Heavy Metals - Dr.Kopec

ARSENIC

• ​Acute arsenic toxicity can present wiht abdominal pain, vomiting, fluid shifts, hemolysis and prolonged QTc.
• Chronic arsenic toxicity leads to peripheral sensory neuropathy, skin hyperpigmentation, Mee's lines and alopecia.
• Arsenic toxicity is associated with lung and skin cancer. 
• Testing for arsenic needs a 24 hour urine sample that is speciated and no ingestion of seafood 72 hours prior to testing. 
• Treatment is with BAL or succimer. 
• Arsine gas classic triad is: abdominal pain, hemolysis and bronze skin.

MERCURY

• Elemental mercury is found in thermometers and is not absorbed by the GI tract, however it is very toxic if it is vaporized.
• Inorganic mercury is associated with renal failure. 
• Inorganic mercury has been associated with Pink's disease (acrodynia) with is a maculopapular rash with desquamation and swollen painful extremities. 
• Danbury shakes were from mercury used in the felt hat industry leading to chronic toxicity and is where the term "mad as a hatter" comes from.
• Organic mercury crosses the BBB and placenta. It is teratogenic and highly fatal, with neurological demise. Classic finding is constricted visual fields. 
• To diagnosis organic mercury toxicity you check a whole blood mercury level.
• To diagnosis inorganic mercury toxicity you check a 24 hour urine mercury level. 
• Treatment for inorganic mercury is succimer or BAL. 

LEAD

• Lead inhibits multiple steps in the heme pathway. 
• Children are more susptible to lead toxicity than adults. 
• Lead toxicity can present with a range of symptoms from: constipation, irritability, abdominal pain, tremors, headache, encephalopathy and seizures.
• Diagnosis is made with a whole blood lead level. 
• Treatment initially is remove the source then chelate based on the level with BAL, EDTA or succimer.
• Classic lead findings are: basophillic stipling, Burton's lines and lead lines on xrays. 
• Iron causes GI symptoms, metabolic acidosis and periportal hepatic necrosis. 
• There are various formulations of iron with different percentages of elemental iron.
• There are 5 stages to iron toxicity: 1) GI symptoms, 2) latent 3) Multiorgan failure 4) Hepatic failure 5) Recovery/Long term effects
• Fatal iron poisonings are >60mg/kg
• Iron level after 4 hours if >500mcg/dL need to be treated. 
• Deferoxamine should be started for severe acidosis, refractory GI symptoms, shock, altered mental status, or level >500mcg/dL .
• Deferoxamine has been associated with hypotension and Yersinia infections. 
• If there are GI symptoms and neurological symptoms think about metal toxicities.

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Remember that metals are caustics. 

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