Oscillometry (the forced oscillation technique) is widely used in the Russian Federation. It is a simple, noninvasive functional diagnostic test that offers unique advantages in cases where spirometry and other pulmonary function tests are not appropriate, such as in young children, debilitated patients, or patients with physical and cognitive barriers to performing tests that require effort and coordination.The aim of this study was to analyze scientific literature data and our own results and to evaluate the significance and applications of oscillometry in clinical practice. The review examined the physiological principles of oscillometry and the basis for interpreting the results. Oscillometry is now recognized as a sensitive diagnostic tool for assessing airway resistance. This article describes sensitivity of the method for bronchodilation and bronchoprovocation tests, as well as its response to drug treatment, especially in asthma and chronic obstructive pulmonary disease. Oscillometry is a useful tool for diagnosing obstructive ventilation disorders. It should be used as an addition to spirometry to clarify phenotypes of small airways diseases. However, despite its great promise as a useful diagnostic tool, further evidence of its clinical utility in restrictive conditions is needed.Conclusion. Thus, oscillometry can be considered an addition and sometimes an alternative to spirometry and bronchodilation test, since it is well standardized. The test results are highly reproducible, the study does not require maximum effort, and the test is carried out during spontaneous tidal breathing.

Body plethysmography (synonyms: plethysmography, whole body plethysmography) is an important method for evaluation of the ventilation function of the respiratory system. This method can be used to measure static lung volumes and airway resistance. Methods. This document on body plethysmography was developed by a group of experts from the Russian Respiratory Society and the Russian Association of Specialists in Functional Diagnostics. All experts have experience in conducting research in accordance with quality criteria, analyzing the test results, and developing national standards. Results. Technical standards for body plethysmography were recommended, including criteria for the measurement quality and assessment of the test quality. The experience and knowledge of the expert group members were used in developing these recommendations. Conclusion. The article presents standards for measuring static lung volumes and airway resistance together with an algorithm for interpreting the results. This should contribute to improving the quality of measurements and uniformity in data interpretation.

Improvements in equipment, new research studies and enhanced quality assurance approaches have led to the need to update the 2005 technical standards for spirometry. The article presents the main updates, developed by an international joint task force by the American Thoracic Society and the European Respiratory Society in 2019. The characteristics of acceptability, usability, and repeatability, criteria grading the quality of the test session, the choice of main reported values are described.

The second part of the article discusses the spirometry interpretation using the latest international and national recommendations. Different systems of predicted values were considered, attention was paid to the GLI‑2012 reference equations advantages and the z-score assessment. The severity classification, obstructive disorders, extrathoracic and intrathoracic airway obstruction and possible spirometry indications of restrictive and mixed ventilation disorders were considered. The algorithm for spirometry evaluation was also presented, and the most common errors in the spirometry interpretation were discussed.

Tuberculosis-related lung damage is very different. Lung ventilation disorders have been studied in patients with pulmonary tuberculosis (TB) during the active process and after treatment, but the main causes of gas exchange changes have not been sufficiently studied. Investigation of diffusing lung capacity in combination with bodyplethysmography is useful for the interpretation of pulmonary gas exchange disorders. The aim was to determine the relationship of gas exchange with the value of alveolar volume (VA) and pulmonary poorly communicating fraction (PCF) in patients with pulmonary TB. A total of 292 patients (117/175 M/W) with verified pulmonary TB with smoking age less than 10 packs-years underwent spirometry, bodyplethysmography, and D_LCO by the single-breath method. PCF was estimated calculating the difference between total lung capacity (TLC) and VA (% TLC). Patients with low D_LCO had statistically significantly lower spirometric values (FVC, FEV₁, FEV₁/FVC, MMEF), lower TLC, higher airway resistance, RV/TLC, air-trapping volume, and PCF. The patients with low level of D_LCO were divided into four groups depending on level VA and PCF. In most patients with infiltrative tuberculosis (50%), the leading syndrome of the D_LCO decrease was alveolar-capillary damage. In patients with tuberculomas, the syndromes of alveolar capillary damage and pulmonary ventilation inhomogeneity were with the same frequency (43%). In patients with disseminated tuberculosis, the most frequent syndrome of the D_LCO decrease was pulmonary ventilation inhomogeneity (33%), then alveolar-capillary damage (29%) and mixed (24%). In patients with cavernous tuberculosis, the leading syndrome of the D_LCO decrease was mixed (39%), then alveolar capillary damage (25%) and pulmonary ventilation inhomogeneity (23%). The syndrome of gas exchange surface reduction in patients with disseminated and cavernous tuberculosis was less common (14%). In conclusion, an additional evaluation of the combination of PCF and VA increases the amount of clinical information obtained using the diffusion lung capacity measurements, since it allows identifying various syndromes of gas exchange impairment. The leading causes of diffusing capacity impairment vary by different types of pulmonary TB.

Improved approaches to quality assurance have led to the need to update the technical standards of spirometry taking into account modern technical capabilities. The aim of the study is to present updated recommendations on spirometry with explanations and additions that are important for everyday work in practical healthcare. Analysis of documents on technical standards of spirometry developed by an joint task force of specialists with expertise in conducting and analyzing lung function tests and ensuring laboratory quality, appointed by the Russian Respiratory Society, the Russian Association of Functional Diagnostics Specialists, the Russian Scientific Medical Society of Therapists, as well as a joint group of the American Thoracic Society and the European Respiratory Society. The 1st part presents sections on indications and contraindications to spirometry; technical conditions of the procedure, including infection control; methods of spirometry; describes the main indicators and criteria for the quality of the study. The implementation of the presented standards and consensus recommendations for clinicians, operators and researchers is necessary for improving the accuracy of spirometric measurements and the patient experience.