Impedance Pneumography in Healthy and Sick Children Aged Between 2 and 35 Months

ABSTRACT Rational Impedance pneumography (IP) non‐invasively records tidal breathing flow‐volume curves over long durations. It measures the ratio of time to peak tidal expiratory flow relative to the total expiration time (T PTEF /T E ) and the Expiratory Variability Index (EVI), which assesses the variability of expiratory flow in the early phase of expiration with a decrease in case of clinical symptoms of bronchial obstruction. Objective To establish reference values for EVI and T PTEF /T E , recorded at home during sleep using IP. Methods We conducted a bi‐centre prospective study to recorded EVI and T PTEF /T E over at least 4 h of sleep, using IP measurement Ventica® (Icare Finland Oy, Finland), in healthy and sick (non‐wheezy and wheezy) children, aged 2 to 35 months. Results Among the 67 healthy children included, 59 were successfully recorded by parents (median [Q1; Q3] (range) age 15.4 [8.6; 26.0] (2.3−35.9) months) and showed median [Q1; Q3] (5th; 95th percentiles) EVI of 16.7 [14.9; 18.9] (12.7; 20.7); and T PTEF /T E ( n = 51) of 0.18 [0.16; 0.22] (0.13; 0.26). In 9 non‐wheezy children with respiratory symptoms and 12 wheezers, EVI (13.5 [9.6; 14.6] and 7.0 [6.0; 12.5], respectively) and T PTEF /T E (0.16 [0.13; 0.18] and 0.12 [0.09; 0.18], respectively) were significantly lower compared to healthy. The values of EVI and T PTEF /T E in 68 healthy and sick children with both measurements (12 missing data) were concordant (> or < 5th percentile) in 62 cases (91%). Conclusions We provide reference values of EVI and T PTEF /T E measured at home by parents using IP in young children. IP shows lower values in wheezy and non‐wheezy sick young children.