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Snakes

Snakes. Snakes.

hamish-barnett
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Snakes

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  1. Snakes

  2. Snakes Venomous snakes are undoubtedly the most significant cause of both major morbidity and mortality among all terrestrial venomous and poisonous animals. Although poisoning by other animals may affect large numbers of people, mortality is comparatively rare, and thus venomous snakes are the leading cause of death from venomous and poisonous animals in all environments.

  3. Snakes In some parts of the rural tropics, snakebite is in the top 10 to 15 most important health problems. 2.54 million venomous snakebite and at least 125000 death per year. Even though there are aproximately 3000 species of snakes globally, only about 600 species are venomous, and all of them are found in some snake families:

  4. Colubridae • Elapidae:Walterinnesiaaegyptia , Naja spp. or African and Asian cobras) • Hydrophidae

  5. Viperidae(Cerastes spp., Echis spp., Pseudocerastes spp.) • Crotalidae( Agkistrodon spp., crotalus spp.

  6. Aglyphous(Nonvenomous snakes) phyton and boa • Opistoglyphous(Colubridae) African tiger snake

  7. Solenoglyphousviperidae-crotalidae • Proteroglyphouselapide-hydrophidae

  8. Snakes venoms Snake venome generally consist of a complex mixture of substances, each of witch may exhibit one or more distinc toxic action. • Function: acquisition, digestion, defense. • water soluble • Acidy

  9. Biochemical Classification of Snakes venoms Activation

  10. Medical Classification of Snakes venoms Activation 1)Neurotoxin Paralytic effect mediated at the neuromuscular junction. • Postsynaptic neurotoxin • Presynaptic neurotoxin • Anticholinesterase 2) Myotoxin Systemic myolysis of skeletal muscle Massive release of myoglobin, creatinkinase and potassium

  11. Medical Classification of Snakes venoms Activation 3) Hemostatic system toxin Interference with normal hemostasis causing either bleeding or thrombosis 4) Hemorrhagins Vascular wall damage(endothelium ) causing bleeding 5) Nephrotoxins Direct renal damage 6) Necrotoxin Direct tissue injury at the bite site/bitten limb

  12. Clinical effect of envenoming The clinical effect of a snakebite will vary with the species of snake; the age, size and geographic origin of the snake; the quantity of venom injected; the rout of injection; The age, size, and previous health of the victim; and past exposure to venom.

  13. Clinical effect of envenoming • Local effect Bit mark vary from a single fang puncture to classic double puncture from paired fangs. Local swelling, erythma,hemorrhage, blistering, frank necrosis. • General effect Headache, nausea, vomiting, abdominal pain, diarrhea, dizziness, collapse, hypotension/hypertension, tachycardia/bradycardia and ….

  14. Clinical effect of envenoming • Specific effect Paralysis:That caused by neurotoxins affects skeletal muscle and respiration muscle. Ptosis, dysphonia, droolin and diplopia. Myolysis:Muscle pain, tenderness, weakness and paralysis, myoglubinuria. Cardiotoxicity: arrhythmias to cardiac arrest Coagulopathy and hemorrhaging effect

  15. Elapidae (neourotoxic) Pain; Inflammation (++) Nausea & vomiting Drowsiness Blurred vision Lethargy Weakness Paralysis of skeletal and respiratory Lower necrosis and hemorrhage of the site

  16. Crotalidae & viperadae (hemotoxic) Pain and inflammation(+++) improve in organ Higher necrosis and hemorrhage at the site Hemorrhage from Other site (GI, GU, ORAL) Nausea & vomiting Weakness Drowsiness Lower paralysis Coagulation disorder

  17. Hydrophidae(neurotoxic and myotoxic) Pain and inflammation (+) High muscle pain Drowsiness Nausea and vomiting Paralysis skeletal and respiratory Myoglubinuria (urine color)

  18. Treatment Pressure Immobilization? For bites by nonnecrotic species includig many elapidae ( but not most cobras) is both safe and effective. Incision and suction?

  19. Treatment Cutting :× or ІІІ and suction Tourniquet(±): good for hydrophidea Ice compress(-) Gently washing : N/S or diluted betadin NSAID Tetabulin FFP (after antiserum) Prophylaxy antibiotic (no recommended) AB: ( metronidazol, cephalosporine)

  20. Treatment Antiserum Minimal: 2-5 vial Moderate: 5-10 vial Sever:10-20 vial Dilute With N/S (1:10) 50 % within first hour Slow rapid infusion 50 % within 24 h Prevention of anaphylaxy: chlorpheniramin- hydrocortizone Dose no dependent to weight

  21. Minimal: Minor local swelling and discomfort only, without systemic symptoms or hematologic abnormalities. Moderate:Progression of swelling, with local tissue destruction, hematologic abnormalities, or systemic symptoms. Severe: Marked progressive swelling and pain, with blisters, bruising, and necrosis; systemic symptoms.

