What labs and imaging studies should be ordered for a patient with suspected metal toxicity from occupational exposure to powdered metals, presenting with metallic taste, cough with grey-colored sputum, and pleuritic chest pain?

Diagnostic Workup for Metal Toxicity in Occupational Exposure

For a patient with occupational exposure to powdered metals (particularly copper) who presents with metallic taste, cough with grey-colored sputum, and pleuritic chest pain, a comprehensive panel of laboratory tests and imaging studies should be ordered to evaluate for metal toxicity and respiratory complications.

Laboratory Tests for Metal Exposure

Essential Blood Tests:

• Complete blood count (CBC) with differential
• Comprehensive metabolic panel including:
  • Liver function tests (ALT, AST, GGT, bilirubin)
  • Kidney function tests (BUN, creatinine)
  • Serum electrolytes
• Inflammatory markers:
  • C-reactive protein (CRP)
  • Erythrocyte sedimentation rate (ESR)

Specific Metal Testing:

• Serum copper levels (priority given occupational exposure) 1
• 24-hour urine copper levels
• Heavy metal panel including:
  • Blood lead levels
  • Urine arsenic
  • Urine mercury
  • Urine cadmium
  • Other metals relevant to workplace exposure 2

Additional Laboratory Tests:

• Sputum analysis:
  • Culture and sensitivity
  • Cytology (to evaluate for cellular changes)
  • Examination for metal particles
• Pulmonary function tests (PFTs) with diffusion capacity 1

Imaging Studies

Initial Imaging:

• Chest X-ray (posteroanterior and lateral views) - first-line imaging test 1
  • To evaluate for pneumoconiosis, pleural thickening, effusions, or infiltrates

Advanced Imaging:

• High-resolution CT scan of the chest (HRCT) 1

  • Superior to chest X-ray for detecting early occupational lung disease
  • Can identify ground-glass opacities, nodules, interstitial changes, pleural thickening
  • Essential for evaluating suspected hard metal lung disease or metal-induced pneumoconiosis

• Consider CT with contrast if malignancy is suspected 1

Special Considerations

For Suspected Hard Metal Disease:

• Beryllium lymphocyte proliferation test (BeLPT) if beryllium exposure is possible 1
• Consider bronchoscopy with bronchoalveolar lavage (BAL) to:
  • Evaluate for lymphocytosis (suggestive of hypersensitivity pneumonitis)
  • Analyze for metal particles
  • Obtain samples for culture 1

For Suspected Pleural Disease:

• If pleural effusion is present, thoracentesis with:
  • Pleural fluid analysis (cell count, protein, LDH, pH)
  • Cytology
  • Culture 1

For Persistent/Severe Symptoms:

• Consider lung biopsy (via bronchoscopy or VATS) if diagnosis remains unclear after non-invasive testing 1
• PET-CT may be considered if malignancy (such as mesothelioma) is suspected, particularly with history of asbestos exposure 1

Clinical Pearls and Pitfalls

• Metal fume fever from copper exposure can present with influenza-like symptoms and self-limiting neutrophil alveolitis 2
• Grey-colored sputum may indicate metal particle deposition in the lungs
• Pleuritic chest pain with occupational metal exposure requires exclusion of pneumonitis, pleuritis, and early pneumoconiosis
• Metallic taste is a classic symptom of metal toxicity, particularly with copper and mercury exposure 3
• Hard metal lung disease can present with giant cell interstitial pneumonitis, particularly with cobalt exposure 2
• Chronic metal exposure may lead to both pulmonary and systemic effects, including liver and kidney damage 1, 4

Follow-up Recommendations

• Serial monitoring of pulmonary function tests to assess for progressive decline
• Repeat chest imaging at 3-6 month intervals initially to monitor for progression
• Periodic reassessment of metal levels to evaluate effectiveness of removal from exposure
• Occupational health assessment of workplace to identify and mitigate exposure sources

Remember that early identification and removal from exposure are key components of treatment for occupational metal toxicity 1.