The Chemical Incident

1
The Chemical Incident

• Management of Chemical Casualties

2
Hospital Provider Management of Chemical Agent
Casualties
3
Chemical Warfare AgentsTerminal Objective

• Describe types of chemical warfare agents
• Recognize signs and symptoms of exposure
• Describe management of chemical agent attack
  victims

4
Chemical Warfare AgentsHistorical Perspective

• Chemicals used in military operations to kill,
  injure, or incapacitate
• Battlefield use
• World War I and Middle East conflicts
• Terrorist use
• Matsumoto and Tokyo, Japan

5
Chemical Agent Terrorist Attacks

• Matsumoto
• Approximately 280 injured
• 7 dead
• Tokyo
• 12 dead
• Approximately 1,000 hospitalized
• 5,500 sought medical care
• 10 of first responders injured

6
Chemical Warfare Agents

• Tabun, Sarin, Soman, VX
• Mustard, Lewisite
• Phosgene, Chlorine, Ammonia, Cyanide
• Mace, Pepper Spray

• Nerve Agents
• Vesicants
• Industrial Chemicals
• Riot Control Agents

7
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)

8
Normal Nerve Function
ACh
9
Normal Nerve Function
ACh
10
Normal Nerve Function
AChE
ACh
11
How Nerve Agents Work
AChE
GB
ACh
12
Effects of Nerve Agents

• Organs with cholinergic receptors
• Muscarinic
• Smooth muscles
• Glands
• Nicotinic
• Skeletal muscles
• Ganglia

13
Signs and Symptoms of Nerve AgentsMuscarinic
Sites

• Increased secretions
• Saliva
• Tears
• Runny nose
• Secretions in airways
• Secretions in gastrointestinal tract
• Sweating

14
Signs and Symptoms of Nerve AgentsMuscarinic
Sites

• Smooth muscle contraction
• Eyes miosis
• Airways bronchoconstriction (shortness of
  breath)
• Gastrointestinal hyperactivity (nausea,
  vomiting, and diarrhea)

15
Signs and Symptoms of Nerve AgentsNicotinic Sites

• Skeletal muscles
• Fasciculations
• Twitching
• Weakness
• Flaccid paralysis
• Other (ganglionic)
• Tachycardia
• Hypertension

16
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

17
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

18
Signs and Symptoms of Nerve Agents Liquid
Exposure

• Mild exposure (to 18 hours)
• Localized sweating
• Fasciculations
• No miosis
• Moderate exposure (ltLD50) (to 18 hours)
• Gastrointestinal effects
• Miosis uncommon
• Severe exposure (LD50) (lt30 minutes)
• Sudden loss of consciousness
• Seizures
• Apnea
• Flaccid paralysis
• Death

19
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

20
Nerve AgentTreatment

• Airway/ventilation
• High resistance
• Antidotes
• Atropine
• 2-PAMCl
• Diazepam

21
Nerve Agent 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

22
Nerve AgentTreatment

• 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

23
Nerve AgentTreatment

• 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

24
Nerve AgentTreatment

• Pralidoxime Chloride (2PAM-Cl)
• 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

25
Nerve AgentTreatment - Autoinjectors
26
MARK I Injection vs. IM or IV
27
Nerve AgentTreatment

• Diazepam
• Decreases seizure activity
• Reduces seizure-induced brain injury
• Give to severely-intoxicated casualties whether
  convulsing or not

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Nerve AgentTreatment

• Treatment regimen
• No signs/symptoms
• Reassure
• Observe
• Vapor 1 hour
• Liquid Up to 18 hours

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Nerve AgentTreatment

• 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

30
Nerve AgentTreatment

• Moderate vapor or liquid exposure
• One or two MARK I kits
• Or give IV
• 2 to 4 mg atropine
• 1gm 2-PAMCl (infusion)

31
Nerve AgentTreatment

• Severe - vapor or liquid
• Give 3 MARK I kits or 6 mg atropine and 1 gram of
  2-PAMCl as soon as possible
• Airway
• Ventilation/O2
• Consider diazepam 10 mg IM (2 to 5 mg IV)
• Repeat atropine every 5 to10 minutes as needed
• Repeat 2-PAMCl in one hour

32
Nerve AgentAge-Related Treatment

• Atropine
• Infant (0 to 2) 0.5 mg IM
• IV for infants and children 0.02 mg/kg
• Child (2 to 10) 1.0 mg IM
• Adolescent (gt 10) 2.0 mg
• Elderly 1.0 mg IM

33
Nerve AgentAge-Related Treatment

• 2-PAMCl
• lt 20 kg 15 mg/kg IV
• gt 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

34
Nerve AgentAge-Related Treatment

• Diazepam
• - Infants gt 30 days old 0.2 - 0.5 mg/kg IV
• to 5 years q 2 to 5 min
• (max 5 mg)
• - Children gt 5 years 1 mg IV
• q 2 to 5 min
• (max 10 mg)

