Snake Bite Management Protocol
Immediately activate emergency medical services for any person bitten by a venomous or possibly venomous snake, as definitive treatment with antivenom is only available in hospital settings and cannot be administered in the field. 1
Immediate Field Actions (Do These)
Rest and immobilize the bitten extremity while minimizing any exertion by the victim—walking or physical activity for ≥10 minutes increases systemic venom absorption through enhanced lymphatic flow. 1, 2
Remove all rings, watches, and constricting jewelry immediately from the affected limb before swelling develops, as progressive edema can cause ischemic injury to digits and constriction damage. 1, 2
Keep the bitten extremity at or below heart level during transport to slow venom dissemination through the lymphatic system. 2
Transport the patient rapidly to the nearest medical facility by EMS rather than private vehicle, as this allows delivery of supportive care (airway management, IV access, hemodynamic monitoring) en route to the hospital. 1
Critical Actions to AVOID (These Are Harmful)
Do NOT apply ice or cold therapy—this has unproven benefit for snakebite and case reports demonstrate tissue injury from aggressive cryotherapy. 1, 2
Do NOT use suction devices (with or without incision)—systematic reviews show these are completely ineffective at removing venom and cause additional tissue damage. 1, 2
Do NOT apply tourniquets—human and animal studies demonstrate they are ineffective at preventing systemic envenomation while worsening local tissue necrosis. 1, 2
Do NOT use electric shock therapy—systematic reviews of human experience and animal experiments confirm this is both ineffective and potentially harmful. 1, 2
Do NOT apply pressure immobilization bandaging for North American snakebites—this technique may worsen tissue injury with the cytotoxic venoms of pit vipers (rattlesnakes, copperheads, cottonmouths) that cause >95% of venomous bites in the United States. 1, 2 Note: This recommendation is specific to North American species; pressure immobilization IS appropriate for neurotoxic snakes in other parts of the world. 1, 3
Hospital-Based Definitive Treatment
Antivenom is the cornerstone and only definitive treatment for venomous snakebites—it must be administered in a hospital setting where hypersensitivity reactions can be managed. 1, 2
For pit viper envenomation (rattlesnakes, copperheads, cottonmouths), Crotalidae Polyvalent Immune Fab (CroFab) is the preferred antivenom in the United States as it causes fewer adverse reactions than older polyvalent antivenins. 4, 5
Antivenom therapy is most effective when administered within 4 hours of the bite, though it retains benefit even when given later. 6
Administer antivenom to patients showing pain, swelling, ecchymoses, systemic symptoms, or abnormal laboratory findings within 30 minutes to 1 hour of the bite. 6
Clinical Monitoring Parameters
Monitor continuously for:
- Respiratory rate and airway patency (neurotoxic effects can cause respiratory paralysis) 4, 7
- Blood pressure and heart rate (hypotension from venom-induced vasodilation) 4, 7
- Coagulation status (pit viper venom causes coagulopathy and bleeding) 4, 7
- Renal function and fluid balance (venom can cause acute kidney injury) 4, 7
- Compartment syndrome development via serial physical examination and compartment pressure measurement if indicated 5
Envenomation Severity Grading
Grade severity based on clinical findings:
- No envenomation ("dry bite"): No symptoms despite bite 4
- Mild: Local edema and pain only 4
- Moderate: Pain and edema spreading beyond bite zone with systemic signs 4
- Severe: Shock, severe coagulopathy, massive edema 4
Special Considerations for Coral Snakes
Coral snakes (Elapidae family) produce primarily neurotoxic effects with minimal to no local tissue injury—the absence of pain or swelling does NOT rule out serious envenomation. 8
Neurotoxicity onset can be delayed up to 13 hours but progresses rapidly once symptoms begin, requiring hospitalization for minimum 48 hours with continuous monitoring. 8
All patients with confirmed or suspected coral snake envenomation showing any neurotoxic signs should receive North American Coral Snake Antivenin. 8
Common Pitfalls to Avoid
Do not delay transport to attempt field interventions—time to antivenom is the single most important prognostic factor, and ineffective field measures waste critical minutes. 2, 8
Do not assume no envenomation based on lack of immediate symptoms—approximately 20-25% of venomous snakebites are "dry bites" with no venom injection, but symptoms can also be delayed, particularly with coral snakes. 8, 4
Do not discharge patients prematurely—even with minimal initial symptoms, delayed toxicity can occur and requires extended observation. 8
Do not apply techniques developed for other geographic regions—pressure immobilization bandaging is appropriate for neurotoxic snakes in Australia and Asia but contraindicated for cytotoxic North American pit vipers. 1, 2