Application of Impulse Oscillometry in Respiratory System Evaluation in Elderly Patients

Introduction: Spirometry, which is a basic diagnostic tool of the respiratory system, may cause problems to patients of advanced age because of required cooperation and specific respiratory manoeuvres. Impulse oscillometry (IOS) may be an interesting alternative for spirometry as the examination is made during quiet breathing and gives information about resistive properties of the respiratory system. Materials and Methods: This work presents the results of oscillometric measurements made in 277 patients aged 65–96 years, in whom spirometry was also performed. Results: Resistances measured with IOS (R5, R5-R20) and the resonant frequency Fn correlated significantly with FEV₁ (r = −0.503; −0.570 and −0.673, respectively). A comparison of the results from patients with airway obstruction confirmed in spirometry with those of the non-obstructed group showed highly significant differences in mean values of oscillometric parameters (p < 0.001). Conclusions: As R5-R20 is regarded as a measure of peripheral airways resistance, IOS may serve as an interesting complementary or alternative method for spirometry in elderly subjects for evaluation of the state of respiratory system.