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Envenomations Royal Darwin Hospital RMO education Laura K. reg ED

Northern Territory  Snakes  Spiders  Stingers

SNAKES

Sources  Article Bart Currie  RDH guideline  Pictures from the web and myself  Rural EM skills training syllabus, ACRRM  eTG

Article Bart Currie

Envenoming  All year but highest incidence during March to May  Highest rate among Top End rural Aboriginal adult males (45.2 per )  59% on foot / ankle, less bites on hands in Aboriginals  Continuing snake activity in evenings / nights  Three cases of overambitious feeding attempts  Average 2 deaths/yr in Au, > 70% no first aid or antivenom

4 Highly venomous snakes  Western brown = pseudonaja nuchalis = gwardar  Mulga (black snake) = pseudechis australis = king brown  Death adder = acanthophis praelongus  Taipan = oxyuranus microlepitodus / scutellatus

Symptoms 1

Symptoms 2  Bite swelling, lymphadenitis and non-specific systemic features are most prominent in Mulga snake  Myotoxicity is the major feature of Mulga snake  Early collapse with recovery in > 50% of syst env. from Wester Brown snakes (consumptive coagulopathy)  Neurotoxicity most important feature of Death Adder, this study in < 50% pts  Mulga and Brown snake have neurotoxins, but neurotoxicity uncommon = ‘brown snake paradox’

RDH g u I d.

Treatment bite  Apply or reinforce with pressure bandage Eslet S 3A  Immobilize limb with splint  Fenestrate at bite site, take swab  Have snake identified if possible  Tetanus status check +/- ADT  Continuous cardiac monitoring  Hourly neuro obs  Investigations 

Investigations  UA  VDK urine (hold if asymptomatic and WBCT < 10min)  VDK bite swab (ord.swab soaked in NS), same procedure  Bloods: WBCT, FBC, UEC, CK, LDH, Coags, D-dimer, Fibrinogen, serology tube  VDK high fals pos rate, esp for brown snake, esp on urine WBCT = whole blood clotting time (no additive blue container) VDK = venom detection kit, only on arrival

Bloods  On arrival  Immediately before administration of antivenom if > 30 min later than bloods taken on arrival  30 min after each antivenom infusion  4 hourly until normal results  8 hourly until discharge = 12h after bite when non- envenomed

Symptoms by snake type  Western brown  Transient early hypotension / collapse with procoagulation. Neurotox rare, no myotox  Mulga (King Brown = black snake group)  Early anticoagulant, marked myotox, occasionally neurotox  Taipan  Transient early hypotension / collapse, procoagulation, neurotox +/- myotox  Death adder  Neurotox only

Symptoms minor  N, V. abdo pain, headache  Tender regional lymph nodes +/- enlargement  DO NOT REQUIRE ANTIVENOM

Symptoms major  Coagulopathy 0-4h after bite  Neurotoxicity 1-6h after bite up to 24h in death adder  Myotoxicity 1-2h after bite  Cardiac  Also:  Thrombotic micro-angiopathy in ass with coagulopathy  Resulting in kidney damage  REQUIRE ANTIVENOM

 Coagulopathy 0-4h after bite  WBCT > 10 min  Procoagulant = APPT, PT and D-dimer   Anticoagulant = APPT and PT  D-dimer =  UA pos blood  Bleeding  Neurotoxicity 1-6h after bite up to 24h: ptosis, then ophtalmoplegia, then bulbar palsy,finally resp paralysis  Myotoxicity 1-2h after bite  Dark urine  Pos dipstick for blood can be true hematuria or myoglobinuria or haemoglobinuria (intravsc haemolysis)  Cardiac  Early transient hypotension +/- collapse within 30 min  Rarely arrhytmias 1-12h

Treatment envenomation ACDE approach Continuous cardiac monitoring Neuro obs CT brain in every pt with conc. head strike or headache Contact consultant + Bart Currie / Geoff Isbister Antivenom when major symptoms 

Antivenom 1  All groups of poisonous elapids are possible, except tiger snake. Thus alle snake antivenoms available in RDH:  Polyvalent  Brown  Black  Taipan  Death adder  Sea snake

Antivenom 2  Administer in resus  In stable patients commence specific antivenom (snake identified or pos VDK result, takes min)  In unstable patients give 1 vial polyvalent and change to specific when identified  In clin. significant bleeding from Brown snake give 2 vials  Dilute antivenom 1:10 with NS, infuse over 30 min

Antivenom 3  In anaphylaxis (25%) (5% severe) stop infusion, Tx normally (PM: Adrenaline im safer)  Same amount for children  Remove PBI towards the end of the antivenom infusion  Admit unless snake identified as non-venomous by reptile specialist  D/c pts bitten in Darwin urban area at 12h if asymptomatic and bloods normal, all others 24h (Death adder)

Sea snake  Treat bite as land snake bite  CSL sea snake antivenom, 1 vial

SPIDERS

Sources  tm tm  Common spiders in the Darwin area, Chin, july 2014  Rural EM skills training syllabus, ACRRM

Red back

Mechanism  Venom depletes neurotransmitters at  Neuromuscular junction -> patchy paralysis  Adrenergic nerve ending -> autonomic dysfunction  Can cause serious illness / death.  No fatalities since antivenom 1956, but painful.

