The lungs are responsible for gas exchange within the body. They take in oxygen—which is essential for human life—from the air and release carbon dioxide, a metabolic waste product. A pulmonary function test can determine whether the lungs are able to fully perform their functions.
Here you will find further information as well as a list of doctors who perform pulmonary function tests.
A lung function test is designed to determine whether the lungs and airways are functioning properly. It can help detect conditions such as asthma or COPD in their early stages, even before a definitive diagnosis is made.
COPD stands for chronic obstructive pulmonary disease. This term refers to a group of conditions characterized by
. This condition primarily includes
The latter is the result of various lung diseases that ultimately cause the alveoli to become overinflated.
The pulmonary function test plays an important role in diagnosis during the early stages. Later on, it can be used to monitor the progression of a lung disease. Among other things, this allows doctors to determine whether the treatments initiated are having the desired effect.
In addition, further preventive measures can be taken as soon as test results regarding
of the lungs are available.
The location and anatomy of the lungs in the human body © yodiyim | AdobeStock
A pulmonary function test is performed when the patient
as symptoms. Patients who have been smoking for many years should also undergo regular lung function tests. This allows for the early detection and treatment of potential complications resulting from smoking.
Typical findings that prompt a pulmonary function test include:
In addition, a pulmonary function test is part of various fitness evaluations, such as those in sports medicine and occupational medicine. A pulmonary function test is also performed before surgery to better assess the risk to the patient.
There are various testing methods available to assess lung function. Although these differ in procedure and detail, they share a common goal: the primary focus is on evaluating the patency of the bronchial system, where lung function disorders most frequently occur.
Conditions such as bronchial asthma or chronic obstructive pulmonary disease do not directly affect the lungs. Instead, they damage the bronchial system.
Blood gases—that is, the oxygen that enters the body’s bloodstream via the lungs—are only measured in specific cases. This applies, for example, to patients who are on mechanical ventilation.
Performing a spirometry test © Victor Koldunov | AdobeStock
The most commonly used procedure is spirometry. This involves measuring airflow during breathing. The test is generally performed during a phase of quiet breathing, but the patient is also asked to take a maximum inhalation and exhalation.
During spirometry, the patient inhales and exhales through a mouthpiece. The nose is closed off with a clip.
Because this procedure examines airflow, it allows for the measurement of other values in addition to peak flow. These include resting tidal volume, reserve volume, and vital capacity. Vital capacity is considered an important parameter for assessing lung function.
In spirometry, the one-second capacity is often determined. This refers to the volume of air that the patient can exhale within one second. Vital capacity can be determined as follows: After a period of resting respiration, the patient exhales as fully as possible and then inhales as deeply as possible. The difference between these two volumes indicates the vital capacity.
The results of spirometry can also be presented graphically. A so-called flow-volume curve is typically used for this purpose. This plot shows the flow rate of exhaled air—represented on the X-axis—against the volume—represented on the Y-axis. This graph makes it relatively easy to identify pathological changes in the lungs and the bronchial system.
In principle, spirometry can be performed by any general practitioner. However, if the measured values deviate from the norm, it is advisable to consult a pulmonologist. A pulmonologist is better equipped to interpret the measured values.
In addition to spirometry, three other methods are available for testing lung function.
Whole-body plethysmography is another commonly used method for testing lung function. This procedure measures respiratory resistance. Unfortunately, whole-body plethysmography cannot measure the air pressure within the alveoli.
Whole-body plethysmography is performed in a chamber that resembles a telephone booth. Inside the chamber is a sealed volume of air. This method is significantly more involved than spirometry.
The advantage of whole-body plethysmography is that it also allows for the measurement of chest expansion or compression. A pressure sensor measures changes in air pressure inside the chamber, which result from changes in air pressure within the chest and alveoli.
By measuring the air volume, additional values can also be derived. These include, for example, the maximum possible volume of air in the lungs or the residual volume that cannot be exhaled.
To obtain truly concrete results, spirometry should be performed in addition to this method.
Oscillometry measures resistance by blowing bursts of air into the lungs.
The shutter method, on the other hand, is based on the assumption that pressure between the lungs and the oral cavity will equalize on its own when the airways are briefly closed. However, in cases of respiratory disease, this method becomes increasingly less reliable as the disease progresses.
Furthermore, these alternative methods cannot determine the residual volume. For this reason, they are used only in relatively rare cases.
Every physician listed in the Leading Medicine Guide has attained the highest level of training and certification within their respective medical specialty society. Furthermore, we contacted this physician based, among other factors, on their case volume (surgeries, treatments, and therapies), which we determined by cross-referencing various publicly available sources. Following discussions with the selected physicians and the directors of the medical facilities, as well as a subsequent internal review, they were admitted to the Leading Medicine Guide.
The quality assurance of the Leading Medicine Guide is further ensured by 8 admission criteria. Each member must meet at least 6 of them:
