Capnometry in the Assessment of Pulmonary Ventilation in Patients with Bronchial Asthma

Abstract

Background: Bronchial obstruction as characteristic feature of bronchial asthma (BA) can lead to gas exchange disorders. The distinction of asthma is that even in patients without clinical symptoms and almost normal spirometry parameters may have been significant gas exchange disorders including that due alveolar ventilation reducing. This study aimed to investigate lung ventilation pecularities in patients with BA. Results: Among patients with uncontrolled course of 40% have a smoking history with index (25,8 ± 8,8) pack-years. In patients with uncontrolled asthma "dead" space ventilation volume is (211 ± 8) ml, and part of the "dead" space of the tidal volume - (30,5 ± 1,5)%, which is statistically significantly greater than that rate for patients with controlled asthma - (176 ± 11) ml and (24,6 ± 0,5)%, respectively, p < 0.05. Alveolar ventilation in patients with uncontrolled disease course is lower, namely (7,3 ± 0,4) l/min. than when controlled asthma - (8,3 ± 0,2), p < 0.05. Conclusions: Lung ventilation parameters in patients with asthma without exacerbation in general slightly different from those in healthy subjects, but the effectiveness of alveolar ventilation is reduced by 14% in uncontrolled asthma due to high waste "dead" space ventilation.