Snake Bite Management
The mainstay of treatment for venomous snakebites is antivenom administration in a hospital setting with close monitoring for adverse reactions, preceded by appropriate first aid measures including rest and immobilization of the bitten extremity. 1
Initial First Aid and Assessment
DO:
- Call emergency services immediately
- Rest and immobilize the bitten extremity to reduce venom spread
- Remove rings and constricting jewelry from the affected limb
- Apply pressure immobilization bandage (40-70 mmHg for upper extremity, 55-70 mmHg for lower extremity) for non-North American pit vipers 1
DO NOT:
- Apply ice to the bite area
- Use suction devices (no clinical benefit and may worsen injury)
- Apply electric shock
- Apply tourniquets
- Use pressure immobilization bandaging for North American pit vipers 1
Hospital Management
Immediate Assessment
- Grade the severity of envenomation (mild, moderate, severe)
- Clean the wound thoroughly
- Obtain baseline laboratory studies:
- Complete blood count
- Coagulation studies (PT, PTT, fibrinogen)
- Renal function tests
- Electrolytes
- Cardiac monitoring 1
Antivenom Administration
- Indications: All moderate and severe envenomations, and certain mild cases 2
- Dosing:
- Mild envenomation: Up to 5 vials
- Moderate envenomation: 10-15 vials
- Severe envenomation: 15-20 vials 2
- Administration:
- Administer ONLY intravenously
- Perform skin testing before administration to predict anaphylactic reactions
- Have diphenhydramine and epinephrine readily available for potential anaphylaxis 2
- Types:
- Equine-derived antivenin (standard of care)
- Sheep-derived antigen binding fragment ovine (CroFab) - less allergenic 1
Additional Treatments
- Administer broad-spectrum antibiotics to prevent infection 2
- Provide tetanus prophylaxis if needed 1, 2
- Implement appropriate pain management 1
- Monitor for delayed reactions to antivenom (serum sickness) 1
Special Considerations
Thrombotic Microangiopathy (TMA)
- Monitor for microangiopathic hemolytic anemia (schistocytes on blood film), thrombocytopenia, and acute kidney injury 3
- Diagnostic criteria: anemia with >1.0% schistocytes, plus thrombocytopenia (<150 × 10⁹/L) or >25% decrease in platelet count 3
- Early antivenom remains the mainstay of treatment; therapeutic plasma exchange has not shown evidence of effectiveness 3
Compartment Syndrome
- Monitor for signs of compartment syndrome (pain, pallor, paresthesia, pulselessness, paralysis)
- Fasciotomy is indicated only in rare cases with elevated intracompartment pressures 2, 4
- Delayed presentation can lead to wound infection, abscess, necrotizing fasciitis, and gangrene requiring surgical intervention 4
Pregnancy
- Treat pregnant women similarly to non-pregnant individuals, including appropriate antivenom
- Implement maternal and fetal monitoring in a healthcare facility
- Use a multidisciplinary approach involving emergency medicine, obstetrics, and toxicology 1
Sickle Cell Disease
- Monitor closely for signs of vaso-occlusive crisis triggered by envenomation
- Ensure adequate hydration with appropriate fluids to prevent sickling
- Monitor oxygen saturation and provide supplemental oxygen if hypoxic 1