snakebite Flashcards
Snakebite epidemiology
-rainy season
-heat, rains, flooding
-mating season
high risk:
-farmers, rural communities, ground sleepers, hunter-gatherers
Patient with “early morning paralysis” ; usually sleeps ont he ground
Bungarus bite-SE Asia
What are the two main families of snakes
Vieridae -vipers, adders, pit-vipers, moccasins, rattlesnakes (short, tick body, short tail, distinctive dorsal pattern, slow moving but strike like lightning)
Elapidae : cobras, kraits, mambas, coral snake, oceanian venmous snakes (they have a long thin body, long tail, uniform color, very fast)
What are the medically important snakes
Atractaspididae: live in burrows, nocturnal, reclusive, emerge after heavy rains, bites sleepers
Colubridae: Non front fanged snakes
What are the 4e main families of snak venoms
Phospholipases A1, Metalloprotesases, serine proteases, three finger toxins (neuro, cytotoxins)
What are local effects of envenoming?
Cytotoxicity: local swelling, bruising, blistering, necrosis
What are systemic effects of envenoming?
Hemotoxicity (bleeding, coagulopathy)
Neurotoxicity (descending paralysis)
Cardiovascular toxicity: myocardial damage
Myotoxicity: Generalized rhabdo, hyperK
Nephrotoxicity AKI
What snakes cause cytotoxicity
cobras, vipers, burrowing asps
What snakes cause hemato toxictiy
vipers, oceanian elapids, colubrids
what snakes cause neurotox
elapids, vipers
what snakes cause hypovolemia/cv shock
vipers
what snakes cause increased capillary permeability
russelsls vipers, rattlesnakes
what snakes cause myocardial toxicity
vipers, burrowing asps
what snakes cause rhabdo
seasnakes, elapids, vipers
what snakes cause nephrotoxicity
russells vipers, elapids, colubrids
pre-hospital tx of snake bites
reassure, immobilize the body-bitten limb, remove tight rins/bracelets, apply pressure pad immobilization, transport rapidly, consider anticholinesterase for neurotoxicity
medical treatment of snakebite patients
admit x 24 hours, resuscitate, Tdap
Check for envenoming (bed side test for coagulopathy-put the blood in a glass jar)
-If you give antivenom, treat with epinephrine first and then obs x 4 hours
Antivenom indications for snake bites
shock, bleeding, incoagulable blood, neurotoxicity, black urine, rapid progressive local swelling
What snake causes descending flaccid paralysis starting with ptosis
elapidae (cobras, kraits, mambas, coral snakes, australian snakes, sea snakes)
What causes severe local swelling, brusing, blistering, necrosis
viperidae (vipers, adders, pit, rattlesnakes, moccasins)
adverse reactions of antivenom
early anaphylaxis or pyrogenic reactions; late serum sickness antivenom reactions
after the initial dose of antivenom, what is the indication for repeat dosage
failure of restoration of blood coagulability after 6 hours
Where are the most deaths from scorpion stings?
Brazil , Mexico, Iran
most common symptom with scorpion sting
immediate agonizing local pain with minimal swelling (exception is the hemiscorpius lepturus-painless)
systemic envenoming effects in scorpions
Na, K, Ca–>release of autonomic storm and then neurotoxic effects “pseudo convulsions” fasiculations, paralysis
How to treat scorpion stings:
Local pain: regional block
Systemic: antivenom via slow infusion
how do you prevent scorpion stings
wear gloves, solid boots, long trousers, shake out clothes, UV light
Neurotoxic spiders
Necrotic spiders
Neurotoxic-black/brown widow, Armed/wandering
Necrotic-Brown rcluse, tarantula, funnel web spider
What does a brown recluse look like? What does it cause
violin
Cutaneous (dermonecrotic) loxoscelism
initially painless, then progressive local discomfort
Has a red/white/blue sign with serous hemorrhage vesicles/blisters
Then systemic symptoms
Wide bite marks, at the site of the bite, piloerection, goosebumps, sweating
Wandering spider-neurotoxic spider
most deadly spider
australian funnel web spiders
Envenoming by new world tarantula spider
physical trauma from fangs, keratitis nodulosa (more local, lesssystemic)
Fatal anaphylaxis from bees
hymenooptera sting fatal anaphylaxis; treat with adrenaline
most dangerous caterpillar in the world
Lonomia -giant silk worm moth-fatal bleeding, kidney failure
fish sting treatmetn
hot water
jelly fish stings
intense pain, wheals, vasospasm
how to treat jelly fish stings
lignocaine HCL spray -DO NOT use acetic acid as it may stimulate the nematocyst discharge
timings of seafood poisoning
scrombroid: 1-120 minutes
Puffer fish 10-180
Shellfish: 30-180
Ciguatera 60 mins-24 hours
60yoF sailor ate some fish in New Zealand, next morning had abd pain and within 3-4 days, had neuro symptoms, les and back pain, unsteady gait
Ciguatera fish poisoning
which fish should you never eat
trigger, parrot, moray eel
diarrhea, abdominal colic, vomiting, causes paradoxical dysaesthesia/cold allodynia, pruritis
ciguatera fish poisoning
perioral tingling after eating dark meat of tuna
immediate peri-oral tingling
what are the toxins in shellfish poisoning?
okadaic acid (acute gastro)
Brevetoxins -red tide (parasthesia)
tetrahydropurine (descending paralysis
domoic acid (amnesia)
Treatment of marine poisoning
Ciguatera: mannitol, fluids
Scrombroid: antihistamines
Paralytics (tetrodotoxin, shellfish): ventilation
how do you tell the death cap mushroom
Gills of death cap are WHITE, and they have a sac at the bottom: Basidiomycota, causes amatoxin mushroom poisoning
amatoxin mushroom treatment
silibinin, N actetyl cysteine, penicillin, hemodialysis, sterodis
red as a beet, dry as a bone, urinary retention-what are you concerned about
atropine poisoning–>after eating night shade
how do you treat night shade poisoning
they present as atropine poisoning ; tret with physostigmine (anticholinesterase)
how to get cyanide poisoning in latin america or east africa
chronic cassava-neuro ataxic neuropathy (can be confused with tropical spastic)
