© 1999 lockheed martin energy research corporation ca128 nerve agent exposure
TRANSCRIPT
© 1999 Lockheed Martin Energy Research Corporation CA128
NERVE AGENT EXPOSURE
NERVE AGENT EXPOSURE
© 1999 Lockheed Martin Energy Research Corporation
OBJECTIVE
• Identify the specific signs and symptoms of nerve agent exposure
CA129
© 1999 Lockheed Martin Energy Research Corporation CA130
HOW NERVE AGENTS WORK
• Attack nervous system– nervous system controls body functions through use of
chemicals which act as “instructions” to nerves, muscles and glands
• Nerve agents interfere with normal chemical instructions
Nerve synapse
© 1999 Lockheed Martin Energy Research Corporation CA131
NORMAL NERVOUS SYSTEM
• At nerve ending, acetylcholine is released
• Acetylcholine crosses synapse between nerve endings– if junction with skeletal muscle, muscles cells contract
– if junction with smooth muscles, muscles move rhythmically
– if junction with gland, glandular cells secrete
• Acetylcholine is inactivated by acetylcholinesterase
Normal activity at nerve synapse
© 1999 Lockheed Martin Energy Research Corporation
HOW NERVE AGENTS WORK
• Nerve agents block acetylcholinesterase so it cannot destroy acetylcholine– acetylcholine
accumulates and continue to stimulate target nerve
– muscles twitch uncontrollably and repetitively
– excess secretions of glands
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Nerve agent interferes with normal synapse activity
© 1999 Lockheed Martin Energy Research Corporation CA133
ROUTES OF EXPOSURE
• Inhalation
• Ingestion
• Direct Contact
© 1999 Lockheed Martin Energy Research Corporation
• Nerve agents enter through respiratory system
• Rapidly and effectively enter into blood stream
Respiratory failurechief cause of death
after severe exposure
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INHALATION
Nerve agent inhaled into respiratory system
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DIRECT CONTACT
• Skin or eyes are touched with agent vapor or liquid• Nerve agents absorbed through skin
– VX remains on skin and absorbed more completely
– GB evaporates quickly, but still a threat
• Scrapes, cuts or other skin damage offer direct entry points– freshly shaven skin, sunburn, insect bites, rashes
• Eyes most sensitive organ for nerve agent vapor effects
© 1999 Lockheed Martin Energy Research Corporation CA136
INGESTION
• Ingestion of contaminated food or drink, incidental hand to mouth or eye contact, smoking
• Unlikely that agent will contaminate food or drink
Gastrointestinal system
© 1999 Lockheed Martin Energy Research Corporation
SIGNS AND SYMPTOMS
• Signs are objective evidence of a medical condition• Signs are observed (runny nose, drooling)• Symptoms are subjective evidence• Symptoms are verbally communicated
(headache, eye pain)
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Not all signs and symptoms may appear . . .
Dose, duration, and route of exposure
make a difference
© 1999 Lockheed Martin Energy Research Corporation CA138
SIGNS AND SYMPTOMS OF
NERVE AGENT EXPOSURE• Miosis• Dim or blurred vision• Respiratory trouble• Difficulty in breathing• Increased oral/nasal
secretions• Localized sweating• Nausea and vomiting
• Abdominal cramping• Involuntary urination or
bowel movements• Heartbeat irregularities• Generalized weakness• Twitching or muscles
spasms• Convulsions and coma
© 1999 Lockheed Martin Energy Research Corporation CA139
OTHER SIGNS AND SYMPTOMS OF
NERVE AGENT EXPOSURE
• May result from early or mild exposure:– headache
– anxiety
– restlessness
– giddiness
– irritability
© 1999 Lockheed Martin Energy Research Corporation CA140
FACTORS AFFECTING NERVE AGENT SIGNS AND
SYMPTOMS• Signs and symptoms may appear immediately or be
delayed• Reaction time depends on
– type of agent
– amount of agent person has been exposed to
– dose (how much a person has absorbed)
– duration of exposure
– route of exposure
– sensitivity of person’s system
© 1999 Lockheed Martin Energy Research Corporation
Immediate if moderate to large amounts areinhaled
if moderate to large amounts are spilled onto the skin
Delayed if small amounts are involvedif agent has been absorbed through
skin in small localized area
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FACTORS AFFECTING NERVEAGENT SIGNS AND
SYMPTOMS
© 1999 Lockheed Martin Energy Research Corporation CA142
INHALATION PEAK EFFECTS
FROM NERVE AGENT• Effects can occur after single breath• Immediate response within seconds• Peak effects usually within
15 - 20 minutes• After about 20 minutes,
effects usually maximized and will not worsen
Respiratory system
© 1999 Lockheed Martin Energy Research Corporation CA143
DIRECT CONTACT PEAK EFFECTS
FROM NERVE AGENT
• Absorption may continue for hours even after decontamination
• Effects may not occur for 1 to 18 hours– effects usually not lethal
© 1999 Lockheed Martin Energy Research Corporation CA144
OTHER POSSIBLE CAUSES
• Signs and symptoms may also be caused by– epilepsy– gastroenteritis– exposure to agricultural insecticides– emphysema– strokes– head trauma– drug overdose– heat illnesses– allergies– upper respiratory illnesses
© 1999 Lockheed Martin Energy Research Corporation CA145
INITIAL FIRST AID TREATMENT
• Immediate removal from source of exposure– severity directly proportional to absorbed dose
• Decontamination– preferred decontamination solution is undiluted household
bleach
• Antidote administration with airway management support as necessary
• Must be provided by properly trained and equipped personnel
© 1999 Lockheed Martin Energy Research Corporation CA146
NERVE AGENT ANTIDOTE
• Atropine– administered to block receptor sites of acetylcholine
• 2-PAM Chloride– restores acetylcholinesterase
Two-part nerve agent antidote