1. Diploma in software based statistics.
Snake bite
Dr S.Parthasarathy
MD., DA., DNB. PhD., FICA., IDRA.
Diploma in software based statistics.
Associate editor – IJA

2. Number of deaths
India has the highest number of deaths due to snake bites in the world with 35,000–50,000 people dying per year—statistics !! ??
Pakistan – 8200 deaths
Nepal – 1000
Sri Lanka - ?? 15000
10 – 20 % case fatality

3. Critical points Mean age – 30 years Male : female 2:1
Farmers – most affected
Rains and floods – more
Bites – nocturnal – krait , diurnal – cobras
bite-to-treatment delay varies greatly, ranging from 30 minutes to 15 days.- six hours is common..
50 % used harmful first aid measures
Lower limbs in day bites – face in night bites

4. Innumerable types Elapidae ----- rat snakes look like but not venomous
Viperidae
-- wolf snakes look like – not venomous
Can you make ASV ??

5. Cobras
Krait
Viper

6. Belief – 100 % venomous
Not so – non venomous and dry bites by venomous snakes more common
60 % in India

7. Viperidae ( viriyan)
Local pain and tissue damage, characterised by swelling, blistering, bleeding, and necrosis at the bite site, sometimes extending to the whole limb…
Coagulopathy and platelet dysfunction
Haemorrhages including ICH
persistent bleeding from fang marks, wounds, or gums
Procoagulases
Metallo proteinases

8. Viper bites

9. Viper bites

10. Can also cause !!
In addition, Russell’s viper can cause acute renal failure and neurotoxicity, as has been shown in several studies conducted in south India and Sri Lanka---
bites by kraits or sea snakes do not usually cause signs of local envenoming and can be virtually painless

11. Cobra and nerves
Cobra venom contains mainly postsynaptic neurotoxins, which bind and block acetylcholine receptors of the neuromuscular junction, while krait venom in addition contains presynaptic toxins---
Ptosis and the sleeping story of villagers

12. Neurotoxins Sweating and salivation increase Difficult swallowing
Speech difficulty
Weakness of knees
Slow progressive diaphragm failure and death
May take 30 minutes for diaphragm to paralyse
Krait bites – slow paralyses

13. Some bites may confuse
Myotoxic
Rhabdomyolysis and renal failure
Snakes do not exhaust their store of venom, even after several strikes, and they are no less venomous after eating their prey.

14. What is the common early symptom of systemic envenoming??
vomiting
Manson Bahr tropical disease !!

15. First AID !!
The bite victim should be reassured, the bitten limb immobilized with a makeshift splint or sling, and the patient transported.
Walking is contraindicated, because muscular contractions promote venom absorption
Danger ?? Incisions big and tight tourniquet are followed !!

16. “Do it R.I.G.H.T.” R = Reassure I = Immobilise GH = Go to Hospital
T = Tell the doctor about history

17. Now what is wrong Sucking Shock Extreme cold Herbs
Water wash with soap – detergent vasdilates
Catch the snake
Incisions

18. What does traditional treatment say ??
Constricting bands or tourniquets may cause pain, swelling and congestion that suggest local envenoming.
Ingested herbal remedies may cause vomiting.
Instillation of irritant plant juices into the eyes may cause conjunctivitis.
Forcible insufflation of oils into the respiratory tract may lead to aspiration pneumonia, bronchospasm, ruptured ear drums and pneumothorax.
Incisions, cauterization, immersion in scalding liquid and heating over a fire can result in devastating injuries.

19. Clinical diagnosis Fang marks – identification ?
Snake dead are brought – misidentification – problem
Tourniquet or venom – which has caused necrosis ??
Non venomous snakes can also cause cellulitis

20. Syndromes
Local envenoming (swelling etc.) with bleeding/clotting disturbances = Viperidae
Local envenoming (swelling etc.) with bleeding/clotting disturbances, shock or acute kidney injury = Russell’s viper
Local envenoming (swelling etc.) with paralysis = cobra or king cobra
Paralysis with dark brown urine and acute kidney injury:
Krait or sea snakes or viper

21. Tricky sometimes !!
Loin (low back) pain and tenderness in a case of snake bite signifies ??
Renal ischemia

22. 20-minute whole blood clotting test (20WBCT)
Place 2 ml of freshly sampled venous blood in a small, new or heat cleaned, dry, glass vessel.
Leave undisturbed for 20 minutes at ambient temperature.
Tip the vessel once.
If the blood is still liquid (unclotted) and runs out, - yes envenomation – go ahead with ASV – safety 10 minutes extra

23. Tip it !!
Don’t shake !!

24. Danger of twenty minutes test
If the vessel used for the test is not made of ordinary glass, or if it has been cleaned with detergent, its wall may not stimulate clotting of the blood sample (surface activation of factor XI – Hageman factor) and test will be invalid

