What is the protocol for managing a snake bite?

Snake Bite Protocol

Activate emergency services immediately for any venomous or possibly venomous snake bite and transport the victim to a hospital for definitive antivenom treatment. 1, 2

Immediate Field Management (First 5 Minutes)

DO These Actions:

• Call 911 immediately – Antivenom is only available in hospitals and is the definitive treatment for snake envenomation 1, 2

• Rest and immobilize the bitten extremity – Keep the limb below heart level and minimize all patient movement to reduce systemic venom absorption through lymphatic flow 1, 2

• Remove all rings, watches, and jewelry from the affected limb immediately before swelling develops and causes ischemic injury to digits 1, 2

• Transport by EMS when possible – This allows delivery of supportive care en route to the hospital 1

DO NOT Do These Actions (Potentially Harmful):

• NO tourniquets – Systematic reviews show they worsen local tissue injury without preventing systemic envenomation 1, 2

• NO ice or cryotherapy – This has unproven benefit and causes additional tissue injury 1, 2

• NO incision or suction (with or without devices) – These are ineffective at removing venom and cause tissue damage 1, 2

• NO electric shock therapy – This is both ineffective and potentially harmful 1, 2

• NO pressure immobilization bandaging in North America – This may worsen tissue injury with cytotoxic pit viper venoms that predominate in the US 1, 2

Hospital Assessment and Grading

Severity Classification:

• Grade 0 (No envenomation/"dry bite"): No local or systemic symptoms 3

• Grade 1 (Mild): Local edema and pain only 3

• Grade 2 (Moderate): Pain and edema spreading beyond bite zone with systemic signs 3

• Grade 3 (Severe): Shock, severe coagulopathy, and massive edema 3

Initial Hospital Management:

• Clean the wound and administer broad-spectrum antibiotics 4

• Update tetanus prophylaxis if needed 4

• Monitor continuously: respiratory rate, blood pressure, heart rate, renal function, fluid balance, and coagulation status 3

• Laboratory studies: Complete blood count, coagulation studies (PT/PTT), fibrinogen, platelet count, and urinalysis 4, 5

Antivenom Administration Protocol

Indications for Antivenom:

• All moderate and severe envenomations require antivenom 4

• Selected mild cases with progression of symptoms require antivenom 4

• Patients with pain, swelling, ecchymoses, systemic symptoms, or abnormal labs within 30-60 minutes of the bite are candidates for antivenom 5

Dosing by Severity:

• Mild envenomation: Up to 5 vials 4

• Moderate envenomation: 10-15 vials 4

• Severe envenomation: 15-20 vials 4

Administration Requirements:

• Intravenous route only – Antivenom is only effective when given IV 4

• Skin testing mandatory before administration to predict anaphylactic reactions 4

• Have diphenhydramine and epinephrine immediately available at bedside for anaphylaxis management 4

• Most effective within 4 hours of the bite 5

Special Considerations by Snake Type

Pit Vipers (95% of US bites - Rattlesnakes, Copperheads, Cottonmouths):

• Venom effects: Tissue injury, low blood pressure, bleeding, and muscle fasciculations 1

• Local findings: Red, warm, tender, swollen wounds 1

• Treatment: Standard protocol above with NO pressure immobilization 1, 2

Coral Snakes (Elapidae - Southeast/Southwest US):

• Venom effects: Primarily neurotoxic with minimal local tissue injury 2, 6

• Critical pitfall: Absence of pain or swelling does NOT rule out serious envenomation 6

• Monitor for: Muscle weakness, ptosis, difficulty swallowing, respiratory distress 6

• Hospitalize minimum 48 hours – Neurotoxicity onset can be delayed up to 13 hours 6

• Treatment: Administer North American Coral Snake Antivenin to all patients with confirmed or suspected bites showing any neurotoxicity 6

Critical Pitfalls to Avoid

• Delaying transport to attempt field interventions – Time to antivenom is the most important prognostic factor 2, 6

• Assuming no envenomation based on lack of immediate symptoms – Coral snakes and some pit vipers cause delayed systemic toxicity despite minimal local findings 6

• Excessive patient movement during transport – Walking or physical activity increases venom absorption 1, 2

• Premature discharge – Neurotoxicity can be delayed; observe all suspected envenomations for at least 24-48 hours 6

• Failing to remove constricting items – Rings can cause ischemic injury as swelling progresses 1, 2

Rare Complications Requiring Surgical Intervention

• Fasciotomy is only indicated in rare cases with documented elevated intracompartment pressures via direct measurement 4, 7

• Serial physical examination and compartment pressure monitoring is the reliable method for determining if surgical intervention is needed 7