What is the management of a snake bite?

Management of Snake Bite

The cornerstone of snake bite management is prompt administration of antivenom (such as CroFab) with an initial dose of 4-6 vials administered as soon as possible after envenomation, followed by additional doses until initial control is achieved. 1

Initial Assessment and First Aid

• Do:

  • Call emergency services immediately
  • Rest and immobilize the bitten extremity
  • Remove constricting jewelry
  • Transport the patient to the nearest emergency department as quickly as possible

• Do Not:

  • Apply ice
  • Use suction devices (except possibly within first 5 minutes with a venom extractor)
  • Apply electric shock
  • Use tourniquets
  • Use pressure immobilization bandaging for North American pit vipers 1

Hospital Management

Antivenom Administration

1. Initial Assessment:

   • Assess severity of envenomation using clinical signs (local injury, coagulation abnormality, systemic signs)
   • Grade severity to guide treatment decisions

2. Antivenom Dosing:

   • Initial dose: 4-6 vials IV (range from minimum of 4 to maximum of 12 vials based on severity)
   • Reconstitute each vial with 18 mL of 0.9% Sodium Chloride
   • Further dilute to a total volume of 250 mL with 0.9% Sodium Chloride
   • Observe for up to 1 hour following completion of first dose 1, 2

3. Administration Protocol:

   • Infuse dose intravenously over 60 minutes
   • Start slowly at 25-50 mL/hour for first 10 minutes to monitor for allergic reactions
   • If no reaction occurs, increase to full 250 mL/hour rate
   • If initial control is not achieved, administer additional 4-6 vial doses until control is achieved
   • Once initial control is achieved, give 2-vial doses every 6 hours for up to 18 hours (3 doses) 2

4. Definition of Initial Control:

   • Local injury progression stops
   • Systemic symptoms resolve
   • Coagulation parameters normalize or trend toward normal 1, 2

Laboratory Monitoring

• Complete blood count
• Coagulation studies
• Renal function tests
• Electrolytes
• Cardiac monitoring 1

Supportive Care

1. Respiratory Support:

   • Monitor oxygen saturation
   • Provide supplemental oxygen if hypoxic
   • Initiate early intubation and mechanical ventilation at first sign of respiratory compromise 1

2. Fluid Management:

   • Aggressive fluid resuscitation with normal saline (initial rate 1000 mL/h)
   • Taper by at least 50% after 2 hours
   • Avoid potassium-containing balanced salt fluids due to risk of hyperkalemia 1

3. Wound Care:

   • Clean the wound
   • Administer broad-spectrum antibiotics
   • Check tetanus status and administer tetanus toxoid if necessary 1

Special Considerations

1. Pregnant Patients:

   • Should receive the same treatment as non-pregnant individuals
   • Risk to fetus appears higher in cases with significant maternal systemic envenomation 1

2. Patients with Sickle Cell Disease:

   • Require close monitoring for vaso-occlusive crisis triggered by envenomation
   • Ensure adequate hydration with appropriate fluids to prevent sickling 1

Monitoring and Follow-up

• Monitor for recurrent coagulopathy for at least one week following treatment
• Watch for delayed allergic reactions or serum sickness (rash, pruritus, urticaria)
• Long-term follow-up is essential as persistent renal involvement may occur in up to 41% of patients 1, 2

Complications to Watch For

• Vaso-occlusive crisis and acute chest syndrome in patients with sickle cell disease
• Allergic reactions to antivenom
• Delayed serum sickness
• Coagulopathy and thrombocytopenia
• Renal failure
• Unusual bruising or bleeding up to one week or longer following initial treatment 1, 2

Pitfalls to Avoid

• Delaying antivenom administration (should be given within 6 hours of snakebite for best results)
• Inadequate initial dosing (failure to achieve initial control is often due to insufficient antivenom)
• Neglecting to monitor for recurrent coagulopathy
• Performing unnecessary fasciotomy (rarely indicated, only for cases with elevated intracompartment pressures)
• Using outdated first aid techniques like tourniquets, ice application, or wound incisions 1, 2