May 20 2008
Patients with chronic obstructive pulmonary disease (COPD) who are in their final years of survival do not get the same benefits from pulmonary rehabilitation (PR) as patients who have more years left to live-regardless of their age, complicating illnesses or lung function, according to new research funded by the Veteran's Administration, which will be presented at the American Thoracic Society's 2008 International Conference in Toronto on Tuesday, May 20.
The researchers recruited 106 patients with COPD who completed an eight-week course of PR. Each patient was evaluated at the beginning and the conclusion of the course for exercise capacity, dyspnea in daily activities, such as walking and carrying groceries, fatigue, quality of life, and other indices of health. The researchers then compared the results of patients who died within two years of the program to those who survived longer and found that even after controlling for potentially complicating factors-such as lung function, age and other present illnesses-patients who lived longer than two years were able to obtain more positive results from their PR program than those who had end-stage COPD (defined retrospectively as having died within two years of the program).
"Although people who died within two years after entering a pulmonary rehabilitation program improved their exercise capacity during the program, they improved less on this and other key variables than did those who lived longer," said Bonnie Steele, A.R.N.P., Ph.D., a respiratory clinical nurse specialist at the VA Puget Sound Health Care System in Seattle. "The finding was independent of age, lung function and the number of other illnesses they had."
The researchers anticipated that those with end-stage COPD would be more ill with lung or other diseases. "Previous work has taught us that even with severe obstructive lung disease based upon pulmonary function, people can derive significant benefits from PR," said Dr. Steele, "but our limited findings suggest that other, presently unappreciated factors present at end of life may contribute to poorer outcomes in end-stage patients with respect to exercise capacity and quality of life."
There are several possible explanations for the findings, including the possibility that patients in end-stage disease have overall poorer muscle function and greater levels of deconditioning and the possible specific impact of selected co-morbidities, such as heart failure.
"Our sample was too small to explicate this fully," said Dr. Steele, "but it suggests that treatments for end-stage patients with COPD may still be effective and introducing exercise training sooner in the course of their disease results in more improvement."
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