Anti-Snake Venom Administration Protocol
The recommended initial dose of Anti-Snake Venom (ASV) for treating a snake bite is 10 vials administered intravenously, which provides optimal efficacy while minimizing the risk of adverse reactions. 1
Initial Assessment and Preparation
- Ensure airway management and ventilatory support if needed, especially for neurotoxic envenomation 1
- Remove rings and other constricting objects from the bitten extremity to prevent damage from swelling 1
- Perform hypersensitivity testing before administering ASV to reduce risk of allergic reactions 1
Administration Protocol
- Administer ASV intravenously as the preferred route for rapid distribution of antivenom 1
- For most pit viper envenomations in North America, 12 vials is the recommended initial quantity to have available, though 10 vials is typically sufficient for initial treatment 2
- For specific species like common krait, the recommended initial dose is 10 vials 3
Monitoring and Additional Dosing
- Monitor for progressive venom injury (worsening local swelling, ecchymosis, coagulation abnormalities, or systemic effects) 4
- Additional doses may be required for marked progressive local signs or if systemic manifestations persist 5
- Be vigilant for potential recurrence of venom effects due to the shorter half-life of some antivenom preparations 4
Managing Adverse Reactions
- Watch for potential adverse reactions including anaphylaxis (3.7% of cases) and serum sickness (3.7% of cases) 5
- Have epinephrine readily available for treatment of anaphylactic reactions 2
- The recommended dose of epinephrine for anaphylaxis is 0.01 mg/kg in children (up to 0.3 mg) and 0.3 to 0.5 mg in adults, preferably administered intramuscularly in the anterolateral thigh 2
Dosing Considerations
- Evidence suggests that higher initial doses (10-20 vials) may be more effective in preventing coagulopathy complications compared to lower doses (4-6 vials) 6
- However, for neurotoxic snake envenoming, research indicates that low-dose protocols may be as effective as high-dose protocols 7
- Insufficient antivenom dosing can lead to persistent free venom and severe complications such as rhabdomyolysis 8
Hospital Preparedness
- Hospitals should perform a hazard vulnerability assessment to determine appropriate stocking levels of antivenom 2
- Geographic location and endemic venomous snake species should guide hospital stocking decisions 2
- Consider the potential need for treating multiple bite victims simultaneously when determining stocking quantities 2