snake2

You’re finally going to do it. Become the very best. Like no one ever was.

Become a pokemon master.

As you search along the mountain trail for the elusive EKANS with your eyes fixed on your phone, you step backwards onto a SNAKE. A sharp pain suddenly starts in your leg reinforcing how much better virtual animals are compared to those in real life.

What is the most common venomous snakebite in the U.S.?
 Crotaline bites.  Crotalinae – a subfamily of Viperidae, are the most common venomous snakes in the U.S. and account for the overwhelmingly majority of poisonous bites. They are commonly known as pit vipers and include rattlesnakes, copperheads and coppermouths. The remaining venomous snake in the U.S. is the coral snake, family elapidae. They account for a small minority of bites and their treatment is not discussed in this post as it differs from pit vipers.
What are the characteristics of a snake bite? What is a dry bite?
A snake bite can result in envenomation- or not (dry bite). Envenomation is defined by a snakebite plus evidence of tissue injury which can be local (pain, edema, ecchymosis), hematologic (thrombocytopenia, change in coagulation factors) or systemic (oral edema, paresthesia, change in taste, hypotension, tachycardia). The absence of such symptoms for 8-12 hours indicates a dry bite.
What should you do in the field before coming to an ED?
Contrary to popular culture, DO NOT suck or cut the wound. Remain calm and immobilize the limb in a neutral position below the heart. Do not use a tourniquet as it can obstruct arterial blood flow. A constriction band can be applied proximal to the bite if there is no nearby hospital. It is a wide, flat piece of material such as an elastic bandage or piece of clothing that restricts superficial venous and lymphatic flow while maintaining capillary filling and distal pulses. One or two fingers should easily slip underneath it and care must be taken not to impede arterial flow. If possible, take a picture of the snake while avoiding further envenomation and excessive movements.
What is the initial treatment in the ED?
The patient should have IV catheter placed, monitor attached, oxygen and fluids administered, and labwork drawn – including CBC, chemistry, coagulation factors, fibrinogen, fibrinogen degradation products, type and screen, creatine kinase and urinalysis. ECG is recommended for patients older than 50 with a history of heart disease. The wound should be thoroughly cleaned and a tetanus booster should be administered. The leading edge of the swelling should be marked.  Poison control center should also be contacted.
Who do you treat with antivenom?
All bites that result in progressive symptoms should be treated as soon as possible with antivenom. Any worsening local injury, abnormal lab results, or systemic symptoms/signs should warrant a large “initial control” dose followed by 3 smaller antivenom doses. IV or IO access should be used; IM may be ineffective as hypovolemia may retard absorption.
How long should you observe in the ED if there is a dry bite?
At least 8-12 hours. Any patient that is treated with antivenom should be admitted to the hospital.
snake

References:

Dart RC and J. White. Chapter 212. Reptile Bites. In: Tintinalli JE, Stapczynski J, Ma O, Cline DM, Meckler GD, T. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e. New York, NY: McGraw-Hill; 2016

Juckett G and JG Hancox. Venomous Snakebites in the United States: Management Review and Update. Am Fam Physician 2002 Jul 1;66(1):30

Note for non-pokemon fanatics: “Ekans” is a snake pokemon (name is snake spelled backwards)

 

 

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