Presentation on theme: "Marine Toxicology Rob Hall PGY3 and Dr. I. Vicas Toxicology Rounds Jan 9 th, 2003."— Presentation transcript:
Marine Toxicology Rob Hall PGY3 and Dr. I. Vicas Toxicology Rounds Jan 9 th, 2003
GOALS FOR TODAY ENVENOMATIONS Three mechanisms of envenomation Standard treatment for each mechanism Recognize life – threatening MARINE FOOD POISONING Common causes Presentation, diagnosis, management!
BITES Octopi Local wound care: irrigate, debride, dress, tetanus, analgesia Blue - ringed Octopus can be lethal (tetrodotoxin like venom)
BITES Seasnakes 50 species, all toxic, 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
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)
Box Jellyfish (Seawasp) Australia, Indian ocean MOST deadly of all envenomating marine life 25% fatality rate; more deaths than sharks! One box can kill 10 humans Cardioresp arrest within minutes Mx: ABCs, remove tentacles, VINEGAR, credit card scrape, ANTIVENOM (Chironex)
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, NO antivenom exists
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
STINGS Starfish Most nonvenomous Crown - of - thorns: severe local reaction
STINGS Sea Urchins Toxic coated spines Severity depends on species Usually only local reaction Imbedded spines problematic
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
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
MARINE FOOD POISONING Consider the patient who is sick after eating seafood…………..
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
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?
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!
FISH POISONINGS Ciguatera Scombroid Tetrodotoxin
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
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
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
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
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
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
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
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
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%)
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)
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
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
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
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