Chronic Obstructive Pulmonary Disease, from measuring to reactivating patients

Patients with chronic obstruction pulmonary disease (COPD) present with respiratory symptoms and systemic manifestations including, but not limited to, muscle dysfunction, exercise intolerance, health status impairment and physical inactivity. These clinical features result in a deteriorating health condition with needed attention from health care providers. This PhD thesis has addressed some important aspects in the handling of patients with COPD patients, from the assessment of the rate of decline over time to interventions to reactivate patients. Quadriceps weakness is related to hospitalization and mortality of patients with COPD. Importantly, this dysfunction can be reverted by an adequately prescribed exercise training program. However, quadriceps muscle force is not often measured in pulmonary rehabilitation centers around the world. This may be partly explained due to the high cost of the gold standard device for this measure. We showed that a strain gauge is equally valid and reliable to measure isometric quadriceps force of patients with COPD. This is a simpler and cheaper alternative for the computerized dynamometry. The early detection of dysfunction is fundamental for secondary prevention. Therefore, we investigated the changes in systemic manifestations of COPD from an early diagnosis of mild to moderate airflow obstruction. Our cohort of subjects with airflow obstruction did not present a faster deterioration in maximal exercise outcomes compared to controls without airflow obstruction, with and without a smoking history. The findings of this longitudinal study adds new information to the literature about the effects of aging on exercise capacity in these cohorts. This was done by including both the traditional peak exercise measures and the efficiency slopes, relatively new outcomes which are less effort dependent. In the latter outcome (oxygen efficiency slope), subjects with airflow obstruction even deteriorated slower compared to controls. Similarly, health status of subjects with early airflow obstruction did not deteriorate faster than in control subjects. Acute respiratory exacerbations contributed to a faster deterioration in our cohort of interest. The absolute change in health status did not correlate well with changes in functional outcomes, which reinforces we cannot estimate health status based on the functional condition of a patient. When subjects with overall fast deterioration were singled out, they presented with characteristics that may be linked to an emphysematous phenotype. This may help to guide the selection of patients with mild disease at risk for rapid deterioration. Patients with more advanced disease, who remain symptomatic despite optimal pharmacotherapy, are referred to pulmonary rehabilitation. This comprehensive therapy does not result in enhanced physical activity in its current conventional form. We found that implementing a semi-automated telecoaching program after twelve weeks of pulmonary rehabilitation does increase the amount of physical activity in patients with COPD. This without changing other clinical outcomes, which are enhanced during the first three months of pulmonary rehabilitation alone. Therefore, combining both interventions for patients who improved their functional capacity seem to optimize the therapy.status: publishe