Pulmonary Function Test
A pulmonary function test (PFT) is a group of tests that measure how well the lungs are working. These tests can help diagnose and monitor lung conditions such as asthma, chronic obstructive pulmonary disease (COPD), and interstitial lung disease. PFTs can also be used to evaluate lung function before and after surgery or to determine a person’s ability to tolerate certain types of work or activity. Some common PFTs include spirometry, which measures how much air a person can inhale and exhale, and lung diffusion capacity, which measures how well gases such as oxygen and carbon dioxide can move in and out of the lungs.
What is included in a Pulmonary Function Test?
A pulmonary function test, also known as a lung function test, typically includes a series of measurements to assess the function of the lungs, including the amount and rate of airflow, and the ability of the lungs to transfer oxygen into the bloodstream. Some common tests that may be included in a pulmonary function test are:
- Spirometry: measures the amount and rate of airflow in and out of the lungs
- Peak flow measurement: measures the maximum speed of airflow when breathing out forcefully
- Lung volume measurement: measures the total amount of air in the lungs at different times during the test
- Diffusing capacity: measures the ability of the lungs to transfer oxygen from the air into the bloodstream
- Arterial blood gases: measures the levels of oxygen and carbon dioxide in the blood
These tests are non-invasive and harmless and are performed by a respiratory therapist or pulmonologist. They are used to diagnose and monitor lung conditions such as asthma, chronic obstructive pulmonary disease (COPD), and interstitial lung disease.
Why would you need a Pulmonary Function Test?
A pulmonary function test (PFT) is used to evaluate the function of the lungs and to diagnose and monitor lung conditions. Some reasons why a person may need a PFT to include:
- Suspected lung disease: PFTs can help diagnose conditions such as asthma, chronic obstructive pulmonary disease (COPD), and interstitial lung disease by measuring lung function and identifying any abnormal patterns.
- Monitoring lung conditions: PFTs can be used to monitor the progression of lung diseases and to evaluate the effectiveness of treatments.
- Assessing lung function before and after surgery: PFTs may be used to assess lung function before surgery, such as lung resection or transplantation, to ensure that the patient is able to tolerate the procedure and to evaluate lung function after surgery to monitor recovery.
- Occupational lung diseases: PFTs are used to diagnose and monitor lung conditions related to a person’s occupation such as exposure to dust, chemicals, or other harmful substances.
- Evaluating lung function in athletes: PFTs are used to evaluate lung function in athletes and to identify any potential respiratory limitations that may affect performance.
- Assessing lung function in children: PFTs are used to evaluate lung function in children with respiratory symptoms such as wheezing or shortness of breath.
It’s important to note that PFTs are not used to diagnose all lung conditions, and other tests such as chest X-rays, CT scans, and lung biopsies may be needed to confirm a diagnosis.
What is normal for a Pulmonary Function Test?
Normal values for pulmonary function tests (PFTs) vary depending on a person’s age, sex, height, and weight. However, generally, the following values are considered normal for some common PFTs:
Spirometry:
- Forced vital capacity (FVC): the amount of air that can be forcefully exhaled after a deep inhalation, normal values are around 80-120% of predicted normal values, depending on the patient’s age, height, and sex.
- Forced expiratory volume in 1 second (FEV1): the amount of air that can be forcefully exhaled in the first second of a forced exhalation, normal values are around 80-120% of predicted normal values, depending on the patient’s age, height, and sex.
- FEV1/FVC ratio: the ratio of FEV1 to FVC, normal value is around 70-80%.
Lung volume measurement:
- Total lung capacity (TLC): the total amount of air present in the lungs at the end of a deep inhalation, normal values are around 80-120% of predicted normal values, depending on the patient’s age, height, and sex.
- Residual volume (RV): the amount of air remaining in the lungs after maximal exhalation, normal values are around 40-60% of TLC.
Diffusion capacity:
- Diffusion capacity of the lungs for carbon monoxide (DLCO): measures how well oxygen and carbon monoxide are transferred across the lung’s alveolar-capillary membrane, normal values are around 80-100% of predicted normal values, depending on the patient’s age, sex, and height.
- Lung compliance: The ease with which the lungs expand, normal values are around 30-40 mL/cmH2O.
It’s important to note that these values may vary depending on the facility and the equipment used and that a physician’s interpretation of the results is crucial. Abnormal results are not always indicative of a disease, and a patient’s history and symptoms should be taken into account when evaluating the results.
How can I improve my Pulmonary Function?
There are several ways to improve pulmonary function, including:
- Quitting smoking: Smoking damages the lungs and can lead to conditions such as chronic obstructive pulmonary disease (COPD) and lung cancer. Quitting smoking can help improve lung function and reduce the risk of lung disease.
- Exercise: Regular physical activity can help improve lung function and increase lung capacity. Aerobic exercises such as running, cycling, or swimming can be particularly beneficial. You can also try specific exercises such as deep breathing exercises and lung expansion exercises.
- Pulmonary rehabilitation: This is a program of exercise and education that can help improve lung function, reduce symptoms, and improve the overall quality of life for people with lung diseases such as COPD.
- Avoiding lung irritants: Exposure to pollution, chemicals, and other lung irritants can damage the lungs and make it harder to breathe. Avoiding these irritants as much as possible can help improve lung function.
- Maintaining a healthy weight: Being overweight or obese can put extra strain on the lungs and make it harder to breathe. Maintaining a healthy weight through a balanced diet and regular exercise can help improve lung function.
- Medications: Some lung conditions such as asthma and COPD require medications to manage symptoms and prevent exacerbations. Taking the medications as prescribed and following up with your healthcare provider can help improve lung function.
It is important to consult with a healthcare professional before starting any new exercise or treatment program. They can help determine the best course of action and monitor your progress.
