Approach Considerations
A majority of asymptomatic children and adults with elevated lead levels can be safely managed solely by removing the source of exposure. Contact a medical toxicologist or the local poison control center for specific recommendations.
All cases of significantly elevated lead levels should be reported to the local health department. Report any industry- or workplace-related heavy metal toxicities to OSHA. Symptomatic patients with elevated metal concentrations should be treated more aggressively.
Clinical guidelines on treatment of iron and mercury exposure are available from the American Association of Poison Control Centers. [26, 27]
Arsenic is frequently used for homicidal or suicidal purposes. Thoroughly scrutinize all arsenic toxicity cases for evidence of such activity. Report all cases with possible homicidal association to the proper legal authorities before discharge. Patients with suspected suicidal intent should undergo psychiatric evaluation before discharge from hospital.
Please refer to the relevant articles (see Arsenic Toxicity; Lead Toxicity; Mercury Toxicity; Iron Toxicity) or contact a medical toxicologist for more specific recommendations.
Emergency Department Care
Decontamination
Removal of the patient from the source of exposure is critical to limiting dose.
Treatment may include whole-bowel irrigation with polyethylene glycol electrolyte solution if radiographic studies show evidence of retained metal (toys, coins, paint chips) in the gastrointestinal tract.
Resuscitation
Good supportive care is critical. Ensure airway patency and protection, provide mechanical ventilation where necessary, correct dysrhythmias, replace fluid and electrolytes (significant fluid losses generally occur and require aggressive rehydration), and monitor and treat the sequelae of organ dysfunction.
Chelation
Chelation is rarely indicated in the emergent setting. A possible exception is lead encephalopathy. Consideration of chelation therapy for patients with suspected or confirmed metal exposures should be made in conjunction with a medical toxicologist or the local poison control center.
Consultations
Contact a certified poison control center or medical toxicologist. Consult a gastroenterologist if the possibility of corrosive GI effects is present
If intentional ingestion or overdose is suspected, place the patient in a closely monitored unit, screen for coingestion of acetaminophen, and consult a medical toxicologist and psychiatrist.
Prevention
Even small elemental mercury spills can result in extensive contamination. Thermostats should be turned to low settings in buildings where spills have occurred, as heat increases elemental mercury volatilization. Vaporization occurs when spills are vacuumed or swept in an enclosed space, leading to further contamination and inhalation exposure. The proper authorities should be called to handle any spill with the appropriate mercury decontamination kits and procedures. [28]
Tables
Metal |
Acute |
Chronic |
Toxic Concentration |
Treatment |
Arsenic |
Nausea, vomiting, "rice-water" diarrhea, encephalopathy, MODS, LoQTS, painful neuropathy |
Diabetes, hypopigmentation/ hyperkeratosis, cancer: lung, bladder, skin, encephalopathy |
24-h urine: ≥50 µg/L urine, or 100 µg/g creatinine |
BAL (acute, symptomatic) DMSA (succimer) DMPS (Europe) |
Bismuth |
Acute kidney injury; acute tubular necrosis |
Diffuse myoclonic encephalopathy |
No clear reference standard |
* |
Cadmium |
Pneumonitis (oxide fumes) |
Proteinuria, lung cancer, osteomalacia |
Proteinuria and/or ≥15 µg/ g creatinine |
* |
Chromium |
GI hemorrhage, hemolysis, acute renal failure (Cr6+ ingestion) |
Pulmonary fibrosis, lung cancer (inhalation) |
No clear reference standard |
NAC (experimental) |
Cobalt |
Beer drinker’s (dilated) cardiomyopathy |
Pneumoconiosis (inhaled); goiter |
Normal excretion: 0.1-1.2 µg/L (serum) 0.1-2.2 µg/L (urine) |
NAC CaNa2 EDTA |
Copper |
Blue vomitus, GI irritation/ hemorrhage, hemolysis, MODS (ingested); MFF (inhaled) |
vineyard sprayer’s lung (inhaled); Wilson disease (hepatic and basal ganglia degeneration) |
Normal excretion: 25 µg/24 h (urine) |
BAL D-Penicillamine DMSA (succimer) |
Iron |
Vomiting, GI hemorrhage, cardiac depression, metabolic acidosis |
Hepatic cirrhosis |
Nontoxic: < 300 µg/dL Severe: >500 µg/dL |
Deferoxamine |
Lead |
Nausea, vomiting, encephalopathy (headache, seizures, ataxia, obtundation) |
Encephalopathy, anemia, abdominal pain, nephropathy, foot-drop/ wrist-drop |
Pediatric: symptoms or [Pb] ≥45 µ/dL (blood); Adult: symptoms or [Pb] ≥70 µ/dL |
BAL CaNa2 EDTA DMSA (succimer) |
Manganese |
MFF (inhaled) |
Parkinson-like syndrome, respiratory, neuropsychiatric |
No clear reference standard |
* |
Mercury |
Elemental (inhaled): fever, vomiting, diarrhea, ALI; Inorganic salts (ingestion): caustic gastroenteritis |
Nausea, metallic taste, gingivo-stomatitis, tremor, neurasthenia, nephrotic syndrome; hypersensitivity (Pink disease) |
Background exposure "normal" limits: 10 µg/L (whole blood); 20 µg/L (24-h urine) |
BAL DMSA (succimer) DMPS (Europe) |
Nickel |
Dermatitis; nickel carbonyl: myocarditis, ALI, encephalopathy |
Occupational (inhaled): pulmonary fibrosis, reduced sperm count, nasopharyngeal tumors |
Excessive exposure: ≥8 µg/L (blood) Severe poisoning: ≥500 µg/L (8-h urine) |
* |
Selenium |
Caustic burns, pneumonitis, hypotension |
Brittle hair and nails, red skin, paresthesia, hemiplegia |
Mild toxicity: [Se] >1 mg/L (serum); Serious: >2 mg/L |
* |
Silver |
Very high doses: hemorrhage, bone marrow suppression, pulmonary edema, hepatorenal necrosis |
Argyria: blue-grey discoloration of skin, nails, mucosae |
Asymptomatic workers have mean [Ag] of 11 µg/L (serum) and 2.6 µg/L (spot urine) |
Selenium, vitamin E (experimental) |
Thallium |
Early: Vomiting, diarrhea, painful neuropathy, coma, autonomic instability, MODS Late: Alopecia, Mees lines, residual neurologic symptoms |
Alopecia, neuropathy |
Toxic: >3 µg/L (blood) |
MDAC Prussian blue |
Zinc |
MFF (oxide fumes); vomiting, diarrhea, abdominal pain (ingestion) |
Copper deficiency: anemia, neurologic degeneration, osteoporosis |
Normal range: 0.6-1.1 mg/L (plasma) 10-14 mg/L (red cells) |
* |
*No accepted chelation regimen; contact a medical toxicologist regarding treatment plan. MODS, multi-organ dysfunction syndrome; LoQTS, long QT syndrome; ALI, acute lung injury; ATN, acute tubular necrosis; ARF, acute renal failure; DMPS, 2,3-dimercapto-1-propane-sulfonic acid; CaNa2 EDTA, edetate calcium disodium; MDAC, multi-dose activated charcoal; NAC, N-acetylcysteine; DMSA (succimer), dimercaptosuccinic acid. |
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