Emergency pressure treatment when bent?

[DCBC]

Perhaps the discussion has gotten a bit out-of-hand and I blame myself for sidetracking on the portable chamber concept. What I'm now seeing is a IWR discussion around the use of various mixed gases, near surface supplied O2 delivery with a 40 foot umbilical (Dr. Carl Edmonds), full-face masks, etc. so this begs the question: What is practical and reasonable? Please keep in-mind that we are talking about remote locations.

Does the average DM know how to put on a full-face mask on themselves (not to mention someone else who's a victim of DCS)? Can they accurately diagnose the severity and scope of DCS and AGE and suggest a patient management plan? How about the expertise of the safety divers? Is it reasonable that the dive operator possess and maintain the equipment under discussion on each dive boat? What are the liability issues in using IWR, a method which has not been accepted by the hyperbaric medical community at-large?

Because we can do a thing does not mean we should...

 

[ianr33]

A question I have always wondered about is if you are doing your deco, and you start to feel a twinge, do you blow off the rest of your deco and surface, follow your planned schedule, or go back down a stop and bulk up your stop times..

I would go back down a stop or 2 and extend the schedule.(assuming it was just minor pain) If you have significant symptoms while still in the water its probably time to get the wetnotes out and write your will !

Got a sharp pain in my leg once on a 100 foot stop during a 200 foot dive. First thought was this is a bad place to get bent.Second thought was thats impossible,just enjoy the dive.

Personally I would have no problem doing IWR in the following circumstances:
Minor pain only
Warm water
Decent weather
Ample supply of oxygen
Divers capable of acting as support

IWR is probably more appropriate for technically trained divers who understand oxygen and are used to long deco hangs.

 

[DandyDon]

O2 Snuba...?

 

[Thalassamania]

Perhaps the discussion has gotten a bit out-of-hand and I blame myself for sidetracking on the portable chamber concept. What I'm now seeing is a IWR discussion around the use of various mixed gases, near surface supplied O2 delivery with a 40 foot umbilical (Dr. Carl Edmonds), full-face masks, etc. so this begs the question: What is practical and reasonable? Please keep in-mind that we are talking about remote locations.

What is practical and reasonable? - EXACTLY! What can the run of mill DM on a live-aboard be reasonably expected to be capable of doing? What kind of gear can the average live-aboard be expected to carry, maintain and exercise? Frankly, when it comes to remote locations I submit that diving needs be less aggressive and mixes need to be more benign unless the operation is willing to field an Edmonds style system and to have personnel capable and practiced in the use of such a system. If they're not ready to deal with a diver who is vomiting into a full face mask and convulsing ... then they're not ready for prime time.

What I've always felt was the best approach to IWR was a domed stage (like the one that NOAA used to have at Catalina). That way the diver could be out of the water from the chest up.

Does the average DM know how to put on a full-face mask on themselves (not to mention someone else who's a victim of DCS)? Can they accurately diagnose the severity and scope of DCS and AGE and suggest a patient management plan? How about the expertise of the safety divers? Is it reasonable that the dive operator possess and maintain the equipment under discussion on each dive boat? What are the liability issues in using IWR, a method which has not been accepted by the hyperbaric medical community at-large?

Because we can do a thing does not mean we should...

Exactly.

I would go back down a stop or 2 and extend the schedule.(assuming it was just minor pain) If you have significant symptoms while still in the water its probably time to get the wetnotes out and write your will !

Got a sharp pain in my leg once on a 100 foot stop during a 200 foot dive. First thought was this is a bad place to get bent.Second thought was thats impossible,just enjoy the dive.

Personally I would have no problem doing IWR in the following circumstances:
Minor pain only
Warm water
Decent weather
Ample supply of oxygen
Divers capable of acting as support

IWR is probably more appropriate for technically trained divers who understand oxygen and are used to long deco hangs.

An understanding of oxygen and being used to long hangs is only the start, the list of additional skills and knowledge is significant.

O2 Snuba...?

No!

 

[DCBC]

What is practical and reasonable? - EXACTLY! What can the run of mill DM on a live-aboard be reasonably expected to be capable of doing? What kind of gear can the average live-aboard be expected to carry, maintain and exercise? Frankly, when it comes to remote locations I submit that diving needs be less aggressive and mixes need to be more benign unless the operation is willing to field an Edmonds style system and to have personnel capable and practiced in the use of such a system. If they're not ready to deal with a diver who is vomiting into a full face mask and convulsing ... then they're not ready for prime time.

I knew we could agree on something

What I've always felt was the best approach to IWR was a domed stage (like the one that NOAA used to have at Catalina). That way the diver could be out of the water from the chest up.

An interesting option.

 

[DandyDon]

What I've always felt was the best approach to IWR was a domed stage (like the one that NOAA used to have at Catalina). That way the diver could be out of the water from the chest up.

Giant Snuba! What happens when the standing diver in the dome takes an OxTox hit...?

I think I'll stick to heavy hydration, long stops, and fall back on on-board O2. Did see a liveaboard fumble keeping the O2 available once during a heart attack tho.

 

[Thalassamania]

Giant Snuba! What happens when the standing diver in the dome takes an OxTox hit...?

