First Aid in the field

The principles of first aid in the field are to minimise the spread of venom into the blood stream while awaiting transfer to expert medical care. In addition to General First Aid principles, any suspected victims of snake envenomation should receive pressure immobilisation of the affected limb.

No attempt should be made to capture or kill the offending snake. The presence of the snake rarely assists the medical team treating an envenomation as identification requires expert skill. Additionally, the usual outcome of inexperienced hands trying to capture a venomous snake is ……….. a snake bite!

Antivenom

CSL Snake Monovalent Antivenom is available for Tiger snake, Brown Snake, Black Snake, Death Adder and Taipan. Polyvalent antivenom neutralises the venom from all of the dangerous Australian snakes but a greater volume is required which increases the risk of adverse reactions. The antivenom is produced from horse serum.

The antivenom should only be administered if there is clear evidence of symptoms of envenomation. It may be administered in the field but must be administered by experienced medical personnel and all victims of envenomation require transport to hospital. The risk of anaphylaxis to the antivenom is moderately high and although pretreatment with adrenaline and antihistamines is not indicated, capacity to manage anaphylaxis must be available.

The antivenom is administered as an intravenous infusion over 15-30minutes. The initial dose of monovalent antivenom is two ampoules if moderate clotting derangement and four ampoules if severe envenomation. The dose should be repeated as required according to response to treatment.

Following antivenom

The tetanus immunisation status of the victim should be checked and updated if necessary.

The victim should be observed for a minimum of 12 hours following full resolution of symptoms of envenomation.

The victim should receive advice on the potential to develop serum sickness.