Barium toxicity

Background

• Uses
  • Pesticides
  • Depilatory
  • Radiographic contrast
• Most toxicity is seen in pesticides, which contain barium carbonate
• Barium sulfate is used in contrast
  • Insoluble
  • Rarely causes unintentional toxicity
  • When they occur typically seen with oral contrast and barium enemas

Toxicokinetics

• Toxicity seen with as little as 200mg of barium salt
• Lethal dose ranges from 1-30 g of barium salt
• Absorption through the GI tract is 5-10%
• Rapid rate of redistribution
• Half life of 18-85 hours
• Mostly eliminated via GI tract
  • 10-28% renal elimination
• Barium induces hypokalemia by causing extracellular potassium to shift intracellularly

Clinical Features

• Rapid onset
• Within 1 hour of ingestion
  • Abdominal pain
  • Nausea and vomiting
  • Diarrhea
• Hypokalemia
• Ventricular dysrhythmias
• Hypotension
• Flaccid muscle weakness
• Respiratory failure
• Metabolic acidosis
• Lactic acidosis
• Hypophosphatemia
• Rhabdomyolsis
• Intravasation is rare but is most often seen with barium enemas causing bowel perforation

Background

Heavy metal toxicity results from exposure to metals like lead, mercury, arsenic, or cadmium, which interfere with cellular function. Exposure may occur occupationally, environmentally, through ingestion, or from alternative medicines. Chronic toxicity can present insidiously, while acute toxicity may mimic sepsis or encephalopathy. Diagnosis is often delayed due to nonspecific symptoms.

Clinical Features

Symptoms depend on the metal and exposure duration but may include:

Neurologic: Peripheral neuropathy, confusion, tremor, encephalopathy

GI: Abdominal pain, nausea, vomiting, diarrhea, anorexia

Heme: Anemia (especially microcytic or hemolytic), basophilic stippling (lead)

Renal: Tubular dysfunction, proteinuria, Fanconi syndrome

Dermatologic: Mees’ lines (arsenic), hyperpigmentation, hair loss

Others: Fatigue, weight loss, hypertension (cadmium), immunosuppression

Differential Diagnosis

Sepsis or systemic inflammatory response

Drug toxicity or overdose

Metabolic disorders (e.g., porphyria, uremia)

Psychiatric illness (if symptoms are vague or bizarre)

Neurologic diseases (e.g., Guillain-Barré, MS, Parkinson’s)

Vitamin deficiencies (e.g., B12, thiamine)

Evaluation

Workup

History: Occupational exposures, home remedies, hobbies (e.g., jewelry making, battery recycling), diet, water source, imported goods

Labs:

• CBC, CMP, urinalysis
• Blood lead level, serum/urine arsenic, mercury, or cadmium (based on suspicion)
• Urine heavy metal screen (note: spot testing may require creatinine correction)

Imaging: Abdominal X-ray (radiopaque material in GI tract, especially with lead)

EKG: Evaluate for QT prolongation or arrhythmias in severe cases

Diagnosis

Confirmed by elevated blood or urine levels of the specific metal in the context of clinical findings. Hair and nail testing are unreliable for acute toxicity. Interpret results with toxicologist input if possible.

Management

Remove the source of exposure (e.g., occupational control, GI decontamination if recent ingestion)

Supportive care: IV fluids, seizure control, electrolyte repletion

Chelation therapy (in consultation with toxicology or Poison Control):

Lead: EDTA, dimercaprol (BAL), succimer

Mercury/arsenic: Dimercaprol or DMSA

Cadmium: No effective chelation—focus on supportive care

Notify local public health authorities if exposure source is environmental or occupational

Disposition

Admit if symptomatic, unstable, or requiring chelation

Discharge may be appropriate for asymptomatic patients with low-level exposure and outpatient follow-up

Arrange toxicology or environmental medicine follow-up for source control and serial testing

See Also

• Aluminum toxicity
• Antimony toxicity
• Arsenic toxicity
• Barium toxicity
• Bismuth toxicity
• Cadmium toxicity
• Chromium toxicity
• Cobalt toxicity
• Copper toxicity
• Gold toxicity
• Iron toxicity
• Lead toxicity
• Lithium toxicity
• Manganese toxicity
• Mercury toxicity
• Nickel toxicity
• Phosphorus toxicity
• Platinum toxicity
• Selenium toxicity
• Silver toxicity
• Thallium toxicity
• Tin toxicity
• Zinc toxicity

Evaluation

• BMP, including magnesium and phosphate
• Serum barium >0.2mg/L is abnormal
• EKG
• Cardiac monitor
• CPK
• pH
• Lactate
• Consider radiographs, such as CT chest and abdomen to identify location of barium contrast in event of Intravasation

Management

• Decontamination
  • Activated charcoal not recommended
  • NG lavage unlikely to benefit
  • Oral sodium sulfate or magnesium sulfate
    • Prevents absorption by precipitating barium ions into insoluble barium sulfate
    • Do not give these medications IV as they will cause precipitation in renal tubules
    • Magnesium sulfate
      • 250mg/kg for children
      • 30g for adults
• Supportive care
  • Electrolyte repletion
  • Ventilatory support as needed
• Hemodialysis or CVVHDF
  • Both show increase elimination of barium
  • CVVHDF showed to triple elimination with complete neurologic recovery in 24 hours in one case report
• Intravasation
  • Consider prophylactic antibiotics
  • IV extravasation outcomes improved with aspiration of barium sulfate

Disposition

• Symptomatic admit to ICU
• Asymptomatic after 6 hours of observation with a normal potassium can be discharged
• Consult Toxicology or poison control

References

Dawson, A. Barium. In: Goldfrank's Toxicologic Emergencies. 9th Ed. New York: McGraw-Hill; 2011: 1434-1436