Snake bite

From CanyonWiki

Care quickly for the patient

1. Remove from snake's territory.
2. Keep warm.
3. Reassure.
4. Clean wound.
5. Immobilize bitten area in functional position below the level of the heart.
6. Remove all rings, watches, bands and clothing that might become constrictive.
7. Prepare to evacuate to a medical facility.
8. If possible, identify snake. Don't try to pick it up or kill it. Even when dead, a snake may have an intact bite reflex sufficient to envenimate another canyoneer.
   • Venomous rattlesnakes (vipers) have a triangular shaped head and the pupil is elliptical. They also have hollow retractable fangs through which venom is injected into the victim. In contrast, the head of nonvenomous rattlesnakes is rounded as is the pupil. They do not have fangs.
   • Coral snakes (elapid) have small heads and fangs, but can be identified by their brightly colored bands. They can be differentiated from similar nonvenomous snakes by their banding patterns. Venomous coral snakes within the United States have red and yellow bands adjacent to each other ("red and yellow, kill a fellow; red and black, friend of Jack").

Treatment en route

1. Coral snake bites may benefit from pressure dressings as elapid toxin primarily causes neurotoxicity without tissue necrosis.
2. Viper bites may cause necrosis and should not be treated with pressure dressings.
3. Things NOT to do:
   • Don’t cut the bite or try to suck the venom out. This only leads to infection.
   • Don’t apply a tourniquet. This can easily cause profound tissue necrosis.
   • If you’d like, apply clean mechanical suction. However, recent studies suggest only 2% of total body venom are removed with good technique.

Possible Effects of Envenomation

1. Coagulopathy (uncontrolled bleeding).
2. Rhabdomyolysis (muscle breakdown which may cause kidney damage).
3. Nephrotoxicity (kidney damage).
4. Increase in vascular permeability. If severe can cause hypotension (low blood pressure and shock).
5. Local tissue damage, edema, necrosis.
6. Neurotoxicity. Can lead to respiratory depression. (Nerve damage).
7. Local cellulitis from Gram negative and anaerobic bacteria.

Hospital Management

1. Tetanus booster if not current.
2. Wound cleaning and treatment of cellulitis if indicated. Common antibiotics used are Augmentin and Ceftriaxone.
3. Treatment of envenomation with appropriate anti-venom.
4. Close monitoring for envenomation effects for at least 8-12 hours. Only 25% of viper bites and 50% of elapid bites result in envenomation.

Articles:

Gold, BS, Barish, RA, Dart RC. North American snake envenomation: diagnosis, treatment, and management. Emergency Medicine Clinics of North America 2004 22(2):423-43.

Gold, BS, Dart, RC, Barish, RA. Bites of venomous snakes. New England Journal of Medicine. 2002; 347(5):347-56.

Alberts, MB, Shalit, M, Logalbo, F. Suction for venomous snakebite: A study of "mock venom" extraction in a human model. Annals of Emergency Medicine 2004; 43:181.

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