Forced oscillation measurements in patients after lobectomy - A comparative analysis with IPF and COPD patients

Forced oscillation technique (FOT) is becoming increasingly widespread measurement method used for assessment of lung function. In the present study, we attempted to assess FOT values in patients after lobectomy in comparison with IPF and COPD patients.

Twenty-two 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 , FEF_25-75 , MIF₅₀ ), plethysmography (R_aw , TLC, RV, RV/TLC) and a test using the forced oscillation technique- resistance (R at 5Hz, 11Hz and 19Hz, inspiratory, expiratory and total), reactance (Xat 5Hz, 11Hz, inspiratory, expiratory and total), Fres and expiratory flow limitation (∆X). The ANOVA Kruskal-Wallis test followed by a multiple comparison test were used to evaluate the differences in oscillatory parameters between-groups.

Patients after lobectomy presented reduced X5, X11 and moderately increased R5, R11, R19, R5-19, ∆X and Fres. R_insp 5 weresignificantly higher when compared with IPF patients (P = 0.001). In lobectomy patients R5, X5, X11, ∆X and Fres were significantly less affected when compared with patients with COPD (P < 0.05 for all values). R5-19, which reflects small airways dysfunction, occurred to be similarly elevated as in COPD patients (0.5 vs 0.6 cmH₂ O/L/s).Abnormalities of reactance at 11Hz were observed more frequently than at 5Hz in all groups of patients.

Patients after lobectomy due to lung cancer presented FOT abnormalities, which could be caused by lung parenchymal abnormalities following recent thoracic surgery.