1.18k likes | 1.35k Views
ACT FAST. Agent Characteristics and Toxicology First Aid and Special Treatment INSTRUCTOR’S SLIDES AND NOTES. MODULE 1: INTRODUCTION. ACT FAST— A gent C haracteristics and T oxicology: F irst A id and S pecial T reatment. Target Audience. All pre-hospital emergency medical personnel
E N D
ACT FAST Agent Characteristics and Toxicology First Aid and Special Treatment INSTRUCTOR’S SLIDES AND NOTES
MODULE 1: INTRODUCTION • ACT FAST—Agent Characteristics and Toxicology: First Aid and Special Treatment
Target Audience • All pre-hospital emergency medical personnel • Primarily directed toward EMTs with basic life support credentials
Course Goal • Prepare emergency medical personnel to respond to chemical warfare agent release and provide appropriate medical treatment
Primary Training Objectives Prepare students to • Describe initial first-aid treatment for victims of nerve agent exposure • Describe initial first-aid treatment for victims of blister agent exposure
Secondary Objectives In order to master the two primary objectives, you must be able to • Describe potential hazards of nerve agents--what they are, routes of exposure, and how they work • Describe potential hazards of nerve agents--what they are, routes of exposure, and how they work • Identify signs and symptoms of nerve agent exposure • Identify signs and symptoms of blister agent exposure
Relation to Other CSEPP Training Materials • Students should also complete these related courses • Chemical Awareness • Decontamination of People Potentially Exposed to Chemical Agents • Personal Protective Equipment • Use of Auto-Injectors by Civilian Emergency Response Personnel • State and local CSEPP offices may identify other training courses
MODULE 2:BACKGROUND INFORMATION • Objectives • Provide general information about the U.S. Army’s chemical warfare agent stockpile • Enable students to identify chemical warfare agents stored at the local Army installation
Umatilla Chemical Depot, Hermiston, OR Newport Chemical Depot, Newport, IN Deseret Chemical Depot, Tooele, UT Edgewood Chemical Activity, Aberdeen Proving Ground, MD Blue Grass ChemicalActivity, Richmond, KY Pueblo Chemical Depot, Pueblo, CO Pine Bluff Chemical Activity, Pine Bluff, AR Anniston Chemical Activity, Anniston, AL Chemical Stockpile Locations
MODULE 3:CHEMICAL AGENTS—CHARACTERISTICS AND EFFECTS • Objectives: • Describe potential hazards of nerve agents: what they are, how they work, potential routes of exposure • Describe potential hazards of blister agents: what they are, how they work, potential routes of exposure • Identify the most likely routes of exposure
Nerve Agents • Attack the body’s nervous system • Classified as organophosphates • Include three agents in the chemical stockpile • GA (small amount stored at Deseret Chemical Depot, Utah) • GB • VX
Nerve Agents—Physical Properties • Stored in liquid form in stockpile • Become volatile and generate vapor at warm temperatures • Potential for release in vapor or aerosol form • Vapors are heavier than air
GAPhysical Properties • Colorless to brown liquid • Faintly fruity odor (odorless when pure) • Evaporates more rapidly than VX but less rapidly than GB
GBPhysical Properties • Usually colorless, watery in pure form • Has almost no odor • Volatilizes at lower temperature than VX • Evaporates much more rapidly than VX but less rapidly than water
VXPhysical Properties • Oily liquid; resembles light- weight oil • Usually a pale amber color (colorless in pure form) • Odorless • Tasteless • Persistent; designed to cling to whatever it splatters on • Persistence is weather-dependent
Relative Toxicity • Agent VX • LD50 (liquid on skin): 5 mg/155-lb human • LCt50 (vapor inhalation): 15 mg-min/m3 • Agent GB • LD50 (liquid on skin): 1.7 g/155-lb human • LCt50 (vapor inhalation): 35 mg-min/m3 • Agent GA • LD50 (liquid on skin): 1.5 g/155-lb human • LCt50 (vapor inhalation): 70 mg-min/m3
How Nerve Agents Work • Nervous system controls normal functions through use of chemicals • Chemicals act as instructions to nerves, muscles, and glands • Two forms of instructions: • Stimulate (move or work) • Relax (stop or rest) • Nerve agent interferes with normal instructions to relax
Nerve Agent Leads to Destruction of System Control • Over-stimulates nerve endings and central nervous system • Causes muscles and certain glands to malfunction
Normal Nervous System Function • A nerve impulse is transmitted along the nerve cells • Acetylcholine is released and crosses the synapse (gap) between cells
Normal Nervous System Function • The acetylcholine stimulates the target cell • Acetylcholinesterase is released to deactivate the acetylcholine
Normal Nervous System Function • The target cell relaxes
Nerve Agent Interference • Nerve agent inactivates acetylcholinesterase • Excess acetylcholine accumulates • Muscle action becomes uncontrolled and twitchy • Muscle can tire and collapse • Gland continues to secrete sweat, tears, or mucus
Routes of Exposure Inhalation Ingestion Direct Contact
