[Functional status and survival in patients with chronic obstructive pulmonary disease following pulmonary rehabilitation].

OBJECTIVES

To study functional status and survival in patients with chronic obstructive pulmonary disease (COPD) following a pulmonary rehabilitation program.

PATIENTS AND METHODS

We assessed lung function, 6-minute walk distance, Borg score for dyspnea upon completion of the 6-minute walk, workload in watts on a cycle ergometer, quality of life using the St George's Respiratory Questionnaire (SGRQ); the body-mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index; and survival.

RESULTS

One hundred five patients participated in the pulmonary rehabilitation program. The patients had a mean (SD) age of 63.9 (9.3) years, body mass index of 24.5 (4.56) kg/m2, and forced expiratory volume in 1 second (FEV1) of 0.91 (0.46) L. The mean distances walked in 6 minutes were 412.8 (79.4) m before the pulmonary rehabilitation program and 443.46 (81.57) m after rehabilitation. The mean workloads on the cycle ergometer before and after rehabilitation, respectively, were 47.9 (29.6) W and 77.76 (20.88) W. The mean Borg scores were 2.2 (1.37) before and 1.47 (1.37) after rehabilitation, and the SGRQ scores at the same times were 27.63 (16.02) and 25.45 (15.12). Mortality due to respiratory disease (105 months) was 19%. Cumulative survival rates at 1 year, 3 years, and 6 years were 91%, 86.7%, and 6.75%, respectively. Survival was related to an FEV1 greater than 1.02 L (P = .05), a 6-minute walk distance over 448 m before rehabilitation (P = .04) and 454 m after rehabilitation (P = .05), and a workload on the cycle ergometer of over 54 W before rehabilitation (P = .01) and 72 W (P = .02) afterwards. The correlations between survival and both SGRQ and BODE scores were weaker.

CONCLUSIONS

We observed improved exercise capacity, dyspnea ratings, and, to a lesser extent, better SGRQ scores in our COPD patients following pulmonary rehabilitation. The best predictors of survival were FEV1, the 6-minute walk distance, and the cycle ergometer workloads.