The effect of comprehensive outpatient pulmonary rehabilitation on dyspnea.
To evaluate the effect of outpatient pulmonary rehabilitation (OPR) on dyspnea, we measured this symptom using a visual analogue scale during graded treadmill exercise testing and with baseline and transitional dyspnea indices (TDI). The latter measure overall dyspnea in three spheres: functional impairment, magnitude of task, and magnitude of effort. Twenty patients with COPD referred for OPR were randomly assigned to either a treatment group (T, n = 10), with dyspnea evaluated at baseline then shortly following a 6-week OPR program, or a control group (C, n = 10), with dyspnea evaluated at baseline then following a 6-week waiting period. No significant change in maximal exercise performance from baseline to repeated testing was observed in either group. Dyspnea at maximum treadmill workload (Dmax), which did not significantly change in C, decreased from 74.4 +/- 18.9 percent at baseline to 50.5 +/- 23.2 percent post-OPR in T (p = 0.006). The Dmax related to minute ventilation (Dmax/VEmax) and oxygen consumption (Dmax/VO2max) also significantly decreased following OPR. The reduction in exertional dyspnea was apparent by the second minute of exercise. Additionally, TDI focal scores were significantly higher in T than C (2.3 +/- 1.06 vs 0.2 +/- 1.75 units, p = 0.006), indicating decreased overall dyspnea following OPR. These results point to significant improvements in both exertional and clinically assessed dyspnea following OPR.