- ENVENOMATION - Flashcards
Identify common venomous creature found in Australia
- snake
- spider (red back
- jellyfish
- blue ring octopus
- bees, wasps
- sting rays
- toads
- scorpions
- ants
- centipeads
- platypus
etc.
Describe the action of venom in the human body
Not Cool Can Not Move Limbs
Neurotoxins:
- act on neuromuscular junction
- either pre or post-synaptic
e. g. snake neurotoxins cause ptosis
Cardiotoxins:
- exact MOA unclear
- disturbs depolarisation of cardiac muscle cells
Coagulotoxins
- Venom Induced consumption coagulopathy
- prothombin converters in venom result in consumption of fibrinogen
- coagulation cascade activated resulting in either excess clotting or excess bleeding
Nephrotoxins
- effects on kidney due to: hypotension, rhabdomylosis, DIC
- mostly seen in brown snake
Myolysins
- bind to muscles and break them down
- rhabdomyolysis
- hyperkalaemia
Local cytotoxins:
- not really sseen in australian snake bites
- illicit LOCAL cytotoxic reaction
Identify the clinical manifestations of envenomation
.Neurotoxins
- diplopia, opthalmoplaegia, ptosis, dysphasia, dysarthria
Cardiotoxins:
- arrythmias
- arrest
Coagulotoxins:
- bleeding from puncture/ nosocomal sites
- haematuria
Nephrotoxins:
- dysuria
- decreased UO
Myolysis
- muscle tenderness/pain
- pain on movement
- dark or red urine (myoglobinuria)
Local Cytotoxins:
- local inflammation, redness, sweeling, necrosis
Snake envenomation:
MILD (headache, diaphoresis, abdo pain)
MODERATE (nausea, vomiting, hypotension)
SEVERE (neurotix, cardiotoxic, myoglobin, coagulative and nephrotoxic effects)
Outline the assessment of an envenomated patient
Triage:
- Cat 2 usually appropriate on the basis of potential and need to be assessed quickly for early antivenom has better effects.
- Allocated to resus or cardiac monitered cubicle
Hx
- when/where did the bite occur
- one or more bites?
- details of first aid (was the site washed?)
- any symptoms
- relevant PHx (clotting disorder, cardiac Hx)
- medications (e.g. blood thinners)
Primary, Secondary and focused Ax
Outline the management of an envenomated patient
FIRST AID
- PIB (pressure immobilisation bandage) (snake)
- Remover stinger (bee/wasp) (flick off with scalpal etc not tweasers!)
- Neutralise sting (jellyfish)
MONITORING
- mainly supprotive Mx and reactive to toxic effects
INVESTIGATIONS
- Path (FBE,U+E, INR, APTT, PLT, D-dimer, G+H, CK/CKMB
- Urine (VDK, protein, blood, myoglobin)
- VDK being de-emphasised, Tx as per signs and Sx is being encouraged
INTERVENTIONS
- if clinical evidence of snake envenomation, give antivenom (one vial of brown and one tiger) same dose adult and paeds
- admit for observations
- if pt does not sow S+S of envenomation, keep repeating Ax and swab site but dont test at this stage. Remove PIB
- Monitor post antivenom
- ADT
Discuss antivenom administration
- only give when necessary and surely indication
- prepare for anaphylactic reaction
- one vial of each for snake bites(repeat doses not necessary)
- given diluted in saline and infused over time
- if patient is in arrest give neat
- monitor for sins of envenomation and anaphylaxis and serum sickness post antivenom administration
