Snake bite poisoning and its treatment by RxVichuZ!

My 106th powerpoint...that deals with snake bite poisoning.
Different types of venomous snakes, their characteristics, envenomation features and treatment strategies have been explained in a summary.
Hope it is effective for the readers involved.

1. SNAKE BITE POISONING AND ITS MANAGEMENT : A BRIEF INSIGHT PRESENTED BY: DR.VISHNU .R.NAIR, PHARM.D, NATIONAL COLLEGE OF PHARMACY(NCP).

2. INDEX What are snakes? Classification of venomous snakes Common Indian venomous snakes Pathophysiology of snake envenomation Clinical manifestations of snake bite Diagnosis of venomous snake bite Treatment of venomous snake bite How to prevent a snake bite?

3. WHAT ARE SNAKES?

4. Also known as “serpents” Limbless creatures Elongated bodies, covered with scales Body of snakes  divided into head, trunk and tail Venomous snakes  found all over the world, except New Zealand, Ireland and some parts of the Arctic and Antarctic regions. Among 14 families of snakes studied  5 are poisonous in nature!

5. CLASSIFICATION OF VENOMOUS SNAKES

6. CLASSIFICATION OF VENOMOUS SNAKES Family & genera Common name Important catchpoints COLUBRIDAE Mountain racer Western hognose snake Eastern hognose snake Parrot snake Rat snake Wandering garter snake Comprise 78% of snake species in the world Short immobile fangs Fangs consist of toxic saliva delivered via chewing motion Found in all continents EXCEPT AUSTRALIA ATRACTASPIDIDAE Mole vipers(adders) False vipers Side-stabbing snakes Have very long fangs Mainly found in Africa and Middle East countries.

7. CLASSIFICATION OF VENOMOUS SNAKES Family & genera Common name Important catchpoints ELAPIDAE Cobra ( Naja ) Kraits ( Bungarus ) Coral snakes ( Calliophis , etc ) Mambas ( Dendroaspis ) - Have short fangs, which may extend to huge lengths. VIPERIDAE Viperinae (true vipers): Vipers, adders Crotalinae (pit vipers): Rattle snakes, Asian pit vipers. Have highly developed long fangs Channelized in the form of a hypodermic needle. HYDROPHIDAE Sea snakes - Have short, fixed fangs.

8. COMMON VENOMOUS INDIAN SNAKES (THE BIG FOUR) SAW-SCALED VIPER COMMON KRAIT RUSSELL’S VIPER COMMON COBRA

9. COMMON COBRA CHARACTERISTIC DESCRIPTION SCIENTIFIC NAME Naja naja GEOGRAPHICAL DISTRIBUTION All over India PHYSICAL APPEARANCE & NATURE Brown/black in colour Distensible neck  expands in the form of a hood Monocellate / binocellate mark on dorsal side of hood Although diurnal  bites can occur at both day & night! NATURE OF VENOM Predominantly neurotoxic!

10. COMMON KRAIT CHARACTERISTIC DESCRIPTION SCIENTIFIC NAME Bungarus caeruleus GEOGRAPHICAL DISTRIBUTION All over India PHYSICAL APPEARANCE & NATURE Steel-blue in colour (also grey/dark-brown) Whitish bands or half-rings throughout its back Belly is very white Nocturnal in nature NATURE OF VENOM Predominantly neurotoxic(Most venomous snake in India)!!!

11. RUSSELL’S VIPER CHARACTERISTIC DESCRIPTION SCIENTIFIC NAME Vipera russelli GEOGRAPHICAL DISTRIBUTION All over India PHYSICAL APPEARANCE & NATURE Brownish stout snake Grows up to several feet in length Triangular head, with a “V”-mark Fangs are long Hisses loudly when agitated Nocturnal, but may attack at daytime while uncovered! NATURE OF VENOM Vasculo and hemo -toxic May also produce neurotoxic effects Acute renal failure also attributed to its venom!

12. SAW-SCALED VIPER CHARACTERISTIC DESCRIPTION SCIENTIFIC NAME Echis carinatus GEOGRAPHICAL DISTRIBUTION All over India(especially plains and deserts) PHYSICAL APPEARANCE & NATURE Small-snake(1.5-2 feet long) Brownish Diamond-shaped markings extend over its back Triangular head, with small scales Extremely aggressive and may bite with the slightest provocation! NATURE OF VENOM Vasculo and hemotoxic!

