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NERVE AGENT EXPOSURE. CA128. OBJECTIVE. Identify the specific signs and symptoms of nerve agent exposure. CA129. 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
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NERVE AGENT EXPOSURE CA128
OBJECTIVE • Identify the specific signs and symptoms of nerve agent exposure CA129
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 CA130
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 CA131
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 Nerve agent interferes with normal synapse activity CA132
ROUTES OF EXPOSURE • Inhalation • Ingestion • Direct Contact CA133
INHALATION • Nerve agents enter through respiratory system • Rapidly and effectively enter into blood stream Respiratory failure chief cause of death after severe exposure Nerve agent inhaled into respiratory system CA134
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 CA135
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 CA136
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) Notallsignsandsymptomsmayappear . . . Dose, duration,androuteofexposuremakeadifference CA137
SIGNS AND SYMPTOMS OFNERVE 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 CA138
OTHER SIGNS AND SYMPTOMS OFNERVE AGENT EXPOSURE • May result from early or mild exposure: • headache • anxiety • restlessness • giddiness • irritability CA139
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 CA140
FACTORS AFFECTING NERVEAGENT SIGNS AND SYMPTOMS Immediate if moderate to large amounts are inhaled if moderate to large amounts are spilled onto the skin Delayed if small amounts are involved if agent has been absorbed through skin in small localized area CA141
INHALATION PEAK EFFECTSFROM 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 CA142
DIRECT CONTACT PEAK EFFECTSFROM NERVE AGENT • Absorption may continue for hours even after decontamination • Effects may not occur for 1 to 18 hours • effects usually not lethal CA143
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 CA144
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 CA145
NERVE AGENT ANTIDOTE • Atropine • administered to block receptor sites of acetylcholine • 2-PAM Chloride • restores acetylcholinesterase Two-part nerve agent antidote CA146