Toxin

Arsenic

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Arsenic, Arsenic Poisoning, Arsenic Toxicity

  • Pathophysiology
  1. Arsenic blocks cellular respiration (Oxidative Phosphorylation) and Gluconeogenesis at multiple pathway sites
    1. Also affects glutathione metabolism
  2. Arsenic has a Garlic-like odor when ingested
  3. Arsenic Ingestion (or less commonly by skin absorption or inhalation)
    1. Insect poisons (Pesticides)
    2. Manufacturing (Ceramics, semiconductors)
  • Pharmacokinetics
  1. Gastrointestinal absorption is rapid
  2. Inorganic forms (trivalent, pentavalent) are more toxic than organic forms
  3. Lethal dose
    1. Child: >2 mg/kg
    2. Adult: >120 to 200 mg
  1. Gastrointestinal Symptoms (within minutes to hours of ingestion)
    1. Nausea or Vomiting
    2. Abdominal Pain
    3. Watery Diarrhea
  2. Cardiopulmonary symptoms and signs
    1. Hypotension to Cardiovascular collapse
    2. Tachycardia
    3. Acute Respiratory Distress Syndrome (ARDS)
    4. QTc Prolongation
    5. Dysrhythmia
    6. Paradoxically low Systemic Vascular Resistance (vasoplegia)
    7. Systemic Inflammatory Response Syndrome (SIRS)
  3. Neurologic Symptoms
    1. Headache
    2. Vertigo
    3. Fatigue
    4. Encephalopathy with Delirium
    5. Peripheral Neuropathy (motor and sensory) is delayed
      1. Paresthesia
      2. Paralysis
  4. Skin
    1. Skin irritation
    2. Mucosal burning Sensation
  5. Miscellaneous
    1. Acute Renal Failure
    2. Acute Hepatitis
  1. Mottled brown skin
  2. Hyperkeratosis of palms and soles
  3. Cutis edema
  4. Transverse striate Leukonychia
  5. Perforation of nasal septum
  6. Eyelid Edema
  7. Coryza
  8. Limb paralysis
  9. Reduced Deep Tendon Reflexes
  10. Carcinogenic with chronic exposure
  • Labs
  1. See Unknown Ingestion
  2. Comprehensive metabolic panel
  3. Urinalysis
    1. Oliguria
    2. Hematuria
    3. Hemoglobinuria
  4. Complete Blood Count and Peripheral Smear
    1. Macrocytic Anemia
  5. Arsenic Concentration
    1. Urine Arsenic (24 hour level)
      1. Abnormal if >100 mcg
      2. May also be positive with seafood ingestion
  6. Tissue Exam reveals Arsenic deposits
    1. Urine
    2. Nails
    3. Hair
  • Imaging
  1. Abdominal XRay
    1. Arsenic is radiopaque
  • Management
  1. See Unknown Ingestion
  2. Consult poison control
  3. ABC Management
  4. Intravenous Fluids
  5. Antidote (symptomatic patients)
    1. Hemodialysis is NOT typically effective
    2. Dimercaptosuccinic acid (succimer) 10 mg/kg orally every 8 hours for 5 days
    3. Dimercaprol 3-5 mg/kg IM every 4 to 6 hours
      1. Indicated in severe Poisonings
  • References
  1. Kinker and Glauser (2021) Crit Dec Emerg Med 35(9): 19-27
  2. Tomaszewski (2022) Crit Dec Emerg Med 37(1): 32