Snake Bites

T63.0 + (X20.99/W59.99)

DESCRIPTION

In the majority of snakebite incidents, the offending snake is not identified. The table below illustrates the three main envenomation syndromes seen in South Africa: cytotoxic, neurotoxic and haemotoxic.

Venom type Cytotoxic Neurotoxic Mixed cytotoxic and neurotoxic Haemotoxic
Snake species Puff adder, Gaboon adder, spitting cobras(Mozambique, black-necked, zebra), stiletto snake, night adders, horned adders Black and green mamba, non-spitting cobras (Cape, forest, snouted) Rinkhals, Berg adder, Peringuey’s adder, desert mountain adder, garter snakes, shield-nose snake, coral snake Boomslang, vine snakes
Clinical features of
envenomation 		Pain, swelling, bruising, blisters, necrosis, regional lymphadenopathy, hypotension, coagulopathy, compartment syndrome Pins and needles, metallic taste, visual disturbances, ptosis, drowsiness, sweating, drooling, dysphagia, progressive weakness, respiratory paralysis Combined cytotoxic and neurotoxic features Spontaneous bleeding (can present late >24 hours after bite), headaches, dizziness, fainting
Antivenom (when indicated) Polyvalent antivenom for Puff adder, Gaboon adder and spitting cobras only Polyvalent antivenom for all species Polyvalent antivenom for rinkhals only Boomslang monovalent antivenom for boomslang bites only

To view pictures for identification of snakes click on following hyperlink: http://www.cmej.org.za/index.php/cmej/article/view/2546/2581

GENERAL MEASURES

Most snake bites will not result in death.

Supportive and symptomatic management with/without antivenom is required.

Mechanical ventilation may be needed in some cases of neurotoxic envenomation.

Cases of haemotoxic envenomation may require fluid resuscitation including blood products.

MEDICINE TREATMENT

Cleanse wound:

  • Chlorhexidine 0.05% in water.

Antibiotics are seldom needed, except for secondary infection:

T79.3+(X20.99/W59.99)

  • Amoxicillin/clavulanic acid, oral, 875/125 mg 12 hourly for 5 days.

LoEIII [1]

Immunisation, primary or booster:

  • Tetanus toxoid vaccine, IM, 0.5 mL immediately.

In unimmunised or partially immunised patients:

  • Tetanus immunoglobulin, human, IM, 250 units immediately.

Analgesia

For mild pain:

  • Paracetamol, oral, 1 g 4–6 hourly when required.
    • Maximum dose: 15 mg/kg/dose.
    • Maximum daily dose: 4 g in 24 hours.

OR

For severe pain:

ADD

  • Morphine, IV, to a total maximum dose of 10 mg (See Appendix II, for individual dosing and monitoring for response and toxicity).
    • Opioids should be used cautiously in neurotoxic snakebite.

LoEIII

Note: The use of NSAID is not recommended due to the antiplatelet effect and the potential danger of renal failure in a hypotensive patient.

LoEIII [2]