dpt 8.1 emergency management of nerve agent casualties
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DPT 8.1
Emergency Management of Nerve Agent Casualties
DPT 8.1
Hospital Provider Management of Chemical Agent Casualties
DPT 8.1
EMS Management of Chemical Agent Casualties
DPT 8.1
Objectives
• Describe physiological actions of nerve agents
• Recognize signs and symptoms of nerve agent
exposure
• Describe emergency management of nerve
agent victims
DPT 8.1
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)
DPT 8.1
Normal Nerve Function
AChACh
DPT 8.1
Normal Nerve Function
AChACh
DPT 8.1
Normal Nerve Function
AChACh
AChEAChE
DPT 8.1
How Nerve Agents Work
AChEAChE
AChACh GBGB
DPT 8.1
Effects of Nerve Agents
Muscarinic
– Smooth muscles
– Exocrine glands
– Cranial nerves (vagus)
Nicotinic
– Skeletal muscles
– Ganglia
Two types of cholinergic receptors:
DPT 8.1
SLUDGE-MSLUDGE-M
SSalivation
LLacrimation
UUrination
DDefecation
GGI upset – nausea/vomiting, cramps, diarrhea
EEmesis
MMuscle twitching
Signs and Symptoms of Nerve Agents Mnemonic
DPT 8.1
DUMBELSDUMBELSDDiarrhea
UUrination
MMiosis
BBradycardia, Bronchorrhea, Bronchospasm
EEmesis
LLacrimation
SSalivation, Sweating
Signs and Symptoms of Nerve Agents Newer Mnemonic
DPT 8.1
Signs and Symptoms of Nerve Agents Muscarinic Sites
• Increased secretions– Saliva
– Tears
– Runny nose
– Secretions in airways
– Secretions in gastrointestinal tract
– Sweating
DPT 8.1
Signs and Symptoms of Nerve AgentsMuscarinic Sites
• Smooth muscle contraction– Eyes: miosis
– Airways: bronchoconstriction (shortness of breath)
– Gastrointestinal: hyperactivity (nausea, vomiting, and diarrhea)
DPT 8.1
Signs and Symptoms of Nerve Agents Nicotinic Sites
• Skeletal muscles– Fasciculations
– Twitching
– Weakness
– Flaccid paralysis
• Other (ganglionic)– Tachycardia
– Hypertension GBGB
AChACh
DPT 8.1
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
DPT 8.1
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
DPT 8.1
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
DPT 8.1
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
DPT 8.1
Nerve AgentsTreatment
• Removal from exposure
• Decontamination
• Airway/ventilation
– High resistance
• Antidotes
– Atropine
– 2-PAMCl
– Diazepam
DPT 8.1
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 ventricular fibrillation
DPT 8.1
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
DPT 8.1
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
DPT 8.1
Nerve AgentsTreatment
• 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
AChEAChE 2-PAMCl
Nerve Nerve AgentAgent
DPT 8.1
Nerve AgentsTreatment - Autoinjectors
DPT 8.1
MARK I Injection IM vs. IV
DPT 8.1
MARK I InjectionsDispersal
DPT 8.1
Nerve AgentsTreatment
• Diazepam
– Decreases seizure activity
– Reduces seizure-induced brain injury
– Give to severely intoxicated casualties whether convulsing or not
DPT 8.1
Nerve AgentsTreatment
• No signs/symptoms
• Reassure
• Observe
– Vapor: 1 hour
– Liquid: Up to 18 hours
DPT 8.1
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:
DPT 8.1
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:
DPT 8.1
Nerve AgentsTreatment
• Severe vapor or liquid exposure
– 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
DPT 8.1
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
DPT 8.1
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
DPT 8.1
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)
DPT 8.1
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
DPT 8.1
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