Snakes and Venomous Creatures Flashcards
Case fatality from snake bites
25%
Issues with antivenom
very expensive
difficult to make
specific to each type of snake
there is imitation anti-venom being sold illegally given high price.
Limited number of producers in limited countries
snake venoms are complex - 20-30 enzymes
Receptors affected by venom toxins
Sodium channels
Calcium channel blockers
Anticholinesterases
muscarinic antagonists
alpha neurotoxins
Venom toxin effects (generalised)
consumptive coagulopathy
myocardial damage
arrhythmias
AKI
local tissue swelling and necrosis
systemic haemorrhage
neuromuscular paralysis
myotoxicity and rhabdomyolysis
cardiovascular effects
types of snakes and their effects
Vipers (puff adder) - swelling, necrosis, coagulation
Elapids (cobra/mombas) - neurotoxicity
Sea snakes - myotoxicity
Puff daddy is a VIP, puff = swelling
cobra/momba - give lap dance
sea snakes - myotoxins so you cant swim away
Effect of anti-toxin on different venom types
Post-synaptic - is competitive inhibition therefore anti-venom can reverse the effects and has a better outcome
Pre-synaptic - permanently binds and cannot be reversed by antivenom - antivenom prevents it from worsening.
Envenomation management and side effects of treatment
Management:
First aid
Immobilisation and compression
Do not use tourniquets
Antivenom
Anticholinesterases - eg neostigmine, pyridostigmine. (for neurotox)
Routine antibiotic prophylaxis
tetanus injection
Do not surgically debride. Compartment syndrome very rare.
Can reduce reactions by giving pre-medications - adrenaline/hydrocort
Side effects:
Acute anaphylactic reasons
Delayed serum sickness reactions
Snake bite control measures
Cut grass
wear boots
torchs
no rats
bed nets
do not sleep on floor
LMIC test for clotting species (Vipers)
20min whole blood clotting test
Non-snake venemous creatures and locations
Widow spider (Lactodectus) - worldwide
Recluse spides (Laxoceles) - Americas
Funnel web - East australia
Banana spider - Brazil
Scorpions - Americas, North Africa and middle east, South asia.
Jellyfish
Stonefish
Stingrays
Treatment for non-snake envenomation by species
Widow spider (Lactodectus) - Antivenom
Recluse spides (Laxoceles) - Surgery
Funnel web - Compression and antivenom
Banana spider -
Scorpions - Antivenom, atropine, prazocin
Jellyfish - Ice, vinegar, hot water, opiates
Stonefish - hot water, remove spike
Stingrays - hot water, remove spike
General bite/sting avoidance strategies
listen to local knowledge
check shoes
use torch
good waste disposal
