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Robert,
I have to say that you are making some great contributions to this list.
Please keep it up!
>>Robert
>>good response Can you provide me the paper reference on the cig vs
>>altitude, that is excellent information.
>
>It was quite some time ago I came across that "tidbit". I believe it was
>from either the Navy's Flight Surgeon Manual or the Aerospace
>Physiologist's Manual.
>What it was really refering to was the increased levels of carbon
>monoxide in cigarette smoke. As most of you are aware, this bonds to the
>hemoglobin in red cells irreversibly tying up receptor sites (normally 4
>per hemoglobin molecule). Physiologically, since you have fewer available
>sites, it looks to the body as if the air is "thinner" with less O2
>available going into a normal number of hemoglobin-O2 pick-up sites (what
>you really have is a normal concentration of O2 with a reduced number of
>pick-up sites). It's a crude approximation, but "close enough for
>government work". While I've not seen the Navy's undersea medicine manual
>yet (that's next on my agenda) you're still tying up the same O2
>receptors when you smoke and dive as when you smoke and fly...I can't see
>how that's a good thing in either case. A red cell normal survives in the
>body for about
>120 days, so once you start to tie up receptor sites, the effects hang
>around a bit.
>
>We haven't even gotten into the physical effects on the lungs, like the
>lose of the hair cells (cilia) that clean the debris out or the changes
>in the cells ("dysplasias") and other "doc-speak" that means that the
>cells start to look "funny" on their way to becoming cancerous (which is
>decidedly *NOT FUNNY*).
>
>>
>>Also, I like some others find it difficult to state someone is in good
>>shape when they do not exercise. Having been involved in diving and
>>exercising the majority of my life I discovered that to be in shape I
>>had to workout.
>
>Aerobically conditioned people have more "efficient", toned
>cardiovascular systems and O2 utilization. Just as a conditioned runner
>may have a resting heart rate of say 47 compared to the typical person in
>the 70's. They're more relaxed, they breath slower. They have a
>physiologic reserve in the event they need to respond to a crisis.
>
>My diving experience is so minimal at this stage of training, I shouldn't
>comment further, but the above state of health sure sounds like an ideal
>state of affairs at depth where you're trying to get the most "bang for
>the buck" from a limited, finite air supply.
>
>>
>>Drugs and diving, we have a lot of information that reflects that
>>decongestants such as sudafed may contribute to diving accidents, which
>>we published three years ago. correct me if I'm wrong but drugs are
>>effective by producing biochemical changes in the physiology, if this
>>is true they have to effect divning safety one way or another. It would
>>seem that unless a drug had a proven positive side effect on diving and
>>diving related disorders that the RULE SHOULD BE DO NOT DIVE WHEN ON
>>DRUGS AND MAEDICATIONS PERIOD. IF YOU NEED A DRUG FOR SOME REASON STAY
>>DRY.
>
>I'm in absolute agreement. Keep in mind that I'm a pathologist and flight
>surgeon, not a pharmacologist, so I can't speak to the individual
>chemical reactions, but drugs react in unpredicable ways at altitude and
>depth. I'm not sure whether its a change in the relative gas saturations
>or what, but the fact is that an aviator at altitude or a diver at depth
>is physiologically, "altered" temporarily from the same person at sea
>level at one atmosphere and the usual gas partial pressures. Drug testing
>usually takes place where everyone else lives (sea level in open air) not
>where aviators and divers live. We give sudafed to aviators *under
>supervision* since it has the least effect on motor-sensory activities at
>altitude. But an aviator doesn't have to contend with the diver's N2
>narcosis effects at depth (or O2 toxicity at even deeper depths). Might
>there be a synergistic effect between such drugs and ppN2 narcosis? Might
>be, but I wouldn't what to be the diver to personally find out! Ain't
>worth it! (as a newbie "dry-behind-the-ears" diver I've heard the one
>about the guy who tried to buddy breath with a grupper!)
>
>I'm personally increasing my excercise program since I took up diving to
>shed a few more pounds if only to hold on to less N2 and carry less lead!
>(the additional conditioning reserve wouldn't hurt either)
>
>Take care.
>
>Robb Wolov
>
>--
>Send mail for the `techdiver' mailing list to `techdiver@terra.net'.
>Send subscription/archive requests to `techdiver-request@terra.net'.
>
>
Dan Volker
SOUTH FLORIDA DIVE JOURNAL
"The Internet magazine for Underwater Photography and mpeg Video"
http://www.florida.net/scuba/dive
407-683-3592
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