🔘 SNAKE BITE

SNAKE BITE:

👉🏻 Introduction:-

- India estimates approx 2,00,000 bites and 35-50,000 snake bite deaths/year

- No reliable National statistics are available

- Males bitten almost twice as often as females.

- Majority of the bites being on the lower extremities.

- 50% of bites by venomous snakes are dry bites, result in negligible envenomation.

👉🏻Snake bite An occupational disease:-

- Farmers

- Snake charmers

- Plantation work

- Hunter

- Workers at site

- Fisherman

👉🏻 Classification of snakes:-

1) Poisonous

2) Non-Poisonous

1. Poisonous:-

a) Elapids:-

- Cobra

- King cobra

- Common krait

- Banded krait

- Coral

b) Vipers:-

- Common green pit

- Russell's viper

- Saw scaled viper

c) Sea snakes:-

- Hydrophiids

- Laticaudids

- Acrochordids

- Homalopsids

- Natricids

2. Non-Poisonous

👉🏻Type of snake:-

- In India, >200 species of snakes, only 52 are Poisonous.

- The bites of saw scaled viper and Russel's viper are of 70-80% Hemotoxic/Vasculotoxin

- Common krait and Indian cobra bites are mostly Neurotoxic(20-30%).

👉🏻 Venomous and Non venomous snakes:-

1) Venomous:-

- Triangle shaped head

- Elliptical pupil

- Pit

- Fangs

2) Venomous:-

- Rounded head

- Round pupil

- No fangs

👉🏻Local Sympotoms and signs in the bitten part:-

- Fang marks

- Local pain

- Local Bleeding

- Brushing

- Lymphangitis

- Lymph node enlargement

- Inflammation (swelling, redness, heat)

- Local infection, abscess formation

- Necrosis

👉🏻Haematological sign:-

- Necrosis of muscle tissue.

- Muscle tissue will begin to die throughout the body, a condition known as rhambdomyolysis.

- Dead muscle cells may even clog the kidney which filters out proteins. This, couoled with hypotension, can lead to acute renal failure, and if left untreated eventually death.

👉🏻Neurotoxic envenoming - Examination:-

- Ask the patient to look up and observe whether the upper lids retract fully.

- Test eye movements for evidence of early external ophthalmoplegia.

- Check the size and reaction of the pupils.

- Krait can cause fixed, dilated non reactive pupils simulating brain stem death - however it can recover Fully.

- The muscles flexing the neck may be paralyzed.

- A common symptom of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs.

👉🏻Do's and Don'ts:-

1) Do's:-

- Immobilize the affected limb.

- Apply basic first aid (wash the wound with soap and water).

2) Don'ts:-

- Take the patient to a tantrik or a snake charmer for treatment

- Suck the wound

- Cut the wound open

👉🏻 Medicolegal:-

- 39 code of Criminal procedure under:- Constitution of India article 21

- MLC to be initiated.

👉🏻Fatal dose and period:-

1) Fatal dose:-

- Dried form:-

Cobra:- 15mg

Krait:- 6mg

Viper:- 20mg

Saw scaled viper:- 8mg

- Quantity injected in one bite:-

Cobra:- 200-350mg

Krait:- 20mg

Viper:- 150-200mg

Saw scaled viper:- 25 mg

2) Fatal period:-

- Cobra:- Few minutes to few hours

- Viper:- Few day

- Sea snake:- Not fatal

👉🏻ASV:-

- ASV is Ig purified from the serum/plasma of a horse/sheep immumised with the venoms of one or more species of snake

- Monovalent/Polyvalent

- The ASV in India is a polyvalent type which is active against the commonly found snakes in India including the four.

- Average dry weight of venom injected:- 63+/-7 mg by Russell's viper or cobra

- Each vial neutrilises the venoms of:-

• 6 mg cobra

• 6 mg Russell's viper

• 4.5 mg of Krait

• 4.5 mg of Saw scaled viper

- Initial dose should be 8-12 vials

- Snake inject same amount of venom into children dose of ASV is same as adults.