Pulmonary Function Test

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Contents 1 More Specific Terms 2 Indications 3 Clinical-significance 4 Procedure 5 More General Terms 6 Additional Terms 7 References

More Specific Terms

• cardiopulmonary exercise testing
• diffusion capacity of carbon monoxide (DLCO)
• flow-volume loop
• forced expiratory flow
• forced expiratory flow (FEF[25-75])
• forced expiratory volume in 1 second (FEV1)
• forced vital capacity (FVC)
• fraction of exhaled nitric oxide
• maximal voluntary ventilation (MVV)
• peak expiratory flow rate (PEFR, PER)
• provocation inhalation challenge test; methacholine challenge test
• respiratory residual volume
• static lung volume
• total lung capacity (TLC)

Indications

• dyspnea
• lung disease

Clinical-significance

• obstructive lung disease

• indicated by decrease in FEV1, FEV1/ FVC & FEF[25-75]
• FEV1/ FVC of < 70%
• asthma, bronchitis, emphysema

• asthma

• obstruction to airflow during inspiration & expiration
• provocation inhalation challenge test

• reversible airway disease

• indicated by increase in flow rate of > 20% after bronchodilator therapy

• restrictive lung disease

• limitation of full expansion of the lungs

• lung parenchymal disease
• chest wall or diaphragm dysfunction

• volumes are diminished, i.e. also includes pneumonectomy
• total lung capacity < 80%
• flow rates are normal

• combination of restrictive & obstructive

• COPD; smokers may have interstitial lung changes along with emphysema [5]
• pulmonary fibrosis

• neuromuscular disease

• decreased maximal voluntary ventilation ( MVV)
• normal flow rates

• upper airway obstruction shows inspiratory abnormalities in flow loop
• no obstruction & no restriction

• isolated low DLCO is consistent with

• anemia
• pulmonary embolism
• pulmonary hypertension

• isolated high DLCO is consistent with

• pulmonary hemorrhage
• obesity
• left-to-right cardiac shunt
• polycythemia

• nonspecific pattern

• normal total lung capacity
• normal FEV1/ FVC
• low FEV1 or FVC (or both)
• generally does not evolve into obstructive lung disease or restrictive lung disease [6]

Procedure

• spirometry is used to measure airflow
• DLCO is a measurement of gas exchange

More General Terms

• clinical specialty test

Additional Terms

• age-associated changes in pulmonary function
• dyspnea (shortness of breath {SOB})
• lung
• lung disease
• pulmonary

References

1. Diagnostic History & Physical Examination in Medicine, Chan & Winkle, Current Clinical Strategies, Laguna Hills, CA 1996
2. Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
3. American Thoracic Society, Am Rev Respir Dis 144:1202-18, 1991
4. Medical Knowledge Self Assessment Program (MKSAP) 11, 14, American College of Physicians, Philadelphia 1998, 2006
5. Washko GR et al. Lung volumes and emphysema in smokers with interstitial lung abnormalities. N Engl J Med 2011 Mar 10; 364:897 PMID: [1]
   - King TE Jr. Smoking and subclinical interstitial lung disease. N Engl J Med 2011 Mar 10; 364:968 PMID: [2]
6. Iyer VN et al. The nonspecific pulmonary function test: Longitudinal follow-up and outcomes. Chest 2011 Apr; 139:878. PMID: &dopt=Abstract
7. National Guideline Clearinghouse Infant/toddler pulmonary function tests-2008 revision & update. American Association for Respiratory Care ngc-guideline: [3]

pulmonary function test (PFT)