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Emergency Management of Nerve Agent Casualties. Hospital Provider Management of Chemical Agent Casualties. EMS Management of Chemical Agent Casualties. Objectives. Describe physiological actions of nerve agents Recognize signs and symptoms of nerve agent exposure
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Objectives • Describe physiological actions of nerve agents • Recognize signs and symptoms of nerve agent exposure • Describe emergency management of nerve agent victims
Nerve Agents • Tabun (GA), Sarin (GB), Soman (GD), VX • Most toxic of the chemical agents • Penetrate skin, eyes, lungs • Loss of consciousness, seizures, apnea, death after large amount • Diagnosis made clinically; confirmed in laboratory (cholinesterase)
Normal Nerve Function AChE ACh
How Nerve Agents Work AChE GB ACh
Effects of Nerve Agents Muscarinic • Smooth muscles • Exocrine glands • Cranial nerves (vagus) Nicotinic • Skeletal muscles • Ganglia Two types of cholinergic receptors:
Signs and Symptoms of Nerve Agents Mnemonic SLUDGE-M Salivation Lacrimation Urination Defecation GI upset – nausea/vomiting, cramps, diarrhea Emesis Muscle twitching
Signs and Symptoms of Nerve AgentsNewer Mnemonic DUMBELS Diarrhea Urination Miosis Bradycardia, Bronchorrhea, Bronchospasm Emesis Lacrimation Salivation, Sweating
Signs and Symptoms of Nerve Agents Muscarinic Sites • Increased secretions • Saliva • Tears • Runny nose • Secretions in airways • Secretions in gastrointestinal tract • Sweating
Signs and Symptoms of Nerve AgentsMuscarinic Sites • Smooth muscle contraction • Eyes: miosis • Airways: bronchoconstriction (shortness of breath) • Gastrointestinal: hyperactivity (nausea, vomiting, and diarrhea)
Signs and Symptoms of Nerve Agents Nicotinic Sites ACh GB • Skeletal muscles • Fasciculations • Twitching • Weakness • Flaccid paralysis • Other (ganglionic) • Tachycardia • Hypertension
Nerve AgentsOther Signs and Symptoms • Cardiovascular • Tachycardia, bradycardia • Heart block, ventricular arrhythmias • Central Nervous System • Acute • Loss of consciousness • Seizures • Apnea • Prolonged (4-6 weeks) • Psychological effects
Signs and Symptoms of Nerve Agents Vapor Exposure • Mild exposure • Miosis (dim vision, eye pain), rhinorrhea, dyspnea • Moderate exposure • Pronounced dyspnea, nausea, vomiting, diarrhea, weakness • Severe exposure • Immediate loss of consciousness, seizures, apnea, and flaccid paralysis • Vapor effects occur within seconds, peak within minutes; no late onset
Signs and Symptoms of Nerve Agents Liquid Exposure • Mild exposure (to 18 hours) • Localized sweating • Fasciculations • No miosis • Moderate exposure (<LD50) (to 18hours) • Gastrointestinal effects • Miosis uncommon • Severe exposure (LD50) (<30 minutes) • Sudden loss of consciousness • Seizures • Apnea • Flaccid paralysis • Death
Diagnosis of Nerve Agent Exposure • Symptomatic • May be systemic or organ-specific • Combination of symptoms is more definitive • Situational • Multiple casualties with similar symptoms • Time or location factors in common
Nerve AgentsTreatment • Removal from exposure • Decontamination • Airway/ventilation • High resistance • Antidotes • Atropine • 2-PAMCl • Diazepam
Nerve Agents Treatment • Atropine • Antagonizes muscarinic effects • Dries secretions; relaxes smooth muscles • Given IV, IM, ET • No effect on pupils • No effect on skeletal muscles • IV in hypoxic patient Ù ventricular fibrillation
