comfort in the water, experience level, the distance and time from a chamber, and your own personal choice. If you are more than a couple hours out from a chamber, and know you are going to get bent, you can make the choice to descend again and use an extended deco schedule to ascend. Our instructor had said he has seen and done this, but it requires at least a buddy with you during your stops to make sure if you do spit out your reg, he can help hold it in your mouth and help you ascend. This is still though something of a last resort, because of the uncertainty involved, but if I was that far from a chamber, and I knew what I was going to take a hit, I would choose to take the risk and perform an in-water recompression.

 

[2Tours N Iraq`]

I would have to agree with Bipartitus, a water recompression followed by decompression is a bad idea for the untrained recreational diver. The Navy has nearly unlimited resources and support divers to assist the bent diver (such as recompression chambers on board ships). Recreational divers generally have a very limited air supply and only a few buddies at best to assist. Additionally, an in-water recompression still has the potential for bubbles to continue to form while underwater resulting in more complications such as convulsions, paralysis, and/or drowning. You are better off diving on a charter with someone proficient in first aid, preferably someone who can administer an IV, and breathe pure oxygen and wait for the helo to arrive. IF (and only IF) those are not present and the helo is still too far away, then and only then should you attempt an in-water recompression as a LAST RESORT effort to save the diver's life until the chopper can arrive and evac the bent diver out. Just remember, it is easier for a bent diver to become chilled as their blood probably isn't flowing as efficiently resulting in their body temp to drop faster. In-water recompression, even for the Navy, is a LAST RESORT technique and one that is not preferred.

 

[eluzgin]

Good arguments. I agree with the point that IWR is last ressort and a personal choice.

 

[Charlie99]

And some who didn't, like Mia Tegner.....

She made a single dive in this location
without incident. After a surface interval of approximately 1 1/2 hours,
the decedent began her second dive on another wreck which sat in 85 feet of
water. The decedent began the dive with her husband but after about 20
minutes her husband became low on air and surfaced. The decedent continued
to dive until she became low on air then began an ascent. Since there are
no witnesses to this event, it can not be determined whether or not the
decedent made a safety stop. She was seen reaching the surface and made a
statement to the effect that her computer was telling her she need
additional decompression time and she needed a different tank in order to
submerge again.

While I agree that in-water REcompression is dangerous, this isn't an exampe of IWR, but rather this is a case of going back down to do an omitted decompression stop. IWR is going back down to fix DCS symptoms --- a much more serious thing than a symptomless diver immediately resubmerging to complete required stops.

Richard Pyle who has, unfortunately, a lot of experience with IWR summarized things nicely in In-water Recompression as an Emergency Field Treatment of Decompression Illness