organophosphate toxicity

Etiology

absorption through skin

Pathology

• cholinesterase inhibition

Clinical manifestations

• bradycardia
• bronchorrhea & wheezing
• pulmonary edema
• miosis
• fasciculations, rarely seizures
• abdominal pain, nausea, vomiting, diarrhea
• urination, lacrimation, salivation, diaphoresis
• hypoxemia, confusion

Acronyms for manifestations

• SLUDGE
  • Salivation
  • Lacrimation
  • Urination
  • Defecation
  • GI upset
  • Emesis
• DUMBELS
  • Diarrhea
  • Urination
  • Miosis
  • Bronchospams
  • Emesis
  • Lacrimation
  • Salivation

Laboratory

• plasma cholinestesase & erythrocyte cholinesterase levels are < 50% of normal
• serial plasma cholinesterase activity to confirm trend towards normal

Diagnostic procedures

• pulse oximetery
• electrocardiogram, telemetry

Complications

• patients may drown in their own secretions
• cognitive impairment with long-term exposure?

Management

• general
  • health care workers should be gowned & gloved
  • remove patient's clothing
  • shampoo hair
  • clean all skin surfaces
  • resolve respiratory symptoms
  • do not wait for test results to start treatment in seriously ill patients
• ventilatory support as needed
• pharmaceutical agents
  • atropine 0.02-0.05 mg/kg IV every 15 minutes
    • treats muscarinic effects
    • titrate dose to minimize dyspnea, airway resistance, & bronchial secretions
  • pralidoxime 20-50 mg/kg IV every 2-12 hours
    • treatment of CNS toxicity
    • continuous infusion 1g/hour may be better
    • addresses both nicotinic & muscarinic effects
  • Duodote autoinjector (atropine, pralidoxime)
  • benzodiazepine (diazepam, lorazepam) for seizures

More general terms

• toxicity; poisoning; overdose