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 (p<0.001 for all parameters) when compared with IPF
patients. In FOT this group of patients presented also higher values of
resistance, expiratory reactance and expiratory flow limitation in comparison
with IPF patients. R5-19, which reflects small airways dysfunction, occurred to
be similarly elevated as in COPD patients (0.5 vs 0.6 cmH2O/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.