13. PATHOPHYSIOLOGY OF SNAKE ENVENOMATION

14. PATHOPHYSIOLOGY OF SNAKE ENVENOMATION Usually  snake venom consists of toxic saliva  secreted by modified parotid salivary glands of venomous snake Venom appearance: Clear, and amber- coloured Venom contents: Toxins: Low molecular weight peptides & proteins Enzymes: Proteinases, hydrolases, hyaluronidase, cholinesterase, phospholipase, ATPase, ribonuclease, deoxyribonuclease, etc. Miscellaneous: Neurotoxin, cardiotoxin, hemolysin, hemorrhagins .

15. PATHOPHYSIOLOGY OF SNAKE ENVENOMATION Concentration of snake venom  shows diurnal and seasonal variations Bites inflicted at night & immediately after hibernation  most severe!!! Polypeptide toxins(neurotoxins)  found more in elapid and hydrophiid venoms Postsynaptic alpha neurotoxins(alpha-bungarotoxins & cobrotoxin ) Bind to ACh receptors Block neurotransmission at NMJ

16. PATHOPHYSIOLOGY OF SNAKE ENVENOMATION Pre-synaptic beta neurotoxins( beta-bungarotoxin , cobrotoxin , taipoxin ) Causes initial release of Ach Damages nerve terminal Prevents further ACh release Thus Krait victims take longer time for recovery, as compared to cobra victims!

17. PATHOPHYSIOLOGY OF SNAKE ENVENOMATION Russell’s viper venom  consists of 2 proteases : RVV-X (Glycoprotein) RVV-V (Arginine ester hydrolase) RVV-X  activates Factor X, Factor IX & protein C RVV-V  activates Factor V. Russell’s viper  may also produce neurotoxicity! Echis venom  contains zinc metalloprotein ( ecarin )  activates prothrombin. Activate blood-clotting cascade!

18. PATHOPHYSIOLOGY OF SNAKE ENVENOMATION Hyaluronidase  promotes venom spread through tissues Proteolytic enzymes(hydrolases)  alter vascular permeability  lead to edema, blistering, bruising & necrosis! Biological amines (histamine, 5-HT)  contribute to local pain & permeability changes at bite site!

19. PATHOPHYSIOLOGY OF SNAKE ENVENOMATION Sea snake venom  consists of: Hyaluronidase b. Acetylcholinesterase c. leucine aminopeptidase d. 5- nucleotidase e. Phosphodiesterase f. Phospholipase A. Sea-snake venoms  highly toxic!!!

20. DIFFERENCE BETWEEN VENOMOUS & NON-VENOMOUS SNAKES CRITERIA VENOMOUS SNAKE NON-VENOMOUS SNAKE TAIL ORIENTATION Abruptly tapering Gradually tapering BELLY SCALES Broad Small HEAD ORIENTATION Triangular in shape Rounded/ oval HEAD SCALES Small Large TEETH ORIENTATION Modified to form fangs All teeth are uniformly small in size SALIVA TOXICITY Contains toxic peptides and enzymes Saliva is non-toxic

21. CLINICAL MANIFESTATIONS OF SNAKE BITE

22. ELAPID BITE FEATURES CHARACTERISTIC DESCRIPTION LOCAL FEATURES Indistinct fang marks Burning pain Swelling and discoloration Blood-stained discharge SYSTEMIC FEATURES Pre-paralytic stage Vomiting Headache Loss of consciousness Paralytic stage Ptosis Drowsiness Dysphagia Convulsions Respiratory failure Bulbar paralysis

23. VIPERID BITE FEATURES CHARACTERISTIC DESCRIPTION LOCAL FEATURES Rapid swelling Discoloration & blister Frank bleeding from the bite-site Severe pain. SYSTEMIC FEATURES Generalized bleeding tendency(epistaxis, hemoptysis & bleeding gums) Hematuria Malaena Purpuric spots in the skin Renal failure.

24. HYDROPHID BITE FEATURES: CHARACTERISTIC DESCRIPTION LOCAL FEATURES Minimal swelling & pain Frank bleeding from bite-site Severe pain SYSTEMIC FEATURES Myalgia Muscle stiffness Myoglobinuria Renal tubular necrosis Renal failure.

