Sea Demon and friends, that diagnosis is Acute Neurological Decompression Sickness (DCS). I would not recommend in-water recompression at all, because:
1.
Worsening of paralysis underwater. This can lead to drowning. In cases of DCS, there is a likelihood of the paralysis getting worse.
2.
Decreased conscious level underwater. This will lead to drowning. In cases of DCS, there is a likelihood of the diver getting drowsy, confused, delirious, and total unconsciuosness.
3.
Oxygen toxicity. This will lead to convulsions and drowning. Yes, you guys are right, the treatment table USN 6 will give you pO2 = 2.8 ATA. This is okay when you are in a dry, warm, controlled hyperbaric chamber with a paramedic and doctor looking after you. Not so okay when you are underwater, using SCUBA and sick.
4.
Worsening of general condition. Being sick and cold and dehydrated underwater for prolonged periods will worsen the diver’s general condition.
Are there any variants of IWR that you can use?
1. Air? Air treatment tables takes too long underwater, and it is much less effective than oxygen. Too much trouble for too little benefit.
2. Use Deco stops as treatment? This is not likely to give any relief – a deco stop is used to prevent DCS, but it is insufficient to be used as treatment of DCS. Risks of being underwater still apply.
3. Short table? Again, questionable benefit. Short tables (e.g. USN 5 or 18:60:30) will still give you pO2 = 1.8 (risk of O2 tox), but will not relieve
Other problems?
He will need a buddy. The buddy can't breathe O2 (risk of oxygen toxicity). So you will need to consider his/her decompression schedule. Look at the USN 6 profile (18m max depth for 4 hours 45 minutes) and you realise it is not a conservative No-D dive for the buddy. You can end up bending this otherwise healthy buddy.
What do other diving doctors say?
The diving doctors did have a long, scientific discussion and workshop about this a few years ago - at the Undersea and Hyperbaric Medicine Society Annual Scientific Meeting. Their discussions, references and recommendations are now published in a scientific book and is available for purchase at
www.uhms.org. I do not suggest buying it, as it is full of unreadable medical stuff. There is a copy in Lumut though, if you are still interested. But in short, it says that in order to do IWR, you have to have some very specialised equipment, very knowledgeable and experience people – such that it is almost impossible to have all that during an emergency.
So, in that scenario, I'd recommend:
1. Lying the diver flat
2. Give fluids (by mouth if fully conscious, by iv if there is a paramedic around)
3. Give oxygen - for as long as your supplies last
4. Call the Malaysian Emergency Hotline
5. Get the diver to a medical facility / recompression facility (as advised by no. 4)
This should be easier and safer than IWR, even if it is leads to a longer delay before you start his recompression treatment.
