Bio Terrorism

Bioterrorism • Use of nerve gases which are a potent Ach.esterase inhibitor and cause a cholinergic crisis • A mass casualty with both physical trauma and gas intoxication • Healthy soldiers Vs civilian with different age groups and other comorbidities • The amount, duration and the rout of exposure are the major determine of the clinical course of intoxication • Exposure to vapor→ gives respiratory symptoms (SOB, wheezing, bronchorrhea) with rapid cardiopulmonary collapse (muscarinic effect) • Where dermal exposure→ slow, and gradual S/S→ local muscle twitches and fasciculation (nicotinic effect)→ then resp failure, also carry more risk to the health care personal with direct contact • All the nerve gases causes irreversible inhibition to AchE in both central and peripheral NS • The key point in the management is to give the antidote ASAP, and protect the health care personal

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The gold standard antidote is Atropine, other Scopolamine, Oximes, and BNZ, and possible the need for inotropic support Atropine dose→ 2mg IV q 5-10 min, peds 2mg or 20ug/kg 5-10 min until full atropinization, may need up to 50 mg/24h Scopolamine → 0.25mg IV repeat 30 min then q4-6 h, not recommended for peds Oximes → Pralidoxime chloride 1-2g IV single dose, Obidoxime 250mg IV gtt over 30 min may repeat X3 , and up to 2g if effective, peds → slow gtt of 250mg repeat X3 S/S o CV→ initially HTN, ↑HR, then hypotension, Brady, heart block, ↑QT, arrhythmias o Resp→ upper A/W irritation, laryngeospasm, bronchospasm, bronchorrhea, muscle paralysis, pul edema o CNS→ resp depression, coma, Sz o MSK→ fasciculation followed by weakness and flaccid paralysis o GI→ N&V, diarrhea, cramps

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o GU→ urine incontinence o other→ excessive salivation, lacrimation, miosis the Atropine effect is only on the muscarinic receptors, so you need the oximes to reverse the nicotinic effect, the oximes are a reactivators for AChE. The people at risk could be on pyridostigmine 30mg PO q8h Usually they are volume depleted due to trauma, N&V, diarrhea Need to protect the health care personal by gas mask and special rubber gloves The initial management should be according to ATLS + the above drugs Anesthetic drug interaction o Avoid all histamine releasing drugs(morphine, Demerol, STP) o Ketamine → good bronchodilator, and ↑ BP but ↑ secretions o Etomidate → the best o Avoid sux → prolonged effect, and titrate NDMR if needed Late complication of nerve gases is rhabdomyolysis → volume, bicarb, lasix If Pt present with mild symptoms, and planning to extubate, do it awake

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Need to remove all clothes, and wash with copious amount of water → hypothermia Also consider other possible DDx in a Pt present with S/S of gas intoxication e.g. severe asthma, head injury with ↑ICP, CHF, opioids overdose,