Diseases of the respiratory system in our time are very common. Allergies, stressful situations, bad habits, work at individual enterprises - all these factors negatively affect the bronchi and lungs. In order to timely identify pathological processes occurring in the respiratory system, it is recommended to periodically undergo a spirometric study. This article will highlight the nuances of its implementation.
What is this procedure
Spirometry is a medical test that examines the state of the respiratory system. This diagnostic method helps to detect functional changes in the lungs. Spirometry allows you to evaluate the pathological processes that occur in the respiratory tract, but to make a final diagnosis one of its conduct is not enough.
At present, spirographs, special apparatuses for conducting this study, have been commissioned in a large number of medical centers. With their help, it is realistic to diagnose the functions of the respiratory organs in patients of various age categories in a matter of minutes.
Spirometry devices are open (when they are used, patients breathe atmospheric air) and closed. The principle of operation of closed devices is not based on interaction with the atmosphere. Modern models record the functional state of the human respiratory system, analyze it using computer technology.
Purpose of use
Spirometry is the most simple and popular diagnostic method in medicine. It is performed by patients with the following goals:
- Identification of the origin of some signs of diseases: prolonged cough, respiratory sounds in the lungs, shortness of breath, etc.
- The study of the respiratory system of heavy smokers.
- Detection of violations in the level of gas exchange.
- Assessment of the consequences of surgery.
- Determining the degree of respiratory disease.
- Identification of occupational disease.
Contraindications
Spirometry is a graphical diagnostic method that has a small number of contraindications. It is not recommended to resort to this study in specific cases:
- With a heart attack, stroke.
- Pregnant women with severe toxicosis.
- With an excessive jump in blood pressure in the patient.
- With pulmonary hemoptysis of unknown origin.
- If there is or suspicion of tuberculosis or pneumonia.
- After a recent abdominal or chest surgery.
- After the surgical procedure in front of the eyes.
Useful Tips
This study does not require a special preparatory process. But if you follow certain tips, you can increase the accuracy and reliability of the results of spirometry.
- The procedure is carried out in the morning and on an empty stomach. An hour before she was not advised to drink coffee and smoke. The day before this study, you must stop taking medications that can affect the activity of the muscles of the bronchi.
- Clothing during testing should be free and not constrain the chest.
- Removable dentures are recommended to be removed during this diagnostic test. Measurements are made based on the oral flow of air, in order to avoid its leakage from the nose, a special clip is used.
- During spirometry, the patient stands or sits. Tilting the head forward or backward, tilting the body forward while exhaling the patient is not allowed.
Stages
Spirometry is a method for determining the useful volume of the respiratory organs through a special analysis of the patient's inspirations and exhalations. It consists of the following steps:
- The nasal passages of the patient are clamped with a special device, a mouthpiece is inserted into his mouth in order to prevent air leakage.
- The specialist includes a spirograph, the person under investigation breathes for 10 seconds, and then proceeds to certain maneuvers in his breathing.
- He inhales deeply and then exhales smoothly. In this way, the vital capacity of the lungs is measured.
- The patient takes a deep breath, holds his breath for a couple of seconds and makes a sharp exhale. The spirograph measures a fixed indicator of the vital capacity of the respiratory system.
- When measuring the highest level of ventilation in the lungs, the patient very quickly breathes in and out.
Study statistics
These indicators are measured during the patient’s calm breathing. It is customary to relate to them:
- The volume of air that passes through the patient’s lungs. With spirometry, its norm varies from 500 to 800 ml. The alveolar fraction of the average volume involved in gas exchange is usually two-thirds of this indicator.
- Reserve volume of inspiration. In the time period of his measurement, the patient exhales very deeply after a quiet exhalation.
- The inspiratory capacity displays the amount of air entering the respiratory system after a strong inspiration. The normal spirometry indicator is calculated from the sum of the average and reserve volume.
- The vital capacity of the respiratory system is the volume of inspiration after a deep exhalation. For men, the norm is 3.5-4 liters, for women - 2.5-3 liters.
In conclusion, an indicator of the volume of air passing through the respiratory system in one minute is recorded. Normal spirometry usually shows 50-180 liters. A decrease in this indicator usually indicates certain disturbances in the work of the respiratory system.
Speed indicators
Specialists, making an analysis of the curve issued by the spirograph, measure several speed indicators of spirometry.
- The volume of air exhaled by the patient during the most rapid exhalation. In patients who do not have health problems, the norm is at least 70% of the forced lung capacity.
- The Tiffno Index is the ratio of fixed expiratory volume to lung capacity, which is multiplied by 100%. The level of this indicator is usually not less than 70-75%.
A spirometric study helps to identify symptoms of impaired patency of the bronchial tree. Normal spirometry indicators are correlated with the age category, height, weight of the patient and many other factors. To correctly assess the state of pulmonary ventilation, specialists compare the results of these studies with the main indicators of each patient. Deviations from the main values by more than 15-20% in most cases indicate the presence of pathological processes.
We can say that spirometry is a method of information diagnostics. It allows you to detect the type and degree of pathology of the respiratory system. Thanks to this test, you can check the effectiveness of the course of prescribed treatment and adjust it for the better.