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Dates back many years
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tarix | 19.10.2018 | ölçüsü | 2,48 Mb. | | #74944 |
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Dates back many years First use: World War I Modern use of chemical terrorism - Cyanide: Chicago, Illinois – 1984
- Sarin :Tokyo, Japan-1995
- Carbamate Insecticide: Fresno, California – 1999
- Nicotine: Grand Rapids, Michigan – 2002
Reports of an unknown Chemical Substance have been released during an outdoor family concert. Participants arrive to the ED with C/O copious oral/nasal secretions, labored breathing, and muscle fasciculation. What othre PE finding should you expect? Reports of an unknown Chemical Substance have been released during an outdoor family concert. Participants arrive to the ED with C/O copious oral/nasal secretions, labored breathing, and muscle fasciculation. What othre PE finding should you expect? - A. Dry Skin
- B. Miosis
- C. Normal Mental Status
- D. Constipation
- E. Hypotension
Group of boy scouts present to ED. They were hiking and encountered an oily, dark brown liquid with a mustard odor. They had erythema and blisters of the leg. Some have eye irritation and SOB. Which would be helpful in treating these patients Group of boy scouts present to ED. They were hiking and encountered an oily, dark brown liquid with a mustard odor. They had erythema and blisters of the leg. Some have eye irritation and SOB. Which would be helpful in treating these patients - A. Supportive care only
- B. Atropine and 2-PAM
- C. Sodium Nitrite
- D. Midazolam
- E. Ciprofloxacin
Terrorist release a chemical in a school with an odor of newly mown hay. Few hrs later, students start complaining of ocular and nasal irritation followed by DIB and cough. Those seen in ED have CXR with pulmonary edema. Most likely chemical of use is: Terrorist release a chemical in a school with an odor of newly mown hay. Few hrs later, students start complaining of ocular and nasal irritation followed by DIB and cough. Those seen in ED have CXR with pulmonary edema. Most likely chemical of use is: - A. Phosgene
- B. Sarin
- C. Cyanide
- D. Lewisite
- E.Mase
A foreign diplomat’s 12 yr son presents to the ED with C/O headache and nausea. He soon develops severe dyspnea and cyanosis. As he is moved into the trauma bay, he starts to seize. You suspect he has been exposed to: A foreign diplomat’s 12 yr son presents to the ED with C/O headache and nausea. He soon develops severe dyspnea and cyanosis. As he is moved into the trauma bay, he starts to seize. You suspect he has been exposed to: - A. Soman
- B. Cyanide
- C. Sulfur Mustard
- D. Phosgene
- E. 1-Chloroacetophenone
Terrorist have released a chemical in a school bus full of children across the street from the hospital. In preparation for decon, HOSPITAL PERSONNEL should don what type of PPE? Terrorist have released a chemical in a school bus full of children across the street from the hospital. In preparation for decon, HOSPITAL PERSONNEL should don what type of PPE? - A. Self –containing breathing apparatus (SCBA), fully encapsulating chemical protective suit
- B. SCBA, chemical resistant clothing
- C. Full face air purifying respirator, chemical resistant clothing
- D. Coveralls and safety shoes/boots
- E. Gown and gloves
Apocalyptic groups Apocalyptic groups - Aum Shinrikyo, Japan (1995)
- Restoration of the 10 Commandments, Uganda (2000)
Political groups - Hamas/Hizbollah, Middle East (2000-present)
- Western Group of Federal Forces, Chechnya (2000)
- Revolutionary Armed Forces of Colombia (2001)
- Al Qa’ida (2001-present)
Aum Shinrikyo converge at Kasumigaseki subway station Aum Shinrikyo converge at Kasumigaseki subway station Release lethal sarin gas Terrorists take sarin antidote and escaped Commuters, blinded and gasping for air, rushed to the exits Twelve people died, over 5,000 were treated in hospitals (many comatose state) Japanese police raided Aum Shinrikyo headquarters Arrested hundreds of members, including: Master Shoko Asahara.
