Is the Forced Oscillation Technique a suitable surrogate for more volitional lung function testing in COPD?

The forced oscillation technique (FOT) has been intensively researched for use in patients with respiratory disease. However, since then the technology has progressed and its uses within respiratory testing have increased. This study aims to identify if FOT measurements can be used to identify pathology associated with chronic obstructive pulmonary disease (COPD) in comparison to more volitional lung function assessments. FOT was performed using Resmon Pro (Restech Milano, Italy). Spirometry and body plethysmography were performed using Jaeger Masterscreen (Vyaire Medical, Germany) in 11 patients (3 female, age 65.2years ± 9.3, height 171cm ±11.8 and weight 741kg ± 17.7) with a known diagnosis of COPD as part of a clinic visit in November 2023. Results have been analysed using Pearson’s correlation to determine the relationships between measurements. Analysis identified a strong (R= 0.8) significant (P=0.001) correlation between RV/TLC ratio standardised residual (SR) and AX inspiration (area under the reactance curve) SR (Figure 1). Other correlations were identified but none were significant. <fig><object-id>erj;64/suppl_68/PA2322/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> AX could be used as a surrogate for the RV/TLC ratio and identify lung gas trapping in patients with COPD. Additional further research to greater identify the specificity and sensitivity of these tests against already established markers of pathophysiology in a larger cohort is warranted.