Small airways dysfunction after lobectomy due to lung cancer estimated by forced oscillation technique in comparison with IPF and COPD

Background: Forced oscillation technique (FOT) is becoming increasingly widespread measurement method used for assessment of small airways functions. Objective: In the present study we attempted to assess a presence of small airways dysfunction (SAD) in patients after lobectomy in comparison with IPF and COPD patients. Methods: 22 patients after lobectomy due to lung cancer stage I or II, 28 patients with idiopathic pulmonary fibrosis and 17 patients with chronic obstructive pulmonary disease were enrolled in the study. All patients performed spirometry (FEV1, FVC, FEV1/FVC, MEF50, MEF25, FEF25-75, MIF50), plethysmography (Raw, TLC, RV, RV/TLC) and a test using the forced oscillation technique- resistance (R at 5Hz, 11Hz and 19Hz, inspiratory, expiratory and total), reactance (X at 5Hz, 11Hz), Fres and expiratory flow limitation. The ANOVA Kruskal-Wallis test followed-by a multiple comparison test were used to evaluate the differences in oscillatory parameters between-groups. Results: In pulmonary function tests patients after lobectomy presented small airway dysfunction with statistically significant higher MEF50, MEF25, FEF25-75 (p2O/L/s). Patients suffering from COPD presented the highest limitations of spirometric and oscillometric results with a statistically significant difference when compared with studied groups of patients. Abnormalities of reactance at 11Hz were observed more frequently than at 5Hz in all groups of patients. Conclusion: Patients after lobectomy presents SAD, more expressed than IPF patients but less pronounced than COPD patients.