A pulmonary function test (PFT) is a noninvasive procedure that assesses lung function and helps diagnose and manage respiratory conditions, such as asthma and other lungs disease.
There are five types of pulmonary function test (PFT).
Spirometry
Lung Volume Tests
Diffusion Capacity Test (DLCO)
Bronchodilator Reversibility Testing
Body Plethysmography
Pulmonary function test procedure by spirometry
The patient is seated comfortably and wears a nose clip to prevent nasal airflow. They breathe into a mouthpiece connected to the spirometer.
The patient is instructed to take a deep breath and exhale as forcefully and quickly as possible into the spirometer. This measures Forced Vital Capacity (FVC) and Forced Expiratory Volume in one second (FEV1).
Spirometry may be repeated 2-3 times to ensure accuracy, and the best result is recorded.
Lung Volume Testing procedure
The patient sits in a small, airtight booth and breathes through a mouthpiece.
They perform a “panting” maneuver, which helps measure changes in pressure and volume in the lungs, calculating the lung volumes.
Diffusion Capacity Testing procedure (DLCO)
The patient inhales a small, safe amount of carbon monoxide and holds their breath for about 10 seconds. The test measures how effectively gas transfers from the lungs to the bloodstream.
After holding their breath, the patient exhales into the testing device, which calculates gas exchange efficiency.
Bronchodilator Reversibility Testing procedure
A baseline spirometry test is done first.Administering the Bronchodilator: The patient inhales a bronchodilator (often albuterol) to see if it opens up the airways.
After waiting about 10-15 minutes, spirometry is repeated to measure any improvement in lung function.