To me, the difference between putting some Tiger Balm on a sore muscle and doing in-water recompression is the potential gravity of misdiagnosis and the higher risk of the treatment. Of course that risk is a continuum, and a simple case of type I joint pain seems (and may be) straightforward to treat, but diagnosing it isn't always as simple as it appears. There are a lot of misconceptions, some of which have been demonstrated previously in the thread. You and another poster both mentioned zebras - for the non-medical folks who may not have heard the saying, there is a well-worn piece of medical wisdom that says you don't look for zebras in a herd of horses. Before looking, though, one first has to be able to identify both horses and zebras and any other equids that may be around.
I have never heard this version of zebras before, the only versions i've heard have been based on the one Kevrumbo stated below. We agree that there is a potential for misdiagnosis, but the problem of uncertainty is always present in anything involving biology, the variables are so great we can't possibly know with absolute certainty what's going on. Where do we draw the line, 99% or 90% or 50% chance of being correct with our Dx?
No
@Duke Dive Medicine , the aphorism as it applies to medical differential diagnoses is "When you hear hoofbeats, think horses -NOT zebras. . ."
(
Zebra (medicine) - Wikipedia )
For an example, if a diver comes up to the surface face down and unresponsive -it's probably indicative of an AGE with near drowning, and NOT a "Carotid Artery Dissection."
If a tech diver comes up after an hour of a relaxed Oxygen Decompression and an unremarkable completed profile, and complains later of only sharp shoulder pain -it's probably an instance of an "unexpected" type I simple DCS slow tissue pathology, and NOT an impending sign of Myocardial Infarction. . .
Whoops. I got the zebra analogy bassackwards. Thanks. The edited version is how I heard it. You may have heard it differently.
And no, a face down unconscious diver on the surface is not "probably" anything. You spent enough time at the Catalina chamber to get a little bit of knowledge and I'm not going to argue with you about this, but there's another saying that's applicable to medical diagnosis and lots of other things: don't jump to conclusions. And another saying from Clint Eastwood as Dirty Harry: a man's gotta know his limitations.
Re the second case, granted, but that's not what was discussed in the thread.
Best regards,
DDM
In treating undifferentiated patients, you have to start somewhere, especially in a resource limited environment. The unconscious diver on the surface who is significantly overweight, was smoking on the boat and got winded walking down the dock with no gear and only got 5ft down before LOC is probably having a medical event, the otherwise healthy mid 20s diver doing his third aggressive dive of the day is probably having something closer to what Kevrumbo stated.
While my initial response in either case will be similar, my provisional Dx is vastly different and will change my diagnostic priorities and treatment after initial the initial resuscitation.
I work in remote areas, providing medical care with limited resources and equipment. Within a minute of seeing a patient they all have a "probably" Dx, then the remainder of my history and exam tries to confirm or rebut that Dx.
...
There are very few (if any) maladies that a healthy diver would have that would be made worse by administering Oxygen. OK, that's a no-brainer. There are also very few problems with putting that diver in a chamber with the best medical talent you have onboard. Whatever first-aid that you can administer on deck can be done on the deck plates of a chamber. The patient is no worse off if you deiced it isn't DCS. Doing the same thing except the diver is over the side (or worse, off the beach) is a different story if your guess that it is DCS is wrong.
...
Don't get me wrong, I'm a HUGE proponent of IWR with a well-trained and prepared crew. IMHO, the key is to get a diver in the water and on O2 at the first hint that they "might" have DCS related symptoms. At that point, it isn't any different than making a reped that happens to be shallow and on Oxygen.
If you have access to a chamber and related folks all this (IWR) is a pretty moot point.
Having a well trained team with all the IWR gear is a great idea, but isn't happening in the vast majority of remote dive sites.
Perhaps the discussion we should be having is when is IWR contraindicated?
If we are discussing who should be doing IWR and when:
My default answer to this is the same whether i'm training a rescue team, someone new to the remote medicine arena, or discussing medicine with my wife and her colleagues and residents (who work in an academic centre with all the bells and whistles).
When you get to a situation and go "WTH do i do now/WTH is going on/WTH is this going?" thats when you get help/use a lifeline/call DAN.
The threshold for IWR should be different for everyone/every team based on their skills, knowledge, experience and resources available.
Now going on a philosophical tangent: Will IWR be used inappropriately at some point, yes. No doubt about it. But if we try to establish a limit to IWR that will prevent all of these cases, it will be far too conservative and we will be missing out on timely treatment of a good many cases where IWR could provide a noticeable benefit to the patient.
As with most things in life, the pendulum will swing too far one way, and then too far the other (IWR used to be a taboo subject with no-one talking much about it, now it's becoming more accepted and agencies have courses on it, next people will overuse it and eventually the pendulum will settle somewhere close to the middle)
