Myopathies Workup: Laboratory Studies, Other Tests

Laboratory Studies

See the list below:

• CK with isoenzymes
• Electrolytes, calcium, magnesium
• Serum myoglobin
• Serum creatinine and BUN
• Urinalysis: Myoglobinuria is indicated by positive urinalysis with few RBCs on microscopic evaluation.
• Complete blood count
• Erythrocyte sedimentation rate
• Thyroid function tests
• AST

Other Tests

See the list below:

• Electrocardiogram - Findings suggesting hypokalemia include the following:
  • Diffuse nonspecific ST-T wave changes
  • Increased PR interval
  • U waves
  • Wide QRS
• Steroid therapy should be withheld until a definitive diagnosis is made, but many tests that are essential for distinguishing among the varied causes of myopathy are out of the scope of the emergency physician. These tests include the following:
  • Genetic testing
  • Antinuclear antibody (ANA)
  • MRI
  • Electromyogram (EMG)
  • Muscle biopsy

Treatment & Management

Courtney A Bethel, MD, MPH Clinical Assistant Professor, Department of Emergency Medicine, Mercy Catholic Medical Center, Drexel University School of Medicine

Courtney A Bethel, MD, MPH is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Paul Blackburn, DO, FACOEP, FACEP Attending Physician, Department of Emergency Medicine, Maricopa Medical Center

Paul Blackburn, DO, FACOEP, FACEP is a member of the following medical societies: American College of Emergency Physicians, Arizona Medical Association, American College of Osteopathic Emergency Physicians, American Medical Association

Chief Editor

Barry E Brenner, MD, PhD, FACEP Professor of Emergency Medicine, Professor of Internal Medicine, Program Director for Emergency Medicine, Case Medical Center, University Hospitals, Case Western Reserve University School of Medicine

Barry E Brenner, MD, PhD, FACEP is a member of the following medical societies: Alpha Omega Alpha, American Heart Association, American Thoracic Society, Arkansas Medical Society, New York Academy of Medicine, New York Academy of Sciences, Society for Academic Emergency Medicine, American Academy of Emergency Medicine, American College of Chest Physicians, American College of Emergency Physicians, American College of Physicians

Jerry R Balentine, DO, FACEP, FACOEP Vice President, Medical Affairs and Global Health, New York Institute of Technology; Professor of Emergency Medicine, New York Institute of Technology College of Osteopathic Medicine

Jerry R Balentine, DO, FACEP, FACOEP is a member of the following medical societies: American College of Emergency Physicians, New York Academy of Medicine, American College of Osteopathic Emergency Physicians, American Association for Physician Leadership, American Osteopathic Association

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