Reef Fish wrote:
>
> On Sat, 27 Apr 2002 17:04:00 -0500, Crusty Russ <[log in to unmask]>
> wrote:
>
> >Hi Bob,
> >
> >Reef Fish wrote:
> >>
> >> On Fri, 26 Apr 2002 07:49:29 -0500, Crusty Russ <[log in to unmask]>
> >> wrote:
> >>
> >> >...that beings up a good question, probably for Scubadoc. In the 'bad
> >> >for you' category, how hot is hot for a shower after a dive? Is it
> >> >relative to air temperature or some absolute temp?
> >>
> >> It's relative to the DIFFERENCE in the temperature of the water and
> >> how hot the shower is. That was the subject of controversy between
> >> the Aggressor Fleet (no hot tub) and the PhD Fleet (hot tub). A bunch
> >> of Docs for Dan concluded for WARM water diving (as in the dive
> >> locations served by those fleets, the effect is probably negligible.
> >> BUt even so, they conservatively recommended to wait 30 minutes before
> >> jumping into the hot tub or hot shower of temperature difference of
> >> 15 or more degrees F.
> >
> >Yes, interesting, but the information is conjecture not from a
> >scientific study.
>
> More than a conjecture. Lots of known theory about bubbles. In this
> case, there were lots of observations of liveaboard divers week after
> week in hot tubs. Yup. SOME of them got bent. That were the
> recommendation by DAN, on the observation and recommendation of their
> Docs.
More than conjecture? "Lots of known theory about bubbles." ...known,
tested, and 'proved', but none about immersion in hot water promoting
DCS.
"In this case, there were lots of observations of liveaboard divers week
after week in hot tubs. Yup. SOME of them got bent." ...and some of
them got bent who were merely standing near the hot tub...cause?
coincidence? Who knows? It wasn't a study of hot water immersion and
DCS. Is there a link? That's what I want to know.
"That were the recommendation by DAN, on the observation and
recommendation of their Docs." ...like I said, conjecture. ...but
there's nothing wrong with 'better safe than sorry.'
> I am not aware of any of the recommendations on the avoidance of DCS
> was based on a strictly valid "scientific study". So, one has to make
> judgments on how the THEORY relate to other observational evidence.
>
> >The item about hot showers and tubs was not mentioned
> >in any relationship with the other known causes of decompression
> >sickness listed, but was for information to those interested.
>
> That was based on 62 cases BEFORE 1980, Crusty. None of the
> Aggressor and Hughes Fleet existed then, let alone hot tubs on board.
Let me rephrase my statement above to make it more clear what I intended
to communicate.
"The item about hot showers and tubs was not mentioned BY THE DAN
DOCTORS in any relationship with the other known causes of decompression
sickness listed, but was for information to those interested."
I was not referring to the pre-1980 study in that statement, I was
referring to the recommendations made by the Dan doctors. They did not
state that immersion in hot water after diving promotes DCS. They
provided a 'better safe than sorry' recommendation. I'm not taking
sides here, I just want to know if there is any more evidence one way or
the other.
> >> >...hmmm, I just did a search on Scubadoc and turned up with this URL
> >> >http://www.gulftel.com/~scubadoc/prvndcs.htm with this quote:
> >>
> >> >"There is no evidence that shows that a hot shower after diving
> >> >increases the rate of decompression sickness. "
>
> Read that article you cited AGAIN, a bit more carefully this time.
> He had absolutely no data about hot showers or tubs. His had no
> basis of support for the two-line conclusion other than they were
> NOT observed in the pre-1980 62 cases of DCS.
Again, I never claimed nor intended to communicate that the pre 1980
study had anything in it regarding hot water immersion and DCS and I
read no where that that was the conclusion of that study. The only
statement made was that "There is no evidence that shows that a hot
shower after diving increases the rate of decompression sickness." I am
not aware of any study to date that sheds any light on this question
either pro or con. I believe the jury is still out on this one.
Searches on this question turns up little real information. One study
on one of the boards did indicate that Doppler-detectable gas bubbles
were released into the blood stream after rewarming, but that this did
not provoke decompression sickness. (Dr. Michael Powell, NASA
physiologist, PhD)
Dr. Richard Vann, in the chapter on Mechanisms and Risks of
Decompression in Bove's 'Diving Medicine", p.156, under perfusion
effects - describes warm water immersion increasing nitrogen elimination
and decreasing DCS from 90% to 20% in oxygen breathing before altitude
decompression. Exercise reduced the incidence from 63% to 0%. Cold water
immersion caused an increased incidence of DCS.
