Therapeutic interventions in interstitial lung disease: exercise training and supplemental oxygen

Submission note: A thesis submitted in total fulfilment of the requirement for the degree of Doctor of Philosophy, Discipline of Physiotherapy to the School of Allied Health, College of Science, Health and Engineering, La Trobe University, Bundoora, Victoria.

Thesis with publications.

Exercise training and supplemental oxygen are two promising therapeutic interventions that may improve important health outcomes in people with interstitial lung disease (ILD), a disabling group of lung disorders with limited treatment options. However significant gaps exist in the scientific evidence. This thesis sought to establish the impact and timing of exercise training across the range of ILDs, to identify a clinically applicable and reliable instrument with which to assess skeletal muscle strength and to determine the precise benefit of supplemental oxygen in idiopathic pulmonary fibrosis (IPF), the most common and debilitating ILD. Findings from the four studies undertaken to address these thesis aims were as follows: 1. A Cochrane review found pulmonary rehabilitation (PR) in ILD, an intervention that includes exercise training, resulted in significant improvements in functional exercise capacity, dyspnoea and health-related quality of life, with comparable benefits evident in the subgroup with IPF. The overall quality of evidence was low to moderate and limited evidence was available to establish the long-term effects of PR. 2. A large multi-centre randomised controlled study (n=142) demonstrated exercise training is effective in producing clinically meaningful benefits across the range of ILDs, especially those individuals with asbestosis and IPF, with longer standing benefits in those with milder disease. 3. A reliability study (n=30) found the hand-held dynamometer is a useful and reliable clinical tool for measuring skeletal muscle strength, an important clinical outcome, in people with ILD. xii 4. A placebo controlled crossover trial (n=11) found that in IPF, breathing supplemental oxygen at rest is safe. Improvements in exercise tolerance, exercise induced hypoxaemia and exertional dyspnoea were associated with improved skeletal muscle metabolism. These studies indicated that exercise training and supplemental oxygen have beneficial effects on important clinical outcomes in people within ILD, providing robust evidence which can guide clinical management.