My career goal is full-time clinical research in New Zealand. By combining degrees in science and medicine with relevant employment experience, I am in a strong position to further my development through a PhD. The research objectives are to determine whether high-concentration oxygen therapy increases arterial carbon dioxide tension (PaCO2) in cystic fibrosis, neuromuscular disease, interstitial pulmonary fibrosis and obesity, and investigate the mechanism(s) responsible for any change in PaCO2 observed. I will also determine the dose-response relationship of the oxygen-induced increase in PaCO2 in chronic obstructive pulmonary disease. I will undertake 5 randomised controlled cross over trials in subjects with each of these conditions. Knowledge of the dose-response relationship in COPD and the effect of high concentration oxygen therapy on PaCO2, and risk of hypercapnia in the other respiratory conditions, will have the potential to change clinical practice and lead to safer oxygen therapy.