COVID-19 Pneumonia: Pulmonary Physiology, Health-related Quality of Life and Benefit of a Rehabilitation Program

The pathophysiological processes involved in COVID-19 pneumonia are not fully understood. Specific alterations of the airways, lung parenchyma and pulmonary vascular tree could explain a severe ventilation/perfusion heterogeneity resulting in severe hypoxemia during the active phase of the disease. Additional skeletal muscle impairment related to systemic inflammation may also explain persisting symptoms in the follow-up phase. The first aim of the present project is to explore these different processes by evaluating the impact of the COVID-19 pneumonia on exercise capacity, pulmonary function and perfusion by a physiological and radiologic study. An ambulatory pulmonary rehabilitation will also be studied to assess its impact on the physiological parameter mentioned and the health-related quality of life questionnaire as a potential long-term treatment. The investigators propose a single center randomized controlled study at the University Hospitals of Geneva. 60 adult patients having suffered a hypoxemic COVID-19 pneumonia with persistent symptoms at 3-months after hospital discharge will be included. A functional and physiological study will be performed, including a six-minute walk test, pulmonary function testing, diffusing capacity for carbon monoxide, maximal inspiratory pressure and sniff nasal inspiratory pressure. Those with at least one abnormal value will be invited to fill the Saint Georges Respiratory Questionnaire, the Short Form 36 and the Hospital Anxiety and Depression Scale and will undergo a chest dual energy computed tomography (DECT), a cardiopulmonary exercise testing with non-invasive cardiac output and stroke volume evaluation and an evaluation of the pulmonary shunt by hyperoxia (100% oxygen breathing) at rest and during light effort. Then patients will be randomized on a 1:1 basis for pulmonary rehabilitation program or usual care. All work-up except DECT will be repeated at 6 and 12 months after hospital discharge. The investigators hypot