04-18-2019 What should you do if someone is bitten by a North American pit viper?

Toxicology Question of the Week

April 18, 2019

What should you do if someone is bitten by a North American pit viper?

Warm weather has arrived in Tennessee which means snakebite season is upon us. The venomous snakes native to our region are the pit vipers and consist of copperheads (Agkistrodon contortrix), cottonmouths / water moccasins (Agkistrodon piscivorus), and various species of rattlesnakes (genera Crotalus and Sistrurus). Their bites are rarely life-threatening but may require treatment with antivenin.

Tennessee falls within the group of states that have the second highest rates of snakebites with 2-4 bites per 100,000 inhabitants. In 2018, the Tennessee Poison Center assisted with the care of 226 snakebites.

If you or someone you know is bitten by a snake:

  • Stay calm. While very painful, snakebites can be treated and are rarely fatal.
  • Wash the bite gently with soap and water if this won’t delay transport to the hospital.
  • Remove any jewelry and constricting clothing from the area of the bite.
  • Keep the arm or leg (usual sites for snakebite) immobile and in a neutral position.
  • Call Poison Control (1-800-222-1222) right away. The poison specialists and medical/clinical toxicologists on staff are experts in treating snakebites and will work with the physicians in the emergency department so you’ll get the proper treatment.

Although there are a variety of folklore practices and commercial products for treating snakebites, the evidence shows there is nothing that can be done in the field to significantly alter the outcome of a snakebite. The following practices are big DON’Ts and are potentially harmful to the patient:

  • DON’T risk another bite by trying to capture or kill the snake. If you can take a picture or describe the snake, that is good but not essential for proper treatment. It is also important to know that even a dead snake or decapitated head can still envenomate a person.
  • DON’T apply a tourniquet. These can lead to ischemia, gangrene, and amputation.
  • DON’T cut the wound and suck out the venom (either by mouth or with an extractor device). Experimental models show these do not extract any venom and increase local tissue damage. Additionally, oral suction can introduce bacteria into the wound and cause an infection.
  • DON’T apply ice. This will not slow the spread of venom and can cause significant frostbite.
  • DON’T attempt to shock the wound with a stun gun or other electrical current.  While there are numerous personal testimonials and anecdotal reports (including a few that involve a car and a set of jumper cables), experimental models show no benefit and delayed wound healing.

This question prepared by: Justin Loden, PharmD, CSPI, DABAT – Education Coordinator

References

  1. Alberts MB, Shalit M, LoGalbo F. Suction for venomous snakebite: a study of “mock venom” extraction in a human model. Ann Emerg Med. 2004 Feb; 43(2):181-6.
  2. Ben Welch E, Gales BJ. Use of stun guns for venomous bites and stings: a review. Wilderness Environ Med. 2001 Summer; 12(2):111-7.
  3. Chippaux JP. Incidence and mortality due to snakebite in the Americas. PLoS Negl Trop Dis. 2017 Jun; 11(6):e0005662.
  4. Frank HA. Snakebite or frostbite: what are we doing? An evaluation of cryotherapy for envenomation. Calif Med. 1971 May; 114(5):25-7.
  5. Kanaan NC, Ray J, Stewart M, et al. Wilderness medical society practice guidelines for the treatment of pit viper envenomations in the United States and Canada. Wilderness Environ Med. 2015 Dec; 26(4):472-87.
  6. Lavonas EJ, Ruha AM, Banner W, et al. Unified treatment algorithm for the management of crotaline snakebite in the United States: results of an evidence-informed consensus workshop. BMC Emerg Med. 2011 Feb 3; 11:2.
  7. O’Neil ME, Mack KA, Gilchrist J, et al. Snakebite injuries treated in the United States emergency departments, 2001-2004. Wilderness Environ Med. 2007 Winter; 18(4):281-7.

I am interested in any questions you would like answered in the Question of the Week.  Please email me with any suggestion at donna.seger@vumc.org.

Donna Seger, MD

Executive Director

Tennessee Poison Center

www.tnpoisoncenter.org

Poison Help Hotline: 1-800-222-1222