Pulmonary rehabilitation and COPD:
There are several performance-based measures of functional exercise capacity. During these tests, blood pressure, heart rate and oxygen levels are measured. Several types of COPD exercise testing was described by Divo and Pinto-Plata (2):
- The stair-climbing test (SCT) assesses the ability to ascend and descend a flight of stairs, as well as lower extremity strength, power, and balance. The SCT seems to be most useful for preoperative evaluations and may be used to better determine a maximal exercise capacity when Cardiopulmonary Exercise Testing is unavailable.
- In the 6-minute walk test (6MWT), the patient walks as far as you can up through a corridor in 6 minutes. The 6MWT is the simplest, can be used to evaluate response to several interventions (such as physical rehabilitation, medications, lung volume reduction interventions and transplantation) and is probably the most cost effective.
- The shuttle walk test (SWT) requires you to walk up and down a 10-meter distance at increasing speeds until you get too breathless to continue.
- Cardiopulmonary Exercise Testing (CPET) is non-invasive simultaneous measurement of the cardiovascular and respiratory system during exercise to assess a patient’s exercise capacity; however, it is more technically difficult than all the other tests.
Pulmonary rehab and exercise capacity:
A 7-week hospital based pulmonary rehabilitation program was performed by Egan C, et al with 47 subjects suffering from chronic obstructive pulmonary disease (COPD) in a prospective study. At the end of the study, total energy expenditure and breathlessness (Borg test) was reduced. Exercise capacity improved in the “shuttle walking test” and the 6 minute walk test. Quality of life was also significantly improved measured by a standardized scoring system. It was supported by this study that pulmonary rehabilitation reduces morbidity by improving exercise capacity, but unless the activity is sustained over the long term, benefits of the rehab program will dissipate after a year. There may be greater benefit sustained if a long term behavioral modification can be maintained. (3)