The lungs are a very powerful organ. It has the task of supplying our body with vital oxygen and of transporting away the degradation product carbon dioxide, which is produced during metabolism, with the exhaled air.

With each breath we draw 0.5 liters of air into our lungs, that is 10 liters per minute, 14400 liters a day and 5,265,000 liters a year. This makes the lungs the organ that is most directly exposed to pollutants of all our organs.

Not only these pollutants can damage our lungs, but also congenital disorders or infections can lead to impaired lung function. In this case values, which we can check with the help of spirometry (lung function test), change.

Spirometry is a simple, fast and non-invasive method for measuring lung volumes and respiratory flow rates. Its value lies in the diagnosis of constrictions of the bronchi such as asthma or chronic obstructive pulmonary disease (COPD). As already mentioned in the name of COPD, we are talking about an obstruction. At the same time it can be tested whether asthma sprays can help those affected.

The lung function is also used to determine the severity of the obstruction and helps assess the success of the therapy, the course of the disease and the prognosis.

With the help of the lung function, however, statements can also be made about other disorders of the lung function, which include gas exchange or the function of the breathing pump. However, these can often only be clearly evaluated with the aid of further diagnostic methods.

How is spirometry performed?

With the spirometer we use, we will first put a nose clip on you, as the breathing maneuvers are measured exclusively through the mouth. You will then receive the spirometer and will be asked to completely enclose the mouthpiece with your lips and then inhale and exhale three times normally and then three times deeply or firmly.

During your breathing maneuvers, the static and dynamic lung function parameters as well as respiratory flows through the mouth are measured. The measurements are made either with flow sensors or with the help of ultrasonic sensors or the hot wire anemometer, but also via volume sensors such as the turbine. For all mathematicians among us: With flow sensors, the volume is calculated numerically from the integration of the flow over time. With the volume sensors, the flow is determined by differentiating the recorded volume.

When do we do spirometry?

We use the lung function primarily for diagnosing suspected respiratory diseases (e.g. COPD, bronchial asthma). It is also used when a chronic cough needs to be clarified further.

By default, the lung function is carried out during our major check-up.

Further areas of application of spirometry are the early detection of damage caused by inhalation noxae, for example after smoke gas poisoning, if combined diseases of the lungs and heart are suspected, as well as musculoskeletal diseases with effects on breathing. But lung function is also used when diseases of the breathing pump are suspected, which affect the respiratory center, the associated nerves or muscles, and when monitoring the progress of bronchopulmonary diseases and monitoring therapy.

Additional areas of application are occupational health issues and precaution (e.g. exposure to allergens, inorganic dusts, smoke pollution, etc.) and preoperative diagnostics