Impulse oscillometry in the diagnosis moderate airway obstruction

Background: Impulse oscillometry (IOS) is a non-invasive method for determining respiratory impedance and its parameters. IOS has certain advantages over traditional spirometry. Aim: To assess the potential of IOS in the diagnosis of moderately severe airway obstruction. Methods: We examined 53 patients divided in two groups. The first group consisted of 29 patients (26 males and 3 females aged 42 to 89 years) with moderately severe obstructive abnormalities; the second group included 24 patients (17 males and 7 females aged from 18 to 68 years) without ventilatory defects. Results: Obstructive abnormalities were detected by IOS in 93% of patients in group 1, and the severity of obstruction was more pronounced compared to the results of spirometry in 37% of patients. In group 2, the IOS parameters were normal. There were significant differences in the lung function and IOS parameters between the first and second groups.There were significant correlations between airway resistance and IOS parameters in patients with moderately severe obstructive abnormalities. Conclusion: Thus impulse oscillometry can be used in the clinical practice to diagnose disorders of respiratory mechanics in patients with moderately severe airway obstruction.