India is recognised as having the highest snakebite mortality in the world.
Most of the fatalities are due to the victim not reaching the hospital in time and are preventable.
Research has shown that PHC doctors do not treat snakebite mainly due to lack of confidence.
At the secondary and tertiary care level Emergency departments, multiple protocols are followed mainly from western textbooks which are not appropriate for Indian settings.
Anti snake venom (ASV) are administered when it is not required and/or in doses well in excess of the required amount.
In response, Government of India, Health & Family Welfare Department with WHO, has prepared a National Snakebite Management Protocol to provide doctors and lay people with the best, evidence based approach to dealing with snakebite in India.
The majority of current first aid methods adopted by victims such as tourniquets, cutting and suction and herbal remedies are completely ineffective and dangerous.
It is now recommended to adopt what has been called the ‘Do it R.I.G.H.T.’ approach, stressing the need for Reassurance, Immobilisation as per a fractured limb, Getting to Hospital without delay and Telling the doctor of any symptoms that develop.
20 Minute Whole Blood Clotting Test (20WBCT) in the diagnosis and management of viperine bite- 10ml blood of victim in plain vial is checked for clotting after 20min.
If not clotted- suggest viper.
Pain management – never give NSAIDs- causes more bleeding. Never give morphine- can cause respiratory failure.
ASV Administration Criteria-ASV should be administered if there is significant envenomation i.e. incoagulable blood shown by the 20WBCT or significant limb swelling for viperine bite, neurological signs for cobra & krait bite.
ASV Dosage & Repeat Dosage-The recommended initial dose of ASV is 8-10 vials administered over 1 hour.
Mode of administration of ASV is IV only.
Dose of ASV is same in children, pregnant or elderly, because venom injected is of same amount, so ASV required is of same dose.
Repeat doses for haemotoxic viperine snakes is based on the 6 hour rule.
Repeat doses for neurotoxic snakes is based on the 1-2 hour rule.
The maximum recommended dose for haemotoxic bites in 30 vials of ASV.
The maximum recommended dose for neurotoxic bites is 20 vials of ASV.
ASV Reactions- No ASV Test Doses are to be administered.
At the first sign of an adverse reaction the ASV is halted-0.5mg Adrenaline is given IM- ASV remaining dose should be given- Avil & Effcorlin can be given to prevent ASV anaphylaxis.
Neurotoxic Bite -neostigmine test-Despite the fact that the neostigmine test (Neostigmine 0.5mg IM with atropine 0.6mg IV) was actually an Indian discovery, it is still poorly used in India.
Neostigmine works in cobra bite as cobra venom acts on post-synaptic neurons.
Hemotoxic bites with correct signs of envenomation can be treated with 8-10 vials of ASV, stabilised if any ASV reaction occurs with adrenaline and then transferred to a higher centre with the ability to carry out the required blood tests to identify occult bleeding or renal impairment.
Heparin has no role in curing DIC of snakebite, and can increase bleeding, so contraindicated in viperine bites.
Botrophase should not be used as coagulant in controlling viperine bite bleeding, as it causes consumptive coagulopathy.
Neurotoxic bites with correct signs of envenomation can be treated with 8-10 vials of ASV, stabilised if any ASV reaction occurs with adrenaline and administered the neostigmine test.
If there is no evidence of impending respiratory failure, determined by patient ability to perform a neck lift the patient can be treated locally.
If the patient is unable to perform a neck lift then they will be transferred to a higher centre with mechanical ventilatory capability.
The rational application of ASV and repeat doses has resulted in patients being discharged earlier.