Metal toxicity notes Flashcards
What are the chronic toxicities of the nervous system?
altered mental status, peripheral neuropathy
What are the chronic toxicities of the renal system?
renal insufficiency
What are the chronic toxicities of the hematologic system?
Anemia and cytopenia
What are the chronic toxicities of the dermatologic system?
Rashes
What are the acute toxicities of the nervous system?
Altered mental status, peripheral neuropathy
What are the acute toxicities of the cardio system?
tachycardia, hypotension
What are the acute toxicities of the renal system?
Proteinuria, acute tubular necrosis
What are the acute toxicities of the GI system?
N/V/D
What are the acute toxicities of the derm system?
Skin hair nail changes days to weeks post exposure
What labs need to be checked for suspected toxicities?
• 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
What are the potential sources of arsenic poisoning?
- Inhalation of dust residues (occupational)
- Pesticide sprays
- Arsenic Trioxide (antineoplastic) for leukemia
- Alternative medicines/remedies
- Well water
What are the acute effects of arsenic poisoning?
- 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
What are the chronic effects of arsenic poisoning?
- Skin: dermatitis, hyperpigmentation, malignancy
- Neurologic: Stocking glove parathesias
- Hepatotoxicity
What are the specific dx tests for suspected arsenic poisoning?
- Urine arsenic lead
- Blood arsenic level
- Levels do not correlate with severe clinical findings
What are the treatment options for arsenic poisoning?
- ABC’s
- Activated charcoal to absorb arsenic in GI tract
- Whole bowel irrigation is KUB positive
- Chelation Rx – BAL and succimer and/or DMPS
What are the 3 forms of mercury?
elemental, inorganic and organic
Where can one be exposed to elemental mercury?
o Mining and ore processing industries, paint & battery manufacturing, ceramics, jewelry
Where can one be exposed to inorganic mercury?
o Industries involving fireworks, dye & ink manufacturing, hide and fur processing
Where can one be exposed to organic mercury?
o Farming, pesticide production, embalming fluids, wood preservatives
What are the clinical effects of elemental mercury?
- Acute Exposure: malaise, HA, fever, lung injury, encephalopathy
- Chronic Exposure: stomatitis, psychological changes (mood swings, memory loss, sensory-motor neuropathy)
What are the clinical effects of inorganic mercury salts?
- Acute Exposure: skin blistering, weakness, pallor, shock-like symptoms
- Chronic Exposure: same as elemental mercury + acrodynia and rash
What are the clinical effects of organic mercury?
- Acute Exposure (Methyl & Dimethyl mercury): sensory & motor neuropathy, dysarthia, ataxia, tremor, hearing deficits, psychological changes
- Acute Exposure (phenyl and methoxyethyl mercury): similar to inorganic mercury salt exposure
What are the dx for mercury toxicities?
- Whole blood mercury level
A. Significant level > 20 mcg/dl - 24 hour urine for mercury (gives accurate reading of inorganic, but not organic mercury levels)
- Hair analysis
How is mercury toxicity treated?
- ABC’s
- Activated charcoal to absorb mercuric chloride in GI tract
- Whole bowel irrigation if KUB positive
- Chelation Rx – BAL (elemental and inorganic mercury) & DMSA (organic mercury only)
What are the sources of exposure for Thallium?
- Extremely toxic
- once used as a pesticide
- Manufacture of semiconductors
- jewelry
- optical lenses
- thermometers
What are effects of thallium exposure within hours?
nausea, vomiting, diarrhea and pleuritic chest pain
What are effects of thallium exposure within days?
- CNS: lethargy, coma, psychosis, seizures, central respiratory failure
- PNS: painful, ascending peripheral neuropathy w/o motor involvement
- Autonomic NS: tachycardia, hypertension, diaphoresis, fever
- CV: myocardial necrosis, dysrrhythmias, ARDS
- Skin: alopeica
What are the dx for thallium toxicities?
- Blood thallium level > 5 mcg/dl
* Hair analysis to confirm dx
What is the treatment for thallium toxicities?
- Prussian Blue is used to increase fecal elimination of thallium
- Also use activated charcoal early in decontamination
What are the sources of exposure for lead?
- 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) - Occupational sources
A. Lead welders, Bridge painters; construction workers, Firing range, Shot makers
What are the clinical effects of lead toxicity on children?
- 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) - Mild to Moderate toxicity
A. CNS: hyperirritable behavior, intermittent lethargy, “difficult child”
B. GI: intermittent vomiting, abdominal pain anorexia - Asymptomatic
A. CNS: impaired cognition, behavior, balance, fine-motor coordination
B. Impaired hearing and growth
What are the clinical effects of lead toxicity on adults?
- 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 - 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 - Mild toxicity
A. CNS: fatigue, somnolence, moodiness, lessened interest in leisure activity
B. Impaired kidney function, HTN, CVD, increased risk for cancer
How are children assessed for lead toxicities?
well-child visits at age 1 and 2 by fingerstick, if lead level elevated then draw whole blood
How are adults assessed for lead toxicities?
Whole blood levels
How is lead toxicity treated?
- 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
What are the sources of exposure for iron toxicity?
Excess iron consumption, blood transfusions
What are the clinical effects of iron toxicities?
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
What are the dx tests for iron toxicities?
- Iron levels
- < 300 mcg/dl – nontoxic
- 300-500 mcg/dl – mild-mod toxicity
- > 500 mcg/dl – severe toxicity
- CBC, electrolytes, renal fxn, ABG
How is iron toxicity treated?
• 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