!! Curriculum Update
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.
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.
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.
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 reduce the swelling, and patients often report significant pain relief with elevation.
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.
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.
These curricula recommendations have been created with assistance from the Venom 1+2 Task Force and have been edited to conform to the standards
set by Center for Wilderness Safety and the Wilderness Medical Society in accordance with the WMS National Practice Guidelines.