Inhalation • After nerve agent enters the lungs, it is absorbed rapidly into the blood stream • Respiratory failure is the chief cause of death after severe exposure
Direct Contact • Absorption through skin • All agents can be absorbed • VX persists longer • GB evaporates quickly, but still a threat • Scrape or cut in skin allows immediate entry • Entry also through eyes
Ingestion • Access to bloodstream via digestive system • Effects similar to inhalation, but at greater doses
Critical Routes of Exposure • The critical routes of exposure that you should be most concerned with are • Inhalation of agent vapors or aerosols • Eye and skin contact with agent vapors or aerosols
Blister Agents (Vesicants) • Poisons that destroy individual cells • Blisters are most noticeable effect from exposure • Includes sulfur mustard • H (up to 30% impurities) • HD (much purer) • HT (mixed with other agent to lower freezing temperature) • Stockpile originally also included Lewisite, which has now been completely destroyed
Sulfur MustardPhysical Properties • Mustard-garlic-like odor • Stored as liquids or solids • H and HD freeze at 57oF • HT freezes at 34oF • Becomes volatile and generates vapors if heated • Burns well once ignited • Pale yellow to dark brown in liquid form • Colorless gas in vapor form
Relative Toxicity • LD50 (liquid on skin): 1.4 g/70-kg human • Between 4 and 32 micrograms/70-kg human can cause blistering • LCt50 (vapor inhalation): 1000 mg-min/m3
How Blister Agents Work • Chemical burns to skin—especially warm, moist surfaces • Chemical burns to soft membranes • Membranes surrounding eye • Eyeball • Lung tissue • Mouth • Throat
Sulfur Mustard Exposure • Cell membranes damaged within minutes • Little or no pain at time of exposure • Burning, stinging, and blisters appear in 2 to 36 hours
Routes of Exposure Inhalation Ingestion Direct Contact
Inhalation • Can destroy mucous membrane lining of • Nasal passages • Throat • Bronchial tubes • Can cause inflammation and hemorrhage and allow infection • Most damage to upper airways, but heavy exposure can injure lungs
Direct Contact with Liquid or Vapor • Highly damaging to skin—especially warm, moist areas • Mucous membranes very susceptible to effects • Lining around eyelids • Inside mouth and nose • Warmth and moisture increase effect
Ingestion • Exposure can occur if agent deposited on or in food items, drink, etc. • Injures warm, moist tissues of mouth, throat, and esophagus
Critical Routes of Exposure • The critical routes of exposure that you should be most concerned with are • Inhalation of agent vapors or aerosols • Eye and skin contact with agent vapors or aerosols
MODULE 4:SIGNS AND SYMPTOMSOF EXPOSURE • Objectives • Identify the signs and symptoms of nerve agent exposure • Identify the signs and symptoms of blister agent exposure
Situation Assessment • In treating patients who may have been exposed to a chemical agent, you must be able to assess the situation based on • Information known about the chemical release • Recognition of the event based on signs and symptoms
The Most Important Points to Learn from this Module • The most prominent signs and symptoms of blister agent exposure • Irritation, reddening, and swelling of eye tissues (conjunctivitis) • Reddening of the skin (erythema) • Blisters • Respiratory irritation and distress
Signs and Symptoms: Nerve Agent Vapor Exposure • Affects organs directly contacted by agent • Affects other organs as agent is absorbed into body systems • Signs and symptoms appear in seconds to minutes • Peak effects within 15 to 20 minutes after mild-to-moderate exposure stops
Signs and Symptoms:Mild Vapor Exposure • Pinpoint pupils (w/ or w/o redness, pain) • Dim or blurred vision • Runny nose • Slight chest tightness • Slight difficulty breathing • Secretions (tears, nasal fluids, saliva, sweat, phlegm) • Nausea and vomiting
Signs and Symptoms:Moderate Vapor Exposure • Pinpoint pupils (w/ or w/o redness, pain) • Dim or blurred vision • Excessively runny nose • Pronounced chest tightness • Plentiful secretions • Moderate to severe breathing difficulty • Nausea and vomiting • Diarrhea • Generalized muscle weakness
Signs and Symptoms:Severe Vapor Exposure • Same as for Moderate exposure, plus • Loss of consciousness • Convulsions • Generalized rippling of muscles under skin • Flaccid paralysis • Cessation of breathing • Involuntary urination or defecation
Signs and Symptoms:Liquid Nerve Agent on Skin • Effects differ from vapor exposure • Different signs and symptoms • Different timing of appearance • General rule: the more severe the exposure, the quicker effects appear
Signs and Symptoms:Mild Liquid on Skin Exposure • Sweating at site of exposure • Rippling of muscles under skin at site of exposure • Effects appear in 10 min to 18 hrs, depending on dose
Signs and Symptoms:Moderate Liquid/Skin Exposure • Same as for Mild exposure, plus • Nausea, vomiting, and diarrhea • Generalized sweating • Generalized weakness, tiredness, or ill feeling • Effects appear in 10 min to 18 hrs, depending on dose