25. Toxins affect at ? Multiple levels of coagulation pathway
Hence
prothrombin time ,apTT cannot be standardized
Can be prolonged-- but can we form guidelines ??
Some studies titrate ASV with TEG

26. Broken neck sign Looking for the broken neck sign, which is caused
by paralysis of the neck flexor muscles
thrombocytopenia,
Venom injected to the vessel – platelet may be less than – early
Haemoglobin abnormalities,
PCV,
Peripheral smear

27. Latest !!
PCR amplification and sequencing of snake DNA obtained from bite-site swabs has recently been used to identify biting snakes in an animal model and in clinical cases from Bangladesh and Nepal
Late envenomation – can come after 6 hours

28. Management
Inj. TT
Antivenom !!
Antibiotics ?

29. Common antivenom preparation
Antivenoms are produced by fractionation of plasma obtained from immunized animals, usually horses
N. naja, B. caeruleus, D. russelii, and E. carinatus.
For others ??
Manufacture - State of Tamilnadu
Can it be useful in srilanka ??

30. How to administer ASV and how often ?
The recommended initial dose of ASV is 8-10 vials administered over 1 hour.
Liquid or Lyophilised ASV are equally effective and the choice should be determined by the robustness of the cold chain. -- Mode of administration is IV only
Repeat doses for haemotoxic - based on 6 hour rule
Repeat doses for neurotoxic is based on the 1-2 hour rule.
The maximum recommended dose for haemotoxic bites in 20 vials of ASV
The maximum recommended dose for neurotoxic bites is 30 vials of ASV

31. Manufactured today – may be 100% same with manufactured tomorrow ??
As such – these guidelines exactly true and practicable in a scenario of innumerable species ???
Same ASV – vial
Manufactured today – may be 100% same with manufactured tomorrow ??
One vial of antivenom of Indian production costs around
US$8–10, which is equivalent to several days of salary for poor farmers.
Thus, many cannot afford to purchase the average 10–15
vials needed to reverse envenoming

32. ASV vials usage ?? Children need the same ASV dose
Snakes inject the same venom
Some use inj, avil and hydrocortsione
Do we need test doses ?
Intra cranial bleeds and going for evacuation – go ahead with initial 25 vials
Over a period of one hour

33. Dangers of ASV
Itching, fever, shaking chills, nausea, vomiting, diarrhoea, abdominal cramps, tachycardia, hypotension, bronchospasm and angio-oedema.
Discontinue administer adrenaline dose titrated 0.5 mg IM ----
Once the patient has recovered, the ASV can be restarted slowly for minutes, keeping the patient under close observation. Then the normal drip rate should be resumed

34. Maximum 20 vials of ASV in neurotoxic and 30 vials in hemotoxic
Go ahead with ventilation
Or FFP
50 + vial regimens in INDIA ??
ASV acts for 90 hours – need not repeat

35. Neostigmine Test 2 mg neostigmine IM with 0.6 mg atropine
Observe for 1 hour
Single breath count, mouth opening
Inter incisor distance
If the victim responds to the neostigmine test then continue
with 0.5mg of neostigmine IM half hourly plus 0.6mg of atropine IV over an 8 hour period by continuous infusion.
We give combined infusions

36. Drugs not to be used in viper bites :
Heparin and Botropase

37. Pituitary adrenal insufficiency
Complications
Hypotension
Hemorhage
Vasodilation
Cardiac depression
Sepsis
Pituitary adrenal insufficiency
Treat the cause

38. Monitor !! USG guided absolutely atraumatic central vein cannulation
Sometimes a low dose dopamine may help
Beware of repeated venepuncture to take biochemistry
No arterial puncture in bleeding patients
Healthy patients – urine output is good enough

39. Surgical Fasciotomy – role is limited
Think in terms of compartment syndrome
Strykers compartment pressure monitoring
Removal of dead necrotic material after stabilising !!
Nothing before coagulation stabilises
Even ASV decreases edema and the need for fasciotomy

40. Other complications Persistent bleeding Renal failure
Cardiac complications
Stiffness

41. Cobra spit ophthalmia
First aid consists of irrigating the affected eyes and other mucous membranes with liberal quantities of water or any other available bland liquid.
Instillation of 0.5% adrenaline drops relieves pain and inflammation.
Local ASV – NO

42. Titbits
Bites by small snakes should not be ignored or dismissed. They should be taken just as seriously as bites by large snakes of the same species.
Local administration of ASV near or on to the bite site should not be done.

43. Spiritual touch ??

44. Summary Incidence Types Envenomation – clinical picture WBCT
ASV doses, dos and donts
Neostigmine test
Fasciotomy
Complications
Rehabilitation

45. Thank you all