Arsenic toxicity

Background

  • infamous historical poison
  • heavy metal
  • sources of exposure: poisoning, contaminated drinking water, eruptions, metal and semiconductor industry, wood preservatives
  • seafood arsenic felt to be organic form which is NONTOXIC and cleared from body in few days
  • readily absorbed via GI tract and inhalation, poorly via skin
  • organic trioxide form used as chemotherapeutic agent
  • trivalent form, As3+, is toxic to over 200 intracellular enzymes
  • known carcinogen: skin, lung, other
  • ingestion fatal dose: 100-200mg

Clinical Features

Differential Diagnosis

Diagnosis

  • urine arsenic level (usual normal level is <50mcg/L); both urine spot test and 24h urine collection
  • blood arsenic level not helpful (cleared within 2 hrs of exposure)
  • ECG to eval for QT Prolongation in acute exposure
  • CBC to eval for hemolysis
  • BMP, Mg, phos, Ca, LFTs, CK, type and screen
  • CXR if respiratory symptoms 

Treatment

  • supportive care, ABCs, IV, O2, monitor
  • removal from exposure
  • NO Charcoal - adsorbs poorly to arsenic
  • consider Whole Bowel Irrigation if large radiopaque material in GI tract on xray
  • airway management and mechanical ventilation if acute inhalation of arsine gas and resp distress
  • IV fluids
  • CHELATION therapy: if severe symptoms present
  • Dimercaprol (BAL). 3-5 mg/kg IM Q4-6h

Disposition

  • admit pt's with significant symptoms
  • ED observation and discharge with follow-up for mildly symptomatic

See Also

References