Chemical Warfare AgentsAnna Healey, MD PGY-24/30/2014

Objectives

Warfare history

Qualities of chemical agents

Classes of chemical agents

Management of exposures

Decontamination and protection

Chemical Warfare in History

Poisoned spears and arrows

Peloponnesian War: burning wood and sulfur to create noxious smoke to stall the Athenians

World War I: over 50k tons of gases used, causing 1.3 million deaths

Syrian Conflict

http://www.cnn.com/video/?/video/world/2014/04/21/tsr-dnt-labott-syria-new-chemical-weapons.cnn&video_referrer=http%3A%2F%2Fwww.cnn.com%2Fvideo%2Fdata%2F2.0%2Fvideo%2Fworld%2F2014%2F04%2F21%2Ftsr-dnt-labott-syria-new-chemical-weapons.cnn.html%3Fhpt%3Dhp_t2

Qualities to Consider

Individuals vs. population

Detectable vs. undetectable

Persistent vs. non-persistent

Volatility

Method of distribution (solid, liquid, gas)

System affected (nerve, respiratory, mucous membrane, blood)

Classes of Agents

Nerve agents

Asphyxiants/blood agents

Vesicant/blister agents

Choking/pulmonary agents

Tear agents

Cytotoxic agents

Nerve AgentsMain effects on nicotinic and muscarinic receptors via acetylcholinesterase inhibition

Inhalation or absorption through skin

Signs/symptoms: SLUDGE, killer Bs, seizures, muscle fasciculations

Rx: atropine/2-PAM

Examples:Sarin

Insecticides/pesticides

VX

VR

Nerve Agents

https://www.youtube.com/watch?v=doytZVNltc4

Asphyxiants

Arsine: causes hemolysis

Cyanogen chloride/hydrogen cyanide, carbon monoxide: blocks oxidative phosphorylation

Generally via inhalation

Signs/symptoms: confusion, nausea, altered mental status, lactic acidosis, cherry red skin, seizures

Vesicants/Blister Agents

Acid-forming agents that affect mucous membranes and skin; also respiratory tract

Cause large blisters with secondary effects, skin/eye/mucous membrane irritation, respiratory distress/failure

Examples:Mustard gas

Lewisite

Choking/Pulmonary Agents

Also acid-forming, but work primarily in respiratory tract

Cause respiratory irritation with cough, dyspnea, sore throat, bronchospasm, suffocation

Examples:Chlorine gas

Phosgene

Nitrogen oxides

Hydrogen chloride

Tearing Agents

Tear gas and pepper spray

Temporarily incapacitating with stinging of eyes and blurred vision

Cytotoxic Agents

Biological proteins that inhibit protein synthesis

Ricin and abrin

Inhalation, ingestion, or injection

Exposurelatent periodflu-like illness

Pulmonary edema, dyspnea, GI hemorrhage, kidney and liver failure

Management of Exposures

PERSONAL PROTECTION

DECONTAMINATION

SUPPORTIVE CARE

Specific antidotes:Nerve agents—atropine/2-PAM

Asphyxiants—Cyanokit

All others—no antidote

PPE Presentation