25. DIAGNOSIS OF VENOMOUS SNAKE BITE

26. DIAGNOSIS OF VENOMOUS SNAKE BITE

27. DIAGNOSIS OF VENOMOUS SNAKE BITE Identification of fang marks Identification of snake(not always applicable) Laboratory investigations: Hematological test s(anemia, leukocytosis, thrombocytopenia, prolonged CT and PT) ECG changes (bradycardia, QT- prolongation, etc.) Metabolic abnormalities (hyperkalemia, metabolic acidosis, lactic acidosis, etc.) Urine (Hematuria, proteinuria, hemoglobinuria and myoglobinuria) Renal (Azotemia) Chest X-ray (Pulmonary edema, etc.)

28. TREATMENT OF VENOMOUS SNAKE BITE

29. FIRST AID MEASURES Reassurance(very important)!! Keep the patient warm, and at rest Immobilize bitten limb Use paracetamol (non-sedating, non-salicylate) Avoid incision & suction Cryotherapy is contraindicated!

30. FIRST AID MEASURES TORNIQUET: Should be applied LIGHTLY Apply proximal to bite-site  helps to prevent lymphatic spread of venom Once tourniquet is applied  never loosen it, unless: Antivenom therapy is initiated Bite is confirmed to be non-venomous Sutherland wrap: Modified version of tourniquet In this method  a broad constrictive crepe bandage is applied over the affected area(including entire limb)  limb is placed on a splint.

31. FIRST AID MEASURES Torniquet application measure(note the finger inserted into it, which signifies that it should NOT be tightly bound!) Sutherland Wrap method

32. HOSPITAL MEASURES Observe patient for at least 24 hours before discharging Monitor the following: Pulse rate, RR, BP, WBC count (every hour) Blood urea SCr UOP Vomiting, diarrhea, abnormal bleeding Extent of local swelling & necrosis ECG Blood gas analysis.

33. HOSPITAL MEASURES ANTIVENOM THERAPY: Since antivenom therapy may precipitate serious allergenic reactions  d o not directly go for antivenom therapy (as part of routine measure) Indications for antivenom therapy: Incoagulable blood i . ECG changes. Spontaneous systems bleeding Hypotension Persistent or recurring shock, refractory to treatment Neurotoxic/myotoxic features Reduced consciousness Acidosis Pregnant women, small children

34. HOSPITAL MEASURES NATURE OF ANTIVENOM: In India  only polyvalent antivenom is available Effective against the following snakes: Common cobra Common krait Russell’s viper Saw-scaled viper.

35. HOSPITAL MEASURES Each milliliter of antivenom  has power to neutralize the venoms of following snake species: 0.60 mg of dried Indian Cobra venom 0.45 mg of dried Common Krait venom 0.60 mg of dried Russell’s Viper venom 0.45 mg of dried Saw-scaled Viper’s venom .

36. HOSPITAL MEASURES DOSING OF ANTIVENOM: Begin with 8 to 10 vials After infusion is over  check for improvement (wait for 6 hours) If no improvement(even after 6 hours)  administer additional 5 to 8 vials If no improvement yet  give another 5 to 8 vials After 25 to 30 vials  if no improvement  stop antivenom therapy  focus on: Respiratory support(elapid bite) Hemodialysis( hydrophid / viperid bite) ADVERSE REACTIONS OF ANTIVENOM: Anaphylaxis(always keep adrenaline loaded & ready) Serum sickness.

37. HOSPITAL MEASURES OTHER TREATMENT MEASURES: Clean bite site using povidone-iodine solution Avoid dressings Leave blisters alone For local necrosis  excise slough  do saline dressing Tetanus toxoid Paracetamol (for pain) Rehydration & nutrition

38. HOSPITAL MEASURES MANAGEMENT OF SPECIAL CASES: For severe bleeding  blood or fresh frozen plasma may be required For features of neurotoxicity(elapid bite)  give neostigmine (0.25- 0.5 mg i.v , half-hourly) Before giving neostigmine  give atropine 0.6 mg, i.v For respiratory failure: Oxygen, assisted ventilation, etc.

39. HOW TO PREVENT SNAKE BITE? Wear shoes (long trousers & leather boots) while walking amid long grass Carry electric torch or flashlight when walking outside at night Be careful while collecting firewood or moving rocks or debris, since they can be hiding places for a snake Use repellants in basements, attics & storerooms to ward off rodents & snakes(DDT, naphthalene, pyrethroids, etc ) Do not move near a snake or make sudden movements while it is near. Just slip away quietly!

40. THANK YOU!!!!