External respiration function (VFD) is the main diagnostic method for pathologies of the respiratory system in patients of any age.
The function of external respiration is carried out for those patients who have a genetic predisposition to the development of diseases of the respiratory system, aggravated by allergic manifestations. In addition, the function of external respiration is necessary for people suffering from frequent severe bronchitis and pneumonia, coughing or excruciating shortness of breath, allergic pathologies.
Restrictions in assessing the function of external respiration apply to the category of patients who, due to age, cannot cooperate with a doctor and are not able to fulfill what is asked of them – these are children under the age of five.
The development of a disease such as bronchial asthma is based on an inflammatory phenomenon of a chronic nature, which explains the specific reaction of the respiratory tract to all kinds of effects. The clinical picture of such pathological phenomena is characterized by periods of exacerbation of the disease. With exacerbation, cough, severe shortness of breath, whistles and wheezing during breathing are noted. Obstructive airway phenomena are reversible. Diagnostic methods of the last generation make it possible to give an objective assessment of both the presence of the disease itself in the patient and the nature of its development. Among other things, it is possible to determine the reversibility or irreversibility of the obstructive process and the severity of the pathology from the results of the function of external respiration. Further studies of the function of external respiration make it possible to monitor the effectiveness of the treatment.
To determine the function of external respiration, methods for conducting a study of the respiratory system were developed and brought under a common standard. The most commonly used method due to the elementary nature of the execution is the method, the basis of which is to fix the indicators of the “volume-flow” curve during extremely accelerated exhalation of the volume of lung tissue. In the process of this method, the doctor receives information about ongoing changes in patency of the bronchi based on an analysis of speed indicators, which are used to indicate percentages of the normal value. Among other things, for the function of the external respiration of children, their indicators have been developed and established.
The determination of the reversibility or irreversibility of obstructive changes in the respiratory tract is based on the results of a study using inhaled bronchospasmolytics. For an adequate result, it is necessary several days before the study to stop taking medications. The time of withdrawal of the drug is determined only by a qualified specialist. An increase in indicators after inhalation of bronchospasmolytics indicates that pathological phenomena are reversible, which most often indicates the development of bronchial asthma. After obtaining the results of samples of drugs with the property of expanding the bronchi, it is possible to optimally select the necessary bronchospasmolytic to correct the condition.
Conducting tests using bronchospasmolytics is also prescribed for patients with the goal of revealing a latent spasm of the bronchi. This phenomenon is noted when the patient has practically no symptoms of obstructive changes in the tissues of the bronchi, and the results of spirography indicate a significant increase in indicators after conducting tests using drugs with bronchospasmolytic action.
The rules for preparing for the analysis of the function of external respiration are determined by the doctor.