Toxic effects: Toxic effects: - Topical injury
- Skin
- Eyes
- Mucous membranes of respiratory tract
- Systemic absorption
General treatment of contaminated victims: General treatment of contaminated victims: - Triage
- Emergent resuscitation
- Decontamination if needed
- Airway / cardiopulmonary support
- Emergent antidotal therapy
Decontamination Decontamination - Appropriate level PPE required (hot zone)
- Field / Special designated area outside the ED
Simple disrobement: removes ≥ 80-90% Irrigation with soap and tepid water 0.5% sodium hypochlorite (adults) Pediatrics Considerations: - Warmer water (>37.8C)
- Low pressure systems
Vapor exposure: clothing removal and hair-washing (sufficient) Vapor exposure: clothing removal and hair-washing (sufficient) Liquid dermal exposure: thorough decontamination necessary Ocular exposure: copious irrigation
Level A Level A - Highest level of protection
- Highly contaminated area (hot zone)
- Self contained breathing apparatus (SCBA)
- Fully encapsulated suit
- Hot, bulky and clumsy
Level B Level B - Lower level than A
- Respiratory protection, less skin protection
- Outside hot zone / partially decontaminated pts
- SCBA
- Non-pressurized suit
- Butyl rubber gloves/boots
- Hot, bulky and clumsy
Level C Level C - Lower than Levels A & B
- Contaminants have been identified (low [ ])
- Air-purifying respirator: sufficient
- Some protection against skin contact
- Equipment: easier to work with
Nerve agents Nerve agents Vesicants Pulmonary agents (irritant gases) Riot control agents Incapacitating agents Cyanide
Highly toxic Highly toxic Organophosphate insecticides (signs and symptoms) Powerful inhibitors of acetylcholinesterase (AChE) Acetylcholine accumulation → abnormal neurotransmission
Onset and type of symptoms depends: Onset and type of symptoms depends: - Concentration
- Route of exposure
Vital sign abnormalities: - Sympathetic ganglia
- Parasympathetic ganglia
Low doses: Low doses: - Miosis
- Cojunctival injection
- Pain
- Rhinorrhea
High doses: Severe exposure: Death: - Respiratory depression and apnea
Vapor exposure (triad): Vapor exposure (triad): Dermal exposure (progression): - Localized sweating and fasciculations → nausea, vomiting , diarrhea and fatigue
- Severe exposure → respiratory and neurologic symptoms
Children: Children: - Less likely: miosis and peripheral parasympathetic effects
- More likely: CNS depression, hypotonia, weakness and seizures
Animal studies: children only need 10-33% of lethal dose on an equivalent mg/kg basis
Self protection / PPE (contamination HIGH) Self protection / PPE (contamination HIGH) Agents readily absorbed Patient decontamination: - Warm water / soap
- ? Diluted bleach solution (adults)
Restoring ventilation and oxygenation Restoring ventilation and oxygenation Aggressive use of antidotes Cardiac monitoring: dysrhythmias (torsades) Benzodiazepines – neuroprotective Close observation
Atropine - .05 -.10 mg/kg IV or IM
- Min 0.1mg, max 5mg
- Repeat Q 2-5 min for secretions
- Pralidoxime (2-PAM)
- 25-50 mg/kg IV or IM
- Max 1 gm
- Repeat Q 30-60 min (persistent weakness)
Military Mark I autoinjector kits: Military Mark I autoinjector kits: - 2 mg of atropine
- 600 mg of 2-PAM
Immediate IM use in the field Stockpile (civilian first responder) Not approved in pediatrics Pediatric auto-injector recently approved
Aging: permanent inhibition of AChE activity (irreversible covalent binding) Aging: permanent inhibition of AChE activity (irreversible covalent binding) Need early 2-PAM therapy prior to aging
Difference from organophosphate pesticide poisoning: Difference from organophosphate pesticide poisoning: - Continuous infusions usually not necessary (atropine or 2-PAM)
- Delayed peripheral neuropathies not seen
