PFT Basics
These are the three categories of pulmonary function tests
spirometry, lung volumes, and diffusion studies
Decreased FEV₁/FVC ratio indicates this pattern
Obstructive disease
This test measures airflow and volumes during forced breathing
Spirometry
DLCO measures this function of the lungs
gas diffusion across the alveolar-capillary membrane
First step if spirometry results look abnormal
check patient effort
This tool is used to verify the accuracy of a water-sealed spirometer when measuring lung volumes
calibration syringe
Normal FEV₁/FVC with decreased lung volumes indicates this
Restrictive disease
This test measures lung volumes not seen on spirometry
body plethysmography
DLCO is decreased in this disease due to alveolar destruction
emphysema
Patient coughs during test—results should be this
Rejected
PFTs help diagnose, monitor, and evaluate this
disease progression and treatment effectiveness
Both FEV₁/FVC and lung volumes decreased indicate this
mixed disorder
A bronchodilator response is considered significant at this level
What is ≥12% and 200 mL increase in FEV₁
DLCO is normal in this obstructive disease
chronic bronchitis
Infection control requires this between patients
equipment disinfection or use of filters
This quality describes how closely a device’s measurement matches the true or reference value
accuracy
Air trapping leads to an increase in this lung volume
residual volume (RV)
This test intentionally triggers bronchospasm to assess airway reactivity
bronchoprovocation testing
DLCO is decreased in this restrictive disease
pulmonary fibrosis
Patient has dyspnea but normal spirometry—next best test
DLCO
This organization sets standards for PFT testing procedures
ATS (American Thoracic Society)
This pattern shows scooped-out expiratory flow loop
Obstructive pattern
This medication is commonly used during bronchoprovocation testing
methacholine
This condition can falsely increase DLCO
polycythemia
Best test to confirm restrictive disease
total lung capacity (TLC)