Snake Bite Management
Emergency services should be activated immediately for any person bitten by a venomous or possibly venomous snake, as antivenom is the definitive treatment and is not available in first aid settings. 1
Initial Assessment and First Aid
DO:
- Call emergency services immediately 1
- Rest and immobilize the bitten extremity 1, 2
- Remove rings and other constricting objects from the bitten extremity 1
- Minimize exertion by the person who was bitten 1
DO NOT:
- Apply ice to the bite wound 1, 2
- Use suction devices (ineffective and potentially harmful) 1, 2
- Apply electric shock (ineffective and potentially harmful) 1, 2
- Use tourniquets (can worsen tissue injury) 1, 2
- Use pressure immobilization bandaging for North American pit viper bites 1, 2
Clinical Presentation and Assessment
Snake envenomation can present with:
- Fang marks with or without local pain and swelling
- Progressive tissue injury (redness, warmth, tenderness, swelling)
- Systemic symptoms including hypotension
- Coagulopathy and bleeding
- Neurotoxicity (especially with coral snake bites)
- Potential for renal failure 1, 2
Hospital Management
Grading Envenomation Severity
Grading guides treatment decisions:
- Mild: Local swelling without progression or systemic symptoms
- Moderate: Progressive local injury, systemic symptoms
- Severe: Severe local injury, significant systemic effects, coagulopathy 2
Antivenom Administration
- Antivenom is indicated in certain mild cases and all moderate and severe envenomation cases 2
- Initial dose of 4-6 vials administered intravenously as soon as possible after envenomation
- Additional doses until initial control is achieved (local injury progression stops, systemic symptoms resolve, coagulation parameters normalize) 2
- Monitor for at least 1 hour after initial dose 2
Wound Care
- Clean wound with sterile normal saline
- Remove superficial debris if present
- Avoid deep debridement unless absolutely necessary 2
Laboratory Monitoring
- Complete blood count
- Coagulation studies
- Renal function tests
- Electrolytes
- Cardiac monitoring 2
Management of Complications
Renal Complications
- Aggressive fluid resuscitation with normal saline (initial rate 1000 ml/h, then taper by at least 50% after 2 hours)
- Monitor for hyperkalemia and treat if present
- Consider emergency dialysis for:
- Life-threatening hyperkalemia unresponsive to medical management
- Severe metabolic acidosis
- Volume overload with pulmonary edema
- Uremic encephalopathy or pericarditis 2
Respiratory Compromise
- Early intubation and mechanical ventilation at first sign of respiratory compromise
- Respiratory support may be required for several days 2
Anaphylactic Reactions to Antivenom
- Skin testing to predict possibility of anaphylactic reaction is mandatory before administration
- Have diphenhydramine and epinephrine readily available 3
- Both acute (anaphylactic) and delayed (serum sickness type) reactions can occur 4
Special Considerations
Facial Bites
- May cause prolonged airway compromise requiring extended intubation
- Careful airway monitoring is essential 5
Compartment Syndrome
- Fasciotomy is rarely indicated and only when there are elevated intracompartment pressures 3
Follow-up Care
- Long-term follow-up is essential as up to 41% of patients may show persistent renal involvement
- Risk of progression to chronic kidney disease in approximately 5-20% of cases 2
Pitfalls and Caveats
Delayed Presentation: Symptoms may progress over hours; observation for at least 8 hours is recommended even if initial symptoms are mild.
Inappropriate First Aid: Many traditional first aid methods (cutting, suction, tourniquets) can worsen outcomes and delay proper treatment.
Underestimating Severity: What appears as a minor bite can rapidly progress to severe envenomation.
Antivenom Reactions: Carefully monitor for both immediate and delayed hypersensitivity reactions to antivenom.
Regional Differences: These recommendations are specific to snakebites occurring in the United States and Canada. Snakes in other parts of the world have different venom effects and may require different management approaches 1.