I believe the jury is still out on this one.
> >> The lesson we should learn from this is that the Doc is FULL OF SHIT,
> >> pardon the French I learned in Paris. :-)
>
> I stand by my French remark, based on what I explained in my post,
> and elaborated above.
Standing by it or in it is not the issue. As you have said, know your
limits and dive within them. If you do not feel comfortable taking a
hot shower after a dive, then regulate the temperature until you feel
safe. We are all responsible for our own safety.
> >If you know of good scientific studies that provide evidence that hot
> >tubs (or hot showers) cause an increase in decompression illness I would
> >love to see them. I can't find any evidence in the form of good studies
> >that would indicate one way or the other.
>
> Can you find any evidence of "good studies" on bubble theory, rapid
> ascents, and microbubble theory, or most of the OTHER theories that
> dive medicine doctors and physiologists recommend to divers NOT to do?
At least there are 'studies' targeted at supporting the theories. "I
can't find any evidence in the form of *delete*good*delete* ANY studies
that would indicate one way or the other." I assume you can't find any
either...proving it one way or the other.
> >Until then, I don't see what there is to disagree with in the statement
> >that Dr. Campbell made, "There is no evidence that shows that a hot
> >shower after diving increases the rate of decompression sickness."
>
> Now you've got me curious. Do you believe in ANY of the recommendations
> to avoid DCS? Have you seen or scrutinized any "good scientific
> studies" before you adopted them?
Yes I 'believe' many of the recommendations to avoid DCS and have
'faith' that that the scientists are doing 'good' work. However,
whenever possible, I like to question popular theories as any curious
person would. I don't believe in 'blind faith', I prefer faith with
content. That's what I base the limits that I try to stay within.
For years I've always made my deepest dive first. Now there's evidence
that may no longer be necessary. I used to think the world was one
shape and now I'm convinced and believe that the world is surely
round...like a plate. :-)
As for the whole issue with hot showers and tubs, you will never catch
me dead or alive in a hot tub after diving or otherwise, except to rinse
off my gear in Coz. Since I don't dive cold climate or cold water, I
don't ever expect to experience much of a temperature differential
anyway. As a certified ice diver, YMMV :-)
As far as the recommendations based on conjecture go for hot showers,
waiting 30 minutes is an easy one for me since it usually takes at least
that long to climb the ladder, doff the and stow the gear, dry off,
shoot the merde with the other divers, rinse the camera and celebrate
because it didn't flood, and then head down to the cabin -or- take a
long boat ride back to the hotel, before taking that hot shower. Geeeze
Bob, it takes us old farts at least 30 minutes just to get out of our
wetsuit! :-) YMMV
Do we disagree on any of this?
> Changing gear ...
If you like and no one else volunteers, send me the pics, you've got my
address. I can put them up with the CAIV2002NEDfest logo on our site
and later move them to the trip report area.
Jeff if you've got you ears on, I can send you an extra weight belt and
some lead to wear around the house till you replace all that blubber.
:-)
How long will you and Sue be in Coz? I assume you'll be staying in your
usual room overlooking the pro dive pier. If I don't talk to you
before, have a great trip!
Best regards,
Russ
> I asked Jeff to pose in front of his monitor at home, wearing your
> NEDfest shirt. They pics turned out great, and Jeff was in incrediblely
> good condition, having gained about 25 of the lbs he had lost, but is
> still a skinny trumpetfish. :0)
>
> Unfortunately, my scanner crapped out with my deceased-then-revived PC,
> so I wasn't able to scan anything until I remembered my copier/scanner/
> printer could scan, very low-quality pix, which was why I hadn't used
> it for scanning, but only as printer/copier.
>
> Then I had trouble sending that pic to you because Windows XP was too
> clever to let me do simple things like I did with pics in other Windows
> before. So ... I am just re-sending you the bounced email because it
> had edited your email address to something completely unrecognizable
> even by me. :-)
>
> If anyone can scan and put on a webpage the two HARD COPY PRINTS of
> Jeff (front and back views) of the Previews of your CAIV02NEDfest shirt,
> email me your snail mail address so that I can mail them to you before
> I leave early Monday.
>
> -- Bob.
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