In-Water Recompression

[John Gulliver]

This thread has its roots in the thread on the recent fatality at the Farnes.
Although all agencies seem to frown on IWR and the problems involved in carrying it out are daunting, I personally think there are circumstances where it might be justified. What real alternative is there if a serious case of DCI occurs when you're on a liveaboard in the far southern part of the Red Sea, i.e. in Yemeni or Eritrean waters? It may well take days to get the victim to a chamber and you've probably only got enough O2 for a few hours' treatment.
Anyway, this is what the US Navy Diving Manual Volume 5 has to say on the subject:

21-4.2 In-Water Recompression. Recompression in the water should be considered an option of last resort, to be used only when no recompression facility is on site and there is no prospect of reaching a recompression facility within 12 hours. In an emergency, an uncertified chamber may be used if, in the opinion of the Diving Supervisor, it is safe to operate. 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 in-water 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.
21-4.2.1 Surface Oxygen Treatment. For less life-threatening cases, have the stricken diver begin breathing 100 percent oxygen immediately if it is available on site. Continue breathing oxygen at the surface for 30 minutes before deciding to recompress in the water. If symptoms stabilize, improve, or relief on 100 percent oxygen is noted, do not attempt in-water recompression unless symptoms reappear with their original intensity or worsen. Continue breathing 100 percent oxygen as long as supplies last, up to a maximum time of 6 hours. If surface oxygen proves ineffective after 30 minutes, begin in-water recompression.
21-4.2.2 In-Water Recompression Using Air. In-water recompression using air is always less preferable than using oxygen.
1. Follow Treatment Table 1A as closely as possible.
a. Use either a full face mask or, preferably, a surface-supplied UBA.
Never recompress a diver in the water using a scuba with a mouthpiece unless it is the only breathing source available.
b. Maintain constant communication.
2. Keep at least one diver with the patient at all times. Plan carefully for shifting UBAs or cylinders. Have an ample number of tenders topside.
3. If the depth is inadequate for full treatment according to Treatment Table 1A:
a. Recompress the patient to the maximum available depth.
b. Remain at maximum depth for 30 minutes.
c. Decompress according to Treatment Table 1A. Do not use stops shorter than those of Treatment Table 1A.
21-4.2.3 In-Water Recompression Using Oxygen. If a 100 percent oxygen rebreather is available and individuals at the dive site are trained in its use, the following in-water recompression procedure may be used instead of Table 1A:
1. Put the stricken diver on the UBA and have the diver purge the apparatus at least three times with oxygen.
2. Descend to a depth of 30 feet with a standby diver.
3. Remain at 30 feet, at rest, for 60 minutes for Type I symptoms and 90 minutes for Type II symptoms. Ascend to 20 feet even if symptoms are still present.
4. Decompress to the surface by taking 60-minute stops at 20 feet and 10 feet.
5. After surfacing, continue breathing 100 percent oxygen for an additional 3 hours.
6. If symptoms persist or recur on the surface, arrange for transport to a recompression facility regardless of the delay.
21-4.2.4 Symptoms After In-Water Recompression. The occurrence of Type II symptoms after in-water recompression is an ominous sign and could progress to severe, debilitating decompression sickness. It should be considered life-threatening. Operational considerations and remoteness of the dive site will dictate the speed with which the diver can be evacuated to a recompression facility.
21-4.3 Symptoms During Decompression (No Chamber Available). Development of decompression sickness in the water is uncommon when U.S. Navy decompression procedures are followed, but when it does occur it is likely to be at shallow stops. The symptoms are usually Type I and respond quickly to minimal recompression.
Follow the flowchart in Figure 21-3 for proper management. Only recompress an additional 10 feet if no significant improvement was noted after the first 10-fsw recompression. Remain at treatment depth 30 minutes in addition to any required decompression stop time. If no decompression time is required at the treatment depth, remain there for 30 minutes. Shift diver to 100 percent oxygen at depths of 30 feet and shallower if possible. If symptoms persist after surfacing, have the diver breathe 100 percent oxygen while arranging evacuation to a recompression facility. Do not conduct in-water recompression for residual symptoms after surfacing. Once a recompression facility is reached, any symptoms are treated as a recurrence of Type II symptoms.

[Mark Powell]

TDI teach that if there is really, really no option, i.e. you are 24hrs away from the nearest chamber then if you have all the right equippment and safety divers then it is acceptable as a very, very last resort.

However, it is NEVER an option in the UK. There is always a better alternative.

We are blessed with an amazing coastguard/SAR service and a good selection of recompression facilities within easy reach of most places in the UK.

I'm not sure about Sweden or other European countries but in the UK at least it is not a recommended option.