  22. Treatment For Crotalineenvenomations, antivenom should be considered as first-line therapy for patients with moderate- to- severe envenomations The infusions are initiated at a slow rate. If no signs of anaphylactoid reaction develop, the rate is increased to complete the infusion over 1 hour.

  23. Scorpion

  24. Scorpion Scorpions are arthropods with a hard exoskeleton, two anterior pinching claw and a tail ending with bulbous enlargement. The poison gland and stinger are located at he distal part of the tail. Their habitat is warm and arid areas. Scorpion venom is a mixture of mucopolysaccharides, hyaluronidase, serotonin, histamine,phospholipase, protease inhibitors, histamine releasers, neurotoxins, and ….

  25. Scorpion Toxin: soluble in water and pH=7-8 Mechanism: • Increase of neuronal Na+ influx • Increase of current Ca+ to presynaptic neuron Release NEP and Ach sympathetic/parasymphatetic stimulation low relation between color and toxicity

  26. Iran south scorpion • Scorpionidae: hemiscorpius lepturous (گادیم) عقرب هفت دم • Butidae: androctonus crassicauda عقرب سیاه

  27. Scorpion envenomation Usually only pain at the site (70%) • ScorpionidaeBurning, pain, edema, vesicle, necrosis, coagulation disorder, hemolysis and arrest of cardiac and respiratory. • ButidaeHigher pain and burning, lower vesicle and necrosis, arrest of cardiac and respiratory. Both of them: Sympathic : Cardiotoxicity (CVS) Parasympathic: NMJ ,GI ,GU seizure

  28. Treatment NSAID local anesthetic injection Cold compress (+) if low local injury Washing N/S Tetanus FFP (after antiserum) Skeletal spasm (methocarbamol) GI spasm (hyoscine) diazepam

  29. Treatment Antiserum : 1-2 vial no dependent to child and adult and weight Hypertension : no ACEI bradykinin and toxicity Choice : SNP, hydralazine, prazocin BRADYKININ VASCULAR PERMEABILITY IN RESPIRATORY SYSTEM PULMONARY EDEMA

  30. Bees

  31. Bees • Apoidea: honey bee , bumble bee • Vespoidea: wasp , hornet , yellow jacket

  32. Honey bee • Melitin : 50% dry weight Cytolysis - hemolysis - rhabdomylysis Pain Inflammation Inhibition of Ach , Na/K/ATPase

  33. Honey bee • Phospholipase A2:10-12% inflammation • Apamine: 3% inhibit of Ca-dependent K channel • Mast cell degranualating: 2% inflammation • Others: serotonin, kinin, dopamine WASP: like honey without melitin , apamine

  34. Clinical effect • Pain • Edema • Pruritus, urticaria • Anaphylaxy • Many sting: respiratory depressoin, CVS complicatoin (hypotension, arrhythmia) , seizure

  35. Treatment • Remove sting with sac (caution) • Honey bee: rinse with lemon juice, vinegar • Wasp: rinse Na bicarbonate, cigarette remnant • Antihistamine • NSAID • Glucocorticoid • Salbutamol • Adrenaline (under tongue)

  36. Spiders

  37. Spiders Spiders • LoxosceleBrown recluse spider • Latrodectus Black widow spider Female are larger and danger than male

  38. Loxosceles Sphingomyelinase Cytotoxic for RBC release Hb Cytotoxic for skin cells necrosis Cytotoxic for endothelial vascular system bleeding and adhesion of neutrophils inflammation and damage to tissue Hyaluronidase Facilitate spreading in tissue

  39. Clinical effect Low pain at bite Erythema, edema, blister, necrosis and hemorrhagic (increase in lesion diameter) Nausea, vomiting, fever,weakness, internal bleeding, hemolysis (blood in urine), convulsion

  40. Treatment • Clean the lesion (N/S ,betadin) • Analgesic ( NSAID, opioid) • Anti tetanus • Anti venom • Antibiotic (high spectrum)

  41. latrodectus α - latrotoxin Bind to presynaptic receptors(neurenin, latrophilin) INFLUX OF Ca2+ release NEP, Ach and neurotransmitters

  42. Clinical effect Low pain at bite Lower local reaction Mostly Neurotoxic Muscle spasm and pain in many part of body Sympathic and parasympathic stimulation (GI,CVS,GU)

  43. Treatment NSAID OPIOID BZD Methocarbamol Hyoscine Antivenom Antitetanus

  44. Thanks for your attention

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