Arsenic toxicity: Difference between revisions

(arsenic)
(arsenic)
Line 104: Line 104:
*supportive care, ABCs, IV, O2, monitor  
*supportive care, ABCs, IV, O2, monitor  
*removal from exposure  
*removal from exposure  
*NO [[Charcoal]] - adsorbs poorly to arsenic
*NO [[Charcoal]] if co-ingestion is not suspected - adsorbs poorly to arsenic
*consider [[Whole Bowel Irrigation]] if large radiopaque material in GI tract on xray
*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  
*airway management and mechanical [[ventilation]] if acute inhalation of arsine gas and resp distress  

Revision as of 20:22, 20 October 2015

Background

  • 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

Typical rash associated with chronic exposure

Acute ingestion

"Mees lines"

Arsine gas exposure

Subacute or chronic poisoning

  • Anemia
  • peripheral neuropathy
    • typically symmetric "glove and stocking" distribution
  • skin changes
  • White lines on the finger nails known as "Mees lines"
  • ataxia
  • CNS Depression

Differential Diagnosis

Acute diarrhea

Infectious

Noninfectious

Watery Diarrhea

  • Enterotoxigenic [[E. coli]
  • Norovirus (often has prominent vomiting)
  • Campylobacter
  • Non-typhoidal Salmonella
  • Enteroaggregative E. coli (EAEC)
  • Enterotoxigenic Bacteroides fragilis

Traveler's Diarrhea

Diagnosis

  • urine arsenic level (usual normal level is <50mcg/L); both urine spot test and 24h urine collection
    • lab must differentiate inorganic from organic arsenic (treat for inorganic exposure only)
  • blood arsenic level not helpful (cleared within 2 hrs of exposure)
  • ECG to eval for QT Prolongation in acute exposure
  • CBC and retic count, expect hemolytic anemia
  • BMP, Mg, phos, Ca, LFTs, CK
  • type and screen for possible transfusion in arsine gas exposure
  • CXR if respiratory symptoms 
  • Consider other ingestion labs including acetaminophen and salicylate level in intentional ingestions

Treatment

  • supportive care, ABCs, IV, O2, monitor
  • removal from exposure
  • NO Charcoal if co-ingestion is not suspected - 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