Nerve AgentsTreatment • Starting dose - 2 mg • Maximum cumulative dose - 20 mg • Total dose calculated over time; but enough must be administered to abate severe symptoms if casualty is to survive • Insecticide poisoning requires much more • Side effects in normal people • Mydriasis • Blurred vision • Tachycardia • Decreased secretions and sweating
Nerve AgentsTreatment • Atropine - How much to give? • Until secretions are drying or dry • Until ventilation is “easy” • If conscious or casualty is comfortable • Do not rely on heart rate/pupil size
Nerve AgentsTreatment Nerve Agent 2-PAMCl AChE • Pralidoxime Chloride (2-PAMCl) • Remove nerve agent from AChE in absence of aging • 1 gram slowly (20-30 minutes) in IV infusion • Hypertension with rapid infusion • No effects at muscarinic sites • Helps at nicotinic sites
Nerve AgentsTreatment • Diazepam • Decreases seizure activity • Reduces seizure-induced brain injury • Give to severely intoxicated casualties whether convulsing or not
Nerve AgentsTreatment • No signs/symptoms • Reassure • Observe • Vapor: 1 hour • Liquid: Up to 18 hours
Nerve AgentsTreatment Mild vapor exposure Miosis, rhinorrhea - observation only Increasing SOB – treat Mild liquid exposure Localized fasiculations & sweating - treat One MARK I kit (2 mg atropine/ 600 mg 2-PAMCl) OR 1 gram 2-PAMCl IV 2 mg atropine, IM or IV Parenteral atropine will not reverse miosis Treat with:
Nerve AgentsTreatment Moderate vapor or liquid exposure More severe respiratory distress Muscular weakness Nausea, vomiting, and diarrhea One or two MARK I kits OR IV: 2 to 4 mg atropine 1gm 2-PAMCl (infusion) Treat with:
Nerve AgentsTreatment Severe vapor or liquidexposure Unconscious Seizing or post-ictal Apneic or severe dyspnea Twitching or flaccid Effects in 2 or more body system 3 MARK I kits OR 6 mg atropine IV and 1 gram of 2-PAMCl IV Airway Ventilation/O2 Consider diazepam 10 mg IM (2 to 5 mg IV) Repeat atropine every 5 to 10 minutes as needed Repeat 2-PAMCl in one hour
Nerve AgentsAge-Related Treatment • Atropine • Infant (0 to 2) 0.5 mg IM • Child (2 to 10) 1.0 mg IM • Adolescent (> 10) 2.0 mg IM • Elderly 1.0 mg IM • IV for infants and children 0.02 mg/kg
Nerve AgentsAge-Related Treatment • 2-PAMCl • < 20 kg 15 mg/kg IV • > 20 kg 600-mg IM autoinjector • Elderly 1/2 adult dose (7.5 mg/kg IV) • 2-PAMCl-induced hypertension • Phentolamine Adult - 5 mg IV Child - 1 mg IV
Nerve AgentsAge-Related Treatment • Diazepam • - Infants > 30 days old 0.2 - 0.5 mg/kg IV • to 5 years q 2 to 5 min • (max 5 mg) • - Children > 5 years 1 mg IV • q 2 to 5 min • (max 10 mg)
Nerve AgentsSummary • Vapor exposure • Symptoms develop suddenly • Most ambulatory victims require minimal intervention • Risk of secondary contamination, which is minimized by removing the victim’s clothing • Requires immediate access to antidotes • Liquid exposure • Symptoms delayed minutes to hours • Greater need for decontamination • High risk of secondary contamination; victims require decontamination (clothing removal & washdown) • Requires immediate access to antidotes
Reference DOMESTIC PREPAREDNESS TRAINING TEAM HELPLINE: (800) 368-6498FAX: (410) 612-0715 E-MAIL: cbhelp@apgea.army.mil U.S. ARMY SBCCOM ATTN: AMSSB-RDP 5183 BLACKHAWK ROAD ABERDEEN PROVING GROUND MARYLAND 21010-5424