Re: More on Altitude changes... And all that fizz...

["robert and carla lawson" <robandcarla@hotmail.com>]

I think I need to go back to my Biology, General Science, and Chemisty 
teachers and Apologize that I didn't pay much attention in class!!!


>From: "Patricia E. Peters" <patpeters1@juno.com>
>To: robandcarla@hotmail.com
>CC: ridecamp@endurance.net
>Subject: More on Altitude changes... And all that fizz...
>Date: Thu, 7 Sep 2000 17:54:56 -0700
>
>On Thu, 07 Sep 2000 <robandcarla@hotmail.com says...
>
>One of my mares experienced ... depression ..was told it may have been
>climate, altitude change. .
>...I remeber something maybe Steph and Krusty was in France about a week
>or two? correct me if I am wrong here. I know that the plane ride was no
>picnic for a horse.
>
>SO KIRSTEN SAYS... (re: what about higher altitude changes? would that
>not effect the horses oxygen?)  Humans take time to adjust because it
>takes time for the body to ramp up its RBC production rate.  Horses OTOH,
>store RBCs and therefore have an extra supply readily available.
>Therefore, unless the elevation gain is extreme (say Sea Level to 11,000
>feet), a horse should have sufficient RBCs on hand to accommodate the
>reduced concentration of oxygen.
>
>THEN TOM SAYS... (re:  How can you get past the slower recovery times
>since the oxygen would be somewhat thinner than what they are used to?)
>  You can’t That takes time. And an exercise challenge or two. Weeks.
>ti
>
>SO PAT THROWS ALL CAUTION TO THE WIND AND SAYS...
>
>No doubt I am stretching my neck out WAY too far,  and I will probably
>vaporize in the resulting flame-fest, but what the heck… I might like the
>abuse… so go ahead and flame me, spank me, make me write tearful
>retractions… gosh…I like it already…
>
>Please allow me to add another possible factor for your
>consideration…Inert gas in solution in the blood and body tissues, and
>Henry’s Law. (The basic idea says that the solubility of any gas in a
>given liquid is almost directly proportional to the partial pressure that
>that gas exerts on the liquid).
>
>Pilots and scuba divers know that there has been a lot of research done
>on pigs, sheep, humans, dogs, cats and monkeys as to the effect of
>pressure changes on dissolved inert gasses in the body.  Given the solid
>principles of physics that govern these effects, I cannot see why horses
>would be significantly different.
>
>Let me explain what I mean…
>
>We all know that the atmospheric pressure at sea level is about 14.7psi,
>and this pressure drops as we ascend to altitude.  We also know that,
>except for some trace elements, the air that you and your horse breathes
>is comprised of roughly 20% O2 and about 80% N2 (Nitrogen), so the
>partial pressure of N2 in this mixture at sea level is .80 x 14.7psi.  Of
>course, when you ascend to altitude, the percentages stay the same, but
>the partial pressure exerted by the gas drops along with the total
>ambient pressure.
>
>Now this next part might surprise you.  You already know that you have O2
>in solution (in liquid form) traveling around your body right now; it got
>there through your lungs, and your body is metabolizing it (using it to
>help fuel your body).  But did you also realize that you and your horse
>have N2 in solution in your blood and body tissues right now?  Its not
>doing anything (inert gas); its just there because as the blood passes
>through the lungs, the tension of N2 in the air in your lungs causes that
>N2 to either flow into the blood or out of the blood until the gas
>tensions on both sides (air in lungs vs. in blood) are equal.
>
>So, then, When you go up to the mountains (or up in a partly-pressurized
>airplane cabin or cargo bay), and you start breathing air at a lesser
>pressure, the N2 wants to flow out of your body tissues and out of your
>blood, and into your lungs.  You then start to exhale more N2 than you
>inhale, until the partial pressures are again equal on both sides.
>
>This would not present a problem were it not for two things.  The first
>problem is that it takes over 12 hours for the body to get even CLOSE to
>eliminating enough of the excess N2 to bring itself back into balance.
>The second problem then, is Henry’s law (governing the solubility of the
>gas under changing pressures).  Because the gas cannot stay in solution
>as well at the lesser pressure, some of the N2 actually starts to come
>out of solution right in the blood….
>
>It makes microscopic BUBBLES….  It FIZZES… you know, like soda pop.  No
>joke.  A lot of solid research has been done on a variety of animals and
>on humans to study this.  Your body can tolerate a small amount of this
>fizzing.  Way too much causes a clinical case of decompression sickness…
>scuba divers know it as the bends.
>
>But few laymen fully appreciate the scope of physiological challenges
>presented by even a little bit of fizzing. Most notably is the cascade of
>chemical reactions that occur as these inter-vascular bubbles bounce off
>of the platelets in the blood, and stimulate them to coagulate, while
>causing the tissue cells that make up the vessel walls to take on a shape
>that invites plasma to leak out of the blood vessels and into the
>tissues.
>
>So, the blood kind of gets like sludge, some body tissues swell with
>edema, and the immune system spends some of its resources on trying to
>fight fizz. Of course, fatigue is a very common symptom, and the overall
>efficiency of the circulatory system is somewhat compromised for a while,
>but the biggest challenge to the system overall is DEHYDRATION.  Big time
>challenge to hydration status here, and that challenge can continue to
>one extent or another for a few days while the body is busy washing out
>the used platelets and other such battle waste.
>
>To me, it seems reasonable to hypothesize that any area of the body that
>has less than optimal circulation will suffer a bit more, and be more
>prone to injury during this time.  The horses legs come to mind, as do
>any sites of prior injuries anywhere in the body.  I do not know how long
>it takes for the horse’s body to fully recover from this, but humans,
>pigs and sheep can take up to 72 hours (although most of the challenge
>happens within the first day or two).
>
>As far as I know, the only do-able way to mitigate this effect (beyond
>hydration of course) is to breathe pure O2 for as long as practicable,
>which for obvious reasons results in a much faster rate of elimination of
>N2 from the blood into the lungs, and in so doing, significantly reduces
>the volume of fizzing in the blood.
>
>So what do you think?  Substance or stretch?

_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

Share information about yourself, create your own public profile at 
http://profiles.msn.com.