Marine toxicology
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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

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Marine toxicology

Marine Toxicology

Rob Hall PGY3 and Dr. I. Vicas

Toxicology Rounds

Jan 9th, 2003


Goals for today

GOALS FOR TODAY

  • ENVENOMATIONS

    • Three mechanisms of envenomation

    • Standard treatment for each mechanism

    • Recognize life – threatening

  • MARINE FOOD POISONING

    • Common causes

    • Presentation, diagnosis, management!


Not the band venom

Phil

Tony

Robbie Drummond

Not the band Venom!


Marine envenomations

MARINE ENVENOMATIONS

  • 2000 species of venemous marine animals

  • General Mx

    • Remove from water: drowning MCC of death

    • Local wound care

    • ? Specific antivenom

    • Be prepared to manage anaphylaxis


Three mechanisms of envenomation

Three Mechanisms of Envenomation


Bites

Octopi

Local wound care: irrigate, debride, dress, tetanus, analgesia

Blue - ringed Octopus can be lethal (tetrodotoxin like venom)

BITES


Bites1

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

BITES


Nematocysts

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)


What is a nematocyst

What is a Nematocyst?


Nematocysts1

NEMATOCYSTS

  • General Mx

    • Cut off tentacles

    • Inactivate nematocysts: VINEGAR

    • Remove nematocyts: credit card scrape

    • Antihistamine, analgesia

    • Antivenom only exists for seawasp


Nematocysts2

Jellyfish

Usually only local reaction

Remove tentacle, vinegar, credit card scrape, antihistamine, analgesia

NEMATOCYSTS


Nematocysts3

NEMATOCYSTS


Nematocysts4

NEMATOCYSTS

  • 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)


Nematocysts5

NEMATOCYSTS


Nematocyts

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

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


Stings1

Starfish

Most nonvenomous

Crown - of - thorns: severe local reaction

STINGS


Stings2

Sea Urchins

Toxic coated spines

Severity depends on species

Usually only local reaction

Imbedded spines problematic

STINGS


Stings3

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


Stings4

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

STINGS


The goods on marine envenomations

The Goods on Marine Envenomations


Marine food poisoning

MARINE FOOD POISONING

  • Consider the patient who is sick after eating seafood…………..


Marine food poisoning1

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 poisoning2

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

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

FISH POISONINGS

  • Ciguatera

  • Scombroid

  • Tetrodotoxin


Ciguatera

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


Ciguatera1

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


Ciguatera2

CIGUATERA


Ciguatera3

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


Scombroid

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


Scombroid1

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


Scombroid2

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

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


Tetrodotoxin1

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


Tetrodotoxin2

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

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

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

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

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

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


Summary of fish poisoning

SUMMARY of FISH POISONING


Summary of shell fish ingestion

SUMMARY of SHELL FISHINGESTION


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