Why not treat DCS yourself?

[boulderjohn]

DoctorMike and RainPilot already covered most of this, but I will pile on in a couple of cases.

Because from what I've heard DCS symptoms don't come on instantly.

it varies quite a bit. Chris Rouse died within a few seconds of reaching the surface. Don Shirley, safety diver for David Shaw, had his severe DCS hit while still deep in the water.

So, if you realized you ascended too fast or accidentally blew through a safety stop, such that you're likely to get DCS but haven't had any bad symptoms yet, it seems to me that the most responsible thing to do would simply be to re-descend and do that safety stop, rather than ending the dive and waiting for symptoms to develop into an emergency on the surface.

So, if a diver blows through a safety stop by accident, wouldn't it make sense to go back down and redo the safety stop?

o, if a diver blows through a safety stop by accident, wouldn't it make sense to go back down and redo the safety stop? Yet nowhere in my training did they cover "re-doing" missed safety stops.

Missing a safety stop is rarely an issue--it is not a requirement to do it in the first place. That is why most agencies recommend against going back down in the event it is missed. On the other hand, missing a decompression stop is more serious, and every agency I know does recommend going down and doing it, with the exact procedure depending upon what was missed and how long it took to get back down.

However, it is not usually recommended for divers carry around a backup O2 cylinder for this purpose. Instead, it's recommended that you "leave it to the professionals" to take care of you, despite that it will necessarily delay your oxygen treatment, increasing risk of problems later on, and breathing O2 from a medical O2 tank is not exactly rocket science and could easily be learned by any diver.

I have never heard that recommendation. I have usually heard the opposite.

 

[Rred]

Lemme see now. You've taken a hit, which tells you that you might have an ignorable skin rash, or, you might be paralyzed and die. So not knowing what your outcome will be, the OP wants to DIY with in water recompression and random oxygenation, rather than going to a controlled stable environment where trained medical experts can constantly evaluate their condition and take care of whatever develops.

Gee. Decisions, decisions. Whatever to do.

The incredible inefficiencies and costs of the US medical system are an entirely different issue.

 

[rjack321]

I'WR simply IS associated with significant risks of death, believe it or not. So while it sometimes may make sense (severe DCS symptom far from a chamber), to imply that if we just were smart enough about it we could do IWR "in a safe way" is simply incorrect.

Yet the number of fatalities from IWR is shockingly low. The Pyle paper reported none at all.

 

[rjack321]

Lemme see now. You've taken a hit, which tells you that you might have an ignorable skin rash, or, you might be paralyzed and die. So not knowing what your outcome will be, the OP wants to DIY with in water recompression and random oxygenation, rather than going to a controlled stable environment where trained medical experts can constantly evaluate their condition and take care of whatever develops.

Gee. Decisions, decisions. Whatever to do.

The incredible inefficiencies and costs of the US medical system are an entirely different issue.

When the chamber is 6, 20, 48 hours away and the water is right there, hell yes.

 

[boulderjohn]

Yet the number of fatalities from IWR is shockingly low. The Pyle paper reported none at all.

I would first like to make it clear that I support well-conducted IWR in the right circumstances, but poorly conducted IWR may not be counted in the statistics.

The one that leaps to mind is Opal Cohen. She was a dive shop owner in Cozumel who went on a poorly conceived dive with 2 others with the intent of going to 300 feet while the customers and regular DM on the boat did a routine dive. They ended up going to 400 feet when she either got thoroughly narced or blacked out (maybe both), and the 3 had to buddy breathe off one tank to make a normal ascent with no deco stops. She showed immediate DCS symptoms on the surface, but the boat captain could not/would not take them to shore because he had divers in the water. Opal got a fresh tank and went into the water to perform IWR on her own. She was eventually taken to the chamber, but she eventually died.

Would she have survived if she had been taken to the chamber immediately rather than doing her poor version of IWR? We will never know.

 

[doctormike]

Yet the number of fatalities from IWR is shockingly low. The Pyle paper reported none at all.

That may be because it’s not done for any and all cases of DCS, in every setting, by divers of all degrees of experience. There must be a selection bias. But I’m not sure about the details, so would be open to learning more about that...

 

[Rred]

OK, let's say you are diving in Palau and the nearest chamber is something like six hours away, weather permitting and transport available. If you do IWR, and after twenty minutes in the water you lose all feeling below the waist....Did you gain anything by adding another hour of delay to the trip? Or do you stay down till all the available oxygen is used, or you reach an O2 tox limit, and then hope you'll feel better when you surface?

I'm not saying that "first aid" isn't appropriate, but when you have no real way to evaluate the problem, is there no value to "get expert help right away" ?

If you are diving anywhere near NDL limits, part of planning your dive is to plan for an incident, and that includes "How am I going to pay for that?"

DAN membership and insurance (among other options) is pretty much the same as the price of two or three boat dives anyway. And way cheaper than dive travel. Before we had DAN, or cell phones, or an internet, I had the direct number to many chambers right on my log book. But then again, I was never into car roof highway surfing either.

 

[rjack321]

That may be because it’s not done for any and all cases of DCS, in every setting, by divers of all degrees of experience. There must be a selection bias. But I’m not sure about the details, so would be open to learning more about that...

Read for yourself
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.546.2906&rep=rep1&type=pdf

 

[Bubblesong]

We take on blood nitrogen at the point of diffusion in our lungs, with a lot of safe surface area of lung membranes up against liquid blood. But once we have DCS, the bubbles fizzing inside our capillaries, are jamming up against artery walls, not against lungs tissue where they can diffuse out, and even if you go back down to depth and shrink the bubbles, they can just recombine to make fewer large bubbles still jammed in your capillaries, or spinal nerve centers, and not near your lungs to diffuse out. The bubbles still take time to diffuse back into blood and then diffuse out again at lungs. This is why decompressing slowly and correctly at end of Dive takes a fraction of the time that recompressing and trying to beat down the renegade blood bubbles does. It takes many (6-8) hours at 100% O2, which would mean many tanks of O2, plus the many tanks to keep support divers at depth, so unless your boat has a reserve of 5 steel 120’s with full face masks and 10 nitrox tanks for support divers, it does not compare at all to a chamber ride.

 

[doctormike]

Read for yourself
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.546.2906&rep=rep1&type=pdf

Thanks! This is interesting (haven't read it fully yet), and I just want to be clear that I'm not saying that IWR should never be done. But it's also important not to read beyond the data in this or in any published article. Pyle (in this 1999 paper) cites the same caution. The two reports discussed are retrospective case series, and there is always going to be a selection bias if you collect data after the fact relying on individual reporting. As was alluded to upthread, do failed IWR efforts make it into the studies?

Certainly, people with real insight into this problem (e.g;. Doolette and Mitchell) have more recently said that IWR isn't a good first option in all cases of DCS, and despite this report raise the concern of the risks of IWR:

"The risk of IWR is not justified for treatment of mild symptoms likely to resolve spontaneously or for divers so functionally compromised that they would not be safe in the water. However, IWR conducted by properly trained and equipped divers may be justified for manifestations that are life or limb threatening where timely recompression is unavailable."

Does that mean that IWR never should be done? Of course not. But going back to the OP, a gross oversimplification of the problem and casting aspersions on experts in the field isn't the same thing as thoughtfully exploring where and when IWR is appropriate.