What is the treatment approach for an adult patient with no significant past medical history who has suffered a viper snake bite?

Treatment of Viper Snake Bite

Immediately activate emergency services, immobilize the bitten extremity, remove all constricting objects, and transport rapidly to a medical facility where antivenom—the cornerstone of treatment—can be administered based on severity of envenomation. 1

Immediate Field Management

Critical First Actions

• Activate emergency medical services immediately for any venomous or possibly venomous snake bite, as definitive antivenom therapy is only available in healthcare settings 1, 2
• Immobilize and rest the bitten extremity at or below heart level to minimize systemic venom absorption through the lymphatic system 1
• Remove all rings, watches, and constricting objects from the affected limb immediately before progressive swelling causes ischemic injury 1, 2
• Minimize patient exertion during transport, as physical activity accelerates venom absorption 2

Harmful Practices That Must Be Avoided

• Do NOT apply ice to the bite wound—it has no proven benefit and may cause additional tissue injury 1
• Do NOT use suction devices (with or without incision)—they are ineffective for venom removal and may worsen tissue damage 1
• Do NOT apply tourniquets—they can significantly worsen local tissue injury and necrosis 1
• Do NOT use pressure immobilization bandaging for pit viper bites in North America, as this technique worsens tissue injury with cytotoxic venoms 1, 2
• Do NOT apply electric shock—it is completely ineffective and potentially harmful 1

Hospital-Based Management

Assessment of Envenomation Severity

• Pit viper bites cause immediate local tissue injury with pain, swelling, redness, warmth, and tenderness at the bite site, with progressive edema developing within 30 minutes and continuing to spread 3
• Monitor for systemic manifestations including hypotension, shock, muscle fasciculations, and potential progression to paralysis in severe cases 3
• Serial physical examination and compartment pressure monitoring are reliable methods for determining if surgical intervention is required for rare compartment syndrome 4

Antivenom Administration

• Antivenom is the cornerstone of treatment for venomous snakebites and should be administered based on the degree of envenomation 1, 2
• Crotalidae Polyvalent Immune Fab (CroFab) is safe and effective for managing both local and systemic effects of pit viper envenomation 4
• Administer polyvalent antivenin based on severity: mild envenomation with only local symptoms may not require antivenom, while moderate to severe cases with progressive swelling or systemic signs require prompt administration 2, 5
• Perform hypersensitivity testing before antivenom administration and take precautions to prevent allergic reactions 5

Supportive Care

• Elevate the affected extremity after initial assessment to reduce swelling 4
• Provide adequate pain control as pit viper bites cause significant pain 5
• Correct metabolic and hematologic complications as pit viper venom contains anticoagulant factors and can cause hemorrhage 5
• Irrigate the wound with copious amounts of water or saline 2
• Administer tetanus prophylaxis and consider antibiotics for wound care 5

Critical Pitfalls to Avoid

• Delaying transport to attempt ineffective first aid measures rather than prioritizing rapid hospital arrival 1
• Failing to remove constricting items early, leading to ischemic injury as swelling progresses 1, 2
• Underestimating severity based on initial presentation—symptoms can progress rapidly, and compartment syndrome, though rare, requires close monitoring 4
• Using early corticosteroids, which remains controversial and is not routinely recommended 6
• Performing cryotherapy, which should be completely avoided 6

Special Considerations

• Most pit viper bites respond to elevation and observation, with only some requiring antivenom administration 4
• Severity is highly variable, ranging from minimal local symptoms to marked tissue necrosis, hemorrhage, and shock 6
• Fasciotomy may be necessary when severe edema impairs arterial perfusion, but surgical intervention has no place in routine acute snakebite treatment 6, 5
• Monitor for serum sickness as a delayed complication of antivenom therapy 5