M Anto ED prov fellow MVH 12 Jan 2017 Snakes M Anto ED prov fellow MVH 12 Jan 2017

Intro 3000 snake bites per yr Large proportion are dry bites or non-venomous 200-500 receive antivenom 1-2 fatal 50% brown snake 50% tiger/taipan/death adder

Hx and exam Bite site Neurological Haematological

Hx and exam Bite site: Usually painless May have fang marks Usually lacs/scratches Bruising bleeding swelling Local tissue destruction uncommon with Aus snakes Assoc lymphadenopathy

Early symptoms (<1hr): Headache Irritability Nausea D+V Confusion Syncope (?2dary to hypotension)

Symptoms (1-3hrs): CN paralysis Abdo pain Haemoglobinuria HT Tachycardia Haemorrhage

Late sx (>3hrs): Limb/resp paralysis Shock Myoglobinuria Death

Toxin syndromes [Syncope] VICC Neurotoxicity Myotoxicity + ARF

Sydney/NSW snakes Brown snake: - Syncope, VICC Red-bellied black snake: - VICC, paralysis, hypotension Eastern tiger snake: - Hypotension, paralysis, VICC, seizures Death adder: - Paralysis

1st aid

1st aid Do not wash site, do not suck out venom Do not cut or incise bite PIB - 15cm, elasticised, <4hrs from bite Splint Immobilise How about head/neck/back?

Management Critically ill patients Other patients IV access Bloods (?POC test) Urine ?Other tests

Antivenom What to give? How to give How much to give Once AV given, what do we do with our PIB? What are potential complications?

AV indications Absolute: Abnormal INR History of sudden collapse, seizure or cardiac arrest Any evidence of paralysis (ptosis +/- ophthalmoplegia earliest signs) Relative: Systemic symptoms (vomiting, headache, abdominal pain) Abnormal aPTT Leukocytosis CK > 1000U/L

Further management Disposition? Further tests? Discharge advice?

Summary 1st aid AV if symptomatic, no pre-med (caution with adren) VDK does not tell you if the patient is envenomated Look for subtle CN/eye signs Check ADT status Bloods/examination up to 12hrs Serum sickness

References/resources Snakebite and Spiderbite Clinical Management Guidelines (3rd ed, 2014) http://www.anaesthesia.med.usyd.edu.au/resources/venom/snakebite.html Wikipedia: List of fatal snake bites in Australia