From the Guidelines
Pulmonary function tests (PFTs) are a group of tests that measure how well the lungs take in and release air and how well they move gases such as oxygen from the air into the body.
Types of PFTs
- Spirometry: measures how much air a person can breathe in and out, and how quickly they can do it 1
- Lung volumes: measures the amount of air in the lungs after a person inhales and exhales normally, and after forced inhalation and exhalation 1
- Diffusion capacity: measures how well oxygen moves from the air into the blood 1
- Forced oscillation technique (FOT): measures the resistance and reactance of the respiratory system 1
- Interrupter technique: measures the resistance of the respiratory system 1
- Gas washout techniques: measures the amount of gas in the lungs and how quickly it is washed out 1
Clinical Applications
PFTs are used to diagnose and monitor respiratory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis 1. They are also used to monitor the effectiveness of treatments and to assess the risk of respiratory problems in people who are exposed to certain environmental or occupational hazards 1.
Interpretation
The interpretation of PFT results requires careful consideration of the individual's age, sex, ethnicity, and medical history 1. The results are compared to reference values that are based on healthy individuals of the same age, sex, and ethnicity 1.
Special Considerations
In preschool children, PFTs can be challenging to perform due to the child's limited ability to cooperate and follow instructions 1. Specialized equipment and techniques are used to make the tests more comfortable and engaging for young children 1.
From the Research
Definition and Purpose of Pulmonary Function Test (PFT)
- Pulmonary function testing (PFT) is an important tool in the diagnosis and management of most respiratory conditions 2.
- PFT serves many purposes in clinical practice, including distinguishing normal from abnormal lung function, and its interpretation depends on the clinical context 3.
- The primary reasons for performing PFTs include follow-up of known respiratory disease, investigation of specific symptoms, and possible specific lung disease 2.
Components and Interpretation of PFT
- PFT interpretation requires a comprehensive approach, including consideration of the clinical context, laboratory methodology, and reference standards 3.
- The goal of PFT interpretation is to distinguish normal from abnormal, which is affected by the selection of reference standards and the choice of cut-off values 3.
- Controversies regarding PFT analysis may lead to important differences in interpretation, highlighting the need for valid criteria describing what constitutes a real clinical change in PFT parameters 2.
Clinical Applications of PFT
- PFT has a long and rich history in the definition, diagnosis, and management of chronic obstructive pulmonary disease (COPD) 4.
- Pulmonary function testing is essential for diagnosis and treatment-guidance of COPD, and should include the assessment of airway obstruction, lung hyperinflation, and pulmonary emphysema 5.
- PFT results are used to guide treatment decisions, including pharmaceutical and non-pharmaceutical interventions, such as lung volume reduction, long-term oxygen therapy, and lung transplantation 5.