Snakebite Protocol: What to Do and What Not to Do

What Venom Actually Does

Pit viper venom (rattlesnakes, copperhead, cottonmouth): Predominantly cytotoxic and hemotoxic. Destroys tissue at the bite site, disrupts blood clotting, causes systemic bleeding. The swelling, discoloration, and tissue destruction you see spreading from the bite site is the venom enzymes digesting tissue. Secondary effects include coagulopathy (inability to clot blood properly), renal damage from myoglobin released by muscle destruction, and in some species (Mojave rattlesnake), direct neurotoxicity.

Coral snake venom: Primarily neurotoxic. The bite site itself may look minor — swelling is minimal, pain is often mild. The venom blocks neuromuscular transmission, causing progressive ascending paralysis. The deceptive mildness at the bite site is dangerous because people underestimate the severity.

Pit Viper Bite — Field Management

Immediate Actions

Remove from striking range first. A snake that has bitten once will bite again. Back away from the snake before doing anything else.

Keep the bite site below heart level. This slightly slows venom spread through the lymphatic system. Have the patient sit or lie down rather than walking — exertion dramatically increases venom absorption.

Remove constrictive items immediately. Rings, watches, bracelets, and tight clothing near the bite site. Swelling from pit viper envenomation can be extreme and fast — anything constrictive can become a tourniquet.

Mark swelling progression. Draw a line at the leading edge of erythema (redness) or swelling with a marker and write the time. This gives the treating hospital information about venom spread rate and informs antivenom dosing decisions.

Splint the limb loosely to reduce movement and swelling, as you would for a suspected fracture. Immobilization reduces absorption rate.

Transport immediately. Every minute matters for significant envenomation.

Monitoring During Transport

• Vital signs: heart rate, blood pressure, respiratory rate
• Swelling progression (check against your marks)
• Neurological status — Mojave rattlesnake can produce ptosis (drooping eyelids) or difficulty swallowing as early signs of neurotoxicity
• Signs of systemic effect: nausea, metallic taste, lip tingling, visual changes are all signs of systemic envenomation

Antivenom

CroFab is the primary US antivenom for crotaline envenomations. It is Fab fragment-based, meaning it binds and neutralizes venom but has a relatively short half-life — repeat dosing over 18 hours is common. It requires IV access in a monitored setting.

Dose is based on clinical severity, not patient weight. A child who is significantly envenomated receives the same or more antivenom than an adult with mild envenomation.

Do not give antivenom in the field. Allergic reactions, including anaphylaxis, occur in a meaningful percentage of patients. Administration requires the ability to manage anaphylaxis immediately.

Coral Snake Bite — Field Management

The Danger of Appearing Fine

A coral snake bite victim who feels relatively well 30-60 minutes after the bite is not out of danger. The neurotoxic venom of coral snakes has a delayed onset of 4-8 hours. By the time muscular weakness, slurred speech, or difficulty swallowing appears, significant venom has already bound to neuromuscular junctions.

Once neurological symptoms begin, they can progress to respiratory paralysis within hours.

Response

All coral snake bites require immediate hospital evaluation, regardless of apparent severity. There is no safe "wait and see" approach for coral snake envenomation.

Immobilize and transport. Field pressure immobilization bandaging (as used for Australian elapids) is sometimes recommended for coral snakes — a firm bandage from the distal bite to proximal, similar to a compression bandage but not a tourniquet. This approach is controversial for North American coral snakes but not harmful. Do not delay transport for bandage application.

Airway is the concern. Breathing support — positioning, rescue breathing if needed — is the field intervention if respiratory compromise begins.

Antivenom Scarcity Issue

No US pharmaceutical company currently manufactures coral snake antivenom. Wyeth discontinued production of North American coral snake antivenom (NACSA) in 2004. Existing hospital stockpiles are limited and expiring. FDA has extended the use-by dates on existing lots repeatedly.

Alternative antivenoms from Central and South American manufacturers are being evaluated but are not FDA-approved. This is an evolving situation — some facilities have antivenom, some do not. This fact makes hospital evaluation and transport even more critical for coral snake bites.

Dry Bite Assessment

Approximately 20-25% of venomous snakebites result in negligible venom injection ("dry bites"). Signs of a dry bite:

• Puncture marks present but minimal local reaction
• No significant swelling after 1-2 hours
• No systemic symptoms (nausea, metallic taste, abnormal bleeding)

Even suspected dry bites require 6-8 hours of hospital observation. Envenomation can sometimes appear delayed. Laboratory tests (CBC, coagulation studies, metabolic panel) will show the early signs of envenomation before clinical symptoms appear.

What Happens Without Antivenom

For pit viper bites in a true grid-down scenario where antivenom is unavailable:

Cytotoxic envenomation: Progressive tissue necrosis at the bite site. The wound will require debridement. Coagulopathy can produce systemic bleeding that is difficult to manage without blood products.

Supportive care only:

• Immobilize the limb in a position of function
• Wound care as tissue necrosis develops
• Fluid replacement (IV if available, oral if not)
• Pain management (ibuprofen and acetaminophen; opioids if available for severe pain)
• Watch for infection — necrotic tissue is an infection risk
• Watch for compartment syndrome (severe pain with passive stretch of fingers/toes, hard muscle compartment) — requires surgical intervention

The majority of pit viper envenomations in healthy adults are survivable without antivenom, though with significant tissue loss. Coral snake envenomation with progressive respiratory failure without antivenom is a much more difficult scenario — respiratory support (rescue breathing, improvised airway management) is the only intervention available.