INFORMATIVENESS OF IMPULSE OSCILLOMETRY IN THE DETECTION OF RESTRICTIVE TYPE VENTILATION DISORDERS

Abstract

At present, there are a number of problems associated with the diagnosis of restrictive type of ventilation disorders: first, to identify restriction, it is necessary to perform body plethysmography, which is a laborious technique and requires the active cooperation of the patient with medical personnel; secondly, methodological issues that concern the criteria for the diagnosis of restriction are still under development. Impulse oscillometry (IOS) is a non-invasive and effortless technique for the patient to identify ventilation disorders, especially obstructive ones. In order to assess the informative value of IOS in the diagnosis of the restrictive ventilation disorders, respiratory impedance and its parameters were measured in 82 patients with various bronchopulmonary pathologies. The restriction was established on the basis of spirometric and bodyplethysmography studies. The results showed that IOS is a low-sensitivity method for detecting the restrictive type of ventilation disorders with mild reduced total lung capacity (TLC≥70%pred.), since in this case, the basic parameters of the IOS, such as the resistive component of the respiratory impedance (Rrs) at 5 and 20 Hz (Rrs5 and Rrs20, respectively), as well as the reactive component of the respiratory impedance at 5 Hz (Xrs5) remain within the normal values. When TLC was less than 70%pred., there was a decrease of Xrs5 with an increase in the resonance frequency and the preservation of the normal values of Rrs5 and Rrs20. The abnormal absolute frequency dependence of Rrs was determined at any degree of change in the TLC, increasing as it decreased.