What is the approach to a patient with a snake bite?

Approach to Snake Bite Management

Immediately activate emergency services, immobilize the affected extremity, remove all constricting objects, and transport the patient rapidly to a medical facility for antivenom administration—the cornerstone of definitive treatment. 1

Immediate On-Scene Management

Critical First Actions

• Call 911 or activate emergency medical services immediately for any venomous or possibly venomous snake bite, as definitive treatment is only available in healthcare settings 1
• Immobilize the bitten extremity and minimize all patient exertion to reduce systemic venom absorption through the lymphatic system 1
• Remove rings, watches, jewelry, and all constricting objects from the affected limb before progressive swelling causes ischemic injury 1, 2
• Transport the victim to a medical facility as quickly as possible—do not delay transport to attempt ineffective first aid measures 1

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 completely ineffective for venom removal and cause tissue damage 1
• Do NOT apply tourniquets—they worsen local tissue injury and are contraindicated 1
• Do NOT use electric shock therapy—it is ineffective and potentially harmful 1
• Do NOT use pressure immobilization bandaging in North America—this technique may worsen tissue injury with cytotoxic pit viper venoms that predominate in the US 1

Emergency Department Assessment

Identify the Snake Type and Venom Pattern

Pit Viper Envenomation (Rattlesnakes, Copperheads, Cottonmouths):

• Immediate local tissue injury with pain, swelling, and redness at the bite site developing within 30 minutes 3
• Progressive swelling and edema that continues to spread, with warmth and tenderness around the bite 3
• Hypotension and shock can occur in severe cases, with muscle fasciculations that may progress to paralysis 3
• Coagulopathy and thrombocytopenia develop due to venom effects on platelets and clotting factors 4

Coral Snake Envenomation (Neurotoxic):

• Minimal to no local tissue injury at the bite site—absence of swelling or pain does not rule out serious envenomation 3
• Progressive paralysis developing within minutes to hours (can be delayed up to 13 hours) 3, 2
• Neuromuscular weakness that rapidly progresses to respiratory compromise 3
• Any signs of respiratory difficulty require urgent antivenom therapy 3

Initial Hospital Management

• Clean the wound and irrigate with copious water or saline 2
• Obtain rapid laboratory studies: complete blood count with platelet count, coagulation studies (PT/PTT/INR), fibrinogen, fibrin degradation products, electrolytes, renal function 4
• Grade the severity of envenomation based on local signs (swelling extent, ecchymosis) and systemic symptoms (hypotension, coagulopathy, neurotoxicity) 5
• Administer tetanus prophylaxis if immunization status is not current 5
• Consider broad-spectrum antibiotics for wound prophylaxis 5

Antivenom Administration

Indications for Antivenom

• Antivenom is the cornerstone of treatment for venomous snake bites 1
• For pit viper bites: Administer antivenom to patients with progressive swelling, systemic symptoms, or coagulopathy 2, 5
• For coral snake bites: Administer North American Coral Snake Antivenin to all patients with confirmed or suspected neurotoxic envenomation showing any signs of neurotoxicity 2

Dosing Guidelines

• Mild envenomation: 5 vials of polyvalent antivenin 5
• Moderate envenomation: 10-15 vials 5
• Severe envenomation: 15-20 vials 5
• Antivenom is most effective when administered within 4 hours of the bite 6

Critical Safety Measures

• Perform skin testing for hypersensitivity before antivenin administration 5, 6
• Have diphenhydramine and epinephrine readily available at the bedside in case of anaphylactic reaction 5
• Administer antivenin only intravenously—no other route is effective 5

Observation and Admission Criteria

• Hospitalize all patients with neurotoxic envenomation for a minimum of 48 hours with continuous monitoring, as neurotoxicity onset can be delayed up to 13 hours 2
• Admit patients with pit viper bites who develop pain, swelling, ecchymoses, systemic symptoms, or abnormal laboratory findings within 30 minutes to 1 hour 6
• Monitor for compartment syndrome in severe cases with massive swelling—fasciotomy is only indicated in rare cases with documented elevated intracompartment pressures 5

Common Pitfalls to Avoid

• Failing to recognize coral snake envenomation due to minimal local findings—always consider neurotoxic effects even without swelling 3
• Delaying antivenom administration while waiting for definitive snake identification—treat based on clinical presentation 1
• Inadequate antivenom dosing—do not underdose in moderate to severe cases 5
• Premature discharge of coral snake bite victims—observe for at least 48 hours due to delayed neurotoxicity 2