35
Nerve Agent Summary

• Vapor exposure
• Symptoms develop suddenly
• Most ambulatory victims require minimal
  intervention
• Risk of secondary contamination, which is
  minimized by removing the victims 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

36
Vesicants (Blister Agents)

• Vesicants
• Sulfur mustard
• Lewisite

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Mustard

• Properties
• Vapor liquid threat
• Latent period between exposure effects
• Systemically toxic - similar to radiation

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Mustard Effects

• Quickly cyclizes in tissue
• Alkylates cell components, including DNA
• DNA damage, cell death

39
Mustard EffectsEye Injury

• Mild conjunctivitis
• Moderate/severe conjunctivitis, lid inflammation
  and edema, blepharospasm, and corneal roughening
• Corneal opacification, ulceration, and/or
  perforation
• Well over 95 had only mild to moderate
  conjunctivitis
• Under 1 had permanent damage to cornea

40
Mustard EffectsEye Injury
41
Mustard EffectsSkin Injury

• Erythema
• Small vesicles later coalesce
• Blisters/bulla
• Possible coagulation necrosis with liquid

42
Mustard EffectsAirway Injury

• Upper nose sinuses, pharynx
• (epistaxis, sore throat, hacking cough)
• Mid Larynx (hoarseness)
• Lower Bronchioles (dyspnea, productive cough)
• Pulmonary edema is rare

43
Mustard EffectsGI Injury

• Gastrointestinal
• Within 24 hours
• Nausea and vomiting
• Cholinergic effects
• After 3 to 5 days
• Tissue destruction

44
Mustard EffectsBone Marrow Damage

• Damages stem cells
• Decreased WBC, RBC, platelets after 3 - 5 days
• Survival rare if WBC lt 200

45
Skin Treatment

• Decontamination must be done within minutes to
  reduce damage
• Delays in decontamination will not prevent
  illness, but will prevent cross-contamination
• Supportive care - soothing lotions, frequent
  irrigation, topical antibiotics, pain medication
• Do NOT overhydrate not a thermal burn

46
Eye Treatment

• Topical mydriatics
• Topical antibiotics
• Vaseline on lid edges
• Topical steroids (only in the first 24 hrs)

47
Airway Treatment

• Cool mist, cough suppressants for mild symptoms
• Oxygen
• Assisted ventilation
• Early intubation
• Bronchodilators (steroids)
• Antibiotics AFTER organism identified

48
Lewisite Effects

• Causes severe irritation to eyes, skin, and
  airways IMMEDIATELY on exposure (no delay)
• Tissue necrosis, pseudomembranes
• Increased capillarypermeability
• No bone marrow effects

49
Lewisite - Treatment

• Immediate decontamination
• British anti-Lewisite (BAL) for systemic effects
• Supportive Care
• Oxygen

50
Vesicant Agent Summary

• Agents damage eyes, skin, respiratory system
  cause additional systemic effects
• Mustard
• Fast acting symptoms delayed, no specific
  antidote
• Lewisite
• Fast acting, symptoms immediate, BAL antidote
  available
• Decontamination is best initial treatment

51
Phosgene

• At high concentrations
• Irritates eyes, nose, upper airways possible
  laryngospasm
• Toxic to lungs by inhalation
• Carbonyl group damages alveolar-capillary
  membrane
• Non-cardiac pulmonary edema onset 2 to 12 hours
• Dyspnea, cough with sputum
• Management of non-cardiac pulmonary edema
• Hypoxia, fluid loss requires pulmonary care,
  careful fluid replacement
• ABSOLUTE REST POST-EXPOSURE

52
Chlorine

• High concentration or prolonged exposure
• Pulmonary edema, sudden death
• Eye irritation, cough, dyspnea
• More severe airway and lung
• damage with high concentration
• Management
• Remove from exposure manage airway
• Oxygen, ventilation, PEEP
• Intubation, bronchodilators

53
Ammonia

• Anhydrous Ammonia
• pHgt12 (household ammonia pH lt 12)
• Wide industrial use
• Plastics, fertilizer, explosives
• Irritating, corrosive causes necrosis, severe
  pain
• Serious injury to eyes, lungs, skin, GI tract
• Management
• Remove from exposure, decontaminate
• Symptomatic maintain airway

54
Riot Control Agents

• Irritating agents, lacrimators, tear gas
• Cause reaction in
• Eyes burning, tearing, eyelid spasm, redness
• Airways burning, coughing, dyspnea
• Skin burning, erythema
• Eye irrigation and supportive care

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Chemical Agent Summary

• Vapor exposure
• Nerve agent symptoms develop suddenly, mustard
  and phosgene symptoms are delayed
• Most ambulatory victims require minimal
  intervention
• Risk of secondary contamination
• Requires airway management antidotes for nerve
  agents and Lewisite

56
Chemical Agent Summary

• Liquid exposure
• Symptoms delayed minutes to hours
• Greater need for decontamination
• Risk of secondary contamination, victims require
  clothing removal decontamination
• Requires immediate access to antidotes