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Trauma & Injuries

Snakebite Management

Management of bites from snakes, which can range from local effects (non-venomous or 'dry' bites) to severe systemic envenomation (cytotoxic, neurotoxic, hemotoxic) depending on the snake species and venom injected.

Also known as: Snake Envenomation

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Referral and warning signs

When to refer

ALL suspected snakebites should be referred to a health facility (HC2/HC3/HC4) for observation. Urgent referral to HC4/Hospital required if: Any signs of systemic envenomation develop (neurotoxic, hemotoxic, cardiovascular). Rapidly progressive local swelling. Need for antivenom administration. Need for respiratory support. Significant bleeding or shock.

Red flags

  • Difficulty breathing, shortness of breath, respiratory distress
  • Drooping eyelids (ptosis)
  • Difficulty swallowing or speaking
  • Generalized muscle weakness or paralysis
  • Spontaneous bleeding (gums, nose, urine, vomit, stool) or positive WBCT20
  • Signs of shock (low BP, rapid pulse, confusion)
  • Rapidly spreading swelling crossing major joints
  • Impaired consciousness

Signs and symptoms

  • Local signs: Fang marks, pain, swelling (can be extensive), redness, blistering, local bleeding, skin discoloration/necrosis, lymphadenopathy.
  • Systemic signs (Envenomation):
  • - General: Malaise, nausea, vomiting, abdominal pain, weakness, confusion, loss of consciousness, shock.
  • - Neurotoxic (e.g., Mambas, Cobras): Progressive weakness, paralysis (descending), ptosis (drooping eyelids), difficulty swallowing (dysphagia), difficulty speaking (dysarthria), double vision (diplopia), difficulty breathing (respiratory muscle paralysis), excessive sweating/salivation. Onset often rapid (15-30 mins).
  • - Cytotoxic (e.g., Puff Adder, Gaboon Viper): Extensive local swelling, severe pain, blistering, necrosis. Systemic effects like shock can occur. Onset often 10-30 mins.
  • - Hemotoxic (e.g., Boomslang, Vine Snake): Oozing from bite site/gums/mucosa, excessive bruising, bloody blisters, hematuria, hematemesis, prolonged bleeding from wounds, signs of Disseminated Intravascular Coagulation (DIC), shock. Onset may be delayed.
  • - Combined toxicity possible.

Risk factors

  • Walking barefoot or in sandals in grassy/bushy areas.
  • Handling snakes.
  • Sleeping on the floor in areas where snakes are prevalent.
  • Living in rural agricultural areas.

Diagnosis

Clinical assessment

History of snakebite (description of snake if possible). Examination for fang marks. Assessment of local signs (pain, swelling, necrosis) and systemic signs (neurological, hematological, cardiovascular, respiratory) consistent with envenomation. Monitor progression of signs/symptoms.

Investigations

  • Whole Blood Clotting Test (WBCT20): Bedside test. Place 2-5 ml fresh venous blood in a clean, dry glass tube. Leave undisturbed for 20 minutes. Tilt gently. If blood remains liquid (unclotted), indicates significant coagulopathy (hemotoxic envenomation). Repeat every 4-6 hours initially.
  • Vital Signs Monitoring: SpO2, Pulse Rate, Blood Pressure, Respiratory Rate.
  • Laboratory (Hospital level, if available/indicated): Hemoglobin/PCV, Platelet count, PT/INR, aPTT, D-dimer, Fibrinogen. Serum Creatinine/Urea/Potassium. Urinalysis (proteinuria, hemoglobinuria, myoglobinuria). ECG.
  • Neurological assessment: Check power, reflexes, cranial nerves (esp. ptosis, ophthalmoplegia, bulbar function).

Diagnostic criteria

Diagnosis based on clinical signs of local and/or systemic envenomation following a snakebite. Positive WBCT20 indicates hemotoxicity. Specific syndrome (neurotoxic, cytotoxic, hemotoxic) guides management approach.