Life support + antidotal therapy →prognosis good Potential advances in treatment: - More effective oximes: HI-6
- Fetal bovine serum acetylcholinesterase
Vesicants: agents that produce blistering Vesicants: agents that produce blistering Severe dermal manifestation in children Released as an aerosol 3 primary vesicants:
Most viable threat ( ≥ 12 countries have SM in their arsenals) Most viable threat ( ≥ 12 countries have SM in their arsenals) Easiest to synthesize WWI: more casualties then all chemical agents combined 1980’s: >45,000 casualties in Iran-Iraq war
Alkylating agent, highly reactive and electrophilic Alkylating agent, highly reactive and electrophilic Oily liquid with odor of garlic, mustard or horseradish LD 50 is approximately 1.5 teaspoons Clinical effects: dose dependent Symptoms usually delayed for 4-8 hours
Symptoms: Symptoms: - Low doses: vessication
- Higher doses: vessication and systemic toxicity
Skin: erythema → blister formation Ocular: edema, conjunctival injection, corneal ulceration Respiratory: cough/hoarseness, tachypnea, bronchospasm, pulmonary edema
Systemic absorption involves: Systemic absorption involves: Expected mortality = 3% for those reaching medical facility Children:
Potency similar to sulfur mustard Potency similar to sulfur mustard Oily, colorless liquid with geranium odor Released by Japan during wartime Known stockpiles in Russia Active ingredient: trivalent arsenic Inhibits various enzymes and glycolysis Skin irritation and pain present within 15-30 minutes, blister formation by 2 hours
Skin lesions: Skin lesions: - less erythema
- more tissue destruction then sulfur mustard lesions
Ocular pain and irritation within minutes Central airway inflammation and upper airway irritation Edema in severe cases Hypotension and hemolytic anemia rare
BAL (British anti-Lewisite) or dimercaprol: BAL (British anti-Lewisite) or dimercaprol: - Arsenic chelator
- Prevents / decreases severity of skin and eye lesions if applied within minutes of exposure
- Topical form not widely available
- IM BAL reduces mortality from systemic effects of lewisite
Extensive tissue damage Extensive tissue damage Instantaneous pain and irritation of the skin, eye and airways Skin → blanches → turns gray → urticarial, erythematous and edematous → necrosis / eschar formation True vesicle formation DOES NOT occur
Ocular findings similar to lewisite Ocular findings similar to lewisite Pulmonary edema is common and may see bronchiolitis
Vesicant toxicity: clinical diagnosis Vesicant toxicity: clinical diagnosis Death most frequently occurs 5-10 days after exposure (pulmonary insufficiency / infection) Long-term hospitalization expected
PPE for healthcare workers PPE for healthcare workers Immediate decontamination (water and soap) Only water for phosgene oxime exposure Dilute hypochlorite solution (adults) – for water insoluble mustards and lewisites
No antidote No antidote Aggressive airway, fluid, electrolyte and pain management ? GCSF - mustard induced leukopenia Infection prevention with antibiotics Burn center referral
Pulmonary agents classified according to anatomical infliction Pulmonary agents classified according to anatomical infliction Affect central or peripheral pulmonary system Central: Upper airways (cough or stridor) Peripheral: lower airways (pulmonary edema)
Gas with a density 4X that of air Gas with a density 4X that of air Found in plastics, pharmaceutical and textile industries When released: - forms a white cloud
- odor of newly mown hay
Water insoluble
Initially asymptomatic with perception of odor Initially asymptomatic with perception of odor Mild exposure: - Eyes, nose, throat and upper airway irritation
Major toxicity: - Acid burn to lower airways
