SNAKE BITES

VINAY VERMA GROUP#612

INTRODUCTIONSnake bite is one of the major public health problems in the tropics. Occupational disease of agricultural workers In rural areas of tropical and subtropical countries situated in Africa, Asia, and Latin America.

Cold Blooded:No efficient thermoregulatory mechanism.(no sweat glands)

- Venom has digestive enzymes which starts working even before the prey is swallowed.

THE VENOM APPARATUS

SNAKE BITE INCIDENCE

SNAKE BITE DEATHS WORLDWIDE

EPIDEMOLOGYWorldwide is about 5 million deaths400000 snakebite-related amputations each year Children have both higher incidence rates

CLASSIFICATION• The family Viperidae.

• The family Elapidae.

Viperidae Russell’s Vipers.,Saw scaled Vipers.,Pit Vipers.

Hemotoxic

Elapidae Cobra, Kraits Neurotoxic

Krait

Pit Viper

Cobra

SNAKE VENOMCombination of

Enzymes & Non-Enzymatic polypeptides.

-Acidic-Sp Gravity: 1.030-1.070-On drying Fine needle like crystals. -Water Soluble.-Lethal Dose:

Cobra-0.12gm, Krait0.06gm- Russell’s V-0.15gm

IDENTIFICATION FEATURES

PATHOGENESIS Snake bite-venom injected

enters surrounding tissue direct venom action

blood vessels lymphatics

Target organs-systemic effect

PRIMARILY NEUROTOXIC

Death results from respiratory depression.

PRIMARILY HEMOTOXIC& CYTOTOXIC

Viperidae – vipers Death from pit viper bites results from hemorrhagic shock, adult respiratory distress syndrome, and renal failure.

CLINICAL FEATURES.

WOUND SITE

Fang marks

Persistent bleeding from fang marks 40min after bite of pit viper

Blistering at site of bite

SPECIES: SIGNS AND SYMPTOMS Signs/Symptoms and Potential Treatments

Cobra Krait Russell’s Viper Saw Scaled

Viper Other Vipers

Local pain/ Tissue Damage Yes No Yes Yes Yes

Ptosis/Neurotoxicity Yes Yes Yes! NO No

Coagulation No No Yes Yes Yes

Renal Problems No No Yes NO Yes

Neostigmine & Atropine Yes No? No? NO No

INVESTIGATIONS

Twenty-minute whole blood clotting test (20WBCT) Hb/platelet count/peripheral smear prothrombin timeUrine examination Biochemistry for serum creatinine/Urea/PotassiumImaging (ABG)(ELISA) to confirm snakespecies.

SEVERITY OF ENVENOMATION.

MANAGEMENT

•Local•Specific•Supportive

• Tourniquet: • Immobilize affected limb. • Clean with Normal Saline. if bite <1hr old: Short skin incision and

suction

SPECIFIC MANAGEMENT

• Anti Snake Venom (ASV)• Mechanical ventilation

WHAT IS ASV?

• Antivenom is immunoglobulin purified from the serum or plasma of a horse or sheep that has been immunised with the venoms of one or more species of snake. • Potency; 1 ml ASV neutralizes:

0.6mg Cobra, 0.45mg Krait, 0.6mg Rusell’s V, 0.45mg Saw scaled Viper.-Lethal Dose: Cobra-0.12gm, Krait0.06gm- Russell’s V-0.15gm

ANTI-SNAKE VENOM ADMINISTRATION

INDICATIONSEvidence of systemic toxicity.Hemodynamic or respiratory instabilityHemotoxicityNeurotoxicityEvidence of local toxicity

FOLLOW-UP• After discharge from hospital, victim should be followed.

• If discharged within 24 hours, patient should be advised to return if there is any worsening of symptoms such as bleeding, pain or swelling at the site of bite, difficulty in breathing, altered sensorium, etc.

• The patients should also be explained about serum sickness which may manifest after 5–10 days

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