Exertional dyspnea in chronic obstructive pulmonary disease: mechanisms and treatment approaches

Abstract

The purpose of this review is to identify new advances in our understanding of dyspnea in patients with chronic obstructive pulmonary disease (COPD). Specifically, we highlight new scientific discoveries concerning the language of dyspnea, its underlying mechanisms and its clinical management. Recent studies have confirmed that dyspnea is multidimensional and that sensory intensity and quality dimensions of the symptom are readily distinguishable by the individual. When respiratory discomfort is sufficiently unpleasant in COPD, an emotive response is evoked which encompasses feelings of fear and anxiety. Such descriptors appear to be unique to the disease state and are rarely reported in health. Recent brain imaging studies have proposed a central role of the limbic and paralimbic systems in the genesis of perceived dyspnea or its affective component. There is new indirect evidence that the elaboration of endogenous opioids may modulate dyspnea intensity during exercise in COPD. New physiological studies in COPD have provided novel insights into mechanisms of dyspnea both in early disease and in the setting of coexistent obesity. The effective management of dyspnea in COPD remains a significant challenge for caregivers but recent treatment innovations such as helium-oxygen, inhaled furosemide and breathing feedback techniques have yielded early positive results.