Metal toxicity notes

Question 1

What are the chronic toxicities of the nervous system?

Answer 1

altered mental status, peripheral neuropathy

Question 2

What are the chronic toxicities of the renal system?

Answer 2

renal insufficiency

Question 3

What are the chronic toxicities of the hematologic system?

Answer 3

Anemia and cytopenia

Question 4

What are the chronic toxicities of the dermatologic system?

Answer 4

Rashes

Question 5

What are the acute toxicities of the nervous system?

Answer 5

Altered mental status, peripheral neuropathy

Question 6

What are the acute toxicities of the cardio system?

Answer 6

tachycardia, hypotension

Question 7

What are the acute toxicities of the renal system?

Answer 7

Proteinuria, acute tubular necrosis

Question 8

What are the acute toxicities of the GI system?

Answer 8

N/V/D

Question 9

What are the acute toxicities of the derm system?

Answer 9

Skin hair nail changes days to weeks post exposure

Question 10

What labs need to be checked for suspected toxicities?

Answer 10

• CBC with diff: check for hemolysis or basophilic stippling
• Renal fxn: BUN, Cr
• UA – proteinuria
• LFT’s
• KUB – may show evidence of metal ingestion
• ECG: abnormalities suggest specific metals
• Metal specific testing:
o Whole blood levels
o Urine excretion levels
o Hair analysis
o Chelator mobilization tests NOT considered reliable

Question 11

What are the potential sources of arsenic poisoning?

Answer 11

1. Inhalation of dust residues (occupational)
2. Pesticide sprays
3. Arsenic Trioxide (antineoplastic) for leukemia
4. Alternative medicines/remedies
5. Well water

Question 12

What are the acute effects of arsenic poisoning?

Answer 12

• GI – n/v/d/bleeding
• CV – shock, dysrhythmia, prolonged QT (Torsades)
• CNS – coma, seizures, agitation
• Renal – acute tubular necrosis, hematuria/proteinuria
• Bone marrow suppression
• Peripheral neuropathy

Question 13

What are the chronic effects of arsenic poisoning?

Answer 13

• Skin: dermatitis, hyperpigmentation, malignancy
• Neurologic: Stocking glove parathesias
• Hepatotoxicity

Question 14

What are the specific dx tests for suspected arsenic poisoning?

Answer 14

• Urine arsenic lead
• Blood arsenic level
• Levels do not correlate with severe clinical findings

Question 15

What are the treatment options for arsenic poisoning?

Answer 15

• ABC’s
• Activated charcoal to absorb arsenic in GI tract
• Whole bowel irrigation is KUB positive
• Chelation Rx – BAL and succimer and/or DMPS

Question 16

What are the 3 forms of mercury?

Answer 16

elemental, inorganic and organic

Question 17

Where can one be exposed to elemental mercury?

Answer 17

o Mining and ore processing industries, paint & battery manufacturing, ceramics, jewelry

Question 18

Where can one be exposed to inorganic mercury?

Answer 18

o Industries involving fireworks, dye & ink manufacturing, hide and fur processing

Question 19

Where can one be exposed to organic mercury?

Answer 19

o Farming, pesticide production, embalming fluids, wood preservatives

Question 20

What are the clinical effects of elemental mercury?

Answer 20

1. Acute Exposure: malaise, HA, fever, lung injury, encephalopathy
2. Chronic Exposure: stomatitis, psychological changes (mood swings, memory loss, sensory-motor neuropathy)

Question 21

What are the clinical effects of inorganic mercury salts?

Answer 21

1. Acute Exposure: skin blistering, weakness, pallor, shock-like symptoms
2. Chronic Exposure: same as elemental mercury + acrodynia and rash

Question 22

What are the clinical effects of organic mercury?

Answer 22

1. Acute Exposure (Methyl & Dimethyl mercury): sensory & motor neuropathy, dysarthia, ataxia, tremor, hearing deficits, psychological changes
2. Acute Exposure (phenyl and methoxyethyl mercury): similar to inorganic mercury salt exposure

Question 23

What are the dx for mercury toxicities?

Answer 23

1. Whole blood mercury level
   A. Significant level > 20 mcg/dl
2. 24 hour urine for mercury (gives accurate reading of inorganic, but not organic mercury levels)
3. Hair analysis

Question 24

How is mercury toxicity treated?

Answer 24

1. ABC’s
2. Activated charcoal to absorb mercuric chloride in GI tract
3. Whole bowel irrigation if KUB positive
4. Chelation Rx – BAL (elemental and inorganic mercury) & DMSA (organic mercury only)

Question 25

What are the sources of exposure for Thallium?

