SNAKE BITE

• Snake bites injure, or disable hundreds of thousands of people and kill close to 46000 Indians each year. The three major families of venomous snakes are the Elapidae, the viperidae and the hydrophidae
• The big four highly venomous snakes in India are common or spectacled cobra, Russell’s viper, Saw scaled viper and common krait. Other medically important poisonous snakes are banded krait, hump nosed viper, king cobra and sea snake
• Snake venom is a cock tail of enzymes, polypeptides, glycoproteins and compounds of low molecular weight. More than 90% snake venom is protein. Snake venoms are predominantly neurotoxic ( Cobras and kraits) or haemotoxic (Vipers)

• Person bitten by a snake may not develop any features of envenomation if the bite is a dry bite (when a venomous snake bites a person and the victim does not suffer from any signs or symptoms of envenomation) or bite is by a non venomous snake.
• Features of snake bite envenomation include local and systemic features
• Local envenoming: Local Pain (throbbing, burning, bursting), fang marks (appear as two punctured wounds at the site of bite), swelling that may extend up the limb, enlarged lymph nodes, blistering, necrosis, and local bleeding. Krait bites are typically painless
• Systemic envenoming: Early features include nausea, vomiting , malaise, abdominal pain and weakness - these features occur frequently with krait bite
• Bleeding and clotting disorders are common with viper bite. Features include bleeding from recent wounds, spontaneous systemic bleeding
• Cardiovascular features occur commonly with vipers. These include fainting, dizziness, collapse, shock, hypotension, cardiac arrhythmias and pulmonary oedema
• Sea snake produce rhabdomyolysis producing hyperkalaemia and its associated cardiac complaints
• Neurological features develop with cobra, krait and sometimes with Russell viper bites. Paralysis is usually descending which initially presents as bilateral ptosis, usually within a few hours of the bite. External opthalmoplegia, diplopia and facial muscle weakness follow. The paralysis then descends to the bulbar muscles and neck muscles. Few patients develop respiratory muscle weakness which require mechanical ventilation
• Endocrine features are common with Russell’s viper and include acute pituitary and adrenal insufficiency presenting as shock and hypoglycaemia in acute phase
• Renal involvement occurs with Russell’s viper and hump nosed viper. The patient may develop loin pain, haematuria, haemoglobinuria, myoglobinuria and acute kidney injury

• 20 minute whole blood clotting test (20 minute WBCT)- indicator of viperidae envenomation
• Hb, WBC, platelet count
• Peripheral smear
• Renal function tests
• Coagulation screen (prothrombin time, activated partial thromboplastin time, fibrinogen and fibrin degradation products)
• Urine microscopy – to detect erythrocytes and red cell casts
• Arterial blood gas analysis
• Chest radiography- to detect pulmonary oedema, haemorrhages, pleural effusions
• ECG –to detect arrhythmias, myocardial damage and hyperkalemia
• Echocardiography – to check for myocardial dysfunction

First aid

• Follow RIGHT approach
• Reassure as fear triggers sympathetic activity and boost absorption of venom
• Immobilise the injured limb with a makeshift splint or sling
• Get to the nearest Hospital
• Tell the doctor about symptoms

Medical Management: ABCDE approach

• Airway: If airway is compromised, use head tilt and chin lift or jaw thrust manoeuvre
• Breathing: Measure Spo2. Supplement oxygen if hypoxic
• Circulation : Normal saline is given if there is hypotension, cardiopulmonary resuscitation if the patient develops cardiac arrest
• Disablity of the nervous system (level of consciousness)
• Exposure ( to look for other inuries)

Administer ASV (Anti snake venom ) whenever there are signs of envenomation

• Ventilator support if there is weakness of respiratory muscles
• Haemodialysis or peritoneal dialysis in acute kidney injury

Management of complications :

• Swelling – sigru punarnavdai lepa
• Pain & swelling – Eri taila ext application , Arka patra sweda

Post bite ulcer-

• Njottanjodiyan ksheera kashaya
• Vilwadi gutika
• Visha vilwadi gutika
• Patolakaturohinyadi kashaya
• Nimba nilavakadi kashaya
• Paranthaydi dhara
• Karaskara ksheera dhara
• Guduchi kashaya dhara