- Diffuse capillary leak
- Pulmonary edema
Pulmonary edema: delay 4-6 hrs (as late as 24 hrs)
Management Management - Primarily supportive care
- Decontamination: removal of victim to fresh air
- Respiratory:
- Pulmonary secretions
- Bronchospasm
- Pulmonary edema
- Aggressive treatment of secondary bacterial infections
Management: Management: - Steroids: ?severe bronchospasm
- Anti-inflammatory agents (NAC/ibuprofen): ? pulmonary edema
- 24- hour observation for all asymptomatic patients
Poor prognosis: dyspnea or pulmonary edema within 4 hours Poor prognosis: dyspnea or pulmonary edema within 4 hours Patients usually survive if symptomatic after 6 hrs and ICU available Recovery within 3-4 days
Widely available Widely available Dense, green-yellow gas with pungent odor Intermediate water solubility → upper + lower airways affected Early inflammatory injury - Formation of acids and oxidants upon contact with moist mucous membranes
Mild Exposure: Mild Exposure: - Immediate ocular, nasal and upper airway irritation
- Nausea and vomiting
Severe Exposure: (sx within 12-24 hrs) - Coughing and hoarseness
- Pulmonary edema
- Permanent reactive airway disease (inhalation)
Management: Management: - Supportive care
- Humidified oxygen
- Bronchodilators
- ? Nebulized sodium bicarbonate (3.75%) solution
- Skin decontamination
Silo gas: Silo gas: - Product of fire combustion
- Industrial process
- Military blast weapons
Limited water solubility Lower airway toxicity - Nitrogen oxide converted to nitric acid → alveolar injury → pulmonary edema
Triphasic illness: Triphasic illness: - Dyspnea and flu-like symptoms
- Transient improvement
- Pulmonary edema with worsening dyspnea (24-72 hrs)
Other consequences: - Methemoglobinemia
- Bronchiolitis obliterans (late complication)
Fertilizer and industrial chemical Fertilizer and industrial chemical Highly water soluble Colorless, alkaline, corrosive gas Rapidly reacts with water to form ammonium hydroxide Pungent odor
Immediate eye, mucous membrane and throat irritation Immediate eye, mucous membrane and throat irritation Lower airway involvement: - Bronchospasm
- Pulmonary edema
- Reactive airway disease
Treatment
Lacrimators or “tear gas” Lacrimators or “tear gas” Significant disruption and panic in crowds Transient but intense noxious effects Symptoms resolve within a few hours Pulmonary edema with large exposure in confined spaces
Symptoms Symptoms - Immediate irritation of eye and respiratory tract
- Blepharospasm
- Lacrimation
- Coughing, sneezing and rhinorrhea
- Burning sensation: exposed skin and mucous membranes
- Nausea, headaches and photophobia
- ↑ [ ], skin blistering / pulmonary involvement
Management Management - Removal from exposure
- Copious ocular irrigation
- Skin decontamination
Military incapacitating agents: physiologic or mental effects Military incapacitating agents: physiologic or mental effects Usually not lethal Recovery: several hours to days Anticholinergic deliriants (QNB, BZ)
Signs and symptoms (Anticholinergic): Signs and symptoms (Anticholinergic): - Delirium
- Hallucinations
- Mydriasis
- Tachycardia
- Ileus
- Dry mucous membranes
- Absent axillary sweat
- Urinary retention
- Hyperthermia
Treatment: Treatment: - Supportive care
- Benzodiazepines to prevent:
- Hyperthermia
- Rhabdomyolysis
- Physostigmine:
- Refractory seizures
- Profound tachycardia
Other incapacitation agents: (besides military agents) Other incapacitation agents: (besides military agents) - Stimulants
- Potent opioids (carfentanyl, aerosol fentanyl)
- Hallucinogens (LSD, Cannabinoids)
- Vomiting Agents
Long term use as a toxin for sinister purposes Long term use as a toxin for sinister purposes Chemical terrorism agent: limited - volatility in open air
