Rationale: Respiratory resistance (Rrs) and reactance (Xrs) as measured by oscillometry and their intrabreath changes have emerged as sensitive parameters for detecting early pathological impairments during tidal breathing. Objectives: This study evaluates the prevalence and association of abnormal oscillometry parameters with respiratory symptoms and respiratory diseases in a general adult population. Methods: A total of 7,560 subjects in the Austrian LEAD (Lung, hEart, sociAl, boDy) Study with oscillometry measurements (computed with the Resmon Pro FULL; Restech Srl) were included in this study. The presence of respiratory symptoms and doctor-diagnosed respiratory diseases was assessed using an interview-based questionnaire. Rrs and Xrs at 5 Hz, their inspiratory and expiratory components, the area above the Xrs curve, and the presence of tidal expiratory flow limitation were analyzed. Normality ranges for oscillometry parameters were defined. Measurements and Main Results: The overall prevalence of abnormal oscillometry parameters was 20%. The incidence of abnormal oscillometry increased in the presence of symptoms or diagnoses: 17% (16–18%) versus 27% (25–29%), P < 0.0001. All abnormal oscillometry parameters except Rrs at 5 Hz were significantly associated with respiratory symptoms/diseases. Significant associations were found, even in subjects with normal spirometry, with abnormal oscillometry incidence rates increasing by 6% (4–8%; P < 0.0001) in subjects with symptoms or diagnoses. Conclusions: Abnormal oscillometry parameters are present in one-fifth of this adult population and are significantly associated with respiratory symptoms and disease. Our findings underscore the potential of oscillometry as a tool for detecting and evaluating respiratory impairments, even in individuals with normal spirometry.

Objective: Monitoring infants’ breathing activity is crucial in research and clinical applications but remains a challenge. This study aims to develop a contactless method to monitor breathing patterns and thoracoabdominal asynchronies in infants inside the incubator, using depth cameras. Methods: We proposed an algorithm to extract the 3D displacements of the ribcage and abdomen from the analysis of depth images. We evaluated the accuracy of the system in-vitro vs. a reference motion capture analyzer. We also conducted a feasibility study on 12 patients receiving non-invasive respiratory support to estimate the mean and the variability of the chest wall displacements in preterm infants and evaluate the suitability of the proposed system in the clinical setting. Results: In-vitro, the mean (95% CI) error in the measurement of amplitude, frequency and phase shift between compartmental displacements was -0.14 (-0.57, 0.28) mm, 0.02 (-0.99, 1.03) bpm, and -0.40 (-1.76, 0.95)°, respectively. In-vivo, the mean (95% CI) amplitude of the ribcage and abdomen displacements were 0.99 (0.34, 2.67) mm and 1.20 (0.40, 2.15) mm, respectively. Conclusions: The developed system proved accurate in-vitro and was suitable for the clinical environment. Clinical Impact: The proposed method has value for evaluating infants’ breathing patterns in research applications and, after further development, may represent a simple monitoring tool for infants’ respiratory activity inside the incubator.

Background: Novel therapies are needed for bronchopulmonary dysplasia (BPD) because no effective treatment exists. Mesenchymal stromal cell extracellular vesicles (MSC-sEVs) have therapeutic efficacy in a mouse pup neonatal hyperoxia BPD model. We tested the hypothesis that MSC-sEVs will improve lung functional and structural development in mechanically ventilated preterm lambs. Methods: Preterm lambs (~129d; equivalent to human lung development at ~28w gestation) were exposed to antenatal steroids, surfactant, caffeine citrate, and supported by mechanical ventilation for 6-7d. Lambs were randomized to blinded treatment with either MSC-sEVs (human bone marrow MSC-derived; 2x10¹¹ particles iv; n=8; 4F/4M) or vehicle control (saline iv; 4F/4M). Treatment was at 6 and 78 hours post-delivery. Physiological targets were pulse oximetry O₂ saturation 90-94% (PaO₂ 60-90 mmHg), PaCO₂ 45-60 mmHg (pH 7.25-7.35), and tidal volume 5-7 mL/Kg. Results: MSC-sEVs-treated preterm lambs tolerated enteral feedings and maintained weight compared to the vehicle control group. Respiratory severity score, oxygenation index, A-a gradient, distal airspace wall thickness, and smooth muscle thickness around terminal bronchioles and pulmonary arterioles were lower (*) for the MSC-sEVs group versus the vehicle controls. S/F ratio, radial alveolar count, secondary septal volume density, alveolar capillary surface density, and protein abundance of VEGF-R2 were higher (*) for the MSC-sEVs versus the vehicle control group. Conclusions: MSC-sEVs improved respiratory system physiology and alveolar formation in mechanically ventilated preterm lambs. MSC-sEVs may be an effective and safe therapy for appropriate functional and structural development of the lung in preterm infants who require mechanical ventilation and are at-risk of developing BPD.

Despite recent insights into the dynamic processes during lung aeration at birth, several aspects remain poorly understood. We aimed to characterize changes in lung mechanics during the first inflation at birth and their relationship to changes in lung volume. Intubated preterm lambs (gestational age, 124–127 days; n = 17) were studied at birth. Lung volume changes were measured by electrical impedance tomography (V_{L EIT}). Respiratory system resistance (R₅) and oscillatory compliance (C_x5) were monitored with the forced oscillation technique at 5 Hz. Lambs received 3–7 s of 8 cmH₂O of continuous distending pressure (CDP) before delivery of a sustained inflation (SI) of 40 cmH₂O. The SI was then applied until either C_x5 or the V_{L EIT} or the airway opening volume was stable. CDP was resumed for 3–7 s before commencement of mechanical ventilation. The exponential increases with time of C_x5 and V_{L EIT} from commencement of the SI were characterized by estimating their time constants (τC_x5 and τV_{L EIT}, respectively). During SI, a fast decrease in R₅ and an exponential increase in C_x5 and V_{L EIT} were observed. C_x5 and V_{L EIT} provided comparable information on the dynamics of lung aeration in all lambs, with τC_x5 and τV_{L EIT} being highly linearly correlated ( r² = 0.87, P < 0.001). C_x5 and V_{L EIT} decreased immediately after SI. Despite the standardization of the animal model, changes in C_x5 and R₅ both during and after SI were highly variable. Lung aeration at birth is characterized by a fast reduction in resistance and a slower increase in oscillatory compliance, the latter being a direct reflection of the amount of lung aeration.