Testing and Diagnosis of COPD
Chronic obstructive pulmonary disease (COPD) is a term that is used to describe progressive lung diseases like emphysema, chronic bronchitis, and non-reversible asthma. In the United States, 24 million people suffer from COPD.
Testing for COPD
COPD is a common misdiagnosis among smokers. Sometimes smokers actually have simple deconditioning or less common lung conditions. On the other hand, many people who do have COPD are not diagnosed until they have serious symptoms and have reached the later stages of the disease.
If you have a history of smoking or encountering other lung irritants a doctor may suggest tests to determine if it is COPD. Doctor’s testing for COPD will measure breathing volume and/or take chest x-rays to determine if it is COPD or something with similar symptoms.
COPD Medical Tests
Chest X-Ray or a Chest CT Scan
Chest x-rays or CT scans can detect problems with your lungs or even help rule out other conditions, such as heart failure that could also be the source of the symptoms. This is best used to catch the form of COPD called emphysema, but it is less effective in catching the second form, chronic bronchitis.
The CT scan will be useful in deciding if it would benefit the sufferer by undergoing surgery for their COPD.
Arterial Blood Gas Tests
Arterial blood gas tests can show how severe the COPD is by detecting oxygen levels in the blood as well as the body’s ability to remove carbon dioxide.
Spirometry
Spirometry is the simplest and most conclusive test for COPD. The physician conducts the test by having the patient take a deep breath and blow as hard as they can into a tube connected to a small machine that measures the speed and volume of the air the patient expels. Spirometry can be used to detect COPD before symptoms make themselves known. After COPD is diagnosed, spirometry can also be used to determine the point of progression of the disease.
They will measure “Forced Vital Capacity” or FVC, which is the amount of air you can exhale in one breath. After taking a deep breath, they will ask you to blow out as fast and as long as you can into the Spirometer tube. A similar version of this test only requires you to quickly exhale for 6 seconds, which is safer for patients with lung disease. They also measure FEV1 or the amount of air exhaled in the first second of exhaling. Low FEV1 may be a sign of a blockage in the lungs. Peak Flow tells the doctor the fastest rate during your exhale. The combination of these results will be used to determine the diagnosis, along with health history and the list of symptoms provided by the patient.
Other Pulmonary Function Tests or PTF’s
Other tests may be done to measure the volume of air you can breathe in and out, and the speed at which you can expel air from your lungs. Lung volume tests such as Nitrogen Washout, Helium Dilution, and Body Box provides doctors with total lung capacity and residual volume (the amount of air left in your lungs even after expiration). Too much air being left in the lungs is a sign of lung damage.
- Nitrogen Washout: They have the patient inhale pure oxygen and measure the exhalation for nitrogen levels.
- Helium Dilution: The patient breathes in a mixture of oxygen and helium, and the exhalation levels are measured.
- Body Box: sitting in an enclosed glass chamber, the patient exhales short breaths.
- Diffusing Capacity tests report how well oxygen is being transported from lungs to the bloodstream.
All of the test results found will be read in comparison to normal results based on age, size, and sex. Any miscommunication of height, age, or sex could cause skewed results, so make sure all physical information is correct and up-to-date.
