© 1999 lockheed martin energy research corporation ca128 nerve agent exposure

© 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

© 1999 Lockheed Martin Energy Research Corporation CA135

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