Pulmonary Function Tests (PFT’s)


Indications


Technique

Flow-Volume Loop

  • Variable Extrathoracic Upper Airway Obstruction: adversely affects predominantly inspiratory flow (as inspiratory negative intraluminal pressures exacerbate the inspiratory airway narrowing, while expiratory positive intraluminal pressures splints the obstruction open)
  • Variable Intrathoracic Upper Airway Obstruction: adversely affects predominantly expiratory flow (as inspiratory negative pressures decrease the inspiratory airway narrowing, while expiratory positive intrapleural pressures exacerbate the airway obstruction)
  • Fixed Upper Airway Obstruction: adversely affects both inspiratory and expiratory flows

Use of Predicted Value Equations for Interpretation of PFT Data

ABSTRACT The aim of this study was to determine the diagnostic and interpretative consequences of adopting the Global Lungs Initiative (GLI) 2012 spirometric prediction equations. We assessed spirometric records from 17 572 subjects (49.5% females), aged 18-85 years, from hospitals in Australia and Poland. We calculated predicted forced expiratory volume in 1 s (FEV1), forced expiratory volume (FVC), FEV1/FVC and lower limits of normal (LLN) using European Community for Steel and Coal (ECSC), National Health and Nutrition Examination Survey (NHANES) III and GLI 2012 equations. Obstruction was defined as FEV1/FVCLLN and FVC20% underdiagnosis of airway obstruction up to the age of 55 years and to 16-23% overdiagnosis in older subjects. GLI 2012 equations increase the prevalence of a “restrictive spirometric pattern” compared to ECSC but decrease it compared to NHANES.

Spirometry

Forced Expiratory Volume in One Second (FEV1)

Bronchodilator Responsiveness Trial

Forced Vital Capacity (FVC)

Forced Expiratory Volume in One Second (FEV1)/Forced Expiratory Volume (FVC) Ratio

Lung Volumes

Diffusion Capacity for Carbon Monoxide (DLCO)

Technique


Pulmonary Function Test (PFT) Obstructive Pattern (see Obstructive Lung Disease)

Pulmonary Function Test Features of Obstructive Pattern

Etiology of Obstructive Pattern

Upper Airway Obstruction

Tracheobronchial Airway Obstruction

Other Airway Obstruction


Pulmonary Function Test Restrictive Pattern

Pulmonary Function Test Features of Restrictive Pattern

Etiology of Restrictive Pattern -> P-A-I-N-T-O-P-P-M

Pleural Disease

Alveolar Filling Process

Interstitial Lung Disease (ILD)

Neuromuscular Disease

Thoracic Cage Abnormality

Obesity

Pulmonary Hypertension

Poor Cooperation

Miscellaneous


Pulmonary Function Test Non-Specific Pattern (Chest, 2009) [MEDLINE] (Chest, 2011) [MEDLINE]

Epidemiology

Diagnostic Pulmonary Function Test Features of Non-Specific Pattern

Clinical Features (Chest, 2009) [MEDLINE]


Pulmonary Function Abnormalities in Diffusion Capacity for Carbon Monoxide (DLCO)

Etiology of Increased Diffusion Capacity for Carbon Monoxide (DLCO)

Etiology of Decreased Diffusion Capacity for Carbon Monoxide (DLCO)


References