Exercise Physiology and Breathlessness
Research focuses on better understanding the mechanisms for patient perception of breathlessness in health and disease, and evaluating therapeutic interventions to relieve symptoms of breathlessness. Current projects include evaluation of the physiologic response to exercise in patients with CT evidence of emphysema but normal lung function, and examination of the sensation of "chest tightness" associated with methacholine induced bronchoconstriction in patients with spinal cord injury. The spinal cord study is designed to build upon previous work that suggests that much of the discomfort of asthma arises from receptor molecules within the lungs and not from the chest wall. In addition, a study investigates patients with asthma who are relatively sensitive or insensitive to changes in lung function to determine a) which aspect of the physiology of asthma is most important in determining sensations, and b) to determine if the perceptual sensitivity of asthmatics predicts clinical outcomes and use of medical resources. Another area of research seeks to examination of the effect of inhaled furosemide on the sensation of "air hunger" in a model in which dyspnea is induced with hypercapnia and restricted ventilation. Furosemide is postulated to alter the activity of pulmonary stretch receptors.