OBJECTIVES • Learn how to perform a rapid assessment of a nerve agent terrorism situation. • Recognize characteristic signs and symptoms of nerve agent poisoning.
OBJECTIVES • Understand proper decontamination for nerve agent poisoning. • Learn medical management of nerve agent exposed victims. • Learn specific antidotes for nerve agent poisoning victims.
ScenarioFriday, January 31 – 8:47 AM (Rush Hour) • An unknown gas is released in the downtown rapid transit station. It is described as a thick mist, and was found in 5 separate stops. Thousands of commuters rapidly fled the stations to the streets. EMS transport is overwhelmed, and several local ED’s are unable to absorb the patients presenting by ambulance, car, taxi, and on foot. • Many patients present to offices and local health departments.
ScenarioFriday, January 31 – 10:02 AM • One patient that presents to a local health clinic complains of tearing and runny nose. He also has mild shortness of breath. Mild wheeze is noted on exam. • Ten other patients at the clinicare asymptomatic, but are very worried.
ScenarioFriday, January 31 – 10:27 AM • Public health officials confirm that the gas was Sarin, similar to the toxin used in the subway of Tokyo.
Things to Consider • Has your staff been adequately trained about chemical weapons? • Does your staff understand basic principles of decontamination? • Who should your staff alert? • Who will alert your staff in the event of a chemical terrorism event?
Characteristics of Nerve Agents • Liquids that disseminate in the vapor/aerosolized form • Onset is abrupt (seconds to hours) • Designed to irritate, incapacitate, injure or kill • Predominantly inhalational and dermal threats • If death occurs, usually respiratory cause
Characteristics of Nerve Agents • Chemical incidents are obvious shortly after exposure. • Biological agents will take days to cause symptoms. • ONE patient can contaminate your facility • First responders/health care providers are in the line of fire
History of Nerve Agent Weapons Use • First used as a weapon during WWI • Most recent event - Japanese subway incident in 1995 • Aum Shinrikyo cult released Sarin into 5 subway cars in downtown Tokyo • 12 deaths, hundreds injured, 5500 sought care – 4,600 self-referred • 135 first responders were injured
General Characteristics • Military • Tabun (GA), Sarin (GB), Soman (GD), VX • Commercial • Parathion, Sevin • Therapeutic Drugs • Antilirium® • Prostigmine ® • Mestinon ®
General Characteristics • Effects of vapor - immediate • Wide range of symptoms - Affects sensitive organs of the face and respiratory system - Over-stimulation of the central nervous system
Normal Nerve Function AChE ACh
Nerve Agent Action AChE GB ACh
Signs and SymptomsMuscarinic Effects SLUGBAM: • Salivation • Lacrimation • Urination • GI distress (Nausea, Vomiting, Diarrhea) • Bronchorrhea (Bradycardia, Bronchospasm) • Abdominal cramps • Miosis
How Bad Is This Stuff? VX – LD50
Signs and SymptomsEffect on pupil at x number of days 3 6 13 20 41 62
Diagnosis • Clinical picture is key • Erythrocyte acetylcholinesterase activity level - Amount of inhibition does not correlate with symptoms • Various electronic and “paper” detectors are available - for HAZMAT use
General Management • PPE (mask, gloves and protective suit) • Decontamination • Don’t let your setting become contaminated • ABC’s • Communicate with public health officials • Poison Control Center (800 222-1222) • Antidotes where appropriate
Prehospital Management • Soap and Water • Hypochlorite Solution • 0.5% for skin • 6 oz calcium hypochlorite in 5 gallons water • 5.0% for equipment • 48 oz calcium hypochlorite in 5 gallons water
Treatment • Adult atropine dose: “enough” • Give atropine regardless of heart rate • Pediatric Considerations • 0.01mg/kg • Atropine used until endpoint achieved (resolution of secretions)
Nerve Agent 2-PAMCl AChE Antidote • Atropine - Blocks the effects of neurotransmitter • 2-PAMCl (Pralidoxime) - Removes nerve agent from the enzyme • Military Autoinjector • MARK I
Question #1 • What was the public health lesson learned from the 1995 Sarin terrorists attack in the subway system of Tokyo, Japan? • This bioterrorist attack could only occur in a large city with an enclosed underground subway system. • The walking wounded and hysterical patients often overload the medical system • Religious cults should be placed under strict federal surveillance • Ample supplies of the antidotes are readily available
Question #2 • In the acute phase of poisoning, one of the consistent findings that differentiates Sarin poisoning from hysteria is: • Cholinesterase enzyme blood levels • Garlic smell on victims • Pinpoint pupils • Tachycardia
Question #3 • Based on past experience, which of the hospital supplies/equipment below is most likely to run out after a mass casualty exposure to Sarin gas? • Ventilators • Personal Protective Equipment • Hemodialysis machines • Atropine