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Pulmonary Function Test Lower Limit of Normal

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Pulmonary Function Test Lower Limit of Normal, Spirometry Lower Limit of Normal, PFT LLN

  • See Also
  1. Pulmonary Function Test
  2. Lung Volumes
  3. Diffusing Capacity
  4. Inhalation Challenge Test
  5. Exercise Spirometry
  6. Functional Residual Capacity
  7. Vital Capacity
  8. Peak Expiratory Flow Rate (PEFR)
  9. Obstructive Lung Disease
  10. Restrictive Lung Disease
  • Indications
  1. Pulmonary Function Test Interpretation (Used in ATS Guidelines)
  • Background
  1. Based on Third National Health and Nutrition Examination Survey (NHANES III) PFT data
  2. Calculated the lowest 5% (fifth percentile) cut-offs for FEV1 to FVC, FVC and FEV1
  3. Replaces GOLD Criteria which are less accurate
    1. Miss up to 50% of young adults with Obstructive Lung Disease and
    2. Overdiagnose Obstructive Lung Disease in healthy non-smokers
  4. Recently manufactured PFT software calculates the LLN based on patient age, gender and height
  • Resources
  1. Spirometry Calculator (CDC NIOSH)
    1. https://www.cdc.gov/niosh/topics/spirometry/refcalculator.html
  2. Online calculator
    1. http://hankconsulting.com/RefCal.html
  • References
  1. Johnson (2014) Am Fam Physician 89(5): 359-66 [PubMed]
  2. Mannino (2007) Thorax 62(3): 237-41 [PubMed]