Venomous Snakebites 101

Western Diamondback Rattlesnake

The danger of venomous snakes in North America is (typically) nothing more than a severe case of human exaggeration and paranoia. Deaths due to snakebites are all things considered, very rare. This irrational fear of snakes has led to many innocent and often non-venomous snakes being killed on sight. In general, snakes only attack if you disturb and startle them. North American snakebites are seldom fatal but can be extremely painful.

There are two main types of venom: neurotoxins and hemotoxins. Neurotoxins paralyze your muscles. These are very dangerous as they can paralyze your heart and respiratory muscles. Hemotoxins are used by Snakes to soften up the prey and make it easier to digest. This venom can cause serious tissue damage. Some Snakes have venom that combines both effects.

Avoiding Snakebites
Signs of Envenomation

Signs or symptoms associated with a snake bite may vary depending on the type of snake, but may include:

Closely examine the bite and check if it has actually caused venom to enter your body. The fangs of a snake leave bigger and deeper marks than its other teeth.

Treating a Venomous North American Snakebite

Remain Calm

Easier said than done; most people get hysterical when they are bitten by snake, as they expect to die at any moment. While the truth is in fact that roughly 80–90% of all bites from venomous snakes result in an envenomation, only about 10–20% of all venomous snakebites are what are called dry bites where the snake bites the person, but does not inject any venom. Presuming that you were in fact envenomated, getting excited will only cause the venom to spread through your body more rapidly. If you are hyperventilating, use a bag or cup your hands in front of your mouth to bring carbon dioxide levels back to normal. Settle down, you are not dead yet!

Try to identify the snake or at least note down the snake’s characteristics. This information will help medical personnel in your treatment. You do not have to kill the snake and bring it with you. This would just increase the chance of more bites. But if you already killed the snake in your panic reaction, then you might as well bring it with you.

Rinse the Bitten Area with Water

Closely examine the bite and check if it has actually caused venom to enter your body. The fangs of a snake leave bigger and deeper marks than its other teeth.

Additional Recommendations

If you have a venom suction device, use it as soon as possible. If nothing else, it’s a great placebo. Even the “best” device out there, the Sawyer Extractor, has only been scientifically proven to remove 1/1000 of the venom! If you do not have a suction device, do NOT suck out the poison with your mouth! You’re not John Wayne! Do NOT apply a tourniquet. Do NOT cut around the wound.

North American Snake ID Poster
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Curriculum Update   July 2020

These curricula recommendations have been created with direction from Miami-Dade County Fire Rescue Venom Response Task Force protocols, and have been edited to conform to the standards set by Center for Wilderness Safety and Wilderness Medical Society in accordance with the WMS National Practice Guidelines.

Aside from the coral snake, most of the venomous snakes in North America are pit vipers (rattlesnakes, copperheads, water moccasins, etc.). The good news is that most of these use a common synthetic antivenin to treat all of them. Especially in a wilderness or remote setting (and sadly, even in many urban settings), the biggest problem is inappropriate field treatment. For pit vipers, which have a cellular toxin, it is NOT recommended to apply a tourniquet of any kind to the area above the wound. Otherwise, the toxin will pool in the area around the wound and cause additional cellular damage.

(North American) Venomous Snakebites 101

The first priority in prehospital care is scene safety. It is essential to prevent creating additional victims. There is no need to capture or transport the snake to the hospital. Even a recently killed snake can envenomate because bite reflexes may persist for several hours. Severe envenomation and death have resulted from bites from decapitated snakes. It is reasonable to obtain a photograph of the snake, but only if it can be done so safely and does not delay transport. Identifying the species of snake can be helpful if it expedites treatment, facilitates antivenom selection where relevant, or enables experts to tailor therapy.

Cottonmouth (Water Moccasin) Snake
Proper positioning of the affected extremity in the prehospital setting is controversial. Previously, experts recommended keeping the injured extremity below heart level to minimize the spread of the venom. However, this could exacerbate local swelling, which is almost always present in crotalid envenomation. Elevating the extremity ABOVE heart level can actually aide in reducing the swelling, and patients often report significant pain relief with elevation.

Analgesia should be provided; however, nonsteroidal anti-inflammatory drugs (NSAIDs) are NOT recommended because of their potential hematologic effects, which could compound with venom-induced coagulopathies.

Some people fear that elevation can accelerate systemic absorption of the venom; however, there is no evidence demonstrating this occurs. In areas where bites are unlikely to cause significant systemic toxicity, elevation is recommended. If systemic illness is a major concern, it is reasonable to keep the affected extremity at heart level. Once the patient arrives in the hospital, however, elevation is recommended for all pit viper envenomations. Coral snake envenomations do not result in tissue damage. Place the affected extremity in whatever position the patient finds most comfortable.
Polyvalent Antivenin for North American Pit Viper Bites (CroFab)
Polyvalent Antivenin for North
American Pit Viper Bites (CroFab®)
North American Coral Snake Antivenin (Wyeth® Antivenin)
North American Coral Snake
Antivenin (Wyeth® Antivenin)
Juvenile Copperhead Snake

Most of the interventions that had once been proposed to treat snakebites in the prehospital environment (tourniquets, ice packs, “cutting and sucking” and even electrical shock) have failed to show benefit, and have actually proven to be harmful.

Additionally, various commercially available suction devices which promise to remove venom if applied shortly after the envenomation, are NOT advised. The amount of venom they actually remove is negligible. In a number of studies, these devices removed less than 2% of the envenomation load.

The Basics

Their are a couple of ground rules when it comes to first aid and emergency situations: