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Marine Toxicology

Marine Toxicology. Hussein Unwala , Dr. Ingrid Vicas February 4, 2010. GOALS FOR TODAY. MARINE ENVENOMATIONS Three mechanisms of envenomation Standard treatment for each mechanism Recognize life threatening. MARINE ENVENOMATIONS. 2000 species of venemous marine animals General Mx

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Marine Toxicology

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  1. Marine Toxicology Hussein Unwala , Dr. Ingrid Vicas February 4, 2010

  2. GOALS FOR TODAY • MARINE ENVENOMATIONS • Three mechanisms of envenomation • Standard treatment for each mechanism • Recognize life threatening

  3. MARINE ENVENOMATIONS • 2000 species of venemous marine animals • General Mx • Remove from water: drowning MCC of death • Local wound care, analgesia • ? Specific antivenom • Be prepared to manage anaphylaxis

  4. Three Mechanisms of Envenomation Cone Snails

  5. BITES • Octopi • Local wound care: irrigate, debride, dress, tetanus, analgesia • Blue - ringed Octopus can be lethal (tetrodotoxin like venom)

  6. BITES • Seasnakes • 52 species, all venemous, 7 fatal • Most bites do not result in envenomation b/c fangs short/loose ---> poor delivery of venom • Local wound care + polyvalent sea snake antivenom

  7. BITES • Cone Snails • Envenomation occurs with handling • Contain a tooth bathed in venom • Peptides currently being studied in chronic pain • Supportive Care

  8. NEMATOCYSTS • Nematocyst = spring - loaded venom gland that suddenly everts and delivers venom • Often located on tentacles • Remain functional after animals death • May still be “loaded”when in skin • Local reaction, allergic reaction, toxic reaction (N/V/D, CP, cramps, SOB, paralysis, cardiorespiratory collapse)

  9. What is a Nematocyst?

  10. NEMATOCYSTS • General Mx • Cut off tentacles • Inactivate nematocysts: VINEGAR • Remove nematocyts: credit card scrape • Antihistamine, analgesia • Antivenom only exists for box jellyfish

  11. NEMATOCYSTS • Jellyfish • Usually only local reaction • Remove tentacle, vinegar, credit card scrape, antihistamine, analgesia

  12. NEMATOCYSTS

  13. NEMATOCYSTS • Box Jellyfish (Seawasp) • Australia, Indian ocean • 15-20% fatality rate; more deaths than sharks! • Severe pain, whiplike linear rash, then systemic symptoms • Cardioresp arrest within minutes = Irukandji syndrome • Mx: ABCs, remove tentacles, VINEGAR, credit card scrape, ANTIVENOM (Chironex)

  14. NEMATOCYSTS

  15. NEMATOCYTS • Portuguese Man -o - war • Southern US coast line • Not a true jellyfish • Usually only local reaction • Potential for full CV collapse • Many deaths reported • Mx: ABCs, remove tentacles, vinegar, credit card scrape, ice packs for mild stings • NO antivenom exists

  16. STINGS • Stinger = specialized apparatus that punctures skin and delivers venom • Mx • Remove stinger (? Xray to r/o stinger in tissue) • Irrigate copiously, tetanus, analgesia • HOT WATER for 30 - 90 min (inactivates the heat labile venom; hot as possible) • Antivenom exists for stonefish stings

  17. STINGS • Starfish • Most nonvenomous • Crown - of - thorns: severe local reaction

  18. STINGS • Sea Urchins • Toxic coated spines • Severity depends on species • Usually only local reaction • Imbedded spines problematic

  19. STINGS • Stingray • Barbs on tail • Stepped on in shallow water • Tail spines ---> laceration • Stinger: local +/- systemic rxn (N/V/D, cramps, CP, SOB) • Remove stinger, irrigate, HOT water, tetanus, abx to cover vibrio

  20. STINGS • Bony fish (Lionfish, Stonefish) • Venomous spins on fins • Stepped on or handled • Will attack b/f swimming away • Severe local rxn: pain, swelling • Systemic rxn: N/V/D, syncope, SOB, paralysis, CV collapse • ANTIVENOM exists

  21. The Goods on Marine Envenomations Consider pressure bandage

  22. Cases??

  23. MARINE FOOD POISONING • Consider the patient who is sick after eating seafood…………..

  24. MARINE FOOD POISONING • 30YO male at fish from BOYD’S SEAFOOD on New Year’s Eve • Presents 2hrs after eating fish (Red snapper and Mahi mahi) • Nausea, vomiting, diarrhea, cramps • Perioral peresthesias, burning fingertips, ataxia, vertigo, ice pack on forehead felt hot, watery eyes, diaphoretic

  25. MARINE FOOD POISONING • What is your ddx? • Is this tetrodotoxin…..why or why not? • How are you going to make the diagnosis? • What is your management?

  26. MARINE FOOD POISONINGS • Food Poisoning • Allergic reaction • Other ddx of ? Food poisoning presenting with neurological signs/symptoms…… • MG, botulism, MSG, encephalitis, polio, tick paralysis, carbon monoxide, organophosphates, anticholinergics, heavy metals, diptheria, eaton-lambert, plant ingestion, migraine, the bends!

  27. FISH POISONINGS • Ciguatera • Scombroid • Tetrodotoxin

  28. CIGUATERA • Most common vertebrate fish poisoning • World wide, warm waters, 90% in spring/summer • > 500 species of fish but ALL ARE LARGE • red snapper, seabass, baracuda, grouper, kingfish, sturgeon, parrot fish

  29. CIGUATERA • Ciguatoxin • Algae/protozoa ------- small fish ----- large fish • Heat stable thus cooking does NOT kill • Binds Na+ channels and increases permeability • Variable toxins thus variable symptoms • Ciguatoxin can be assayed (? Can our lab do it) • Toxin is absorbed quickly thus ONSET of symptoms is 1 – 6 hrs after eating

  30. CIGUATERA

  31. CIGUATERA • Management • ABCs (including fluid resusc) • Activated charcoal if < 2hrs • Cathartics if no diarrhea • Mannitol • Case reports of 1 gm/kg over 30 min decreasing neurological effects of ciguatera

  32. SCOMBROID • Any large fish (MahiMahi + amberjack) • Preventable with proper preparation • Spoilage: bacteria convert hisitidine to saurine and histamine which are the toxins • Spoiled fish may have “honeycombing” or peppery taste • Onset of symptoms within minutes - hours

  33. SCOMBROID • Presentation similar to allergic reaction • FLUSHING of face, neck, torso (diffuse erythema) ………can progress to urticaria • Numbness, tingling, burning around mouth • Can have bronchospasm • Diagnosis = increased histamine levels in serum or urine (can also test fish) • NOT a fish allergy if others with same symptoms or if fish can be tested

  34. SCOMBROID • Consider ddx of flushing, bronchospasm, and headache • Anaphylaxis, anaphylactoid reaction, scombroid, MSG, tyramine, ethanol flush, tartrazine, metabisulfites • Management • Benadryl, ranitidine • Ventolin prn • ? Activated charcoal if early, ? Cathartic • Epinephrine if needed

  35. TETRODOTOXIN • Japan, California, Africa, Australia • > 100 fish • Puffer fish (FUGU), blow fish, toad fish, balloon fish, globe fish • Also crab eggs,blue-ringed octopus, newts

  36. TETRODOTOXIN • Toxin • Heat stable • Concentrated in ovary, liver, skin, intestine • Watch out for the female fishy in heat!! • Can be assayed • Blocks Na/K+ activity and blocks neuromuscular activity • Onset within MINUTES of ingestion

  37. TETRODOTOXIN • Presentation • Headache, diaphoresis • Paresthesias of lips, tongue, mouth, fingers/toes • Dysphagia, dysarthria, ataxia, fasiculations • Ascending paralysis and resp arrest • Management • ABCs, supportive, ? AC and cathartics, call the priest (mortality 50%)

  38. SHELLFISH POISONING • General • Mollusks filter dynoflagellates and algae • More common during red tides when dinoflagellates go crazy (can occur inbetween red tides) • Any shellfish ingestion: clam, oyster, muscle, scallops • Three Patterns • Paralytic Shellfish Poisoning (PSP) • Neurotoxic Shellfish Poisoning (NSP) • Amnestic Shellfish Poisoning (ASP)

  39. PARALYTIC SHELLFISH POISONING (PSP) • Onset < 30 min • Saxitoxin blocks Na+ voltage gated channel • Neuro symptoms predominate • Paresthesias, ataxia, vertigo, weakness, paralysis, cranial neuropathies, resp failure • N/V/D/cramps LESS common • Mx • Supportive =/- lavage and cathartics

  40. NEUROTOXIC SHELLFISH POISONING (NSP) • Onset ave 3hrs (15 min – 18hrs) • Toxin = Brevitoxin • GI + Neuro symptoms • GI: N/V/D/cramps • Neuro: paresthesias, temp reversal, ataxia, vertigo, areflexia, NO paralysis • Bradycardic and mydriasis, bronchospasm • Mx • Supportive, ventolin, ? decontamination

  41. AMNESTIC SHELLFISH POISONING (ASP) • Onset ave 5hrs (15 min – 36hrs) • Toxin = Domoic acid (Canadian outbreak 1987) • GI + Neuro + CV • GI: N/V/D/cramps • Neuro: MEMORY LOSS (damage to amydala and hippocampus)……..sz, grimacing, chewing, opthalmoplegia less common • CV: hypotension and arrythmias • Mx: supportive, ? decontamination

  42. OTHER POISONINGS • Botulism • Canned foods classic but can be from fresh fish • GI = neuro (diplopia, dysphagia, dysarthria, weakness) • Toxin binds at NMJ • Consider with……… • Myasenia gravis, eaton lambert, tick paralysis, gullian barre’, miller fisher syndrome

  43. SUMMARY of FISH POISONING

  44. SUMMARY of SHELL FISHINGESTION

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