Snakebite Envenoming Challenge

aka Toxicology Conundrum 026

So you sailed through the toxidrome challenge did you? How are you with elapids? Let’s see how you fare on the ‘Australian Snakebite Envenoming Challenge’…

How this works

For each of the six types of venomous Australian snake see if you can describe the classic findings for each of the clinical questions listed below – click on the link to show/hide the answer. And if you’re ready to manage a snakebite victim, try Toxicology Conundrum 005.

Q1. What is the genus for each type of snake?

  • Pseudonaja
  • Notechis
  • Acanthophis
  • —  Pseudochis
  • Oxyuranus
  • —  Hydrophilidae

Q2. What is the geographic distribution for each type of snake?

  • — Throughout Australia except Tasmania 
  • —  Southern Australia (Tasmania, south of the Moore River and Point Malcolm in WA, the Eyre Peninsula and Kangaroo Island in SA, Victoria) and up the East Coast (as far as Cooktown in North Queensland).
  • — Throughout Australia except the far south: Tasmania, Victoria and  southern WA (south of Mundaring and Esperance)
  • — Most of Australia except the far south (Tasmania and the southern coast from south of the Perth Hills and Kalgoorlie in WA,  across to the Eyre Peninsula in SA) 
  • —  Northern Australia (the Top End of the NT, north of Koolan Island in WA, and within a few hundred kilometers of the coast in Queensland) and Central Australia
  • — Throughout coastal  Australia except the west coast of Tasmania and the southern coast from Sydney to Esperance

Q4. Is coagulopathy a feature? What type?

  • —  Venom-induced consumptive coagulopathy (VICC) is always present with significant envenoming
  • — Venom-induced consumptive coagulopathy (VICC) is always present with significant envenoming, may resolve spontaneously in 12-24h
  • — coagulaopathy does not occur
  • —  a mild anticoagulant effect may be present (raised INR and APTT, with normal fibrinogen) 
  • — Venom-induced consumptive coagulopathy (VICC) is always present with significant envenoming
  • — coagulaopathy does not occur 

Q5. Is (irreversible) presynaptic neurotoxicity a feature of envenoming?

  • — rare (unless you’re a dog or cat!) 
  • — slow onset over hours (up to 12-24h)
  • — absent
  • — absent
  • — may be rapid in onset
  • —  may be rapid in onset

Q6. Is (reversible) postsynaptic neurotoxicity a feature of envenoming?

  • — absent
  • — absent
  • — slow onset over hours (up to 12-24h)
  • —  absent
  • — absent
  • — absent 

Q7. Is rhabdomyolysis a feature of envenoming?

  • — absent
  • — slow onset over hours, may be severe causing renal failure
  • — absent
  • — slow onset over hours, may be severe causing renal failure 
  • — may develop over minutes to hours
  • —  may develop over minutes to hours

Q8. Is renal failure a feature of envenoming?

  • — uncommon: possible direct nephrotoxicity or MAHA
  • — uncommon: possible direct nephrotoxicity or MAHA, also secondary to rhabdomyolysis
  • — absent
  • — secondary to rhabdomyolysis 
  • — uncommon: possible direct nephrotoxicity or MAHA, also secondary to rhabdomyolysis
  • — secondary to rhabdomyolysis

Q9. What other features of envenoming may be present?

  • — microangiopathic hemolytic anemia (MAHA) and thrombocytopenia
  • —  microangiopathic hemolytic anemia (MAHA) and thrombocytopenia
  • — local bite site pain often present 
  • — bite site pain may be significant; envenoming often associated with nausea, vomitng, abdominal pain and headache 
  • — microangiopathic hemolytic anemia (MAHA) and thrombocytopenia
  • — nil

Reference

  • Murray L, Daly FFS, Little M, and Cadogan M. Chapter 2.13 Approach to Snakebite; in Toxicology Handbook, Elsevier Australia, 2007. [Google Books Preview]
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Comments

  1. says

    Great challenge! I will quote, as I am wont to do, from Bill Bryson’s book about Australia ‘In a Sunburned Country’: ” . . . my guidebook blandly observed that ‘only’ fourteen species of Australian snakes are seriously lethal, among them the western brown, desert death adder, tiger snake, taipan, and yellow-bellied sea snake. The taipan is the one to watch out for. It is the most poisonous snake on earth, with a lunge so swift and a venom so potent that your last mortal utterance is likely to be: “I say, is that a sn—-.”

  2. says

    Holy-schmoly. That Taipan looks nasty.

    I once disturbed a cobra nest in an old termite mound. That was an ‘interesting’ couple of minutes.

    Brown snake? Brown trousers more like.

  3. Rahul says

    Unable to workout if i am wrong or the tox book is confusing.
    Re Tiger snake, on table in page 37 it says no post synaptic neurotoxin present and later on page 439 in the toxin section it states that venom contains both pre and post synaptic toxin.
    Please help- give me the correct answer as this may decide if i pass or fail….

    Thats not all——

    Whilst going through the MCQ’s came across a question that the possible answers suggest was about SCIOWRA but question was about……
    Small peri-areolar abscess can be incised under LA?
    a- if recovery of neuro defecit has occured prior to arrival than no futher spinal precautions are needed.
    b- can only be diagnosed if neuro defecits persist without change.
    c- occurs in kids with incompletely calcified vetebral columns.
    d- has good prognosis regardless of level of injury.
    e- can be detected with CT scan of vetebral column.

    Cheers it is a great site and very helpful with exam prepration.

    • says

      Tiger snake venom actually contains multiple neurotoxins -- some such as notexin (the main one) are presynaptic, others like ‘Toxins 1 and 2′ are postsynaptic. In humans, in clinical practice, non-reversible presynaptic toxicity is seen. It’s all very murky when you look into the detail. Similarly there is the brown snake paradox -- brown snake venom contains textilotoxin, which is one of the most potent neurotxins known to man. However, neurotoxicity is rarely seen in human envenomations, whereas vets have told me that paralysis from brown snake envenoming is common in dogs. There is a difference between the toxins present and the toxicity seen (in different species for example). Hope that helps!

      As for the MCQ -- sounds like a balls up…

      C

      • Rahul says

        Thanks Chris,
        i think i will just make things easy for myself and know the table which relates to what is commonly sen clinically.
        Cheer’s.
        Rahul.

  4. Rahul says

    Aust prescriber 10/2012 states that only 1 amp of antivenom is required for envenomation by all 5 groups of Australian snakes -- is this correct answer for exam purposes.

Comments