What is the proper protocol for treating a patient who has been bitten by a snake?

Snake Bite Protocol

For North American pit viper bites (99% of US snakebites), immediately activate EMS, immobilize the extremity, and transport rapidly to a hospital for antivenom administration—do NOT apply suction, tourniquets, or ice, as these are ineffective and potentially harmful. 1, 2

Immediate Field Management

What TO Do:

• Remove all rings, watches, and constricting jewelry immediately before swelling develops, as edema can cause ischemic injury to digits 2

• Immobilize the bitten extremity completely and keep it below heart level to minimize venom absorption through the lymphatic system 2

• Minimize patient exertion during transport—walking or physical activity increases systemic venom absorption 2

• Apply pressure immobilization bandaging ONLY for non-North American snakes (sea snakes, exotic species): Use 40-70 mm Hg pressure in the upper extremity or 55-70 mm Hg in the lower extremity around the entire length of the bitten limb—the bandage should be comfortably tight and snug but allow a finger to be slipped under it 1, 2

• Activate EMS immediately and transport to a hospital with antivenom stocks and capability to manage anaphylaxis 2, 3

What NOT to Do (Potentially Harmful):

• Do NOT apply suction—it removes only minimal venom, has no clinical benefit, and may aggravate the injury 1, 2

• Do NOT apply tourniquets—they worsen local tissue injury without preventing systemic envenomation 2

• Do NOT apply ice or cold therapy—this is ineffective for venom removal and can cause tissue injury 2

• Do NOT make incisions or use mouth suction—these methods are ineffective and cause additional tissue damage 2

• Do NOT use electric shock therapy—this is both ineffective and potentially harmful 2

Critical Clinical Distinctions by Snake Type

Pit Vipers (Rattlesnakes, Copperheads, Cottonmouths) - 99% of US Bites:

• Immediate local tissue injury with pain, swelling, and redness at the bite site developing within 30 minutes 4, 5

• Progressive edema, warmth, and tenderness spreading from the bite site 4

• Potential systemic effects: hypotension, shock, muscle fasciculations, coagulopathy 4, 5

• Not all pit viper bites require antivenom—only moderate to severe envenomations 6, 3

Coral Snakes (1% of US Bites):

• Minimal to no local tissue injury at the bite site—this is a critical pitfall 4

• Progressive neuromuscular weakness and paralysis developing within minutes to hours 4

• Respiratory compromise can develop rapidly 4

• ALL coral snake envenomations require antivenom regardless of initial presentation 6, 7

Sea Snakes and Exotic Species:

• Absence of pain or swelling does NOT rule out serious envenomation—life-threatening systemic toxicity occurs despite minimal local findings 2

• Monitor continuously for neurotoxicity: muscle weakness, ptosis, difficulty swallowing, respiratory distress 2

• Pressure immobilization bandaging IS indicated for these species (unlike North American pit vipers) 2

Hospital-Based Definitive Treatment

• Admit all suspected snakebite patients for at least 12-48 hours with continuous monitoring, as neurotoxicity onset can be delayed 2, 3

• Obtain serial blood testing: activated partial thromboplastin time, international normalized ratio, creatine kinase level 3

• Perform serial neurological examinations 3

• Administer antivenom as soon as there is evidence of envenomation: venom-induced consumption coagulopathy, sudden collapse, myotoxicity, neurotoxicity, thrombotic microangiopathy, or renal impairment 3

• Antivenom is most effective when given within four hours of the snakebite 5

• Test for hypersensitivity to antivenom before administration 5

• One vial of the relevant antivenom is sufficient to bind all circulating venom 3

• Provide supportive care: pain control, plasma expanders, correction of metabolic and hematologic complications 6, 5

Critical Pitfalls to Avoid

• Assuming no envenomation based on lack of local symptoms is dangerous—coral snakes and sea snakes cause minimal local findings despite life-threatening systemic toxicity 2, 4

• Delaying transport to attempt ineffective field interventions wastes critical time—time to antivenom is the most important prognostic factor 2

• Applying pressure immobilization for North American pit vipers is NOT recommended—this technique is only for non-North American species 1, 2

• Deaths from snakebites are rare, but morbidity is often due to overtreatment rather than undertreatment—not all pit viper bites require antivenom 7