Forced Oscillation Technique for Monitoring the Respiratory Status of Adult Cystic Fibrosis Patients

Introduction: Lung function testing is an irreplaceable tool in assessing adult cystic fibrosis (CF) patients, and spirometry is still the gold standard. Aims and objectives: The aim of this study was to evaluate the correlation of forced oscillation technique (FOT) in adults on CF transmembrane conductance regulator modulator therapies, and to investigate the impact of P. aeruginosa colonisation on selected lung function parameters. Methods: We included 55 patients with genetically confirmed CF in regular check-ups at our Center in this retrospective study. Spirometry and FOT (ResmonTM Pro) were performed, along with sputum analysis for P. aeruginosa. Statistical analyses were conducted in MedCalc version 20.011. Measured FOT parameters were respiratory resistance (Rrs), reactance (Xrs), resonant frequency (Fres) and area of reactance (AX). Spearman correlation was used to elucidate relationship between FOT and spirometry, and Mann-Whitney U test to evaluate the impact of P. aeruginosa colonization on lung function. P<0.05 was considered statistically significant. Results: The median age of participants was 25.5 ± 5.4617 years, most were female (29;53.7%), 70% were homozygous for F508del, and mostly had normal lung function measured with spirometry (35; 64%). A statistically significant moderate correlation was observed between FOT parameters (AX, Fres, Rinsp, Rexp at 5Hz), and selected spirometric values (FEV1, FVC, FEF25-75). Fres in P. aeruginosa colonized patients was higher compared to non-colonized patients (p 0.01), as well as AX (p 0.037). Conclusion: Forced oscillation technique is a valuable additional tool in the assessment process of adult cystic fibrosis patients.