Respiratory health outcomes in neonates - lung function, exercise and airway mechanics

My thesis uses data collected during the course of the Respiratory Outcomes in Neonates study, which aimed to identify, investigate mechanisms and establish potential treatments for lung disease in a population of preterm-born children in South Wales. As part of this study, 241 children attended our research unit where they underwent in-depth lung function testing, as reported in my thesis. My results observed preterm-born children with low lung function had increased air trapping on lung volume testing, functional exercise impairment, and greater response to post-exercise bronchodilator. When classifying preterm-born children with low lung function by obstructive versus non-obstructive lung disease, those children with obstructive disease had greater impairment of forced expiratory volume in one second (FEV1) and greater post-exercise reversibility. On oscillometry testing, preterm-born children with low lung function, in particular those with obstructive lung disease, had impaired resistance and compliance, with evidence of peripheral airways being most affected. Post-exercise bronchodilator was effective in improving airway mechanical properties in children with low lung function. Intra-breath oscillometry, unexplored in the preterm population to date, demonstrated impairment throughout the respiratory cycle in children with low lung function, and was not limited to expiration, suggesting a different disease process to that seen in other childhood wheeze disorders. I demonstrated that my method for classification of obstructive and non-obstructive lung disease was appropriate in my population for identification of children with postexercise bronchodilator reversibility, and was comparative to other established methods of defining obstructive lung disease. Finally, I explored differences between two methods of spirometry, and noted systematic bias towards higher results using a pneumotachograph system compared to an infra-red turbine spirometry, with implications for clinical practice