FMMS PRIMER ON BIOTERRORISM

Nerve Agents

• Description
  • Organophosphates bind and inactivate acetylcholinesterase. colorless, nearly odorless
  • Sarin (GB)
  • Tabun (GA)
  • Soman (GD)
  • VX - clear ,
• Diagnosis - acute onset cholinergic crisis. Sarin may cause death in 1-10 minutes
• Symptoms
  • Respiratory - irritation to mucous membranes, cough, airway constriction and increased secretions
  • Neuromuscular -twitch, weakness, paralysis, respiratory failure
  • Autonomic -blurred vision, pinpoint pupils, drooling, sweating, tearing, nausea, vomiting, abdominal pain, diarrhea
  • Central Nervous System -slurred speech, confusion, headache, convulsions, respiratory arrest
  •  Cardiovascular - tachycardia, bradycardia, arrhythmia, heart block
• Decontamination - move victim to fresh air, remove and isolate clothing, wash skin/eyes with water/saline. 0.5% hypochlorite to skin if possible
• Treatment
  • Oxygen/respiratory support, suction secretions. Rush to healthcare facility
  • Atropine (antagonizes muscarinic effects) 2 mg deep IM injection, IV, or ET, Repeat q5-10min until secretions are drying and decreased airway  resistance (to max 20 mg.) Infant (0.5mg IM or 0.02mg/kg), child 2- 10(1 mg IM), elderly lmg) This will not have any effect on pupils or skeletal muscle.
  • Pralidoxime chloride (2 PAM chloride)-helps nicotinic neuromuscular sites. Separates nerve agent from AChE, (but once "aging" has occurred, nerve agent is permanently attached to AChE, 2PAM will no longer be effective) 1g IV over 20-30 min., may repeat in 1 hour (child< 20kg--15mg/kg,child >20kg - 600mg IM autoinjector, elderly 7.5mg/kg) Use Phentolamine for 2PAM induced hypertension (adult 5mg IV, child 1mg IV)
  • Diazepam - 10mg IM (2-5mg IV) Child 1mo-5yr- 0.2-0.5mg/kg;child >5y - 1 mg IV
  • Supportive care for weeks may be necessary

Vesicants

• General Effects
  • Cell damage, tissue necrosis, toxic byproducts, metabolic acidosis, secondary infections, pulmonary insufficiency
• Mustard
  • HD H- latent period hours- erythema and blisters on skin, irritation,  conjunctivitis, mild upper respiratory sx to marked airway damage. Also GI effects, nausea and vomiting, bone marrow suppression
  • Wash with water and dilute hypochlorite
  • Topical antibiotics, pulmonary support, analgesics
• Lewisite
  • L- immediate pain, skin and mucous membrane irritation, erythema, blisters  skin, eye and airway
  • Wash water/hypochlorite. British Anti-Lewisite antidote (BAL)

Industrial Chemicals

• Phosgene - CG- odor of fresh cut grass, hay.
  •  Damages alveolar-capillary membrane. Toxic to lungs by inhalation- immediate burning, eye and airway damage, SOB, cough; Pulmonary edema can develop in 2-12 hours
  • Treatment- Fresh air, wash with water, symptomatic management of lesions, pulmonary care, careful fluid replacement, absolute rest
• Cyanide
  • Inhibits the body's ability to transfer oxygen and CO2 at the capillaries. Agent is volatile
  • Symptoms - seizures, respiratory, and cardiac arrest.
  • Decontamination - remove clothing; wash with water
  • Treatment- antidotes: intravenous sodium nitrite and sodium thiosulfate.
  •  Supportive oxygen and correction of acidosis
• Riot Control Agents (Maceâ, pepper spray)
  • Symptoms - burning pain skin, mucous membranes and eyes
  • Treatment - flush with water, soap and water or dilute sodium bicarbonate solution.  (Hypochlorite should NOT be used)
  • Effects are self-limited, unless underlying asthma/emphysema or hysteria from fear of nerve agent exposure