192 Toxinology Emergencies
SNAKE BITES
Australian snakebite management advice is available from the Poisons Informa-
tion Centre (24 h) on 13 11 26. There are no endemic venomous snakes in New
Zealand, although toxinology advice is still available from the National Poisons
Centre on 03 479 7248 (or 0800 764 766 within New Zealand only).
Snake bite is exceedingly rare in the UK, but may present in zookeepers and
herpetologists, or following a mishap with an exotic pet. Advice on management
is always available from the National Poisons Information Service (24 h) on 0844
892 0111 in the UK.
Elapid snake bites
DIAGNOSIS
1 The 10 most venomous snakes in the world are all elapid snakes found in
Australia.
(i) Elapids have permanently erect front fangs and produce venom
containing haemotoxins, neurotoxins and myotoxins
(a) major species include brown snake, black snake, taipan, tiger
snake and death adder
(b) only 5–10% snake bites by a venomous snake lead to severe
envenomation.
2 Some bites such as from the tiger snake and black snake may cause immediate
local pain, bruising or swelling within hours, although local signs following
a snakebite are usually minimal, with fine scratches or small puncture marks
only.
3 Look for the following signs that indicate systemic envenomation, although
these may be subtle or f luctuate:
(i) Non-specific findings such as headache, sweating, nausea,
vomiting, abdominal pain, diarrhoea and transient hypotension.
(ii) Tissue-specific findings indicating severe envenomation (any one
of):
(a) haemotoxic effects including asymptomatic venom-induced
consumptive coagulopathy (VICC) with undetectable
fibrinogen/raised international normalized ratio (INR)
>3.0/raised D-dimer (10 times assay cut-off) on laboratory
testing, or causing bite- or venepuncture-site oozing,
haematemesis, melaena and haematuria
(b) thrombotic microangiopathy with raised creatinine with or
without renal failure, thrombocytopenia and intravascular
haemolysis on blood film
(c) neurotoxic effects including ptosis, diplopia, dysphagia and
respiratory or distal paralysis