Wilderness Medical Society Clinical Practice Guidelines for the Treatment of Pit Viper Envenomations in the United States and Canada: 2026 Update

Abstract

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of North American pit viper envenomations, and this serves as an update to the initial guidelines. We present a review of pertinent pathophysiology and discuss prevention measures and therapeutic management. Graded recommendations are made regarding each treatment and its role in management. This significant update to the prior guidelines includes a discussion of F(ab′)₂ antivenom treatment, which was not previously approved by the Food and Drug Administration. These guidelines should assist in clinical decision making, but a cookbook approach is often insufficient, because each patient is unique and may respond differently to therapeutics. Physicians must use their experience and frequent clinical assessments to apply these recommendations to their individual patients. Consultation with a local toxicologist familiar with envenomations or a poison control center is recommended to assist in patient management. These guidelines are for crotaline snakes native to the United States and Canada and should not be applied to other snake species or geographic regions. Coral snake envenomations result in fewer serious side effects (<3% of victims) and account for only 1 to 3% of all snakebites reported in the United States and Canada. Due to the differences in management, coral snakes are not covered in these guidelines. This is an updated version of the guidelines published in 2015.