- low lethality compared to nerve gas
Devastating effects in a crowded, closed room
Toxicity: Interference with normal mitochondrial oxidation → lactic acidosis Toxicity: Interference with normal mitochondrial oxidation → lactic acidosis High affinity for ferric iron (Fe3+) Brain and heart targeted because most dependent on oxidative phosphorylation
Clinical presentation: route and dose of exposure Inhalation of gas: LOC within seconds Oral exposure: symptoms from 30 min up to several hours “Bitter almond” smell
Mild exposures: Mild exposures: - Tachypnea and hyperpnea
- Tachycardia
- Flushing
- Dizziness and headaches
- Diaphoresis
- Nausea and vomiting
Serious exposures: - Seizures, coma and apnea
- Cardiac arrest
Laboratory findings: Laboratory findings: - Cyanide levels (levels > 1.0 mg/L produce acidosis)
- Large anion gap (lactic acidosis)
- Venous blood gas: diminished arterial-venous o2 (Ao2-Vo2) difference
- EKG changes
Management: Management: - Removal of victim to fresh air
- Removal of any wet clothing and skin decon
- Intensive supportive care
- 100% oxygen
- Mechanical ventilation
- Circulatory support (crystalloids and vasopressors)
- Correction of metabolic acidosis (IV NaHCO3)
- Benzodiazepines for seizure control
- Antidotes: Sodium nitrite and sodium thiosulfate
Stage I – Sodium Nitrite: Stage I – Sodium Nitrite: - Methemoglobin-forming agent (high affinity for cyanide)
- Antidote should be infused slowly over 5-10 minutes
- Nitrite induced hypotension
- Pediatric dosing based on weight and hgb [ ]
Stage I – Sodium Nitrite: Stage I – Sodium Nitrite: - Methemoglobin levels should be monitored
- Levels peak at 35-70 minutes
- 10-15% (therapeutic level)
- Levels of 20-30%: headaches and nausea
- Levels of 30-50%: weakness, dyspnea and tachycardia
- Levels of 50-70%: dysrhythmias, CNS depression and seizures
- Level of 70%: death
Stage I – Sodium Nitrite: Stage I – Sodium Nitrite: - Amyl nitrite perles: administered first
- Perles crushed in gauze and held near nose and mouth for 30 seconds
- Produces a methemoglobin level of 3-7 %
- Once IV line established, sodium nitrite can be administered
- Little utility in severely toxic patient
Stage II – Sodium thiosulfate: Stage II – Sodium thiosulfate: - Provision of a sulfur donor
- Conversion of cyanide → thiocyanate
- Less toxic
- Renally excreted
- Treatment:
- Efficacious and benign
- Used alone for mild to moderate cases
Taylor Cyanide Antidote Kit: Taylor Cyanide Antidote Kit: • Amyl Nitrite (inhaled) + Sodium nitrite (IV): formation of methemoglobin which combines with cyanide (high affinity) • Sodium thiosulfate (IV) – produces thiocyanate, excreted in urine
New antidote under investigation: New antidote under investigation: - Hydroxocobalamin (vitamin B12a)
Cyanide couples with cobalt → cyanocobalamin (nontoxic) No hypotensive side effects (Na nitrite) Pediatric data lacking
Decontamination Decontamination - Appropriate PPE
- Disrobing, Water/soap
- Peds considerations
Nerve Agents (Sarin) - Acetylcholinesterase inhibitors → cholinergic syndrome (SLUDGE) (3 B’s)
- NMJ: muscle fasciculation and twitching
- Respiratory/neurological symptoms
- Antidote: Atropine/ 2-PAM
Vessicants Vessicants - Derm/ocular manifestations
- Severe: respiratory
- Sulfur mustard: garlic/mustard odor
- Lewisite: geranium odor / antidote: BAL
- Phosgene oxime: no vesicle formation
Pulmonary agents - Severe respiratory symptoms/pulmonary edema
- Phosgene: newly mown hay smell
Cyanide Cyanide - Lactate acidosis
- Bitter almond smell
- Seizures/coma
- Antidote: Sodium nitrite and sodium thiosulfate
- Monitor methemoglobin levels
Other agents: - Riot control agents
- Incapacitating agents
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