Why does my pain go away when I dive??

[TRUETEXAN]

I have a syrinx in my spinalchord, think they also call it syringomyelia, basically a deformation in my spinal chord or a tear I guess. I do not suffer from paralisis but I do have a lot of neurilogical pain an I have to wear 75 microgram Duragesic patches (Fentanyl) to help control it, and yes I have been okayed to dive while wearing them since I have worn them for so long they do not cause any Narcitic effects . I have always wondered why whenever I go diving the deeper I go the more the pain goes away, and I am not talking extreme depths o anything like that, it usually starts to subside at about 30 feet and the deepest I have been is 100 feet where I noticed no pain at all. I was wondering why this could be happening and if it is a pressure thing could I benefit from being put in a chamber from tme to time? Thanks

 

[Dee]

I have a disc problem in my lower back and the same thing happens to me. I think being weightless takes all pressure off the nerves and stuff.

How's that for a technical description?!?

 

[Drew Sailbum]

My guesses are based upon a little diving physiology, but I am not a doctor. I have never played one on T.V. And, alas, I did not stay in a Holiday Inn Express last night.

Two possibilities I can think of, only one of which is depth dependent:

1. The weightlessness of diving may be working its magic for you by relieving pressure on nerves and such by allowing your syrinx to move a bit. But this doesn't explain any depth changes you have noted.
2. As you dive deeper, you on-gas. Some of the gas you are breathing at higher pressure dissolves into your tissues. My (admittedly limited) understanding is that most gases have some anaesthetic effect when breathed at high pressure. Some gases have this affect at less than 1atm pressure; other gases require higher pressure. The pain relief you feel may be due to the numbing effect of nitrogen at high pressure.
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   Just my guesses.

 

[TRUETEXAN]

I really do not think that it is because of an anesthetic effect from the breathing gas for two reasons. The first being that the pain starts to subside as shallow as 30 feet. The second being that this is the type of pain that even class II narcotics such as Morphine and Diuladid do not comletely alieve.

 

[The Chairman]

It is probably a combination of narcosis and pressure relief. However, I am a doctor for Networks and NOT for people. It has been one of my long time contentions that narcosis starts with any pressure and slowly increases with depth. Most do not notice any effects until 80 fsw or better. Since I have chronic pain in my knees and right shoulder I notice me feeling better the deeper I go. Those who say they have never been "narced" do not have any pain marker to guage it with. Consequently, they do not realise just how bad that they have been affected.

 

[Drew Sailbum]

It may or may not be the anaesthic effect. Does the pain relief last for a period of time after your surface? If not, I think it probably is not this effect. If so, it may be due to the effects of residual nitrogen in your system, and be attributed to this.

If your wallet is big enough, and you can find a willing chamber technician, take a chamber ride and see if you experience the same pain relief effect. This may not be not feasible, but it's the only way I know to rule out the weightlessness thing.

Which is not to say that its not some other mechanism entirely.

I've heard many anecodotal stories about divers experiencing pain relief. Are any doctors out there aware of any studies on this phenomenon?

 

[John Reinertson]

There are Four ways that come to mind that would possibly produce relief when diving.

1. Nitorgen is a gas that produces direct anesthetic effects.

As noted above, the relief starts at relatively shallow depths so I'm not convinced this is the main relief mechanism. If the same relief were noticed at 30 ft while breathing Nitrox 36 or richer mix, that would argue against nitrogen effects being the primary source of relief. This is so because Nitrogen concentrations in tissue are lessened (but by no means eliminated) with Nitrox, and would be a simple and enjoyable test.

2. Weightlessness may be a factor. If that were the primary factor, a dive at 10 feet (or five for that matter) should produce the same relief as a dive at fifty feet.

3. The other factor that increases with depth is oxygen partial pressure. We don't know what generates the pain in a syrinx or a spinal cord tethered by scar tissue. It may be that some nerve fibers or nerve endings are wrapped in scar tissue in such a way that their individual blood supply is marginal and they are oxygen-starved at sea level.

There are a couple ways I can think of to test this. One would be to breathe a mix of lower than normal oxygen percentage while at surface pressures and see if pain increases. This could be done in a respiratory lab, or one could simply go to a Colorado Ski resort and hang out at 9,000 feet to see if the pain got worse.

The reverse could be tested by breathing 100 % oxygen at surface pressure. This would give a partial pressure of O2 similar to Scuba at approx 130 ft and should reduce pain dramatically if the pain were caused by low oxygen levels. This sounds much less interesting than going to 30 to 50 feet off Old Blue in Bonaire
with 36% Nitrox for a one hour test of your pain levels.

4 A fourth possibility is the central nervous system effects of doing a very pleasurable activity and the tendency for this to decrease pain sensation.

Probably multiple factors are at work here.

If the suffering diver wanted to arrange a Bonaire trip for some in-depth research, and we could mesh schedules, I could check to see if the IRS would let us write off the trip.. (somehow I doubt it)

Short of that, some research in a local hot tub with a tank of 100% oxygen might be instructive.

Let me know what you find. It's an interesting question.
John

 

[Rick Murchison]

OK, Doc, you've just got to figure out how to get this done! My arthritis pain goes away at depth, too. With all this anecdotal evidence we need a grant to really give it a good study, don't you think? And then the lifelong prescription... now that's the ticket!
Rick

 

[Drew Sailbum]

But what are the odds of an HMO paying for that prescription? :tease:

 

[davidofaustin]

Put me in for the Bonair Rx, and I will start hunting a hottub too!



Dave