Background: Research investigating symptom management in patients with chronic obstructive pulmonary disease (COPD) largely has been undertaken assuming the homeostatic construct, without regard to potential roles of circadian rhythms. Temporal relations among dyspnea, fatigue, and peak expiratory flow rate (PEFR) have not been reported in COPD.
Objectives: The specific aims of this study were to 1) explore the 24-hour patterns of dyspnea, fatigue, and PEFR in subjects with COPD and 2) examine the relations among dyspnea, fatigue, and PEFR in COPD. Methods: The repeated-measures design involved 10 subjects with COPD who self-assessed dyspnea and fatigue by 100 mm visual analog scales, and PEFR by peak flow meter in their home 5 times a day for 8 days. Single and population mean cosinor analyses and correlations were computed for dyspnea, fatigue, and PEFR; correlations were done among these variables.
Results: Circadian rhythms were documented by single cosinor analysis in 40% of the subjects for dyspnea, 60% for fatigue, and 60% for PEFR. The population cosinor analysis of PEFR yielded a significant rhythm (p < .05). The 8-day 24-hour means of dyspnea and fatigue was moderately correlated (r = .48, p < .01). Dyspnea and PEFR, and fatigue and PEFR, were weakly correlated in a negative way (r = -.11, p < .05 and r = -.15, p < .01 respectively).
Conclusions: The findings suggest that (1) the dyspnea and fatigue experienced by COPD patients are moderately related, and (2) temporal variation in lung function may not affect the dyspnea and fatigue experienced by patients with COPD. Replication of this study is suggested with a larger sample size.
Back to Rising Stars of Scholarship and Research
Back to 37th Biennial Convention - Scientific Session
Sigma Theta Tau International