Australian Envenomation — Snake, Spider and Marine

The answer first

Australia is home to the most venomous snakes in the world. Of the 140 terrestrial snake species, about 100 are venomous and the top five medically important groups are all elapids — the brown snake, tiger snake, taipan, death adder and black snake. Brown snakes cause the most deaths (approximately two per year nationally) because they are widespread, fast-moving, and their venom produces a coagulopathy that can kill within hours if a head injury accompanies the collapse ^[1].

Three rules govern everything that follows: ^[1]

1. First aid is the pressure immobilisation bandage (PBI). It retards lymphatic spread of venom, which is how elapids cause systemic effects. Applied early and correctly, it buys hours. Sutherland proved this in 1979 and it remains the foundation of Australian snakebite management ^[8][9].

2. VICC is not DIC. The venom-induced consumption coagulopathy looks terrifying on the bloods — an INR above 10 and undetectable fibrinogen — but it is a toxin-driven defibrination, not a disseminated intravascular process. There are no microthrombi, no end-organ damage from thrombosis, and the coagulopathy is self-limiting once the venom is neutralised ^[4][5].

3. Antivenom is monovalent, one vial, guided by the SVDK. The Australian Snakebite Project (ASP-20) showed that the median antivenom dose fell from four vials to one over a decade with no change in outcomes — one vial of the correct monovalent antivenom is the standard ^[1][2].

DCE trap: In every snake bite long case, state the syndrome first — "this is a VICC-dominant envenomation consistent with a brown snake" — because the syndrome drives the antivenom choice, the monitoring plan, and the complications you must watch for. The snake identity matters, but the syndrome matters more. ^[1]

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References13ShowHide

1. [1]Johnston CI, Ryan NM, Page CB, et al. The Australian Snakebite Project, 2005-2015 (ASP-20) Med J Aust, 2017.PMID 28764620
2. [2]Allen GE, Brown SG, Buckley NA, et al. Clinical effects and antivenom dosing in brown snake (Pseudonaja spp.) envenoming--Australian snakebite project (ASP-14) PLoS One, 2012.PMID 23300888
3. [3]Isbister GK, Little M, Cull G, et al. Thrombotic microangiopathy from Australian brown snake (Pseudonaja) envenoming Intern Med J, 2007.PMID 17640187
4. [4]Isbister GK Snakebite doesn't cause disseminated intravascular coagulation: coagulopathy and thrombotic microangiopathy in snake envenoming Semin Thromb Hemost, 2010.PMID 20614396
5. [5]Maduwage K, Isbister GK Current treatment for venom-induced consumption coagulopathy resulting from snakebite PLoS Negl Trop Dis, 2014.PMID 25340841
6. [6]Isbister GK, Duffull SB, Brown SG Failure of antivenom to improve recovery in Australian snakebite coagulopathy QJM, 2009.PMID 19570990
7. [7]Isbister GK, Buckley NA, Page CB, et al. A randomized controlled trial of fresh frozen plasma for treating venom-induced consumption coagulopathy in cases of Australian snakebite (ASP-18) J Thromb Haemost, 2013.PMID 23565941
8. [8]Sutherland SK, Coulter AR, Harris RD Rationalisation of first-aid measures for elapid snakebite Lancet, 1979.PMID 84206
9. [9]Pearn J, Morrison J, Charles N, Muir G First-aid for snake-bite: efficacy of a constrictive bandage with limb immobilization in the management of human envenomation Med J Aust, 1981.PMID 7300763
10. [10]Currie BJ Effectiveness of pressure-immobilization first aid for snakebite requires further study Emerg Med Australas, 2008.PMID 18549384
11. [11]Hartman LJ, Sutherland SK Funnel-web spider (Atrax robustus) antivenom in the treatment of human envenomation Med J Aust, 1984.PMID 6503783
12. [12]Isbister GK, Brown SG, Miller M, et al. A randomised controlled trial of intramuscular vs. intravenous antivenom for latrodectism--the RAVE study QJM, 2008.PMID 18400776
13. [13]Premawardhena AP, de Silva CE, Fonseka MM, et al. Low dose subcutaneous adrenaline to prevent acute adverse reactions to antivenom serum in people bitten by snakes: randomised, placebo controlled trial BMJ, 1999.PMID 10205101