Envenomation and marine bites — branching viva

Viva on the pressure-immobilisation first aid and antivenom management of a snake-bitten child, the venom-induced consumption coagulopathy pattern and recovery, the management of an antivenom reaction, and the funnel-web and redback spider distinctions.

branching clinical structured oral4 min readVerification in progress

Prompt

Rural emergency department: a 6-year-old boy arrives thirty minutes after a suspected brown snake bite to the calf, a pressure-immobilisation bandage correctly applied at the scene; he is anxious but alert with a tender regional lymph node, and the first coagulation profile shows an unrecordable INR with a D-dimer greater than twenty and a fibrinogen of zero point six; paediatric retrieval is forty minutes away; a skilled nurse and a junior doctor are present.

Opening (candidate)

This is a brown snake envenomation with venom-induced consumption coagulopathy, and my priorities are to keep the pressure-immobilisation bandage in place, confirm the coagulopathy and its pattern, and give brown snake antivenom intravenously at an initial one-vial dose while arranging paediatric retrieval. The unrecordable INR with a very high D-dimer and a low fibrinogen is a true defibrination from a prothrombin-activating venom. I send the full panel and repeat it, I prepare for an antivenom hypersensitivity reaction, and I explain to the family that the INR will take one to three days to recover because the antivenom stops the cause but the liver must resynthesise the factors. [1] [4]

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You have read the opening of this viva. The complete unit — every section and its primary-source references — is part of the Paediatrics Fellowship fellowship atlas.

References6Show ledger

[1]Johnston CI, Ryan NM, Page CB, et al. The Australian Snakebite Project, 2005-2015 (ASP-20). Med J Aust, 2017.PMID 28764620
[4]Abouyannis M, Marriott AE, et al. Handheld Point-of-Care Devices for Snakebite Coagulopathy: A Scoping Review. Thromb Haemost, 2025.PMID 39214143
[5]Little M. Harm due to the use of pressure bandage immobilisation in patients bitten by snakes in Australia. Clin Toxicol (Phila), 2023.PMID 37668172
[6]Isbister GK, Fan HW. Spider bite. Lancet, 2011.PMID 21762981
[7]Isbister GK, Gray MR, et al. Funnel-web spider bite: a systematic review of recorded clinical cases. Med J Aust, 2005.PMID 15850438
[8]Isbister GK, Page CB, Buckley NA, et al. Randomized controlled trial of intravenous antivenom versus placebo for latrodectism: the second Redback Antivenom Evaluation (RAVE-II) study. Ann Emerg Med, 2014.PMID 24999282