That's why there's a tender there with the patient, of course.

I think I'll stick to heavy hydration, long stops, and fall back on on-board O2. Did see a liveaboard fumble keeping the O2 available once during a heart attack tho.

From what I've seen most live-aboards (there are exceptions) have their hands full keeping the boat and the compressor(s) running.

 

[graywhale]

Wayan:

"Remember the problem is Nitrogen. Nitrogen to be eliminated out of the system not have more introduced more into the system."

I am too lazy too look it up now, but in the workshops it was speculated that it was "obvious" that nitrox was better than pure air. Remember, there most IWR treatments have successfully been done on pure air. So why wouldn't Nitrox be even better?

I would say that it is not outside the realm of possibility that nitrox EAN 50 to 100 feet could be even better than 100% 02 to 30 feet due to the physical recompression of the nitrogen bubbles which is the immediate problem to begin with. The secondary problem is clearing out the excess nitrogen via slow decompression.

I also think we should stratify the procedures depending on the equipment available.

1. When only regular air is available
2. When Nitrox is available
3. When 100% oxygen is available
4. When a FFM with the above are available (or not)

IWR would then vary depending on the real world availability for the circumstance. Number 1 is a last ditch treatment when basically only regular scuba is available and nothing else. In many circumstances it could be a life saver. It has been used many times successfully. I think the main ingredient required of the DM or operator is to be patient, because an IWR treatment takes time, especially only using air.

Heliox would be an interesting possibility. Basically, I think more studies should be done using a mix of different gases for treatment options in IWR. Obviously the optimal solution (besides having a chamber close by) is a FFM with 02. But this should not be a show stopper if not available unless the victim is vomiting or otherwise unfit to go into the water with a mouth regulator.

Perhaps safety star ratings should be given to operators depending on the treatment options available to bent divers with the highest rating going to those with a chamber near by and the lowest to those with no training or equipment for even basic air IWR.

 

[Thalassamania]

Wayan:

"Remember the problem is Nitrogen. Nitrogen to be eliminated out of the system not have more introduced more into the system."

I am too lazy too look it up now, but in the workshops it was speculated that it was "obvious" that nitrox was better than pure air. Remember, there most IWR treatments have successfully been done on pure air. So why wouldn't Nitrox be even better?

Nitrox is better than air, Oxygen is better than Nitrox. The higher the ppO2 the better (within tox limits).

I would say that it is not outside the realm of possibility that nitrox EAN 50 to 100 feet could be even better than 100% 02 to 30 feet due to the physical recompression of the nitrogen bubbles which is the immediate problem to begin with. The secondary problem is clearing out the excess nitrogen via slow decompression.

Absolutly not! You run down to 60 ft looking for symptom relief and treat with pure oxygen. If you don't get relief by 60, you've got problems and there's controversy over the best approach. I'm currently favoring continuing down and switching to heliox with a ppO2 held as high as possible for the depth, but that could change any moment.

I also think we should stratify the procedures depending on the equipment available.

I disagree, I think smart divers will limit their time/depth/ppN2 exposure based on the emergency support available.

1. When only regular air is available
2. When Nitrox is available
3. When 100% oxygen is available
4. When a FFM with the above are available (or not)

That's not a bad set of cut offs for the exposure that might be allowed, but I'm sure that many would quibble.

IWR would then vary depending on the real world availability for the circumstance. Number 1 is a last ditch treatment when basically only regular scuba is available and nothing else. In many circumstances it could be a life saver. It has been used many times successfully. I think the main ingredient required of the DM or operator is to be patient, because an IWR treatment takes time, especially only using air.

In this day and age there is no excuse for not having oxygen available at the divesite so options 1 & 2 are to my mind not worth considering. The dicotomy for oxygen might be in-water O2 vs. surface O2.

Heliox would be an interesting possibility. Basically, I think more studies should be done using a mix of different gases for treatment options in IWR. Obviously the optimal solution (besides having a chamber close by) is a FFM with 02. But this should not be a show stopper if not available unless the victim is vomiting or otherwise unfit to go into the water with a mouth regulator.

There are many reasons for a FFM, not just the danger of convulsions (which might not start until the diver is in the water). Other considerations are communications, level of consciousness, etc.

Perhaps safety star ratings should be given to operators depending on the treatment options available to bent divers with the highest rating going to those with a chamber near by and the lowest to those with no training or equipment for even basic air IWR.

Trust me, it's been tried. Operators fight such a system tooth and nail, it could never happen.

 

[Wayan]

This is straight from the USN Diving Manual

"In divers with severe Type II symptoms, or symptoms of arterial gas embolism (e.g., unconsciousness, paralysis, vertigo, respiratory distress, shock, etc.), the risk of increased harm to the diver from inwater recompression probably outweighs any anticipated benefit. Generally, these individuals should not be recompressed in the water, but should be kept at the
surface on 100 percent oxygen, if available, and evacuated to a recompression facility regardless of the delay. To avoid hypothermia, it is important to consider water temperature when performing in-water recompression."

So as you can see it is not as simple as saying this person has a hit get them back in the water. It is a medical management problem and this needs to be the first consideration....Is it medically viable to IWR this person........