ENVIRONMENTAL
SNAKE BITE
PromptExamination/clinical features that suggest envenomation from snakebite
ResponseEarly collapse/cardiac arrest/seizure = envenomated
Neurotoxicity: Progressive, descending paralysis, Ptosis, extraocular muscle, facial and bulbar involvement, paralysis, resp muscles, peripheral weakness.
Myotoxicity: Muscle pain, tenderness, weakness. Rhabdo, Increased CK/myoglobinuria
Coagulopathy: site bruising, bleeding gums/IVC/epistaxis, Intracranial, GI, genitourinary bleeding
Systemic: N/V/D, headache, abdo pain, diaphoresis, apnoea
CVS: collapse, arrest, hypotension
Neurotoxicity: Progressive, descending paralysis, Ptosis, extraocular muscle, facial and bulbar involvement, paralysis, resp muscles, peripheral weakness.
Myotoxicity: Muscle pain, tenderness, weakness. Rhabdo, Increased CK/myoglobinuria
Coagulopathy: site bruising, bleeding gums/IVC/epistaxis, Intracranial, GI, genitourinary bleeding
Systemic: N/V/D, headache, abdo pain, diaphoresis, apnoea
CVS: collapse, arrest, hypotension
PromptImmediate management for snakebite
ResponseResus bed
Pressure immobilisation bandage
IV access
Send snakebite bloods
Pressure immobilisation bandage
IV access
Send snakebite bloods
PromptInvestigations for snakebite
(answer modified to ETG 5/’24)
(answer modified to ETG 5/’24)
ResponseCoags + fibrinogen + D Dimer
FBC + film - red cell framentation/spherocytes in thrombotic microangiopathy
EUC’s
LDH
CK
Urinalysis ? myoglobinuria
Antivenom given: repeat all bloods at 6 and 12h, then Q24h until normal
No antivenom given: repeat (coags + CK only) 1hr after removal of PIB, then 6 +12 hours after time of bite. Normal = cleared.
FBC + film - red cell framentation/spherocytes in thrombotic microangiopathy
EUC’s
LDH
CK
Urinalysis ? myoglobinuria
Antivenom given: repeat all bloods at 6 and 12h, then Q24h until normal
No antivenom given: repeat (coags + CK only) 1hr after removal of PIB, then 6 +12 hours after time of bite. Normal = cleared.
PromptMost important investigations for snakebite
ResponseCK and Coags
PromptVDK - Venom Detection Kit
ResponseNo longer recommended for the treatment of snake bite in Australia (as per eTG)
However, was a Q in 2019 trial
Options for VDK sample:
Swab (Best option), urine (next best), blood (poor)
Only use if snake cannot be identified another way.
However, was a Q in 2019 trial
Options for VDK sample:
Swab (Best option), urine (next best), blood (poor)
Only use if snake cannot be identified another way.
PromptCoagulopathy Snakes - list
ResponseVICC - Brown, tiger, taipan, rough scale
Anticoagulant coagulopathy - Black, Mulga
Anticoagulant coagulopathy - Black, Mulga
PromptNeurotoxic snakes - list
ResponseDeath adder, taipan, tiger, Sea Snake
PromptMyotoxic snakes - list
ResponseMulga, tiger, black
PromptSnakes causing CVS collapse
ResponseBrown ~⅓ of bites, 5% of brown snake bites arrest!
PromptVenom induced consumptive coagulopathy (VICC) bloods
ResponseINR - high
Fibrinogen - low
D dimer - high
Fibrinogen - low
D dimer - high
PromptWhy is the Taipan and Tiger a good answer?
Responsethe taipan seems to do it all (VICC, Neurotoxic, myotoxic, thrombotic microangiopathy)… if in doubt throw in a Taipan!
Tiger lots of crossover too
Tiger lots of crossover too
PromptAntivenom indications
ResponseAbsolute:
Arrest/Seizure/Collapse
Abnormal INR
Paralaysis (ptosis/opthalmolplegia)
Relative
Systemic symptoms (N/V, headache, abdo pain)
Abnormal APTT
CK >1,000
Leukocytosis/lymphopaenia
Arrest/Seizure/Collapse
Abnormal INR
Paralaysis (ptosis/opthalmolplegia)
Relative
Systemic symptoms (N/V, headache, abdo pain)
Abnormal APTT
CK >1,000
Leukocytosis/lymphopaenia
PromptAntivenom administration
ResponseCritical care area (Resus)
IV only (Not IM)
Arrest - 1 amp slow IV push, otherwise
1 amp in 100-500 mL N/S over 15-30 mins
Prepare for hypotension, anaphylaxis in <5% (but still common)
IV only (Not IM)
Arrest - 1 amp slow IV push, otherwise
1 amp in 100-500 mL N/S over 15-30 mins
Prepare for hypotension, anaphylaxis in <5% (but still common)
PromptAntivenom in Paeds and Pregnancy
ResponsePaediatrics: 1 vial but mix in smaller dose of saline (~10 mL/kg or in 100 mL)
Pregnancy: as per adult - look after mother = look after child
Pregnancy: as per adult - look after mother = look after child
PromptAntivenom allergy/anaphylaxis management
Responsecease/suspend antivenom infusion.
Oxygen, fluid bolus, IM adrenaline 300-500 mics lateral thigh
Cautious recommencement of antivenom when under control
May need to titrate adrenaline infusion whilst running antivenom
Seek expert advice (poisons)
Serum sickness (if occurs, delayed presentation) - Pred 50 mg daily for 5 days
Oxygen, fluid bolus, IM adrenaline 300-500 mics lateral thigh
Cautious recommencement of antivenom when under control
May need to titrate adrenaline infusion whilst running antivenom
Seek expert advice (poisons)
Serum sickness (if occurs, delayed presentation) - Pred 50 mg daily for 5 days
PromptAntivenom effects
ResponseVICC - stops progression
Anticoagulant coagulopathy - Rapidly reverses
Neurotoxicity:
Anticoagulant coagulopathy - Rapidly reverses
Neurotoxicity:
- Reverses post synaptic (Death adder)
- Halts progression presynaptic (brown, tiger)
PromptSnake bite - hospital requirements/indications for transfer
ResponseLabs 24/7
Antivenom in adequate stock/quantities
Hospital capacity to treat severe envenomnation + complications (I read that as critical care/ICU available)
Antivenom in adequate stock/quantities
Hospital capacity to treat severe envenomnation + complications (I read that as critical care/ICU available)
PromptDischarge criteria for snakebite
ResponseNormal examination for neurotoxicity
Normal 12h Coags
Normal 12h CK
(Paeds: Daylight hours, Parents educated, safe discharge plan, red flags etc)
Normal 12h Coags
Normal 12h CK
(Paeds: Daylight hours, Parents educated, safe discharge plan, red flags etc)