Comparison of oxygen consumption in performing daily activities between patients with chronic obstructive pulmonary disease and a healthy population.

OBJECTIVE: The purposes of this study were to compare the daily activity oxygen consumption (VO(2)) and peak oxygen consumption (VO(2peak)) for chronic obstructive pulmonary disease (COPD) patients and healthy individuals; to compare dyspnea levels found in COPD patients and healthy individuals when they performed daily activities and exercise tests; and to establish standard VO(2) values for daily activities for COPD patients. DESIGN: This was an exploratory and correlative study. SETTING: The study took place at the Research Center of Sports Medicine at Taipei Medical University, in Taipei, Taiwan. SUBJECTS: The study included 27 COPD patients and 18 healthy subjects whose ages, weights, and heights were matched. OUTCOME MEASURES: VO(2peak) and the VO(2) for performing daily activities including sitting, standing, walking, walking with a 2-kg load, and walking upstairs for 2 stories. INTERVENTION: All data were collected by means of questionnaires and treadmill exercise tests. VO(2) was measured using an AEROSPORT KB1-C metabolic measurement system. RESULTS: There was no significant difference in VO(2) found between the 2 groups when they were performing daily activities, but the VO(2peak) was significantly lower in the COPD group (13.90 +/- 2.93 mL kg(-1) min(-1)) compared with the healthy control group (16.15 +/- 1.86 mL kg(-1) min(-1)) (P =.01). The dyspnea level of the COPD group when they were performing daily activities and exercise tests was more severe than that of the healthy control group. The mean VO(2) values for daily activities in COPD patients were as follows: sitting 3.41 (+/-0.82), standing 3.67 (+/-0.90), walking 10.06 (+/-2.19), walking with a 2-kg load 10.28, and walking upstairs 8.16 (+/-1.36) mL kg(-1) min(-1). CONCLUSION: The results of this study reveal that there were no differences in VO(2) values for performing daily activities between COPD patients and healthy individuals. However, an increase in dyspnea level occurred during daily activities, and it was found to be more severe for COPD patients than for healthy individuals. A key factor was probably that COPD patients had an obviously lower VO(2peak) and higher relative exercise intensity for daily activities than did healthy individuals.

Investigation of the difference between treadmill self-efficacy and actual performance in Taiwanese patients with chronic obstructive pulmonary disease.

OBJECTIVE: Because overactivity or underactivity may result in inadequate physical responses among patients with chronic obstructive pulmonary disease (COPD), the purpose of this study was to examine the difference between treadmill self-efficacy and actual treadmill performance. Factors that influence self-efficacy and actual performance were also examined. DESIGN: The design was a descriptive and correlational study. SETTING: The study took place at the Research Center of Sports Medicine in University. PATIENTS: A total of 48 subjects with COPD were recruited from 4 hospitals. OUTCOME MEASURES: The outcome measures were treadmill self-efficacy and actual treadmill performance. INTERVENTION: Data were collected by means of treadmill exercise testing and 3 structured questionnaires. RESULTS: The findings of the study demonstrated that the average maximal functional capacity was 2.94 METs. A positive significant relationship between treadmill self-efficacy and actual performance was observed. However, the majority of subjects (72.9%) underestimated their treadmill performance and only 7 subjects (14.6%) assessed their treadmill performance accurately. Dyspnea was the most common reason for a subject to stop during the exercise testing. The patient's past experience was the most important predictor for both treadmill self-efficacy and actual treadmill performance. CONCLUSIONS: These results revealed that patients in Taiwan who have COPD have extremely poor functional capacity and most of them underestimated their exercise performance. An assessment of self-efficacy and exercise performance seems imperative in the development of individualized nursing interventions to help COPD patients.