Ville-Pekka Seppä

Inhaled corticosteroid treatment improves expiratory variability index in steroid-naïve asthmatic children aged 4–7 yearshttps://bit.ly/3n4vBT3

Impedance pneumography enables the measurement of the expiratory variability index (EVI) at home during a night9s sleep in infants with recurrent respiratory symptoms. EVI is associated with asthma risk, symptoms and lung function.https://bit.ly/2PF2cx8

Background Lung function testing in small children is cumbersome. However, reduced variability of tidal breathing recorded using impedance pneumography (IP) during sleep was recently found to be a potential objective marker of wheeze in children aged 1‐5 years. We aimed to investigate how an acute bronchial obstruction (BO) and its severity, and recovery thereof reflects in expiratory variability index (EVI). Methods EVI was measured using a wearable IP system (Ventica®) during sleep in 40 healthy controls (aged 1.5‐5.9 y) and 30 patients hospitalised due to acute BO (aged 1.3‐5.3 y). In healthy controls EVI was measured for 1‐3 nights at their homes. Patients were measured for several nights during hospitalisation, as practically feasible, and at home 2 and 4 weeks post‐discharge. Results We received 79 EVI results from 39 controls and 139 from 30 patients. 90 % had previous BO episodes, 30 % used asthma controller medication before and 100 % after hospitalisation. Compared to controls, EVI was significantly lower during hospitalisation (p<0.0001) having significant correlation with number of days to discharge (r=‐0.38, p=0.004). At 2 or 4 weeks post‐discharge, EVI was not significantly different from the controls (p=0.14, p=0.49, respectively). EVI was significantly associated with chest auscultation findings (p=0.0001) being 17.5 (4.9) (median, IQR) with normal auscultation, 15.6 (7.4) in those with prolonged expiration, and 11.4 (6.8) in those with wheeze and/or rales and crackles. Conclusions EVI was found to be a sensitive, objective marker of acute BO, showing strong association with changes in clinical status in wheezy children aged 1‐5 years.

Background: Lung function testing is an essential part of diagnostic workup and monitoring of asthma, but young children are lacking easy, routine testing methods. However, recent discoveries show reduced tidal breathing variability measured using impedance pneumography (IP) at home during sleep as a sign of airway obstruction. In this study, we assessed (a) the discriminative capacity of expiratory variability index (EVI) between healthy controls and young children with recurrent wheeze on‐and‐off controller medication, (b) association between EVI and parentally perceived obstructive symptoms (need for bronchodilator) and (c) measurement success rate.Methods: We included 68 patients (aged 1.0‐5.6) and 40 healthy controls (aged 1.0‐5.9 years). The patients were prescribed a three‐month inhaled corticosteroid (ICS) treatment due to recurrent obstructive bronchitis. We measured EVI using IP at home at the end of the treatment (0W) and 2 (2W) and 4 (4W) weeks after ICS withdrawal.Results: EVI was higher in controls than in patients, and significant within‐patient reduction occurred at 4W as compared to 2W or 0W. Area under curve of the ROC curve (controls vs all patients) at 4W was 0.78 (95% CI 0.70‐0.85). Children who were administered bronchodilator by parental decision had lower EVI than those without bronchodilator need at 4W, but not at 0W or 2W. Patients with parent‐reported airway infection, but no bronchodilator need, had normal EVI. Measurement success rate was 94%.Conclusion: EVI was lower in patients than in controls and it reduced further after controller medication withdrawal, especially in the presence of parentally perceived wheeze symptoms. This technique shows a significant potential for routine lung function testing of wheezy young children.

Background: Diminished variability of the expiratory flow profiles measured using impedance pneumography (IP) during night’s sleep is associated with lower airway obstruction (LAO) in young children with recurrent wheeze (Seppä et al. ERJ Open Res 2019, accepted). Aims and Objectives: We aimed to investigate, how an acute LAO and recovery thereof reflects on the change in expiratory variability index (EVI) in a longitudinal setting. Methods: EVI was measured using a wearable IP system (Ventica, Revenio Research Ltd., Vantaa, Finland) during sleep at night in healthy controls (both sexes aged 4.3 [1.5-6.0] y) and patients hospitalised due to acute LAO (both sexes, aged 3.5 [1.3-6.0] y). In-patients were measured for several nights, as practically feasible, and for 1-2 nights at home after first and second control visit (2 and 4 weeks post-discharge). The controls were measured for 1-3 nights at their homes. Results: We received 79 recordings from 37 controls and 141 from 29 patients. Compared to the controls, EVI of the patients was lower during the in-patient period (rank sum p<0.0001), but not during the control visits showing trend significantly associated with clinical recovery. The sensitivity and specificity of EVI ≤ 14.0 was 78 % and 90 %, respectively, during the first two in-patient nights. Conclusions: EVI shows to be a sensitive, objective marker of acute LAO prone to change with the clinical status in children aged 1-5 years.

Impedance pneumography recordings during sleep at night show reduced variability in specific parts of the expiratory flow–volume curve in children with recurrent wheezehttp://bit.ly/2Wkfap0