The effect of different interventions on the sensory and affective dimensions of dyspnea in patients with COPD during exercise

• Main Author: Perry, Sarah Elizabeth
• Language: English
• Published: University of British Columbia 2012
• Online Access: http://hdl.handle.net/2429/43187

Background: Dyspnea is a complex sensation that has been recognized as a similar entity to the sensation of pain. Research has shown that dyspnea can be caused by a variety of diverse mechanisms and can be interpreted differently by each individual. Hyperoxia, heliox, and BiPAP are able to reduce dyspnea in patients with COPD but it is unknown how they specifically influence the affective (A1) and sensory (SI) dimensions of dyspnea during exercise. The aim of this study was to examine the extent to which hyperoxia, heliox and BiPAP alter A1 and SI scores and if changes in these dimensions of dyspnea are associated with improvements in exercise capacity. Methods: 10 patients with moderate to severe COPD (post-bronchodilator FEV1/FVC <0.7, 30%< FEV1 < 80% pred, >10 pack year history of smoking) who were exacerbation-free for at least six weeks prior to the study performed constant-load cycling at 75% of maximal work rate breathing air, hyperoxia (40% O₂, 60% N₂), heliox (21% O₂, 79% He), or BiPAP (pressure optimized for each individual). Results: At an isotime during exercise, hyperoxia reduced the sensory intensity of dyspnea (p=0.033). The change in A1 and SI were also significantly reduced compared to air with both hyperoxia (p=0.033, p=0.025, respectively) and heliox (p=0.047, p=0.041, respectively) but not with BiPAP. The A1/SI ratio was unchanged with all interventions compared to air. There were no significant changes in the sensory qualities of dyspnea with any intervention, except for the sensation of breathing a lot (rapidly, deeply, or heavily), which was significantly reduced with heliox at isotime. There were no significant differences in dyspnea measures or ventilatory parameters at end exercise. Conclusions: Hyperoxia and heliox altered the affective and sensory dimensions of dyspnea during exercise, leading to improvements in exercise time with hyperoxia. There were considerable individual differences in the reported quality of dyspnea scores, as well as exercise time. These findings suggest that phenotyping patients based on their specific type of dyspnea to a particular therapy before an exercise intervention may be warranted to enhance the known benefits of exercise for patients with COPD. === Graduate Studies, College of (Okanagan) === Graduate