You have received a phone call from a junior colleague at a remote location. A previously well 32-year-old male has presented with nausea and hypotension following a confirmed bite on his leg from a brown snake. A retrieval team will arrive in approximately three hours; until then your colleague is the only medical officer available.
a) Outline the telephone advice you would give them. Include guidance on what complications they might expect to arise and how to manage them. (80% marks)
b) Several days after arrival in your Intensive Care Unit (ICU) the patient develops oliguric renal failure. List the possible causes. (20% marks)
Many candidates ignored the setting of a remote location completely, and gave a management plan that was applicable to a tertiary centre (e.g., TEG and ROTEM; "intubate" without reference to the skill of the junior doctor, etc.).
Some candidates appeared unaware of even the most basic aspects of snake bite management e.g., pressure immobilization, VDK, monovalent versus polyvalent etc.
Many candidates used an ABCDE template which prioritized airway and breathing above the first-aid of snake bite; also, it resulted in not covering the coagulopathy aspects well enough.
The answer for the renal failure again seemed templated (pre-renal, renal, post-renal) and lacked context - there were very few references to the snake bite and antivenom as possible causes of renal failure
The venom itself is a mixture of presynaptic and postsynaptic neurotoxins and procoagulants. There is nothing myotoxic or nephrotoxic in the venom. Acute kidney injury is seen anyway because of thrombotic microangiopathy, which is a side-effect of the procoagulant venom.
Brown snake venom produces the following stereotypical effects:
Specific management steps should include:
Distant back-of-Bourke management should consist of:
ICU-level management should consist of the following supportive steps:
Though the examiners complained bitterly about templated answers being used to mask the candidates' unfamiliarity with snake bites, one cannot help but note that in the absence of specific venom nephrotoxins the patient's renal failure could be due to any of the normal things which cause renal failure. And these things are typically categorised as pre-renal, post-renal and intra-renal. With the exception of VICC-induced microangiopathy, the college list of differentials is certainly no different to a normal list of causes for renal failure in critical illness, featuring such favourites as "sepsis" and "ATN secondary to prolonged hypotension/arrest". In response, here is a classically organised list of plausible-sounding reasons for renal failure in a patient with a brown snake bite:
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