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“Preparing Our Communities”. Welcome!. Faculty Disclosure. For Continuing Medical Education (CME) purposes as required by the American Medical Association (AMA) and other continuing education credit authorizing organizations:
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“Preparing Our Communities” Welcome!
Faculty Disclosure • For Continuing Medical Education (CME) purposes as required by the American Medical Association (AMA) and other continuing education credit authorizing organizations: • In order to assure the highest quality of CME programming, the AMA requires that faculty disclose any information relating to a conflict of interest or potential conflict of interest prior to the start of an educational activity. • The teaching faculty for the BDLS course offered today have no relationships / affiliations relating to a possible conflict of interest to disclose. Nor will there be any discussion of off label usage during this course.
Chemical Events Chapter 6
Overview • Examples of chemical disasters / terrorism • Review Classes of Chemical Weapons • D-I-S-A-S-T-E-R Paradigm for chemicals
Industrial Accidents • Bophal, Indial 1984 • 40 Tons of Methyl Isocyanate released • Population of 900,000 • 6,000-10,000 immediate problems • Up to 400,000 delayed health issues
Transportation Events • Releases of Hazardous Material occur almost daily in the USA • Events requiring patient decontamination are less frequent
Chemicals as Weapons First large-scale use in World War I • Ypres, Belgium • April 1915 • Chlorine, 168 tons • 5,000 deaths • 5 mile front
Chemical Casualties in WWI Country Non-fatal Deaths Britain 180,597 8,109 France 182,000 8,000 Russia 419,340 56,000 Italy 55,373 4,627 U.S. 71,345 1,462 Austria-Hungary 97,000 3,000 Germany 191,000 9,000
Terrorist Use of Chemical Weapons • Tokyo Subway 1995 • Sarin Nerve Agent • 5,500 victims • 11 Dead • 641@ St. Luke’s International Hospital • Poor decontamination • Limited EMS involvement
Agents of Opportunity • Toxic industrial chemicals • Available • Easier to obtain/target • Poisoning consumer products • Examples: • Chlorine Tank Bombs in Iraq • 1982 Tylenol tampering incident
Nerve Agents Tabun, Sarin, Soman, VX Blood Agents Cyanides Irritant Agents Phosgene, chlorine, ammonia, pepper spray Vessicants Mustard, Lewisite, Phosgene Oxime Incapacitating agents BZ, Others? Chemical Weapons
Nerve Agents • Organophosphate chemicals • Similar to common insecticides • Very high lethality • Liquids that are vaporized to disseminate • Rapidly toxic if inhaled • Slower onset with dermal exposure
Acetylcholine Cholinesterase Cholinergic Receptor
Acetylcholine Cholinesterase Organophosphate
Organophosphate Poisoning Signs and Symptoms D: defecation U: urination M: miosis B: BRONCHORRHEA, BRONCHOSPASM E: emesis L: lacrimation S: secretions/ seizures Muscarinic effects Nicotinic effects M: mydriasis T: tachycardia W: weakness tH: hypertension F: fasciculation S: seizures
Nerve Agent Exposure • Low exposure • Miosis, dim vision, eye pain • Rhinorrhea • Dyspnea • Localized sweating & fasiciulation (liquids) • High exposure • Immediate loss of consciousness • Seizures • Apnea • Flaccid paralysis • Vapor – effects occur within seconds • Liquids – onset may be delayed
Nerve Agents: Treatment • ABC’s, supportive care • Antidotes • Atropine • 2 mg IV, IM or ET • Pralidoxine (2-PAM) • 1 gram slow IV or Autoinjector IM (600 mg) • Benzodiazepines, PRN for seizures
Acetylcholine Cholinesterase Organophosphate Atropine 2 PAM Receptors Muscarinic Nicotinic
Atropine Dosing • Starting dose - 2 mg • Maximum cumulative dose - 20 mg • Insecticide poisoning may require more • Atropine – How much to give? • Until secretions are drying or dry • Until ventilation is easy • If conscious or comfortable • Do not rely on heart rate or pupil size
Irritant Gasses • Common industrial chemicals • Agent of opportunity • Combine with moisture to form acids or bases • Low concentration = Minor irritation • High concentration or prolonged exposure = Chemical burns
Irritant Gas Site of Injury Highly water soluble Ammonia Moderately water soluble Chlorine Poorly water soluble Phosgene
Irritant Gases: Triage • Majority – Worried well? • Airway compromise – P1, immediate • Severe shortness of breath- P1, immediate • Mild SOB, No airway compromise – P2, delayed • Mild mucous membrane symptoms – P3, minimal • Respiratory arrest – P4, expectant
Irritant Gases: Treatment • Dry decontamination usually adequate • Water for mucous membrane irritation • ABC’s & Oxygen PRN • Early airway management • highly and moderately water soluble exposures • Inhaled beta agonist PRN wheezing • Observation and support • phosgene 12- 24 hrs?
