1- What is the pulmonary function test?
2- What does it consist of?
3- Why is it performed?
4- Preparing for the pulmonary function evaluation test
5- What does it feel like during the test?
6- Meaning of abnormal results
7- Progress
What is the pulmonary function screening test?
Medical pulmonary evaluation tests are performed to investigate and find out what type of alteration affects the pulmonary organs. They can also be performed to know the state of the disease affecting the lungs as well as data of a temporary nature. Spirometry can be used to evaluate the pathology affecting the lungs through different methods.
What does it consist of?
Spirometry consists of measuring the air flow in the lungs. By performing this type of measurement, both quantity and speed, the threshold for lung disease can be assessed.
In this test the patient breathes into an apparatus called a spirometer, the results may vary slightly depending on whether the patient performs the test sitting or standing up.
Lung volume measurement can be performed in two ways:
- Through plethysmography: this is the most accurate way and consists of sitting in a vacuum-sealed transparent box similar to a telephone booth. After inhaling and exhaling into a mouthpiece, the pressure changes that occur inside the box are decisive in measuring lung volume.
- Breathing helium or nitrogen: this is the other way to measure lung volume. Breathing these gases through a pulmonary tube for a certain time, the gas concentration is checked thanks to a camera in the tube in order to calculate the lung volume.
The patient must avoid smoking for 4/6 hours prior to the medical examination.
Why is it performed?
The pulmonary function evaluation test is performed to:
- Diagnose the types of lung disease (asthma, bronchitis and emphysema).
- To know the cause of a respiratory difficulty.
- Assess whether exposure to pollutants at work affects lung function.
- To study lung function before undergoing surgery.
- To check the effect of a medication.
- To know the progress of a treatment during an illness.
Preparing for the Pulmonary Function Evaluation Test
The patient should be aware that it is not advisable to eat large amounts of food before the medical test. Tobacco should also be avoided for 4/6 hours prior to the medical examination. In cases where the use of bronchodilators or inhaled medications should be abandoned, the specialist will let the patient know. In the same way, there may be a need for the patient to inhale some type of medication in the moments before or after the evaluation test.
What does the test feel like?
During the test, the patient may feel short of breath or feel dizzy due to the rapid and forced breathing he/she will have to do in order to perform the medical test correctly. You may also feel claustrophobic in the cabin part, this may be the most uncomfortable part you may experience.
Meaning of abnormal results
Obtaining an abnormal result after taking a medical test means that the patient may suffer from a lung or chest disease. In cases of emphysema, asthma, chronic bronchitis and infections, the lungs contain too much air and take longer to empty. These types of diseases are called obstructive lung disorders.
There are other types of lung diseases that can reveal this type of test. For example, those that cause the lungs to scar and reduce in size, so that they cannot hold much air and cannot perform the function of sending oxygen to the blood properly. If the patient has weak muscles, this will also be reflected in the test results. Some examples of this type of pathology are:
- Extreme overweight
- Fibrosis of the lungs
- Sarcoidosis and scleroderma
Advances
Pulmonary capacity measurement tests are becoming increasingly important for measuring the respiratory health of patients and also for measuring the performance of physical abilities in athletes. In this regard, there have been new technological advances in terms of the tests that can be performed to measure lung function. Among them we can find the following:
- Spirometry: breathing through a mouthpiece connected to a device that measures the amount and frequency of air inspired and expired during a specific period of time. Diseases such as asthma, bronchitis or pulmonary emphysema can be determined.
- Ultrasound spirometry: respiratory flow can be measured by providing optimal hygienic conditions.
- Pneumological ultrasound: studies can be performed on patients with pneumological pathologies with excellent imaging results.
- Ergospirometry: consists of a stress test that studies the response of the lungs, heart, muscles and metabolic system in the performance of physical activity. The gas exchange with breathing is also measured by means of a mask connected to a device that collects all the necessary data for subsequent objective assessment.
- Polysomnography: consists of monitoring the fundamental values of sleep and rest.