[wreckweasel]

Just forget it in the northern hemisphere, thermal management becomes a major issue very rapidly.

Its not a minor undertaking, regardless of where you are, in water use of high PO2's predisposes to a higher risk of toxicity, which mandates use of full face supplies and the ability to switch the in water diver off of High O2.

If you look at the sort of runs you need to pull to effectively recompress someone, you really do need to a lot of pre-planning etc.

Frankly, I wouldnt consider it except in the most dire of circumstances....

[RichClark]

There's actually a very interesting article on Mark Ellyatt's website regarding In Water Recompression.

http://www.users.totalise.co.uk/~dee...nwaterreco.htm

By posting this link I'm not advocating IWR in anyway, but faced with some of the circumstances in the case studies, I think that I'd opt for IWR too. We're exceptionally lucky that in the UK there really shouldn't ever be the need.

Cheers

Rich

[John Gulliver]

Very interesting link. As I said the problems involved in carrying out IWR are daunting and there is probaly no need ever to do so anywhere in Europe but, judging by Pyles' article, it does seem to have saved many more lives than it has reaped. We have a man here in Gothenburg who developed DCI while on a liveaboard in Sudanese waters about 15 years ago. There was a diving medicine specialist in the group, who refused to let the man's friends take him back under water. The supply of oxygen ran out after a few hours and it took several days to get him to a chamber. He is partially disabled today. There is still a lot of controversy about whether the doctor was right, not only among his companions but also among medical experts. Some say he would probably have died if IWR had been attempted, others that if a couple of his mates had been allowed to take him back down to 10 meters for an hour or so he might well have been spared his permanent injuries, even though it would have meant air IWR with an ordinary regulator. Who knows who is right!

[Snash]

[quote=Mark Powell]However, it is NEVER an option in the UK. There is always a better alternative.

We are blessed with an amazing coastguard/SAR service and a good selection of recompression facilities within easy reach of most places in the UK.

QUOTE]


Mark

Thank you for that - a very well put comment. Helped me work through in my mind what the options are and more importantly what they are not....

Thanks

Simon

[turbanator]

I think that Richard Bull also wrote an article for 990 mag.

[ScubaStu]

With due respect unless the circumstances are exceptional, ie as John stated, that you are more than 24 hours travel from the nearest chamber, forget it. Especially in UK waters
A. The water temperatures have to be taken into account.
B. How many dive boats go out equiped with the sort of gear stated in the US
Diving manual.
Staurt

[RichClark]

Originally Posted by ScubaStu

With due respect unless the circumstances are exceptional, ie as John stated, that you are more than 24 hours travel from the nearest chamber, forget it. Especially in UK waters
A. The water temperatures have to be taken into account.
B. How many dive boats go out equiped with the sort of gear stated in the US
Diving manual.
Staurt

If you were doing the sort of diving where you might seriously consider IWR, then some of the pre-dive planning would be to ensure that the boat did carry the necessary equipment.

But as I had mentioned in my earlier post, we're extremely lucky in the UK with the excellent services provided.

Cheers

Rich

[Mark Chase]

Its important to point out the difference between in water recompression and missed stops.

A diver who has a rapid or uncontrolled ascent and breaks surface has two choices. Get on the boat and await the chopper. Or go back down and do the stops. This is not in water recompression in the true sense. Technical divers in the UK very commonly adopt this practice and I have done it twice. The systems for repeating the stops are detailed in the back of the TDI manual. These are based on the US Navy Omitted Decompression Procedure.

1: you must descend within 5mins of surfacing and repeat all stops below a depth of 40' (12m)

2: Return to 40' and stay there for 1/4 of your 10' (3m) stop time

3: Ascend to 30' (9m) and stay there for 1/3 of your 3m-stop time

4: Ascend to 6m and stay there for 1/2 the 3m stop time

5: Ascend to 3m and stay there for 1 1/2 your 3m stop time

This system is designed for symptom free divers having missed stops. I used it once after a rapid ascent from a 30m dive missing about 20mins deco and once after a 65m dive where the deco station was towed up to the surface by the dive boat. On the second one I broke surface with 35mins of deco left to do.

I got lucky both times and didn’t suffer ay DCI symptoms during or after the dives.

This all comes down to personal choice. Repeating your deco by default means you will be solo. You probably lost your buddy on the way up and your unlikely to find him on the way back down . Some would consider this high risk but I have to say on the occasions I have seen divers miss stops and get out of the water they have all been bent. A few of my diver pals and I have used this system and got away with it. But perhaps that was luck or we are just not that susceptible to bends. Who knows? DCI is not an exact science.

ATB

Mark Chase