Answer 25

1. Extremely toxic 2. once used as a pesticide 3. Manufacture of semiconductors 4. jewelry 5. optical lenses 6. thermometers

Question 26

What are effects of thallium exposure within hours?

Answer 26

nausea, vomiting, diarrhea and pleuritic chest pain

Question 27

What are effects of thallium exposure within days?

Answer 27

1. CNS: lethargy, coma, psychosis, seizures, central respiratory failure 2. PNS: painful, ascending peripheral neuropathy w/o motor involvement 3. Autonomic NS: tachycardia, hypertension, diaphoresis, fever 4. CV: myocardial necrosis, dysrrhythmias, ARDS 5. Skin: alopeica

Question 28

What are the dx for thallium toxicities?

Answer 28

* Blood thallium level > 5 mcg/dl | * Hair analysis to confirm dx

Question 29

What is the treatment for thallium toxicities?

Answer 29

* Prussian Blue is used to increase fecal elimination of thallium * Also use activated charcoal early in decontamination

Question 30

What are the sources of exposure for lead?

Answer 30

1. Environmental sources A. Paint (homes pre-1978), House dust from deteriorated paint, Water leached from leaded plumbing, Leaded gasoline (pre-1976), “natural” dietary supplements, Foreign body/toys (not made in US) 2. Occupational sources A. Lead welders, Bridge painters; construction workers, Firing range, Shot makers

Question 31

What are the clinical effects of lead toxicity on children?

Answer 31

1. Severe toxicity A. CNS: encephalopathy, coma, AMS, seizures, ataxia, loss of developmental skills, cranial nerve palsies, increased ICP B. GI: persistent vomiting C. Hematologic: pallor (anemia) 2. Mild to Moderate toxicity A. CNS: hyperirritable behavior, intermittent lethargy, “difficult child” B. GI: intermittent vomiting, abdominal pain anorexia 3. Asymptomatic A. CNS: impaired cognition, behavior, balance, fine-motor coordination B. Impaired hearing and growth

Question 32

What are the clinical effects of lead toxicity on adults?

Answer 32

1. Severe toxicity A. CNS: encephalopathy, coma, seizure, delirium, HA, papilledema, optic neuritis, increased ICP B. PNS: foot drop, wrist drop C. GI: abdominal colic D. Hematologic: pallor (anemia) E. Renal: nephropathy 2. Moderate toxicity A. CNS: HA, memory loss, decreased libido, insomnia B. PNS: peripheral neuropathy C. GI: metallic taste, abdominal pain, anorexia, constipation D. Kidney: arthritis due to gout E. Mild anemia, myalgias, muscle weakness, arthralgias 3. Mild toxicity A. CNS: fatigue, somnolence, moodiness, lessened interest in leisure activity B. Impaired kidney function, HTN, CVD, increased risk for cancer

Question 33

How are children assessed for lead toxicities?

Answer 33

well-child visits at age 1 and 2 by fingerstick, if lead level elevated then draw whole blood

Question 34

How are adults assessed for lead toxicities?

Answer 34

Whole blood levels

Question 35

How is lead toxicity treated?

Answer 35

* Removal from the source of exposure * Whole bowel irrigation if lead in GI tract * Encephalopathic patients: BAL + CaNa2EDTA for 5 days * Succimer for 20 days

Question 36

What are the sources of exposure for iron toxicity?

Answer 36

Excess iron consumption, blood transfusions

Question 37

What are the clinical effects of iron toxicities?

Answer 37

``` 1. Local Effects A. GI mucosa resulting in n/v/d/bleeding 2. Systemic Effects A. High anion gap metabolic acidosis B. CV toxicity (vasodilation, inotopic effects due to myocyte damage) C. Liver toxicity ```

Question 38

What are the dx tests for iron toxicities?

Answer 38

* Iron levels * < 300 mcg/dl – nontoxic * 300-500 mcg/dl – mild-mod toxicity * > 500 mcg/dl – severe toxicity * CBC, electrolytes, renal fxn, ABG

Question 39

How is iron toxicity treated?

Answer 39

• IV fluids • Aggressive supportive care • Whole bowel irrigation (activated charcoal does not absorb Fe) • Deferoxamine (DFO) o High affinity iron chelator o Removes Fe from ferritin and transferring, chelates Fe in spleen, liver and bone marrow o Typically given IV