The relation of the exersional dyspnea with pulmonary function, exercise tolerance and quality of life in patients with chronic obstructive pulmonary disease

Dyspnea is described as a sensation of difficulty awareness in breathing and it is a common complaint of patients with chronic obstructive pulmonary disease (COPD). This study aimed to investigate the related factors of exersional dyspnea and determine the predictors of it. Across-sectional study was developed on 37 patients with chronic obstructive pulmonary disease referred to Specialized Pulmonary Clinic of Aria Hospital in Ahvaz in 2011. Purposive sampling method was used gathering the samples. The 6Minute Walk Test (6MWT) was performed at the end of the test based on American Thorax Society’s protocol exersional dyspnea was measured by Borg scale. Also the health related quality of life was assessed by the St George’s Respiratory Questionnaire (SGRQ). The data was analyzed using Pearson’s linear correlation coefficient, Spearman’s correlation coefficient and Multivariate linear regression. The finding revealed that there was a negative significant relation between dyspnea and exercise tolerance(r=-0.33, p<0.05).A positive correlation was observed between dyspnea and quality of life (r=0.60, p<0.001).Moreover, no statistically significant correlation was found between dyspnea and blood pressure, respiratory rate, heart rate and O2sat before 6MWT. Multiple regression analysis indicated that the O2sat and respiratory rate after exercise and forced expiratory flow the middle 50% of the FVC (FEF25-75) was identified as independent predictor of the exersional dyspnea(p<0.05). The result showed that the patients with more dyspnea had a lower exercise tolerance and quality of life. Tree factors consist of the O2sat and respiratory rate after exercise and FEF25-75 maybe were the predictors of exersional dyspnea.