Objective: To evaluate the relationship between lower respiratory tract infections (LRTI), in the first 2 years of life and lung function at school age in the Piccolipiù birth cohort (Italy). Methods: Data on LRTI (doctor diagnosis of bronchitis, bronchiolitis, pneumonia) and wheezing (≥3 episodes or a diagnosis of asthmatic bronchitis) in the first 2 years of life were obtained from parental questionnaires. Lung function was assessed at 7 years by spirometry and forced volume vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, forced expiratory flow between 25 and 75%, and at 75% of FVC (FEF25-75 and FEF75) were reported as z-scores. The associations between LRTI and spirometric variables were estimated with linear regression models. Results: Among 877 children studied, 22.1% had LRTI only, 5.4% wheezing only, 13.2% had both, and 59.3% had neither LRTI nor wheezing. Children with LRTI had lower FVC and FEV1 than children without (z-score differences: -0.18 (95% Confidence Intervals, -0.31; -0.06) and -0.15 ( 0.27; -0.03)). When children were stratified by history of both LRTI and wheezing, there was no association between LRTI only and spirometric values. Conversely, having had both LRTI and wheezing was inversely associated with all lung function measures: z-score differences of -0.24 ( 0.42; -0.07); -0.42 (-0.59; -0.24); -0.25 (-0.41; -0.08); -0.37 (-0.54; -0.21); -0.30 (-0.46; -0.14) for FVC, FEV1, FEV1/FVC, FEF25-75 and FEF75, respectively. Conclusion: Infants with wheezing and LRTI, but not those with LRTI only, had reduced lung function at school-age.

Introduction Acute bronchiolitis is the most common respiratory illness and the main cause of respiratory failure in infant. Effective therapy is not available. A relatively new, safe and promising method of non-invasive respiratory support is oxygen delivery by high-flow nasal cannula (HFNC), but several questions concerning HFNC clinical practice remain unanswered. Aim The main aim of our study is to analyse the clinical course of infants hospitalized for bronchiolitis who underwent HFNC in order to identify clinical, laboratory or radiological findings that can have an impact on HFNC failure, which is defined as requirement for mechanical ventilation (MV). Methods We conducted a retrospective data analysis of case records of 130 patients less than 12 months hospitalized for bronchiolitis who underwent HFNC and clinical epidemiological laboratory and radiological data were collected. Results Only 11 (8.5%) out 130 infants required invasive mechanical ventilation for clinical deterioration. Patients who needed to switch from HFNC to MV because of a progressive respiratory failure showed more frequently a complete upper lobe consolidation on CXR (90.9%) than infants exclusively supported by HFNC (14.9%). They were younger with a lower admission weight and they had a lower lymphocyte count than patients who underwent HFNC only. Discussion Our study suggests that a complete upper lobe consolidation in young infants is a significant risk factor for HFNC failure. Further studies are needed to understand if an early identification of consolidation following by an adequate follow-up and proper therapeutic strategies may reduce the number of children who require mechanical ventilation.