What are the guidelines for managing a snakebite?

Snakebite Management Guidelines

Immediate Actions at the Scene

Activate emergency medical services immediately and transport the victim to a medical facility as quickly as possible, as antivenom—the only definitive treatment—is available only in hospital settings. 1

Critical First Steps

• Remove all rings, watches, jewelry, and constricting objects from the bitten extremity immediately before swelling develops, as progressive edema can cause ischemic injury to digits and tissues 1
• Immobilize the bitten extremity and keep it at or below heart level to minimize venom absorption through the lymphatic system 1
• Minimize all physical exertion by the victim during transport, as walking or activity accelerates systemic venom absorption 1
• Reassure the victim to reduce anxiety and physiological stress 2

Geographic-Specific Pressure Immobilization Considerations

The application of pressure immobilization bandaging is controversial and depends critically on snake species and geographic location:

For North American snakebites (pit vipers: rattlesnakes, copperheads, cottonmouths):

• Do NOT use pressure immobilization bandaging, as it may worsen local tissue injury by trapping cytotoxic venom at the bite site 1, 3
• North American pit vipers produce predominantly hemotoxic and necrotoxic venom that causes severe local tissue damage 3, 2

For neurotoxic snakes (coral snakes in North America, sea snakes, or exotic species):

• Pressure immobilization with 40-70 mm Hg in the upper extremity or 55-70 mm Hg in the lower extremity is reasonable to slow lymphatic dissemination of neurotoxic venom 4, 5, 3
• The bandage should be snug enough that a finger can barely slip underneath, applied around the entire length of the bitten limb 4, 5
• This technique is effective for neurotoxic venoms because it slows systemic absorption without worsening local tissue damage, which is minimal with these species 5, 3

Absolutely Contraindicated "First Aid" Measures

These interventions are harmful and must be avoided:

• Do NOT apply ice or cold therapy—no proven benefit and causes additional tissue injury 1, 2
• Do NOT use suction devices (with or without incision)—removes negligible venom amounts, provides no clinical benefit, and may aggravate the injury 4, 1, 6
• Do NOT apply tourniquets—worsens local tissue injury without preventing systemic envenomation 1, 2
• Do NOT use electric shock therapy—completely ineffective and potentially harmful 1
• Do NOT incise the wound or perform excision—increases tissue damage without removing venom 2

Important Nuance on Wound Care

• Irrigating the wound with copious amounts of water is reasonable for cleaning but does not remove venom 4, 3

Hospital-Based Definitive Management

Antivenom Administration

Antivenom is the cornerstone and only specific treatment for venomous snakebites 1, 2, 7

• Crotalidae Polyvalent Immune Fab (CroFab) is the preferred antivenom for North American pit viper bites, as it is more purified and causes fewer hypersensitivity reactions than older equine-derived products 2, 8
• Antivenom is most effective when administered within 4 hours of the bite 9
• Patients with pain, swelling, ecchymoses, systemic symptoms, or abnormal laboratory findings within 30-60 minutes are probable candidates for antivenom therapy 9

Monitoring Requirements

• Monitor respiratory rate, blood pressure, heart rate, renal function, fluid balance, and coagulation status continuously 2
• For neurotoxic envenomation, hospitalize for a minimum of 48 hours with continuous monitoring, as neurotoxicity onset can be delayed up to 13 hours despite minimal local findings 3
• Serial physical examination and compartment pressure measurements are essential for detecting compartment syndrome, though this complication is rare 8

Critical Clinical Pitfalls to Avoid

• Never assume no envenomation based on absence of immediate pain or swelling—neurotoxic bites (coral snakes, sea snakes) cause life-threatening systemic toxicity despite minimal local findings 5, 3
• Do not delay transport to attempt ineffective field interventions—time to antivenom is the most important prognostic factor 5
• Do not apply pressure immobilization techniques developed for neurotoxic snakes to North American pit viper bites, as this worsens cytotoxic tissue damage 1, 3
• Failing to remove constricting items leads to ischemic injury as swelling progresses 1

Venom Type Recognition

Understanding venom types guides appropriate management:

• Hemotoxic/cytotoxic venom (pit vipers): causes progressive local tissue necrosis, coagulopathy, and thrombocytopenia—pressure immobilization is contraindicated 3, 2, 7
• Neurotoxic venom (coral snakes, sea snakes): causes minimal local injury but progressive paralysis and respiratory failure—pressure immobilization is beneficial 3, 2, 7