Symptoms  Immediate pain and local swelling, sweating  20 min: swelling lymph nodes, abdo pain, tachycardia,  60 min: headache, N and V, fever, insomnia, restlessness  Occasionally: severe hypertension, paralysis, convulsions, skin rashes, tongue swelling, jaw rigidity, migratory arthralgia

Treatment  Monitoring and neuro obs  Do not apply pressure bandage, increases pain  Apply ice  Morphine  Benzodiazepine for muscle spasms or extreme anxiety  Antivenom for syst symptoms or severe pain: 2 vials / 500 IE im (adults and kids) and monitor for 4 h after administration. Can be given days / weeks after bite.  Tetanus status check +/- ADT

Northern mouse No fatalities but painful bite, can cause headache and N, treat with funnel-web antivenom

Huntsman Local symptoms, sometimes inflammation, headache, V and irreg. pulse

Orb Occasional N and dizziness

Wolf Local symptoms, less commonly ulceration, sometimes with N and V

STINGERS

Sources  RDH guideline  Resus.com.au  Pictures from the web  Rural EM skills training syllabus, ACRRM  CARPA standard treatment manual  eTG

Box jellyfish

Box Jellyfish  = Chironex fleckeri  About 40 ED visits RDH every wet season = october- may  Bell 20 cm, up to fifteen tentacles on each corner, up to 3 mtrs long, up to 5000 nematocysts on each tentacle  Venom:  Neurotoxins  Cardiotoxins  Dermatonecrotic toxins

Symptoms  Intense pain and tentacle marks  Irrational behaviour  Arrhythmias  In severe envenomation systemic effects WITH CARDIORESPIRATORY ARREST within minutes  Fatalities rare. Last 11 deaths in children

Appearance

Investigations  ECG – ventricular ectopy or arrhytmias?  Cardiac monitoring  Sticky tape test to send to Bart Currie, identifying species

Tx non-systemic  ABCDE  Vinegar to inactivate undischarged nematocysts  Remove tentacles  Apply ice  Analgesia - Morphine  Antivenom 1 ampule if pain not controlled iv or im  No pressure bandage, increases pain  Treat as burn. Tetanus status check +/- ADT  d/c home with advise, RDH guideline

Tx if systemic  Resuscitation and supportive therapy  Incl 2 iv lines and high flow O2  Antivenom 1 ampule 1: 10 diluted in NS, in 5 min iv, up to 3 ampules  Or 3 ampules im at different sites  Repeat if no response, up to 6 ampules

Tx (imp) cardiac arrest  Resuscitation  6 ampules antivenom  20 mmol = 2 ampules MgSO4 iv  Continue CPR until all 6 ampules given

Irukandji

 = Carukia Barnesi  25 cms across, 1 tentacle from each corner  Usually october to april

Symptoms  Severe lower back, chest and abdo pain  On and off muscle cramps  V, restlessness, anxiety, sweating, piloerection  Tachycardia, hypertension, heart failure, pulmonary edema

Tx R D H

Blue ringed octopus  Can penetrate wetsuit. Enough venom to kill 26 adults  Saliva potent fast acting paralytic neurotoxin  Small painless bite  Perioral paraesthesia, then N/V and rapid onset flaccid paralysis in 5-30 min  In severe cases respiratory and cardiac arrest  Irrigate wound, suction, PBI, supportive care  Tetanus status check +/- ADT

Stonefish  Pain, swelling, weakness limb.  Tx degrees water  Local Lignocaine, opioids, nerve block  Antivenom 1 vial  No pressure bandage  Tetanus status check +/- ADT

Catfish  Same as stonefish  No antivenom  X-ray, piece of barb often breaks off into wound

Stingray  Stingray barb injury:  Pain, bleeding wound, then pale / bluish-white wound  Significant local trauma, damage to underlying structures (heart / lung if chest wall puncture)  Rarely systemic symptoms  Pain relieve same as other fish  Xray. May need surgery to remove pieces

Don’t let it be