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Which patient has nerve agent poisoning? 9 year-old with miosis, agitation, copious secretions, uncontrolled urination. HR 120. RR 16/shallow. Sat 83%15 year-old with generalized seizure, tongue fasciculations, absent gag, absent reflexes2 year-old old with fussiness/diarrhea progressing to impaired consciousness, hypotonia
CWA in US– the most important act of terrorism in which
CWA was attempted to use a was the World Trade Center bombing in 1993.
the explosive used by the terrorists contained sufficient cyanide to contaminate the entire structure. Fortunately, the cyanide was destroyed by the blast
Exist as a liquid or a gasLiquid is colorless (g-type) amber-colored (VX)Gas can be odorless, fruity (tabun) or slight camphor odor (soman) Vary in volatility – some more persistent than others– Sarin as volatile as water– VX very persistent
Agents which penetrate the skin may form temporary reservoirs so that delayed absorption may occur (less so, that OPP). Even the vapor of some agents can penetrate the intact skin and intoxication may follow. Wounds/abrasions (even minor injuries caused by shaving ) present areas which are more permeable than intact skin. The penetration of agents through the GI tract or abrasions may not neccessarily be accompanied by irritation or damage to the surfaces concerned.
Giddiness, anxiety, jitteriness, restlessness, emotional lability, excessive dreaming, insomnia, nightmares, headaches, tremor, withdrawal and depression, drowsiness difficulty concentrating, slowness on recall, confusion, slurred speech, ataxia. bursts of slow waves of elevated voltage in EEG, especially on hyperventilation,
Cause of death In the absence of treatment– anoxia resulting from airway obstruction,
weakness of the muscles of respiration and central depression of respiration.
Airway obstruction – due to pharyngeal muscular collapse, – upper airway and bronchial secretions, – bronchial constriction and – occasionally laryngospasm and paralysis of the
With adequate pulmonary support/toilet and atropine, the individual may survive several lethal doses of a nerve agent. However, if the exposure has been many times the lethal dose, death may occur despite treatment as a result of respiratory arrest and cardiac arrhythmia. When overwhelming doses of the agent are absorbed quickly, death occurs rapidly without orderly progression of symptoms.
Diagnosis: Treatment: institute rapidly based on clinical judgment Can measure RBC levels of acetycholinesterase– Assess treatment and recovery.
– Insensitive as a screen Matsumoto: ChE decreased in 43% of severely affectedTokyo: decreased in 74% of admiitted4% have genetic low levelsHave genetic high levels, lose 50%, still be nlOne call to lab, 3 send outs-time is critical
Clinical presentation is likely to vary in children.
Diazepam – For severe seizures/status epilepticus30d to 5 y – 0.05 to 0.3 mg/kg IV to a max of 5mg/dose. May repeat q15-30 minutes5 y.o. – 0.05 to 0.3 mg/kg IV to a max of 10 mg/dose.
Increased minute volume and vapor density increases dose of vapor to childrenSmaller airway will be more easily obstructed– bronchoconstriction and secretions
Skin absorption of liquid may be significant consideration in infants. Large surface to volume ratio in children compared to adultsFat soluble agents (less than OPP)Breaks in skin may permit easier penetration of agent. – Incidence of atopy is approx 4%.
Decontamination - Bleach is a mild to moderate mucosal irritant. 0.5% bleach may cause contact dermatittisIn children can present like “prickly heat”, erythema, edema, blistering.
Mild and early symptoms may be missed due to a child’s inability to communicate symptoms of pain and pressure. Alternatively, a physician might dismiss signs symptoms such as sleepiness, hypotonia, cramps, rhinnorhea as typical of other childhood illnesses and behavior.What will we do with the mother/infant pairs in decon?Unescorted children?
CNS: Organophospate poisoning literature suggests chronic CNS (neurocognitive/cerebellar) and PNS impairmentCarcinogenicity: Limited data in animals suggests no effect. One study suggests genotoxicity in human lymphocytesReproductive Effects: Limited data in animals suggests no effect. – Tokyo - well babies