Venomous Snakes

Small rear fangs indicate what

MINIMALLY venomous snake

No fangs indicate what

NON venomous snake

Long foldable fangs with sheath

VIPER

Short, permanent erect

Elapid

Rear fangs

Colubrid

What are in snake venoms

Digestive enzymes (SVMP), Phospholipase A2, Procoag enz, Polypeptide postsynaptic (a) neuron, presynaptic (b) neurotoxin

SVMP function

Damage basement membrane → EC damage and systemic bleeding

Phospholipase A2 function

Damage MT, blood cells and affects almost every organ

Procoagulant enzyme function

Cause DIC, coagulopathy

Polypeptide postsynaptic (a) neurotoxin function

Bind to AChR at motor endplate

Postsynaptic (b) neurotoxin funtion

Phospholipase that PERMANENTLY damage nerve endings

What are Elapidae

NEUROTOXIC snakes; include cobras, kraits and sea snakes

Banded krait (งูส้ามเหี่ลยม)

Flat tail

Sea snake (งูทะเล)

Malayan krait (งูทับสมิงคลา)

Viperidae

HEMATOTOXIC snakes; can be split into regular vipers and pit vipers

What are crotalidae (pit vipers)

Vipers with pit between the eye and nostril to sense infrared light

Russell’s viper (งูแมวเซา)

Malayan pit viper (งูกะปะ)

Green pit viper (งูเขียวหางไหม้)

Snakes found in urban areas

Green pit, malayan krait

Snakes found in rice field

Cobra, Russell’s viper

Snakes found in the garden

Malayan pit, GPV, Cobra, krait

Snakes found in the sea or mangrove

MPV, sea snake

Teeth marks; snake was NOT venomous

Fang marks; snake IS venomous

Syndrome 1 = Local swelling with bleeding/clotting disturbance

All species of Viperidae

Syndrome 2 = Local swelling + bleeding/clotting problem + shock/acute kidney injury

Russell’s viper

Syndrome 3 = local swelling + paralysis

Cobra or King Cobra

Syndrome 4 = Paralysis with minimal swelling with or without abdominal pain

Krait

Syndrome 5 = Paralysis + dark brown urine + acute kidney injury

SEA = krait or sea snake; India and Sri lanka = Russell’s viper

Neurological symptoms of snake bites

Bilateral ptosis and ophthalmoplegia

Bilateral ptosis

Ophthalmoplegia

First aid for snake bite

Immobilize limb, wrap wound loosely, DO NOT USE TOURNIQUET AND DO NOT SUCK OUT THE POISON