Patterns of domestic activity and ambulatory oxygen usage in COPD

Background: The aim of this study was to examine patterns of domestic activity and ambulatory oxygen usage in patients with COPD in their domestic environment. Methods: Twenty patients (14 men; mean age, 73.4 years [SD, 6.8 years]; FEV1, 1.0 L [SD, 0.5 L]) with stable COPD were recruited after completing a 7-week pulmonary rehabilitation program. Patients were either hypoxic at rest or had desaturation during exercise. Patients were randomized to an 8-week, double-blind, placebo-controlled trial of cylinder oxygen vs cylinder air. Total domestic physical activity and health-related quality of life (HRQL) measures were recorded before and after intervention. Results: There were no significant changes in domestic activity or HRQL measures after the intervention for either cylinder oxygen or cylinder air, except for a worsening of the Chronic Respiratory Questionnaire dyspnea domain on cylinder air. There was a significant increase in mean duration (minutes per day) of cylinder use (p <0.05) between weeks 1 vs 7 and weeks 1 vs 8 for the oxygen group. However, when comparing the two groups together, there were no between-group differences in cylinder use or time spent outside the home. Over the 8 weeks the majority of patients were using the cylinders in the home rather than outside, however, the number of times patients reported using the cylinders outside the home increased over the 8 weeks for the oxygen group. Conclusion: In the short term, ambulatory oxygen therapy is not associated with improvements in physical activity, HRQL, or time spent away from home. However, the use of cylinder oxygen increased over the 8 weeks compared to cylinder air. Patients need time to learn how to use oxygen, and ambulatory oxygen appears to enhance activities rather than increase them.