>As for IV
fluids - electrolytes, esp. potassium, if given too fast or too concentrated can
"burn" a vein causing phlebitis which can lead to scarring - the trick is
that the electrolytes must be sufficiently diluted in the IV
solution. The IV itself should not cause irritation of the
vein because it is in for such a short time. (principles are the same
for humans, as an RN with an Advanced Practice License I teach IV
therapy).
First off, electrolytes as such
should not be given IV anyway UNLESS they are a part of an isotonic solution--to
give a more concentrated solution would further dehydrate the horse, and
could also cause tonicity problems in the bloodstream that could actually
cause damage to red blood cells, etc. One of the biggest
problems with an IV catheter is a bleedback, which makes a lovely place for
bacteria to gather, with the resulting infection (even if low-grade)
causing scarring. This is more of a problem in veterinary medicine than in
human medicine as it is more difficult to control the cleanliness of the
environment around the catheter. Also, sufficiently large quantities of
blood outside the vein can cause scarring on their own, just from the fibrin in
the clot becoming organized. Keep in mind that we are often using a 10-g
or 12-g catheter in a horse's jugular vein as opposed to perhaps an 18-g or
smaller, which seems to be standard for human IV's, judging by what they've used
on me in the hospital. A 10-g hole in a vein is much more apt to have a
significant bleedback if one is not careful than is a significantly smaller
catheter.
