ENVENOMATIONS - Medicine for Mountaineering and Other Wilderness Activities - page 498

Movement, even just walking, increases the circulation of blood and speeds the spread
of venom through the rest of the body. Furthermore, the effects of activity are frequently
worse than would be expected from this consideration alone. The person should be lying
still if possible. No drugs, including alcohol, should be administered. No other treatment
should be attempted.
An individual bitten by a venomous snake who is alone in a remote area has no choice
but to walk out. If a companion is present, the companion could make sure the person is
warm and comfortable and could go for help, preferably a helicopter. If the party is large
enough,thepersoncanbecarriedout.Evenjostlingonamakeshiftstretcherprobablystim-
ulatesbloodflowandvenomabsorptionlessthanattemptingtowalkout.However,stretch-
er evacuation would be slower than walking out. Every situation is different.
Antivenom Therapy
Antivenomistheonlyspecifictreatmentforvenomoussnakebite.Theadministrationof
antivenom should not be attempted by anyone other than a physician, and even then only
in situations such as hospital emergency rooms or intensive care units where reactions can
be monitored and treated. The antivenom used currently is CroFab®, which is produced
in sheep and treated with papain to split the antibody portion (Fab) from the rest of the
immunoglobulin molecule (Fc). The Fc is eliminated, which significantly reduces the in-
cidence of allergic reactions (as does preparing the antivenom in sheep), particularly ana-
phylactic reactions. Treated individuals do have a variety of other problems, particularly
failure of the blood to clot normally.
Afewindividualscarrysinglevialsofantivenomwhentravelinginsnake-infestedareas
so they can be prepared to treat themselves should they be bitten. This practice is not only
useless but dangerous:
◆ A person bitten by a snake who needs crotalid antivenom needs a number of vials, not
one.
◆ If the antivenom was administered and a major allergic reaction occurred, the indi-
vidual or others in the party might not be able to provide effective therapy.
◆ Carryingantivenomcouldimpartafalsesenseofsecuritythatcouldleadtoinadequate
precautions to avoid venomous snakes.
The antivenom that used to be most widely available in the United States was a poly-
valent or general-purpose crotalid antivenom made by Wyeth Laboratories that was effect-
ive against all North American pit vipers. A specific Micrurus fulvius antivenom, which
was the proper one to use for coral snake bites, was made by the same company. However,
that company has ceased manufacturing both antivenoms.