Impulse oscillometry indices to detect an abnormal lung clearance index in childhood cystic fibrosis

Abstract

The objective of our cross-sectional study was to assess the relationships between indices of multiple breath washout (MBW) and impulse oscillometry system (IOS) in cystic fibrosis in forty consecutive children (median age 8.1 years) in stable conditions and to evaluate whether cut-off values of IOS indices may help to avoid MBW, which is time-consuming. IOS measurements took a median duration of 3 min, while MBW measurements took a median duration of 49 min. Lung Clearance Index (LCI 2.5% ) depicted significant linear correlations with z-scores of R5Hz, R5-20Hz, X5Hz, AX, and Fres (r 2 = 0.27 to 0.51). Receiver-operator characteristic curves were constructed and showed that the best compromise was obtained with the z-score of Fres, with a cut-off value of −1.37 that had a sensitivity of 0.966, a specificity of 0.636, and a negative predictive value of 0.875. This z-score is useful for excluding increased LCI 2.5% when below −1.37 using the reference set of Gochicoa et al. In conclusion, IOS measurement is easily and rapidly obtained in children and may be clinically useful for excluding increased LCI 2.5% , thus allowing the time-consuming MBW test to be avoided.

Beneficial short-term effect of autogenic drainage on peripheral resistance in childhood cystic fibrosis disease

“…Impedance of the respiratory system was measured using an IOS (Master Scope Body, Carefusion Technologies, Yorba Linda, California, USA), as previously described [ 8 , 11 ]. The quality criterion for IOS measurements was a coherence value ≥ 0.6 at 5 Hz [ 11 ].…”

“…Impedance of the respiratory system was measured using an IOS (Master Scope Body, Carefusion Technologies, Yorba Linda, California, USA), as previously described [ 8 , 11 ]. The quality criterion for IOS measurements was a coherence value ≥ 0.6 at 5 Hz [ 11 ]. Five trials of IOS were repeated and we kept only the three recordings yielding the lowest coefficient of variation of impedance at 5 Hz for analysis, as previously described [ 11 ] and accordingly to recent guidelines [ 12 ].…”

“…The quality criterion for IOS measurements was a coherence value ≥ 0.6 at 5 Hz [ 11 ]. Five trials of IOS were repeated and we kept only the three recordings yielding the lowest coefficient of variation of impedance at 5 Hz for analysis, as previously described [ 11 ] and accordingly to recent guidelines [ 12 ]. We used the following IOS variables: impedance at 5, 10, 15, 20, 25, 30 and 35 Hz, resistance and reactance at 5 Hz and 20 Hz, fall in resistance between R5 and R20 (R5–20 Hz), area under the reactance curve (AX) and resonance frequency (Fres).…”

Pediatric pulmonology year in review 2021 and 2022: Physiology

“…R at 5 and 10 Hz (R5 and R10, respectively), R5-R20, AX, and Z5 all were higher in patients with active NS. However, no difference was found at high frequency oscillations (15)(16)(17)(18)(19)(20), suggesting that NS affects the distal airways.…”

Spirometry and respiratory oscillometry: Feasibility and concordance in schoolchildren with asthma

“…2 The recent guidelines of the European Respiratory Society (ERS) for the diagnosis of asthma in children 3 Other techniques for studying lung function in asthma have been incorporated into the clinical setting, as commercial equipment has become available for their execution. These include the growing use of respiratory oscillometry (RO), a technique that requires little cooperation from the patient 4 and use of which has been investigated not only in asthma, but also in neuromuscular diseases, 5 cystic fibrosis, 6 postinfectious bronchiolitis obliterans, 7 vocal cord dysfunction 8 or chronic lung disease of prematurity. 9 RO is especially useful for studying changes in the small airways (SA).…”