What is the appropriate medical management for a patient who has been bitten by a snake?

Snakebite Medical Management

Immediately activate emergency medical services and transport the patient to a hospital for antivenom administration—this is the definitive treatment and most critical intervention for reducing mortality and morbidity from venomous snakebites. 1

Immediate Field Management: What TO Do

Universal Actions for All Snakebites

• Activate EMS immediately for any venomous or possibly venomous snakebite, as antivenom is not available in first aid settings and transport by EMS allows stabilizing care en route 1

• Remove all rings, watches, and constricting jewelry from the bitten extremity before swelling develops to prevent ischemic injury to digits 1, 2

• Immobilize the bitten extremity and keep it at or below heart level to minimize venom absorption through the lymphatic system 1, 2

• Minimize patient exertion during transport—walking or physical activity for ≥10 minutes increases systemic venom absorption from the subcutaneous space 1, 2

Critical Geographic and Species Distinctions

For North American pit vipers (rattlesnakes, copperheads, cottonmouths)—which cause >95% of US snakebites:

• Do NOT apply pressure immobilization bandaging, as this may worsen local tissue injury by trapping cytotoxic venom at the bite site 1, 2
• Expect local tissue injury with pain, swelling, redness, warmth, and tenderness developing within 30 minutes 1, 2
• Systemic effects may include hypotension, bleeding, muscle fasciculations, and coagulopathy 1, 2

For coral snakes, sea snakes, or exotic species with neurotoxic venom:

• Apply pressure immobilization bandaging with 40-70 mm Hg pressure in the upper extremity or 55-70 mm Hg in the lower extremity around the entire length of the bitten limb 3, 2, 4
• This technique slows lymphatic absorption without worsening tissue injury for neurotoxic envenomations 3, 4
• Critical pitfall: Absence of pain or swelling does NOT rule out serious envenomation—neurotoxic bites cause minimal local findings despite life-threatening systemic toxicity 3, 2, 4

Immediate Field Management: What NOT To Do

These interventions are potentially harmful and should be avoided:

• Do NOT apply ice or cold therapy—this is ineffective for venom removal and case reports show tissue injury from aggressive cryotherapy 1, 3

• Do NOT use suction devices, incision, or mouth suction—these methods are ineffective at removing venom and may cause additional tissue damage 1, 3

• Do NOT apply tourniquets—systematic reviews show they are ineffective and worsen local tissue injury 1, 3

• Do NOT use electric shock therapy—systematic reviews of human and animal studies show this is both ineffective and potentially harmful 1, 3

Hospital-Based Definitive Treatment

Antivenom Administration

• Antivenom is the mainstay of definitive treatment and is most effective when administered within 4 hours of the bite 5, 6

• For North American pit viper envenomations, Crotalidae Polyvalent Immune Fab (Ovine) [CroFab] is safe and effective for managing local and systemic effects 6

• Administer antivenom to patients with pain, swelling, ecchymoses, systemic symptoms, or abnormal laboratory findings within 30 minutes to 1 hour of the bite 5

• Test for hypersensitivity to antivenom before administration 5

Supportive Care

• Atropine administration is required concomitantly with pralidoxime for organophosphate poisoning (note: this is NOT for snakebites—the pralidoxime evidence 7 is not applicable to snake envenomation management)

• Administer plasma expanders, pain medication, diazepam, tetanus toxoid, antiseptics, and antibiotics as needed 5

• Elevate the affected extremity and provide observation for most patients 6

Monitoring and Admission

• Admit all suspected snakebite patients for at least 12-48 hours with continuous monitoring, as neurotoxicity onset can be delayed up to 13 hours 2, 4

• For neurotoxic envenomations specifically, hospitalize for a minimum of 48 hours as progression is rapid once symptoms begin 3, 4

• Monitor for signs of neurotoxicity: muscle weakness, ptosis, difficulty swallowing, respiratory distress, or altered mental status 3

• Perform comprehensive work-up including hematologic, neurologic, renal, and cardiovascular assessments 8

• Close monitoring via serial physical examination and compartment pressure measurement is reliable for determining if surgical fasciotomy is required (rarely needed) 6

Critical Pitfalls to Avoid

• Assuming no envenomation based on lack of local symptoms is dangerous—coral snakes and sea snakes cause minimal local findings despite life-threatening systemic toxicity 3, 2, 4

• Delaying transport to attempt ineffective field interventions wastes critical time—time to antivenom is the most important prognostic factor 3, 2

• Applying pressure immobilization for North American pit vipers is not recommended—this technique is only for non-North American neurotoxic species 1, 2

• Failing to apply pressure immobilization for sea snakes or coral snakes eliminates the most effective pre-hospital intervention for slowing venom spread 3, 2

• Continuing absorption from the lower bowel after ingestion can cause fatal relapses after initial improvement—additional monitoring and treatment may be needed 7