Transcutaneous two-wave pulse oximetry is the most popular and prevalent method for studying blood oxygenation. However, during its implementation, smokers do not take into account the level of carboxyhemoglobin, which leads to an erroneous overestimation of hemoglobin saturation with oxygen. The computer program developed by us makes it possible, without the use of additional diagnostic equipment, to correct the results of monitoring blood oxygenation for the level of carboxyhemoglobin, correcting the indicated diagnostic inaccuracy in assessing the saturation of hemoglobin by oxygen in smokers.

The purpose of the study — to identify and evaluate the clinical significance of “hidden” disorders of blood oxygenation in smokers with exacerbation of bronchial asthma.Materials and methods: spirometry, pulse oximetry, CO-metry of exhaled air. To diagnose “hidden” disorders of blood oxygenation, including “hidden” violations of the spectral characteristics of the level of hemoglobin oxygen saturation, 19 male smokers (middle age 54,6±2,05 years) with exacerbation of mixed (68 %) or allergic (32 %) bronchial asthma were examined.The results: the accuracy of the clinical assessment of blood oxygenation in smokers increased significantly after the correction of the SpO2 level to the level of carboxyhemoglobin with the help of a computer program developed by us, which made it possible to diagnose a clinically significant lifethreatening exacerbation of this disease in smoking patients with bronchial asthma, since “hidden” respiratory insufficiency was detected in a timely manner.

Aim. To assess the risk of exacerbations of bronchial asthma (BA) in smoking patients with the asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) after inpatient treatment. Materials and methods. 36 smokers with ACO (main group) and 36 non-smoking patients (control group) with severe or moderate exacerbation of bronchial asthma were examined. Assessment of the severity of exacerbation of BA before treatment, levels of control and risk of exacerbations of BA after treatment was determined according to the Federal clinical guidelines for the diagnosis and treatment of BA (2016). Spirometry, monitoring of blood oxygenation using transcutaneous spectral pulse oximetry and enzyme immunoassay for determination of matrix metalloproteinases 9 were performed. Smoking experience, smoking index and pack/years index were taken into account in patients with ACO. The carboxyhaemoglobin level was analyzed by the carbon monoxide fraction in the exhaled air. Results. For the first time in patients with the ACO, the ability of heavy tobacco smoking and associated decrease in blood oxygenation to potentiate the negative impact of other predictors on the risk of exacerbations of the underlying disease was revealed. In smoking patients with the ACO, for the first time, a direct association of higher levels of matrix metalloproteinases 9 (measured before inpatient treatment) with such a predictor of the risk of further exacerbations of the disease as more frequent detection of symptoms of uncontrolled BA was revealed. In non-smoking patients with BA, a direct relationship between increased sputum secretion and eosinophilia of blood and/or sputum (a predictor of exacerbation of BA) and the relative duration of episodes of decreased blood oxygenation was established. Conclusion. It was found that intensive and prolonged smoking increases the duration and reduces the effectiveness of inpatient treatment of patients with ACO, contributing to the preservation of air traps and low (forced expiratory volume in 1 second 60%) ventilation capacity of the lungs with the persistence of moderately reduced blood oxygenation; the risk of further exacerbations of BA in this phenotype of patients is significantly higher than in non-smoking patients with BA without combination with COPD.

The literature review provides up-to-date information about the clinical course of bronchial asthma (BA) in smokers with small airway diseases. Special attention is paid to the combination of bronchial asthma and chronic obstructive pulmonary disease (COPD), namely asthma-COPD overlap syndrome (ACOS). According to literature data, in case of small airway duseases exacerbations are more often and severe in smokers with BA and ACOS. Besides, disease prognosis worsens due to reduction in the efficacy of a baseline therapy. Keywords: bronchial asthma, small airway disease, smoking-related phenotype, asthma-COPD overlap (BA-COPD phenotype). В литературном обзоре представлены современные сведения об особенностях клинического течения бронхиальной астмы (БА) у курильщиков с поражением малых дыхательных путей (МДП). Особое внимание уделено сочетанию бронхиальной астмы и хронической обструктивной болезни лёгких (ХОБЛ; COPD) – синдрому перекрёста БА-ХОБЛ (СПБАХ, asthma-COPD overlap, ACO; фенотип БА-ХОБЛ). Согласно литературным данным, в случае поражения МДП у больных БА с фенотипом курильщика и при сочетании БА-ХОБЛ чаще возникают и тяжелее протекают обострения, ухудшается прогноз заболевания, в т.ч. из-за снижения эффективности базисной терапии. Ключевые слова: бронхиальная астма, поражение малых дыхательных путей, фенотип курильщика, asthma-COPD overlap (фенотип БА-ХОБЛ).

The goal of the paper is to range information about early and delayed clinical and functional disorders of the respiratory and cardiovascular systems after COVID-19. The review focuses on clinical and functional diagnostic methods (laboratory, instrumental and radiation) of disorders of the cardiovascular and respiratory systems in patients after COVID-19. At the moment, enough data has been accumulated confirming early and aftereffect of COVID-19. The need for further rehabilitation may be caused by the presence and severity of clinical and functional disorders of the respiratory and cardiovascular systems. Key words: coronavirus disease (COVID-19), impaired respiratory function and diffusion lung capacity, acute myocardial injury, electrical myocardium instability. Цель – систематизировать сведения о ранних и отсроченных клинико-функциональных нарушениях дыхательной и сердечно-сосудистой систем после перенесенной коронавирусной инфекции. В обзоре основное внимание уделено клинико-функциональным методам диагностики (лабораторным, инструментальным и лучевым) нарушений сердечно-сосудистой и дыхательной систем у пациентов, перенесших COVID-19. На данный момент накоплено достаточно данных, подтверждающих наличие ранних и отсроченных последствий новой коронавирусной инфекции. Необходимость дальнейшей реабилитации может быть обусловлена наличием и тяжестью клинико-функциональных нарушений со стороны органов дыхания и сердечно-сосудистой системы. Ключевые слова: новая коронавирусная инфекция (COVID-19), нарушения функции внешнего дыхания и диффузионной способности легких, острое повреждение миокарда, электрическая нестабильность миокарда.