Non-invasive Pulmonary Testing to Diagnose Asthma and COPD
What is COPD
Pulmonary testing is done to check for asthma and COPD. COPD means chronic obstructive pulmonary disease. This is actually a term that refers to a range of diseases like emphysema, non-reversible asthma, chronic bronchitis, and so on. A person with this condition is unable to let the air out of the lungs properly due to the constriction of the airways; they often spit up phlegm, a thick, viscous substance that is excreted by the mucous membranes lining the respiratory passage.
What are pulmonary function tests?
These are noninvasive tests to check the functionality of your lungs. They measure factors like the lung volume, rates of flow, gas exchange and lung capacity. Reading the results of these tests can help your physician at EPIC Primary Care to arrive at a diagnosis, and chart out a plan of treatment.
There are mainly two types of lung disorders with regard to the air passing in and out:
- Obstructive: This refers to a problem with the air flow out of the lungs due to the constriction of airways; it usually leads to a reduced air flow
- Restrictive: When the chest muscles or lung tissue are unable to expand sufficiently, it leads to low lung volume and creates problems with the air flow.
Pulmonary Function Tests or PFTs are of two methods. They are used individually or sometimes together, depending on what your physician suspects, and is looking to rule out or confirm:
- Spirometry – this is a test conducted using a device called a spirometer that has a mouthpiece attached to an electronic machine
- Plethysmography – this test is conducted with the patient sitting or standing inside an airtight box – it is like a phone booth that’s short and square
What does PFT measure?
- TV: Tidal Volume, or the volume of air inhaled and exhaled in normal breathing
- MV: Minute Volume, or the total volume of air exhaled in a minute
- VC: Vital Capacity, or the total amount of air the patient is able to exhale after inhaling maximum air
- FRC: Functional Residual Capacity, or total volume of lungs when they are filled with the maximum possible air
- Residual Volume: the volume of air remaining in your lungs after you have exhaled to the maximum possible limit
- Total Lung Capacity: Total lung volume when you fill them with the maximum possible amount of air
- FVC: Forced vital capacity is the air you exhale with speed and force, after inhalation of maximum possible air
- FEV: Forced Expiratory Volume is the volume of air exhaled during seconds one, two, and three of the FVC test.
- FEF: Forced Expiratory Flow is the average rate of flow or exhaled air in the middle of the FVC test
- PEFR: Peak Expiratory Flow Rate is the fastest rate at which the patient is able to force air out of the lungs
The ‘normal’ values of these tests are different for different individuals. The amount of air inhaled and exhaled in the PFTs are compared to the average air inhaled and exhaled by individuals of the same age, height, ethnicity and gender; results are usually also compared with your earlier tests. If there is great variation in these comparisons, your physician may ask for other tests to be carried out.
Why do I need pulmonary function tests?
PFTs are conducted for several reasons; in normally healthy people, it may be done just as routine – as a wellness check. People in certain work environments – where there is danger of inhaling hazardous substances like coal, graphite, asbestos etc. – may also be required to undergo pulmonary function tests, to ensure their health. Your healthcare provider may ask for PFTs if they want to rule out or confirm the following diseases or conditions:
- Respiratory infections
- Chronic lung conditions like emphysema, bronchitis, asthma
- Breathing trouble due to chest injury or surgery in recent past
- Asbestosis (caused by inhaling asbestos)
- Scoliosis, lung inflammation, tumors, or scarring or lung tissue due to airway constriction
- Sarcoidosis (this causes cells around organs like the lung and liver to get inflamed and clump together)
- Scleroderma (hardening and thickening of connective tissue)
- To check lung function before major surgery especially if the individual:
o Is a smoker
o Has existing heart or lung conditions
o Has other health problems
- To decide on a course of treatment for chronic conditions like asthma and emphysema
- Any other reason your physician feels fit
Are there any risks associated with the PFTs?
Being a noninvasive test it is absolutely safe, and is done quickly; just make sure to follow instructions properly. However all procedures have some mild risks or side effects. For PFTs, these could include:
- Being short of breath
- Asthma attack because of deep inhalation
Who Should Not Undergo PFTs?
- Anyone who has had an eye surgery recently, because pressure in the eyes increases during the tests
- Anyone who has undergone chest or abdominal surgery recently
- Individuals with unstable heart condition, recent heart attack, chest pain
- Individuals with chest, abdominal or brain aneurysm
- Individuals with respiratory infections or TB
Factors that Affect the Accuracy of PFTs
- The level of patient effort and cooperation
- Bronchodilator medication
- Pain medication
- Abdominal bloating (affects deep breathing ability)
- Any other factors that affect your ability to do the tests
How to get ready for pulmonary function tests?
When you come to EPIC Primary Care, your physician will explain the procedure; you can ask whatever queries you want. You may be required to sign a consent form that permits your healthcare provider to perform the procedure. If you are on any medication (including supplements, herbs etc.), inform your healthcare provider.
Ensure that you:
- Stop certain medications as instructed
- Stop smoking as instructed – check how many hours before you need to stop
- Avoid heavy meals
What Happens during the PFTs?
- First, your height and weight will be checked and noted, as these will help to calculate your results accurately.
- You will need to loosen tight clothes, remove jewelry or anything else that could hamper the test
- You may need to wear your dentures for the test if you use them
- You need to do the test on an empty bladder
- You’ll be asked to sit, and your nose will be closed with a soft clip so as to facilitate all the breathing through the mouth
- A sterile mouthpiece attached to a spirometer will be given to you
- You need to grip the mouthpiece tightly
- You will be instructed to inhale and exhale air in different ways
- The physician will watch you carefully for signs of dizziness, breathing trouble, etc
- Some patients may be given a bronchodilator after some tests, and the tests repeated after the medicine has taken effect
What happens after pulmonary function tests?
The individual with a history of lung or breathing problems may feel tired after the tests, and they are allowed to rest later. Your EPIC Primary Care physician will discuss the results with you and tell you if you need further tests, or give you a clean bill of health.
Are you suffering from any form of breathing difficulty? Do you want to rule out any lung condition? Schedule an appointment for getting your pulmonary function tests done. Early detection is key to a healthier you!