Cyanide Compounds • Widely used in Industry • Cyanide gas is rapidly lethal • Oral poisoning is slower • Odor “bitter almonds”? – “musty” smell • Odor not a reliable indicator
Cyanide in Smoke • Burning wool, plastic and other materials releases cyanide gas • May play a significant role in smoke inhalation and fire-related deaths
Cyanide Blocks Use of Oxygen O2 O2 O2 O2 + H+ O2 H20 ADP ATP Cyt a cyt a3+ Cu Cyt c Metabolic Acidosis
Cyanide - Sources • Pits of many plants • Cherries, peaches, almonds, lima beans • Cassava plant root • Combustion of carbon -> cyanide • Plastics- acrylonitriles • U.S. sources manufacture 300,000 tons of hydrogen cyanide annually
Cyanide Triage • M-A-S-S Triage • Likely few critical victims • Most either dead • Others with minor exposure • Good supportive care may save many in absence of antidote
Cyanide Treatment • Remove to Fresh Air • Oxygen, supportive care • Antidotes ? • 3 Drug Antidote Kit • Hydroxocobalamin
Fe2+ Hb MetHb Fe3+ Fe3+ Excreted in urine Thiocyanate Fe3+ Cyt a3 Amyl Nitrite Inhale for 30 sec Sodium Nitrite 300mg IV Sodium Thiosulfate 12.5g IV
Hydroxocobalamin • Hydroxocobalamin – 5 g IV • Vit. B12a • Chelates Cyanide • Need 50:1 ratio • Cyanocobalamin • Vit. B12 – nontoxic! CN
Blister Agents/Vesicants • Sulfur Mustard • Also - Lewisite, Phosgene oxime
Mustard • Most widely used chemical weapon • Morbidity is higher than mortality • Garlic odor • Freezes at 57 F • Penetrates rubber gloves
Penetrates cells and generates toxic intermediate Alkylates DNA/RNA, Proteins Rapidly dividing cells most susceptible Mustard Mechanism
Vesicant Symptoms • Onset of symptoms ? • High vs low dose • Topical – Eyes, Airway, Skin • Binds Irreversibly within minutes “Fixing” • Systemic effects ?
Mustard - Skin • Erythema 2-24 hours • Small vesicles may coalesce to form bullae • High dose exposure – central zone of coagulationnecrosis
Vesicant Treatment • Immediate decontamination (~2 minutes) • Victim may not undergo decontamination since symptoms delayed • Remove clothes and wash skin with soap and water • Avoid overhydration; fluid losses less than with thermal burns • Possible antidotes • N-acetylcystiene (NAC) for Mustard • Dimercaperol (BAL) for Lewisite
Incapacitating Agents • Not meant to be lethal • “Inability to perform one’s mission” • BZ (quinuclidinyl benzilate) • Aerosolized Anticholinergic • 25x more potent than atropine • Others possible • Benzodiazepines • Opiate derivatives • Psychedelics
BZ: Treatment • Control patient • Consider benzodiazepines • KEEP VICTIM COOL • Physostigmine • 1-2 mg IV • atropine at bedside • seizures and cardiac arrhythmias rare
D: Detection I:Incident Command S: Safety & Security A: Assess Hazards S: Support T: Triage & Treatment E: Evacuation R: Recovery
D:Detection • Clinical presentation • Detection devices • Information sources
Rapid symptom onset Multiple victims and civilian panic Similar signs and symptoms Present at same time History of similar site exposure Absence of traumatic injuries Toxidromes will guide treatment at hospital Unusual or irritating odors Clinical Detection
Chemical Detection Tools All have limited ranges of substances • Chemical Detection Papers • Concentrated vapors or liquids • Air Sampling Devices • Vapors or gasses in low concentration
Shipping Papers & Placarding • ANY hazardous material being transported must have documents identifying the HazMat • Large shipments are placarded • Placard identifies the type of chemical • Emergency Response Guidebook • Decodes ID# and provides information • Health and fire hazards • Protective Equipment needed • Containment & Evacuation • First aid & Emergency response
Red color & pictogram = Flammable UNID # = isopropyl alcohol #3 = Flammable liquid
Material Safety Data Sheet • Required for chemical used in a workplace • Chemical Name • Hazard Identification • Physical & Chemical Properties
NFPA Labels • Flammability • Health Hazard • Instability • 0 = Good • 4 = Very Bad • Special Hazards • Oxidizer • Water Reactive • Radiation