Management

Non-pharmacological management

  • First Aid (DOs): Reassure patient, keep calm. Lay patient down, minimize movement. Immobilize the bitten limb with a splint or sling (pressure immobilization bandage NOT generally recommended for African snakes unless known neurotoxic bite and trained personnel). Remove tight items (rings, bracelets). Transport to medical facility IMMEDIATELY.
  • First Aid (DON'Ts): DO NOT panic. DO NOT apply tourniquet. DO NOT incise or cut the wound. DO NOT attempt to suck out venom. DO NOT apply ice or heat. DO NOT give alcohol. DO NOT apply traditional remedies/herbs.
  • Wound Care: Gently clean the wound with soap and water if possible, but avoid vigorous scrubbing. Apply simple dry dressing. DO NOT suture.
  • Venom in Eyes (Spitting Cobra): Irrigate eyes immediately and copiously with clean water or saline for 15-20 minutes. Apply eye pad. Refer for ophthalmologic assessment.
  • Observation: All snakebite victims require observation for signs of envenomation, typically for at least 12-24 hours even if initially asymptomatic ('dry bite' possible but cannot be assumed).
  • Supportive Care: Manage pain (Paracetamol preferred; AVOID NSAIDs due to bleeding risk). Fluid resuscitation for shock/hypotension. Airway management and respiratory support (oxygen, BVM, intubation/ventilation) for respiratory paralysis (neurotoxic) or distress.
  • Management of Local Necrosis: Clean and dress wound daily. Surgical debridement ONLY after lesion stabilizes (minimum 15 days), avoid premature surgery.

Pharmacological treatment

  • Tetanus Prophylaxis: Give TT 0.5 ml IM if not immunized within last 10 years.
  • Analgesia: Paracetamol. Avoid NSAIDs.
  • Antivenom (Polyvalent Antivenom Serum - specific to region, e.g., Africa): Indications (Signs of significant envenomation):
  • - Systemic signs: Spreading paralysis, respiratory difficulty, spontaneous systemic bleeding (positive WBCT20, hematuria, etc.), shock unresponsive to fluids, cardiovascular collapse, impaired consciousness.
  • - Rapidly progressive local signs: Swelling crossing wrist/ankle within 1-2 hours, reaching elbow/knee within 3 hours, involving > half the limb, significant swelling of head/neck.
  • Administration: IV infusion according to manufacturer's instructions (check package insert). Requires careful monitoring for allergic/anaphylactic reactions (pre-treatment often NOT recommended, manage reaction if it occurs). Usually given in hospital setting.
  • Antibiotics: NOT routinely indicated. Give only if clear signs of secondary bacterial wound infection develop (pus, cellulitis, fever).

Monitoring

Frequent monitoring of vital signs (HR, BP, RR, SpO2). Monitor for progression of local swelling. Frequent neurological assessment (ptosis, muscle power, respiratory effort). Monitor for signs of bleeding. Repeat WBCT20 every 4-6 hours initially if coagulopathy suspected/present. Monitor urine output.

Complications

  • Respiratory failure (neurotoxic)
  • Severe bleeding / DIC (hemotoxic)
  • Shock (all types)
  • Acute kidney injury (hemolysis, rhabdomyolysis, direct nephrotoxicity, hypotension)
  • Compartment syndrome (due to massive swelling)
  • Secondary wound infection, abscess, cellulitis
  • Tissue necrosis, gangrene, requiring amputation
  • Anaphylaxis/serum sickness from antivenom
  • Long-term disability from tissue damage or neurological effects

Prevention

  • Wear protective footwear (boots) and clothing in endemic areas.
  • Avoid walking at night without light.
  • Be cautious when reaching into dark places, woodpiles, thick grass.
  • Keep surroundings clear of debris/tall grass where snakes may hide.
  • Sleep on raised beds, not on the floor.
  • Educate community on first aid and avoidance.

Patient education

  • Reassure patient and explain the need for observation.
  • Explain correct first aid measures (immobilization, avoid harmful traditional methods).
  • Educate on signs of worsening to report immediately.
  • Discuss prevention strategies.
  • If antivenom given, explain rationale and potential side effects.

Uganda-specific notes

Common venomous snakes include Puff Adder, Gaboon Viper (cytotoxic/hemotoxic), Mambas, Cobras (neurotoxic), Boomslang (hemotoxic). Antivenom availability is often limited and expensive; use only when clear indications exist. WBCT20 is a crucial bedside test for coagulopathy. Neurotoxic bites require close respiratory monitoring and potentially ventilatory support. Avoid NSAIDs due to bleeding risk.

References

  • Uganda Clinical Guidelines (UCG) 2023

    Chapter 1, Section 1.2.1.1

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