Download Requisition

---

Full PFT

• Includes Spirometry, Lung Volumes, and DLCO and is therefor useful in providing diagnostic information informed by each component in a synergistic fashion.

• Spirometry
  • Full PFT includes pre & post bronchodilator studies, and flow volume loop.

• Lung Volumes
  • Can help determine whether a restrictive process, an obstructive process, or a mixture  is responsible for a decrease in FVC and FEV1. 
  • The diagnosis of a restrictive process cannot be made by PFT until a reduced total lung capacity (TLC) is documented.

• DLCO when reduced helps in the differential diagnosis of restrictive lung disease identified by reduced Lung Volumes (total lung capacity (TLC) and vital capacity (VC)):
  • Causes of a decreased DLCO:
    • Decreased area for diffusion:
    1. Emphysema
    2. Lung/lobe resection
    3. Bronchial obstruction, (e.g tumor)
    4. Multiple pulmonary emboli
    5. Anemia
    • Increased thickness of alveolar-capillary membrane:
    1. Idiopathic pulmonary fibrosis
    2. Congestive heart failure
    3. Asbestosis
    4. Sarcoidosis, involving parenchyma
    5. Collagen vascular disease- scleroderma, SLE
    6. Drug-induced alveolitis or fibrosis- amiodarone, bleomycin, nitrofurantoin, methotrexate
    7. Hypersensitivity pneumonitis, including farmer's lung
    8. Histiocytosis X (eosinophilic granuloma)
    9. Alveolar proteinosis

• DLCO when reduced is also useful for early detection of interstitial lung disease in high risk patients including those with:
  • Chest irradiation or cancer chemotherapy
  • Hypersensitivity pneumonitis
  • Rheumatic disease (e.g. systemic sclerosis)
  • Sarcoidosis
  • Use of drugs known to have pulmonary toxicity (e.g. amiodarone, bleomycin, nitrofurantoin, methotrexate).

•  An increased DLCO near or above the upper limit of normal may be seen with the following:
  • Asthma
  • Obesity
  • High altitude
  • Polycythemia
  • Pulmonary hemorrhage
  • Left-to-right intracardial shunting
  • Mild left heart failure

Fractional exhaled Nitric Oxide (FeNO) 

•  From ATS Guidelines, "FeNO offers added advantages for patient care including, but not limited to:
  1.  detecting of eosinophilic airway inflammation, 
  2. determining the likelihood of corticosteroid responsiveness, 
  3. monitoring of airway inflammation to determine the potential need for corticosteroid, and 
  4. unmasking of otherwise unsuspected non-adherence to corticosteroid therapy."